Filed pursuant to Rule 424(b)(3)
Registration No. 333-239372

PROPOSED MERGER

YOUR VOTE IS VERY IMPORTANT

To the Stockholders of resTORbio, Inc. and Adicet Bio, Inc.:

resTORbio, Inc. (referred to as “resTORbio”) and Adicet Bio, Inc. (referred to as “Adicet”) have entered into an Agreement and Plan of Merger (referred to as the “merger agreement”) pursuant to which Project Oasis Merger Sub, Inc., a wholly owned subsidiary of resTORbio, will merge with and into Adicet, with Adicet surviving as a wholly owned subsidiary of resTORbio (referred to as the “merger”). Adicet and resTORbio believe that the merger will result in a combined company that will leverage Adicet’s scientific and product development expertise and pipeline of engineered immune cell therapeutics for cancer based on its proprietary gamma delta T cell therapy platform, provide the resources for the combined company to advance multiple programs into the clinic, including Adicet’s lead candidate, ADI-001, a gamma delta chimeric antigen receptor (“CAR”)-T cell therapy targeting CD20, and expand the combined company’s pipeline in oncology and other indications.

At the effective time of the merger, each share of (x) common stock of Adicet, $0.0001 par value per share (referred to as “Adicet common stock”), and (y) preferred stock of Adicet, $0.0001 par value per share (referred to as “Adicet preferred stock” and, together with the Adicet common stock, “Adicet capital stock”), outstanding immediately prior to the effective time, excluding any shares of Adicet capital stock held as treasury stock and shares held by Adicet stockholders who have exercised and perfected appraisal rights, will be converted into the right to receive approximately 0.8555 shares of resTORbio common stock (referred to as the “exchange ratio”), subject to adjustment to account for the effect of a reverse stock split of resTORbio common stock, at a ratio mutually agreed to by resTORbio and Adicet in the range of 1-for-4 to 1-for-12 shares outstanding (or any number in between) (referred to as the “reverse stock split”), to be implemented immediately prior to and contingent upon the consummation of the merger, as discussed in this proxy statement/prospectus/information statement. This exchange ratio is an estimate only and is based upon resTORbio’s and Adicet’s capitalization as of August 4, 2020. The final exchange ratio will be determined pursuant to a formula described in more detail in the merger agreement and in this proxy statement/prospectus/information statement.

At the effective time of the merger, each outstanding and unexercised option to purchase Adicet’s common stock (referred to as “Adicet options”), whether vested or unvested, issued pursuant to the Adicet 2015 Stock Incentive Plan (referred to as the “Adicet 2015 plan”) and a subset of options issued pursuant to the Adicet 2014 Share Option Plan (referred to as the “Adicet 2014 plan” and, together with the Adicet 2015 plan, referred to collectively as the “Adicet plans”) will be converted into options to purchase a number of shares of resTORbio common stock based on the exchange ratio, subject to the terms of and adjustments in the merger agreement. Adicet warrants with rights to acquire Adicet capital stock will be converted into rights to acquire a certain number of shares of resTORbio common stock based on the exchange ratio, subject to the terms of and adjustments in the merger agreement.

resTORbio’s stockholders will continue to own and hold their existing shares of resTORbio common stock, subject to adjustment for the reverse stock split. The vesting of all outstanding resTORbio options will be accelerated in full as of immediately prior to the effective time of the merger. All out-of-the-money resTORbio options will be cancelled for no consideration. All in-the-money resTORbio options will remain outstanding after the completion of the merger in accordance with their terms. In addition, all outstanding unvested resTORbio restricted stock units will be accelerated in full effective as of immediately prior to the effective time of the merger, and for each outstanding and unsettled resTORbio restricted stock unit, the holder thereof shall receive a number of shares of resTORbio common stock equal to the number of vested and unsettled shares underlying such resTORbio restricted stock units (reduced by the number of shares of resTORbio common stock necessary to satisfy applicable tax withholding obligations at the maximum statutory rate).

Immediately following the effective time of the merger, the former equityholders of Adicet are expected to hold approximately 75% of the outstanding shares of resTORbio common stock on a fully-diluted basis and the current equityholders of resTORbio are expected to hold approximately 25% of the outstanding shares of resTORbio common stock on a fully-diluted basis (in each case excluding equity incentives available for grant).

Shares of resTORbio common stock are currently listed on The Nasdaq Global Select Market (referred to as “Nasdaq”) under the symbol “TORC.” In connection with completion of the merger, resTORbio will be renamed “Adicet Bio, Inc.” and expects to trade on Nasdaq under the symbol “ACET.” On August 18, 2020, the last trading day before the date of this proxy statement/prospectus/information statement, the closing sale price of resTORbio common stock on Nasdaq was $2.23 per share.

resTORbio is holding a special meeting of its stockholders (referred to as the “special meeting”) in order to obtain the stockholder approvals necessary to complete the merger and related matters. The special meeting will be held at 8:00 a.m., Eastern Time, on September 15, 2020, unless postponed or adjourned to a later date. In light of the novel coronavirus disease (referred to as “COVID-19”) pandemic and to support the well-being of resTORbio’s stockholders and partners, the special meeting will be completely virtual. You may attend the meeting and vote your shares electronically during the meeting via live webcast by visiting www.virtualshareholdermeeting.com/TORC2020SM. You will need the control number that is printed on your proxy card to enter the special meeting. resTORbio recommends that you log in at least 15 minutes before the meeting to ensure you are logged in when the special meeting starts. Please note that you will not be able to attend the special meeting in person.

At the special meeting, resTORbio will ask its stockholders:

As described in this proxy statement/prospectus/information statement, certain of Adicet’s stockholders who in the aggregate own approximately 98% of the outstanding shares of Adicet capital stock on an as-converted to common stock basis, and certain of resTORbio’s stockholders who in the aggregate own approximately 24% of the outstanding shares of resTORbio common stock, in each case, outstanding as of the date of the merger agreement, are parties to support agreements with Adicet and resTORbio, whereby such stockholders have agreed to vote their shares in favor of the adoption or approval, as applicable, of the merger agreement and the approval of the contemplated transactions, including the merger, in the case of Adicet capital stock holders, and the share issuance proposal and the reverse stock split proposal, in the case of resTORbio stockholders, subject to the terms of the support agreements.

In addition, following the registration statement on Form S-4, of which this proxy statement/prospectus/information statement is a part, being declared effective by the U.S. Securities and Exchange Commission (referred to as the “SEC”) and pursuant to the conditions of the merger agreement and the Adicet support agreement, Adicet’s stockholders who are party to the Adicet support agreement are each obligated to execute an action by written consent of Adicet’s stockholders (referred to as the “written consent”), adopting the merger agreement, thereby approving the contemplated transactions, including the merger, no later than five business days after the registration statement on Form S-4, of which this proxy statement/prospectus/information statement forms a part, is declared effective. Therefore, holders of a sufficient number of shares of Adicet capital stock required to adopt the merger agreement are expected to adopt the merger agreement, and no meeting of Adicet’s stockholders to adopt the merger agreement and approve the merger and contemplated transactions is expected to be held. Nevertheless, all of Adicet’s stockholders will have the opportunity to elect to adopt the merger agreement, thereby approving the merger and contemplated transactions, by signing and returning to Adicet a written consent.

After careful consideration, the board of directors of resTORbio (referred to as the “resTORbio Board”) has (i) determined that the contemplated transactions and the reverse stock split are fair to, advisable and in the best interests of resTORbio and its stockholders, (ii) approved and declared advisable the merger agreement and the contemplated transactions, including the issuance of resTORbio common stock to Adicet equityholders pursuant to the terms of the merger agreement, and the reverse stock split and (iii) determined to recommend, upon the terms and subject to the conditions set forth in the merger agreement, that its stockholders vote “FOR” Proposal No. 1, Proposal No. 2, Proposal No. 3 and, if necessary, Proposal No. 4.

After careful consideration, the Adicet board of directors (referred to as the “Adicet Board”) has (i) determined that the contemplated transactions are fair to, advisable and in the best interests of its stockholders, (ii) approved and declared advisable the merger agreement and the contemplated transactions and (iii) determined to recommend that the Adicet stockholders vote to adopt or approve the merger agreement and thereby approve the contemplated transactions. The Adicet Board recommends that the Adicet stockholders sign and return the written consent indicating their approval and adoption of the merger agreement and the contemplated transactions.

More information about resTORbio, Adicet and the merger is contained in this proxy statement/prospectus/information statement. resTORbio and Adicet urge you to read this proxy statement/prospectus/information statement carefully and in its entirety. IN PARTICULAR, YOU SHOULD CAREFULLY CONSIDER THE MATTERS DISCUSSED UNDER THE SECTION ENTITLED “RISK FACTORS” BEGINNING ON PAGE 28 OF THIS PROXY STATEMENT/PROSPECTUS/INFORMATION STATEMENT.

resTORbio and Adicet are excited about the opportunities the merger brings to both resTORbio’s and Adicet’s stockholders, and thank you for your consideration and continued support.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this proxy statement/prospectus/information statement. Any representation to the contrary is a criminal offense.

This proxy statement/prospectus/information statement is dated August 19, 2020, and is first being mailed to resTORbio’s and Adicet’s stockholders on or about August 21, 2020.

resTORbio, Inc.

500 Boylston Street, 13^th Floor

Boston, MA 02116

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

TO BE HELD ON SEPTEMBER 15, 2020

Dear Stockholders of resTORbio, Inc.:

On behalf of the board of directors of resTORbio, Inc. (referred to as the “resTORbio Board”), a Delaware corporation (referred to as “resTORbio”), resTORbio is pleased to deliver this proxy statement/prospectus/information statement for the proposed merger between resTORbio and Adicet Bio, Inc., a Delaware corporation (referred to as “Adicet”), pursuant to which Project Oasis Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of resTORbio (referred to as “merger subsidiary”), will merge with and into Adicet, with Adicet surviving as a wholly owned subsidiary of resTORbio. A special meeting of resTORbio’s stockholders will be held virtually, conducted via live audio webcast at 8:00 a.m., Eastern Time, on September 15, 2020. You may attend the meeting and vote your shares electronically during the meeting via live webcast by visiting www.virtualshareholdermeeting.com/TORC2020SM. You will need the control number that is printed on your proxy card to enter the special meeting. resTORbio recommends you log in at least 15 minutes before the special meeting to ensure you are logged in when the meeting starts. Please note that you will not be able to attend the special meeting in person. The special meeting will be held for the purpose of allowing stockholders of resTORbio to consider and vote upon the following matters:

If resTORbio is to complete the merger with Adicet, stockholders must approve Proposal No. 1 and Proposal No. 2. The approval of Proposal No. 3 and Proposal No. 4 is not a condition to the completion of the merger with Adicet.

resTORbio common stock is the only type of security entitled to vote at the special meeting. The resTORbio Board has fixed August 13, 2020, as the record date for the determination of stockholders entitled to notice of,

and to vote at, the special meeting and any adjournment or postponement thereof. Only holders of record of shares of resTORbio common stock at the close of business on the record date are entitled to notice of, and to vote at, the special meeting. At the close of business on the record date, there were 36,453,882 shares of resTORbio common stock outstanding and entitled to vote. Each holder of record of shares of resTORbio common stock on the record date will be entitled to one vote for each share held on all matters to be voted upon at the special meeting.

Your vote is important. The affirmative vote of the holders of a majority of the votes properly cast on such matter at the special meeting is required for approval of Proposal No. 1, Proposal No. 3 and Proposal No. 4. The affirmative vote of holders of a majority of the outstanding shares of resTORbio common stock as of the record date for the special meeting is required for approval of Proposal No. 2. Each of Proposal No. 1 and Proposal No. 2 are conditioned upon each other. Therefore, the merger cannot be consummated without the approval of Proposal No. 1 and Proposal No. 2.

Whether or not you plan to attend the special meeting online, please submit your proxy promptly by telephone or via the internet in accordance with the instructions on the enclosed proxy card or complete, date, sign and promptly return the accompanying proxy card in the enclosed postage paid envelope to ensure that your shares of resTORbio common stock will be represented and voted at the special meeting. If you date, sign and return your proxy card without indicating how you wish to vote, your proxy will be counted as a vote in favor of Proposal No. 1, Proposal No. 2, Proposal No. 3 and Proposal No. 4.

By Order of resTORbio’s Board of Directors,

Chen Schor

President and Chief Executive Officer

Boston, Massachusetts

August 21, 2020

THE RESTORBIO BOARD HAS DETERMINED AND BELIEVES THAT EACH OF THE PROPOSALS OUTLINED ABOVE IS ADVISABLE TO, AND IN THE BEST INTERESTS OF, RESTORBIO AND ITS STOCKHOLDERS AND HAS APPROVED EACH SUCH PROPOSAL. THE RESTORBIO BOARD RECOMMENDS THAT RESTORBIO’S STOCKHOLDERS VOTE “FOR” EACH SUCH PROPOSAL.

REFERENCES TO ADDITIONAL INFORMATION

Additional business and financial information about resTORbio can be found in documents previously filed by resTORbio with the SEC. You may obtain this information without charge through the SEC website (www.sec.gov) or upon your written or oral request by contacting the Investor Relations Department, resTORbio, Inc., 500 Boylston Street, 13^th Floor, Boston, Massachusetts 02116, or by calling (857) 315-5521.

You may also request additional copies from resTORbio’s proxy solicitor, The Proxy Advisory Group, LLC, using the following contact information:

18 East 41st Street, 20th Floor

New York, NY 10017-6219

(212) 616-2181

To ensure timely delivery of these documents, any request should be made no later than September 4, 2020 to receive them before the special meeting.

For additional details about where you can find information about resTORbio, please see the section entitled “Where You Can Find More Information” on page 441 of this proxy statement/prospectus/information statement.

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QUESTIONS AND ANSWERS ABOUT THE MERGER

Except where specifically noted, the following information and all other information contained in this proxy statement/prospectus/information statement does not give effect to the proposed reverse stock split described in the section entitled “Matters Being Submitted to a Vote of resTORbio Stockholders—Proposal No. 2: The Reverse Stock Split Proposal” beginning on page 238 in this proxy statement/prospectus/information statement (referred to as the “reverse stock split”).

The following section provides answers to frequently asked questions about the merger. This section, however, provides only summary information. For a more complete response to these questions and for additional information, please refer to the cross-referenced sections.

At the effective time of the merger, each share of Adicet capital stock outstanding immediately prior to the effective time, excluding any shares of Adicet capital stock held as treasury stock and shares held by Adicet stockholders who have exercised and perfected appraisal rights, will be converted into the right to receive approximately 0.8555 shares of resTORbio common stock, subject to adjustment to account for the reverse stock split of within the range between 1-for-4 and 1-for-12. This exchange ratio is an estimate only and is based upon resTORbio’s and Adicet’s capitalization as of August 4, 2020. The final exchange ratio will be determined pursuant to a formula described in more detail in the merger agreement and in the section entitled “The Merger Agreement—Merger Consideration and Exchange Ratio” beginning on page 207 of this proxy statement/prospectus/information statement, and is generally calculated by dividing (a) (i) the Adicet valuation per the merger agreement of $220,000,000 divided by (ii) the number of Adicet’s outstanding shares immediately prior to the effective time on a fully diluted basis (excluding equity incentives available for grant) by (b) (i) the resTORbio valuation per the merger agreement of $73,333,333 divided by (ii) the number of resTORbio’s outstanding shares immediately prior to the effective time on a fully diluted basis (excluding equity incentives available for grant).

Immediately following the effective time of the merger, the former equityholders of Adicet are expected to hold approximately 75% of the outstanding shares of resTORbio common stock on a fully diluted basis, and the current equityholders of resTORbio are expected to hold approximately 25% of the outstanding shares of resTORbio common stock on a fully diluted basis (in each case excluding equity incentives available for grant).

After the completion of the merger, resTORbio will change its corporate name from “resTORbio, Inc.” to “Adicet Bio, Inc.” as contemplated by the merger agreement.

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The resTORbio Board and the Adicet Board considered a number of factors that supported their respective decisions to approve the merger agreement. In the course of its deliberations, the resTORbio Board and the Adicet Board also considered a variety of risks and other countervailing factors related to entering into the merger agreement.

For a more complete discussion of resTORbio’s and Adicet’s reasons for the merger, please see the section entitled “The Merger—resTORbio Reasons for the Merger” beginning on page 177 of this proxy statement/prospectus/information statement and the section entitled “The Merger—Adicet Reasons for the Merger;” beginning on page 179 of this proxy statement/prospectus/information statement.

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The adoption of the merger agreement and the approval of the contemplated transactions by Adicet’s stockholders requires the affirmative vote (or written consent) of the holders of a majority of (a) the outstanding shares of Adicet capital stock (on an as-converted to Adicet common stock basis), (b) the outstanding shares of Adicet preferred stock, voting together as one class (on an as-converted to Adicet common stock basis) and (c) the outstanding shares of Adicet Series B Preferred Stock, par value $0.0001 per share (referred to as “Adicet Series B preferred stock”), voting together as one class, in each case, outstanding on the record date for the Adicet written consent and entitled to vote thereon (referred to as the “Required Adicet Stockholder Vote”).

In addition, following the registration statement on Form S-4, of which this proxy statement/prospectus/information statement is a part, being declared effective by SEC and pursuant to the conditions of the merger agreement and the support agreement entered into by and among Adicet, resTORbio and certain holders of Adicet capital stock (referred to as the “Adicet support agreement”), Adicet’s stockholders who are party to the Adicet support agreement are each obligated to execute the written consent adopting the merger agreement, thereby approving the contemplated transactions, including the merger, no later than five business days after the registration statement on Form S-4, of which this proxy statement/prospectus/information statement forms a part, is declared effective. Therefore, holders of a sufficient number of shares of Adicet capital stock required to adopt the merger agreement are expected to adopt the merger agreement, and no meeting of Adicet’s stockholders to adopt the merger agreement and approve the merger and contemplated transactions is expected to be held.

For a more complete description of the closing conditions under the merger agreement, please see the section entitled “The Merger Agreement—Conditions to the Completion of the Merger” beginning on page 212 of this proxy statement/prospectus/information statement.

Upon the effective time of the merger, each Adicet option, whether vested or unvested, issued pursuant to the Adicet 2015 Stock Incentive Plan (referred to as the “Adicet 2015 plan”) and a subset of options pursuant to the Adicet 2014 Share Option Plan (referred to as the “Adicet 2014 plan”) will be converted into options to purchase a number of shares of resTORbio common stock based on the exchange ratio, subject to the terms of and adjustments in the merger agreement. The assumed options will remain subject to the terms of the Adicet plans under which they were issued, accordingly, and applicable stock option agreements. Adicet warrants with rights to acquire Adicet capital stock will be converted into rights to acquire a certain number of shares of resTORbio common stock based on the exchange ratio, subject to the terms of and adjustments in the merger agreement and the applicable warrant.

For a more complete description of what Adicet’s stockholders, warrantholders and option holders will receive in the merger, please see the section entitled “The Merger Agreement—Merger Consideration and Exchange Ratio” beginning on page 207 of this proxy statement/prospectus/information statement.

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In addition, the merger agreement contemplates that at or prior to completion of the merger, resTORbio, the Holders’ Representative (as defined therein) and the Rights Agent (as defined therein) will execute and deliver a contingent value rights agreement (referred to as the “CVR agreement”), pursuant to which each holder of resTORbio common stock as of immediately prior to the completion of the merger shall be entitled to one contractual contingent value right (referred to as a “CVR”) issued by resTORbio, subject to and in accordance with the terms and conditions of the CVR agreement, for each share of resTORbio common stock held by such holder. Each CVR shall entitle the holder thereof to receive net proceeds of the commercialization, if any, received from a third party commercial partner of RTB101, resTORbio’s small molecule product candidate that is a potent inhibitor of target of rapamycin complex 1 (TORC1), for a COVID-19 related indication, with clinical data expected by the first quarter of 2021. The CVRs are not transferable, except in certain limited circumstances as will be provided in the CVR agreement, will not be certificated or evidenced by any instrument and will not be registered with the SEC or listed for trading on any exchange.

For a more complete description of what resTORbio’s stockholders, restricted stock unit holders and option holders will receive in the merger, please see the section entitled “The Merger Agreement—Merger Consideration and Exchange Ratio” beginning on page 207 of this proxy statement/prospectus/information statement.

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The merger agreement requires that, promptly after the registration statement on Form S-4, of which this proxy statement/prospectus/information statement forms a part, is declared effective, and no later than five (5) business days thereafter, Adicet must solicit for approval by written consent from Adicet’s stockholders the approval and adoption of the merger agreement and other contemplated transactions.

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Please review the information in the section entitled “The Merger—Material U.S. Federal Income Tax Considerations of the Merger” beginning on page 200 of this proxy statement/prospectus/information statement for a more complete description of the material U.S. federal income tax consequences of the merger to U.S. Holders. The tax consequences to you of the merger will depend on your particular facts and circumstances. Please consult your tax advisors as to the specific tax consequences to you of the merger.

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The tax consequences to you of the receipt of CVRs and the resTORbio reverse stock split will depend on your particular facts and circumstances. Please consult your tax advisors as to the specific tax consequences to you.

If you are a stockholder of resTORbio, you may provide your proxy instructions in one of two different ways. First, you can mail your signed proxy card in the enclosed return envelope. You may also provide your proxy instructions via phone or via the internet by following the instructions on your proxy card or voting instruction form. Please provide your proxy instructions only once, unless you are revoking a previously delivered proxy instruction, and as soon as possible so that your shares can be voted at the special meeting.

If you are a stockholder of Adicet, you may execute and return your written consent to Adicet in accordance with the instructions provided by Adicet.

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If your shares are held in “street name,” you may attend the special meeting. In the event that you do not have the control number required to access the special meeting, please contact your broker, bank, or other nominee as soon as possible and no later than September 11, 2020 so that you can be provided with a control number and gain access to the meeting. Please note that if the holder of record of your shares is a broker, bank or other nominee and you wish to vote online at the special meeting, you must request a proxy, executed in your favor, from your bank, broker or other nominee that holds your shares and present that proxy and proof of identification at the special meeting.

Stockholders who choose to participate in the special meeting can vote their shares electronically during the meeting via live webcast by visiting www.virtualshareholdermeeting.com/TORC2020SM. You will need the control number that is printed on your proxy card to enter the special meeting. resTORbio recommends that you log in at least 15 minutes before the meeting to ensure you are logged in when the meeting starts.

Even if you plan to participate in the special meeting online, we recommend that you also vote by proxy as described above so that your vote will be counted if you later decide not to participate in the special meeting.

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The Proxy Advisory Group, LLC

Telephone: (212) 616-2181

If you are a stockholder of Adicet and would like additional copies, without charge, of this proxy statement/prospectus/information statement or if you have questions about the merger, including the procedures for voting your shares, you should contact:

Adicet Bio, Inc.

200 Construction Drive

Menlo Park, California 94025

Telephone: 650-503-9095

Attn: Anil Singhal, CEO

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COMPARATIVE HISTORICAL AND UNAUDITED PRO FORMA PER SHARE DATA

The information below reflects the historical per share information for resTORbio and Adicet and the unaudited pro forma per share information for the combined organization as if resTORbio and Adicet had been combined as of and for all periods presented.

The unaudited pro forma amounts in the tables below have been derived from the unaudited pro forma combined financial information included in the section titled “Unaudited Pro Forma Condensed Combined Financial Information” of this proxy statement/prospectus/information statement. The pro forma amounts are presented for illustrative purposes only and are not necessarily indicative of what the financial position, results of operations or per share information of the combined organization would have been had resTORbio and Adicet been combined as of or for the periods presented. The unaudited pro forma amounts in the table below do not give effect to the proposed reverse stock split because the proposed reverse stock split is a range and is not definitive.

The tables below should be read in conjunction with the consolidated financial statements and related notes thereto of resTORbio and Adicet included elsewhere in this proxy statement/prospectus/information statement.

As the reverse stock split is a range and is not definitive, resTORbio’s historical per share information and the unaudited pro forma per share information have not been adjusted to give retrospective effect to the reverse stock split. Upon the effectiveness of the reverse stock split, the outstanding shares of resTORbio common stock will be combined into a lesser number of shares such that one share of resTORbio common stock will be issued for a

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specified number of shares, which shall be equal to or greater than four (4) and equal to or less than twelve (12), with the exact number within the range to be mutually determined by resTORbio and Adicet prior to the effective time. The exchange ratio will then be subject to adjustment to account for the effect of the reverse stock split of resTORbio common stock to be implemented immediately prior to and contingent upon the consummation of the merger. The following table is presented for illustrative purposes to give effect to the range of the proposed reverse stock split as the unaudited pro forma per share information above does not reflect the proposed reverse stock split that is expected to be effected immediately prior to consummation of the merger.

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MARKET PRICE AND DIVIDEND INFORMATION

resTORbio Common Stock

resTORbio common stock is currently listed on The Nasdaq Global Select Market under the symbol “TORC.” The closing price of resTORbio common stock on April 28, 2020, the full trading day immediately prior to the public announcement of the merger on April 29, 2020, as reported on The Nasdaq Global Select Market, was $1.22 per share. The closing price of resTORbio common stock on August 18, 2020, the last trading day before the date of this proxy statement/prospectus/information statement, as reported on The Nasdaq Global Select Market, was $2.23 per share.

Because the market price of resTORbio common stock is subject to fluctuation, the market value of the shares of resTORbio common stock that Adicet equityholders will be entitled to receive in the merger may increase or decrease.

Assuming successful application for initial listing with Nasdaq, following the consummation of the merger, resTORbio anticipates that the resTORbio common stock will continue to be listed on The Nasdaq Global Select Market and will trade under resTORbio’s new name “Adicet Bio, Inc.” and new trading symbol “ACET” on The Nasdaq Global Select Market.

As of August 4, 2020, there were approximately five (5) holders of record of the resTORbio common stock.

Adicet Capital Stock

Adicet is a private company and there is no established public trading market for its common stock or preferred stock. As of August 4, 2020, there were approximately 56 holders of record of the Adicet common stock and 21 holders of record of the Adicet preferred stock.

Dividends

resTORbio has never declared or paid any cash dividends on the resTORbio common stock and does not anticipate paying cash dividends on the resTORbio common stock for the foreseeable future. Notwithstanding the foregoing, any determination to pay cash dividends subsequent to the merger will be at the discretion of the combined company’s then-current board of directors and will depend upon a number of factors, including the combined company’s results of operations, financial condition, future prospects, contractual restrictions, restrictions imposed by applicable law and other factors the then-current board of directors deems relevant.

Adicet has never declared or paid any cash dividends on shares of the Adicet capital stock. Adicet anticipates that the combined company will retain all of its future earnings to advance the clinical trials for its products, and does not anticipate paying any cash dividends on shares of the combined company’s capital stock in the foreseeable future. Any future determination to declare cash dividends on shares of the combined company’s common stock will be made at the discretion of its board of directors, subject to applicable law and contractual restrictions and will depend on its financial condition, results of operations, capital requirements, general business conditions and other factors that its board of directors may deem relevant.

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RISK FACTORS

The combined company will be faced with a market environment that cannot be predicted and that involves significant risks, many of which will be beyond its control. In addition to the other information contained in this proxy statement/prospectus/information statement, you should carefully consider the material risks described below before deciding how to vote your shares of stock. In addition, you should read and consider the risks associated with resTORbio’s business and Adicet’s business because these risks may also affect the combined company. These risks can be found under the section entitled “Risk Factors—Risks Related to resTORbio” beginning on page 36 and “Risk Factors—Risks Related to Adicet” beginning on page 100 of this proxy statement/prospectus/information statement, including the financial statements appearing elsewhere herein and the annexes hereto, which are incorporated by reference herein. You should also read and consider the other information in this proxy statement/prospectus/information statement, including the financial statements appearing elsewhere herein and the annexes hereto, which are incorporated by reference herein. Please see the section entitled “Where You Can Find More Information” on page 441 in this proxy statement/prospectus/information statement.”

Risks Related to the Merger

Failure to complete the merger may result in resTORbio or Adicet paying a termination fee or expenses to the other party and could significantly harm the market price of resTORbio common stock and negatively affect the future business and operations of each company.

The consummation of the merger is subject to a number of closing conditions, including the approval by resTORbio’s and Adicet’s stockholders, approval by Nasdaq of resTORbio’s application for initial listing of resTORbio common stock in connection with the merger, and other customary closing conditions. The parties are targeting a closing of the transaction in the second half of 2020.

If the merger is not consummated, resTORbio and Adicet may be subject to a number of material risks, and their respective businesses and resTORbio’s stock price could be adversely affected, as follows:

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In addition, if the merger agreement is terminated and the resTORbio Board or the Adicet Board determines to seek another business combination, there can be no assurance that either resTORbio or Adicet will be able to find a third party willing to provide equivalent or more attractive consideration than the consideration to be provided by each party in the merger. In such circumstances, the resTORbio Board may elect to, among other things, divest all or a portion of resTORbio’s business, or take the steps necessary to liquidate all of resTORbio’s business and assets, and in either such case, the consideration that resTORbio receives may be less attractive than the consideration to be received by resTORbio pursuant to the merger agreement.

If resTORbio does not successfully consummate the merger or another strategic transaction, the resTORbio Board may decide to pursue a dissolution and liquidation of resTORbio. In such an event, the amount of cash available for distribution to resTORbio stockholders will depend heavily on the timing of such liquidation as well as the amount of cash that will need to be reserved for commitments and contingent liabilities.

There can be no assurance that the merger will be completed on the timeline anticipated or at all. If the merger is not completed, the resTORbio Board may decide to pursue a dissolution and liquidation of resTORbio. In such an event, the amount of cash available for distribution to resTORbio stockholders will depend heavily on the timing of such decision and, as with the passage of time the amount of cash available for distribution will be reduced as resTORbio continues to fund its operations. In addition, if the resTORbio Board were to approve and recommend, and resTORbio stockholders were to approve, a dissolution and liquidation of resTORbio, resTORbio would be required under Delaware corporate law to pay its outstanding obligations, as well as to make reasonable provision for contingent and unknown obligations, prior to making any distributions in liquidation to resTORbio stockholders. As a result of this requirement, a portion of resTORbio’s assets may need to be reserved pending the resolution of such obligations, and the timing of any such resolution is uncertain. In addition, resTORbio may be subject to litigation or other claims related to a dissolution and liquidation of resTORbio. If a dissolution and liquidation were pursued, the resTORbio Board, in consultation with its advisors, would need to evaluate these matters and make a determination about a reasonable amount to reserve. Accordingly, holders of resTORbio common stock could lose all or a significant portion of their investment in the event of a liquidation, dissolution or winding up of resTORbio.

Some of resTORbio’s and Adicet’s officers and directors have conflicts of interest that may influence them to support or approve the merger.

Certain officers and directors of resTORbio and Adicet participate in arrangements that provide them with interests in the merger that are different from yours, including, among others, their continued service as an officer or a director of the combined company, retention and severance benefits, the acceleration of restricted stock units and option vesting, overlapping ownership and/or commercial interests of their affiliates in Adicet and resTORbio and continued indemnification. These interests, among others, may influence the officers and directors of resTORbio or Adicet to support or approve the merger. For a more detailed discussion please see the section entitled “The Merger—Interests of the resTORbio Directors and Executive Officers in the Merger” beginning on page 192 of this proxy statement/prospectus/information statement and “The Merger—Interests of the Adicet Directors and Executive Officers in the Merger” beginning on page 195 of this proxy statement/prospectus/information statement.

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The merger may be completed even though material adverse changes may result from the announcement of the merger, industry-wide changes and other causes.

In general, either party can refuse to complete the merger if there is a material adverse change affecting the other party between April 28, 2020, the date of the merger agreement, and the completion of the merger. However, some types of changes do not permit either party to refuse to complete the merger, even if such changes would have a material adverse effect on resTORbio or Adicet, to the extent they resulted from the following and do not have a materially disproportionate effect on resTORbio or Adicet, as the case may be:

If adverse changes occur but resTORbio and Adicet must still complete the merger, the combined company’s stock price may suffer. This in turn may reduce the value of the merger to the stockholders of resTORbio, Adicet or both.

The market price of the combined company’s stock may decline as a result of the merger.

The market price of the combined company’s stock may decline as a result of the merger for a number of reasons including if:

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resTORbio’s and Adicet’s stockholders may not realize a benefit from the merger commensurate with the ownership dilution they will experience in connection with the merger.

If the combined company is unable to realize the strategic and financial benefits currently anticipated from the merger, resTORbio’s and Adicet’s stockholders will have experienced substantial dilution of their ownership interest without receiving any commensurate benefit. Significant management attention and resources will be required to integrate the two companies. Delays in this process could adversely affect the combined company’s business, financial results, financial condition and stock price following the merger.

During the pendency of the merger, resTORbio or Adicet may not be able to enter into a business combination with another party and will be subject to contractual limitations on certain actions because of restrictions in the merger agreement.

Covenants in the merger agreement impede the ability of resTORbio or Adicet to make acquisitions or complete other transactions that are not in the ordinary course of business pending completion of the merger. As a result, if the merger is not completed, the parties may be at a disadvantage to their competitors. In addition, while the merger agreement is in effect and subject to limited exceptions, each party is prohibited from soliciting, initiating, encouraging or taking actions designed to facilitate any inquiries or the making of any proposal or offer that could lead to the entering into of certain extraordinary transactions with any third party, such as a sale of assets, an acquisition of resTORbio common stock, a tender offer for resTORbio common stock, a merger or other business combination outside the ordinary course of business. Any such transactions could be favorable to such party’s stockholders.

Because the lack of a public market for Adicet capital stock makes it difficult to evaluate the fairness of the merger, Adicet’s stockholders may receive consideration in the merger that is greater than or less than the fair market value of Adicet capital stock.

The outstanding share capital of Adicet is privately held and is not traded in any public market. The lack of a public market makes it extremely difficult to determine the fair market value of Adicet. Since the percentage of resTORbio’s equity to be issued to Adicet’s stockholders was determined based on negotiations between the parties, it is possible that the value of the resTORbio common stock to be issued in connection with the merger will be greater than the fair market value of Adicet. Alternatively, it is possible that the value of the shares of resTORbio common stock to be issued in connection with the merger to Adicet’s stockholders will be less than the fair market value of Adicet.

The combined company will incur significant transaction costs as a result of the merger, including investment banking, legal and accounting fees. In addition, the combined company will incur significant consolidation and integration expenses which cannot be accurately estimated at this time. These costs could include the possible relocation of certain operations from Massachusetts to other offices of the combined company as well as costs associated with terminating existing office leases and the loss of benefits of certain favorable office leases. Actual transaction costs may substantially exceed Adicet’s estimates and may have an adverse effect on the combined company’s financial condition and operating results.

If the merger does not qualify as a “reorganization” for U.S. federal income tax purposes, Adicet stockholders may be required to pay substantial U.S. federal income taxes.

The U.S. federal income tax consequences of the merger will depend on whether the merger qualifies as a “reorganization” within the meaning of Section 368(a) of the Code. Adicet’s obligation to effect the merger is subject to the satisfaction or waiver, at or prior to the closing date of the merger, of the condition that Adicet receive an opinion of counsel, dated as of the closing date of the merger, to the effect that the merger will qualify as a “reorganization” within the meaning of Section 368(a) of the Code. The opinion will be based on customary assumptions and representations from Adicet and resTORbio, as well as certain covenants and undertakings by

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Adicet and resTORbio. If any of the representations, assumptions, covenants or undertakings upon which the opinion is based is incorrect, incomplete, inaccurate or violated, the validity of the opinion may be affected and the tax consequences of the merger could differ from those described in this proxy statement/prospectus/information statement. An opinion of counsel represents such counsel’s best legal judgment, but is not binding on the Internal Revenue Service (the “IRS”) or any court. Neither Adicet nor resTORbio intends to obtain a ruling from the IRS with respect to the tax consequences of the merger. Accordingly, there can be no assurances that the IRS will not assert, or that a court will not sustain, a position contrary to that contained in such opinion. If, contrary to the opinion from counsel, the IRS or a court determines that the merger does not qualify as a “reorganization” within the meaning of Section 368(a) of the Code, a holder of Adicet capital stock would recognize gain or loss for U.S. federal income tax purposes on each share of Adicet capital stock surrendered in the merger for resTORbio common stock. For a more complete discussion of the material U.S. federal income tax consequences of the merger, please carefully review the information set forth in the section entitled “The Merger—Material U.S. Federal Income Tax Considerations of the Merger” on page 200 of this proxy statement/prospectus/information statement.

Certain stockholders could attempt to influence changes within resTORbio which could adversely affect resTORbio’s operations, financial condition and the value of resTORbio common stock.

resTORbio stockholders may from time-to-time seek to acquire a controlling stake in resTORbio, engage in proxy solicitations, advance stockholder proposals or otherwise attempt to effect changes. Campaigns by stockholders to effect changes at publicly-traded companies are sometimes led by investors seeking to increase short-term stockholder value through actions such as financial restructuring, increased debt, special dividends, stock repurchases or sales of assets or the entire company. Responding to proxy contests and other actions by activist stockholders can be costly and time-consuming, and could disrupt resTORbio’s operations and divert the attention of the resTORbio Board and senior management from the pursuit of the merger. These actions could adversely affect resTORbio’s operations, financial condition, ability to consummate the merger and resTORbio’s common stock value.

resTORbio and Adicet are involved in securities litigation related to the merger and may become involved in additional securities litigation or stockholder derivative litigation in connection with the merger, and this could divert the attention of resTORbio and Adicet management and harm the combined company’s business, and insurance coverage may not be sufficient to cover all related costs and damages.

Securities litigation or stockholder derivative litigation frequently follows the announcement of certain significant business transactions, such as a business combination transaction. resTORbio and Adicet may become involved in this type of litigation in connection with the merger, and the combined company may become involved in this type of litigation in the future. Litigation often is expensive and diverts management’s attention and resources, which could adversely affect the business of resTORbio, Adicet and the combined company.

In connection with the merger, a putative class action lawsuit, Plumley v. resTORbio Inc., et al., 1:20-cv-00858, was filed on June 26, 2020 by purported resTORbio stockholder Patrick Plumley against resTORbio, its directors, Adicet, and Merger Sub in the U.S. District Court for the District of Delaware. On July 2, 2020, in connection with the merger, a complaint, Azzara v. resTORbio, Inc., et al., 1:20-cv-05088, was filed as an individual action by purported resTORbio stockholder Salvatore Azzara against resTORbio and its directors in the U.S. District Court for the Southern District of New York, and an amended complaint was filed on August 11, 2020. On July 6, 2020, in connection with the merger, a complaint, Miller v. resTORbio, Inc., et al., 1:20-cv-05170, was filed as an individual action by purported resTORbio stockholder Megan Miller against resTORbio and its directors in the U.S. District Court for the Southern District of New York. On July 9, 2020, in connection with the merger, a complaint, Feagan v. resTORbio, Inc., et al., 1:20-cv-03063, was filed as an individual action by purported resTORbio stockholder Douglas Feagan against resTORbio and its directors in the U.S. District Court for the Eastern District of New York. On July 10, 2020, in connection with the merger, a complaint, Lowen v. resTORbio, Inc. et al., 1:20-cv-11305, was filed as an individual action by purported resTORbio stockholder Robert Lowen against resTORbio and its directors in the U.S. District Court for the District Massachusetts. On July 19, 2020, in connection with the merger, a complaint, Mercier v. resTORbio, Inc, et al., 1:20-cv-05556, was

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filed as an individual action by purported resTORbio stockholder Ronald Mercier against resTORbio and its directors in the U.S. District Court for the Southern District of New York. The Plumley, Azzara, Miller, Feagan, Lowen and Mercier cases are collectively referred to as the “merger actions.” The merger actions generally allege that resTORbio’s proxy statement/prospectus/information statement filed with the SEC on June 23, 2020 or July 29, 2020 misrepresents and/or omits certain purportedly material information relating to financial projections, analysis performed by JMP, past engagements of JMP, and the process leading up to the execution of the merger agreement. The merger actions assert violations of Section 14(a) of the Exchange Act and Rule 14a-9 promulgated thereunder against resTORbio and its directors and violations of Section 20(a) of the Exchange Act against resTORbio’s directors. The Plumley merger action also asserts violations of Section 20(a) of the Exchange Act against Adicet and Merger Sub. The Azzara merger action also asserts claims for an equitable assessment of attorneys’ fees and expenses against resTORbio and its directors and claims for breach of fiduciary duty against resTORbio’s directors. The merger actions seek, among other things: an injunction enjoining consummation of the merger, costs of the action, including plaintiff’s attorneys’ fees and experts’ fees, declaratory relief, and any other relief the court may deem just and proper.

It is possible that additional similar cases could be filed in connection with the merger.

Failure to complete the merger may result in resTORbio and Adicet paying a termination fee or expenses to the other party and could harm the price of resTORbio common stock and the future business and operations of each company.

If the merger is not completed and the merger agreement is terminated under certain circumstances, resTORbio or Adicet may be required to pay the other party a termination fee of $6,100,000 and/or an out-of-pocket expense reimbursement of up to $1,000,000. Even if a termination fee or out-of-pocket expense reimbursement is not payable in connection with a termination of the merger agreement, each of resTORbio and Adicet will have incurred significant fees and expenses, which must be paid whether or not the merger is completed. Further, if the merger is not completed, it could significantly harm the market price of resTORbio common stock.

The exchange ratio is not adjustable based on the market price of resTORbio common stock, so the merger consideration at the completion of the merger may have greater or lesser value than the market price at the time the merger agreement was signed.

The merger agreement has set the exchange ratio for Adicet capital stock, and the exchange ratio is based on valuations ascribed to each company in the merger agreement and the outstanding Adicet capital stock and the outstanding resTORbio common stock, in each case immediately prior to the completion of the merger as described under the section entitled “The Merger—Merger Consideration” on page 199 of this proxy statement/prospectus/information statement. Applying the exchange ratio formula in the merger agreement, the former equityholders of Adicet are expected to hold 75% of the outstanding capital stock of resTORbio immediately following the merger, and the current equityholders of resTORbio are expected to hold approximately 25% of the outstanding capital stock of resTORbio immediately following merger (in each case excluding equity incentives available for grant), subject to certain assumptions.

Any changes in the market price of resTORbio common stock before the completion of the merger will not affect the number of shares of resTORbio common stock issuable to Adicet’s stockholders pursuant to the merger agreement. Therefore, if before the completion of the merger the market price of resTORbio common stock declines from the market price on the date of the merger agreement, then Adicet’s stockholders could receive merger consideration with substantially lower value than the value of such merger consideration on the date of the merger agreement. Similarly, if before the completion of the merger the market price of resTORbio common stock increases from the market price of resTORbio common stock on the date of the merger agreement, then Adicet’s stockholders could receive merger consideration with substantially greater value than the value of such merger consideration on the date of the merger agreement. The merger agreement does not include a price-based termination right. Because the exchange ratio does not adjust as a result of changes in the market price of resTORbio common stock, for each one percentage point change in the market price of resTORbio common stock, there is a corresponding one percentage point rise or decline, respectively, in the value of the total merger consideration payable to Adicet’s stockholders pursuant to the merger agreement.

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Certain provisions of the merger agreement may discourage third parties from submitting alternative takeover proposals, including proposals that may be superior to the arrangements contemplated by the merger agreement.

The terms of the merger agreement prohibit each of resTORbio and Adicet from soliciting alternative takeover proposals or cooperating with persons making unsolicited takeover proposals, except in limited circumstances when the resTORbio Board or the Adicet Board determines in good faith that a bona fide written acquisition proposal, after consultation with such party’s financial advisors and outside legal counsel, constitutes, or is reasonably likely to result in, a superior takeover proposal and the board of directors of such party concludes in good faith based on the advice of outside legal counsel that the failure to cooperate with the proponent of the proposal would be reasonably be expected to be inconsistent with the resTORbio Board’s or the Adicet Board’s respective fiduciary duties.

resTORbio stockholders may not receive any payment on the CVRs and the CVRs may otherwise expire valueless.

The merger agreement contemplates that at or prior to completion of the merger, resTORbio, the Holders’ Representative (as defined in the CVR agreement) and the Rights Agent (as defined in the CVR agreement) will execute and deliver the CVR agreement, pursuant to which each holder of resTORbio common stock as of immediately prior to the effective time of the merger shall be entitled to one contractual CVR issued by resTORbio, subject to and in accordance with the terms and conditions of the CVR agreement, for each share of resTORbio common stock held by such holder. Each CVR shall entitle the holder thereof to receive net proceeds of the commercialization, if any, received from a third party commercial partner of RTB101, resTORbio’s small molecule product candidate that is a potent inhibitor of target of rapamycin complex 1 (TORC1), for a COVID-19 related indication, with clinical data expected by the first quarter of 2021. The CVRs are not transferable, except in certain limited circumstances as will be provided in the CVR agreement, will not be certificated or evidenced by any instrument and will not be registered with the SEC or listed for trading on any exchange.

Pursuant to the CVR agreement, and subject to the limitations set forth therein, from the closing of the merger until September 30, 2021, the combined company will be required to use its Commercially Reasonable Efforts (as such term is defined in the CVR agreement) to perform the key tasks necessary to continue and conduct resTORbio’s clinical trials for a COVID-19 related indication for RTB101 in strict accordance with such trials’ protocols. Pursuant to the CVR agreement, the Clinical Trial Cap (as such term is defined in the CVR agreement) for the total fees and expenses of resTORbio’s clinical trials for a COVID-19 related indication of RTB101 is $3,000,000, less any fully burdened costs accrued or incurred by resTORbio or its affiliates in connection with such clinical trials, between the date of the merger agreement and the closing of the merger. In the event the total fees and expenses of such clinical trials exceed such Clinical Trial Cap, the combined company may terminate the CVR agreement without any further liability whereupon the combined company shall be relieved of any and all obligations which will be contained therein. In addition, pursuant to the CVR agreement, and subject to the combined company’s termination rights set forth therein, from the closing of the merger until September 30, 2021, the combined company will be required to use its Commercially Reasonable Efforts to reasonably support the Finder (as such term is defined in the CVR agreement) to identify one or more partners and negotiate a CVR Commercial Agreement (as such term is defined in the CVR agreement) with such partner for the commercialization of RTB101 for a COVID-19 related indication, subject to certain limitations set forth in the CVR agreement, which allow for the consideration of a variety of factors in determining the efforts that the combined company is required to use to reasonably support Finder to identify one or more partners and negotiate a CVR Commercial Agreement with such partner for the commercialization of RTB101 for a COVID-19 related indication and it does not require the combined company to take all possible actions to continue efforts to reasonably support the Finder to identify one or more partners and negotiate a CVR Commercial Agreement with such partner for the commercialization of RTB101 for a COVID-19 related indication. Accordingly, under certain circumstances, including if the Clinical Trial Cap is exceeded, the combined company may not be required to continue efforts to reasonably support the Finder to identify one or more partners and negotiate a CVR Commercial Agreement with such partner for the commercialization of RTB101 for a COVID-19 related indication, or may allocate resources to other projects, which would have an adverse effect on the value, if any, of the CVRs. resTORbio currently expects to engage JMP Securities LLC to act as the Finder pursuant to the CVR agreement. The right of any holder of a CVR to receive any payments pursuant to the CVR agreement is contingent upon the combined company entering into a CVR Commercial Agreement with a third party commercial partner prior to September 30, 2021. If the combined company does enter into a CVR Commercial Agreement with a third party commercial partner

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prior to September 30, 2021, the Net Proceeds (as such term is defined in the CVR agreement) received by the combined company pursuant to such CVR Commercial Agreement in consideration for the rights to commercialize a COVID-19 related indication of RTB101 will then be distributed to the holders of the CVRs as set forth in the CVR agreement. If the combined company does not enter into a CVR Commercial Agreement with a third party commercial partner prior to September 30, 2021, or if the combined company does enter into such CVR Commercial Agreement but does not receive any Net Proceeds pursuant to such CVR Commercial Agreement, no payments will be made under the CVRs, and the CVRs will expire valueless. Furthermore, the CVRs will be unsecured obligations of the combined company and all payments under the CVRs, all other obligations under the CVR agreement and the CVRs and any rights or claims relating thereto will be subordinated in right of payment to the prior payment in full of all current or future senior obligations of the combined company. Finally, the U.S. federal income tax treatment of the CVRs is unclear. There is no legal authority directly addressing the U.S. federal income tax treatment of the receipt of, and payments on, the CVRs, and there can be no assurance that the IRS, would not assert, or that a court would not sustain, a position that could result in adverse U.S. federal income tax consequences to holders of the CVRs. The CVR agreement is discussed in greater detail in the section entitled “Agreements Related to the Merger—Contingent Value Rights Agreement” on page 232 of this proxy statement/ prospectus/information statement.

The tax treatment to resTORbio stockholders for the receipt of the CVRs is uncertain.

The U.S. federal income tax treatment of the issuance of the CVRs to resTORbio stockholders is uncertain. resTORbio intends to report the issuance of the CVRs as a distribution of property with respect to its stock for U.S. federal income tax purposes. Under such tax treatment, resTORbio U.S. Holders would be subject to the tax consequences described below under the section entitled “Tax Consequences if Treated as a Distribution of Property” beginning on page 235 of this proxy statement/prospectus/information statement. However, there is no authority directly addressing whether the issuance of contingent value rights with characteristics similar to the CVRs should be treated as a distribution of property with respect to the corporation’s stock, a distribution of equity, a “debt instrument” or an “open transaction” for U.S. federal income tax purposes. As a result, no assurance can be given that the IRS will not assert, or that a court would not sustain, a position contrary to resTORbio’s intended reporting position, and no opinion of counsel shall be given regarding the tax treatment of the issuance of the CVRs. In the event the IRS were to successfully challenge resTORbio’s intended treatment of the CVRs, it is possible that the issuance of the CVRs could be treated as a distribution of equity, a “debt instrument” or an “open transaction” for U.S. federal income tax purposes. The tax consequences of such alternative treatments are described below under the sections entitled, “Tax Consequences if Treated as a Distribution of Equity,” “Tax Consequences if Treated as a Debt Instrument,” and “Tax Consequences if Treated as an Open Transaction” beginning on page 236 of this proxy statement/prospectus/information statement. resTORbio stockholders should consult their tax advisors with respect to the proper tax treatment of the receipt of the CVRs.

Risks Related to the Reverse Stock Split

The reverse stock split may not increase the combined company’s stock price over the long-term.

The principal purpose of the reverse stock split is to increase the per-share market price of resTORbio common stock above the minimum bid price requirement under the Nasdaq rules so that the listing of the combined company and the shares of resTORbio common stock being issued in the merger on Nasdaq will be approved. It cannot be assured, however, that the reverse stock split will accomplish this objective for any meaningful period of time. While it is expected that the reduction in the number of outstanding shares of common stock will proportionally increase the market price of resTORbio common stock, it cannot be assured that the reverse stock split will increase the market price of its common stock by a multiple of the reverse stock split ratio, or result in any permanent or sustained increase in the market price of resTORbio common stock, which is dependent upon many factors, including the combined company’s business and financial performance, general market conditions, and prospects for future success. Thus, while the stock price of the combined company might meet the continued listing requirements for Nasdaq initially, it cannot be assured that it will continue to do so.

The reverse stock split may decrease the liquidity of resTORbio common stock.

Although the resTORbio Board believes that the anticipated increase in the market price of resTORbio common stock could encourage interest in its common stock and possibly promote greater liquidity for its stockholders,

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such liquidity could also be adversely affected by the reduced number of shares outstanding after the reverse stock split. The reduction in the number of outstanding shares may lead to reduced trading and a smaller number of market makers for resTORbio common stock.

The reverse stock split may lead to a decrease in resTORbio’s overall market capitalization.

Should the market price of resTORbio common stock decline after the reverse stock split, the percentage decline may be greater, due to the smaller number of shares outstanding, than it would have been prior to the reverse stock split. A reverse stock split is often viewed negatively by the market and, consequently, can lead to a decrease in resTORbio’s overall market capitalization. If the per share market price does not increase in proportion to the reverse stock split ratio, then the value of the combined company, as measured by its stock capitalization, will be reduced. In some cases, the per-share stock price of companies that have effected reverse stock splits subsequently declined back to pre-reverse split levels, and accordingly, it cannot be assured that the total market value of resTORbio common stock will remain the same after the reverse stock split is effected, or that the reverse stock split will not have an adverse effect on resTORbio’s stock price due to the reduced number of shares outstanding after the reverse stock split.

Risks Related to resTORbio

Risks Related to resTORbio’s Financial Position and Need for Capital

resTORbio has incurred significant losses since inception. resTORbio anticipates that it will continue to incur significant losses for the foreseeable future, and may never achieve or maintain profitability.

resTORbio is a clinical-stage biopharmaceutical company with a limited operating history. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate effect or an acceptable safety profile, gain regulatory approval and become commercially viable. resTORbio has no products approved for commercial sale and has not generated any revenue from product sales to date, and resTORbio will continue to incur significant research and development and other expenses related to resTORbio’s ongoing operations. As a result, resTORbio is not profitable and has incurred losses in each period since resTORbio’s inception in July 2016. resTORbio has devoted a majority of resTORbio’s financial resources and efforts to research and development, including preclinical studies and resTORbio’s clinical trials. resTORbio’s financial condition and operating results, including net losses, may fluctuate significantly from quarter to quarter and year to year. Accordingly, you should not rely upon the results of any quarterly or annual periods as indications of future operating performance. Additionally, net losses and negative cash flows have had, and will continue to have, an adverse effect on resTORbio stockholders’ equity and working capital. For the years ended December 31, 2019 and 2018, resTORbio reported a net loss of $82.7 million and $37.6 million, respectively. For the three and six months ended June 30, 2020, resTORbio reported a net loss of $5.6 million and $12.6 million, respectively. As of June 30, 2020, resTORbio had an accumulated deficit of $166.8 million. resTORbio expects to continue to incur significant losses for the foreseeable future, and resTORbio expects these losses to increase as resTORbio continues research and development of, and seek regulatory approvals for, RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, and other product candidates.

resTORbio anticipates that its expenses will increase substantially if and as it:

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resTORbio’s ability to become and remain profitable depends on resTORbio’s ability to generate revenue. resTORbio does not expect to generate significant revenue unless and until resTORbio is, or any future collaborator is, able to obtain regulatory approval for, and successfully commercialize, RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidates. Successful commercialization will require achievement of key milestones, including demonstrating safety and efficacy in clinical trials, obtaining regulatory, including marketing, approval for these product candidates, manufacturing, marketing and selling those products for which resTORbio, or any of resTORbio’s future collaborators, may obtain regulatory approval, satisfying any post-marketing requirements and obtaining reimbursement for resTORbio’s products from private insurance or government payors. Because of the uncertainties and risks associated with these activities, resTORbio is unable to accurately and precisely predict the timing and amount of revenues, the extent of any further losses or if or when resTORbio might achieve profitability. resTORbio, and any future collaborators, may never succeed in these activities and, even if resTORbio does, or any future collaborators do, resTORbio may never generate revenues that are large enough for it to achieve profitability. Even if resTORbio does achieve profitability, resTORbio may not be able to sustain or increase profitability on a quarterly or annual basis. Additionally, resTORbio’s expenses could increase if resTORbio is required by the FDA or any comparable foreign regulatory authority to perform studies in addition to those currently expected, or if there are any delays in completing resTORbio’s clinical trials or the development of any of resTORbio’s product candidates.

resTORbio’s failure to become and remain profitable would depress the market price of resTORbio common stock and could impair resTORbio’s ability to raise capital, expand resTORbio’s business, diversify resTORbio’s product offerings or continue resTORbio’s operations. If resTORbio continues to suffer losses as resTORbio has in the past, investors may not receive any return on their investment and may lose their entire investment.

resTORbio has a limited operating history and no history of commercializing pharmaceutical products, which may make it difficult to evaluate the prospects for its future viability.

resTORbio was formed in July 2016 and commenced research and development operations in March 2017. resTORbio’s operations to date have been limited to organizing, staffing and financing, raising capital, in-licensing resTORbio’s technology and conducting research and development activities for resTORbio’s product candidates. resTORbio has not yet demonstrated an ability to obtain regulatory approvals, manufacture a commercial-scale product, or arrange for a third party to do so on resTORbio’s behalf, or conduct sales and marketing activities necessary for successful product commercialization. Accordingly, you should consider resTORbio’s prospects in light of the costs, uncertainties, delays and difficulties frequently encountered by companies in clinical development, especially clinical-stage biopharmaceutical companies such as resTORbio. Any predictions you make about resTORbio’s future success or viability may not be as accurate as they could be if resTORbio had a longer operating history or a history of successfully developing and commercializing pharmaceutical products.

resTORbio may encounter unforeseen expenses, difficulties, complications, delays and other known or unknown factors in achieving resTORbio’s business objectives. resTORbio will eventually need to transition from a company with a development focus to a company capable of supporting commercial activities. resTORbio may not be successful in such a transition.

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resTORbio will need substantial additional funding, and if resTORbio is unable to raise capital when needed, resTORbio could be forced to delay, reduce or eliminate resTORbio’s product discovery and development programs or commercialization efforts.

resTORbio’s operations have required substantial amounts of cash since inception. Developing pharmaceutical products, including conducting preclinical studies and clinical trials, is a very time-consuming, expensive and uncertain process that takes years to complete. For the foreseeable future, resTORbio expects to continue to rely on additional financing to achieve resTORbio’s business objectives.

For the years ended December 31, 2019 and 2018, resTORbio used $73.7 million and $35.5 million, respectively, in net cash for resTORbio’s operating activities, of which a majority related to research and development activities. For the six months ended June 30, 2020, resTORbio used $20.4 million in net cash for resTORbio’s operating activities, of which a majority related to research and development activities. If resTORbio obtains regulatory approval for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidates, resTORbio expects to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Some of these expenses may be incurred in advance of regulatory approval and could be substantial. Furthermore, resTORbio expects to incur significant additional costs associated with resTORbio’s continued operation as a public company. Accordingly, resTORbio will need to obtain substantial additional funding in connection with resTORbio’s continuing operations. If resTORbio is unable to raise capital when needed or on attractive terms, it may be forced to delay, reduce or eliminate resTORbio’s research and development programs or any future commercialization efforts.

resTORbio may use resTORbio’s existing cash, cash equivalents and marketable securities, to fund the development of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for Parkinson’s disease (referred to as “PD”) and other indications, and the remainder, if any, for working capital and general corporate purposes. resTORbio will be required to expend significant funds in order to advance the development of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, as well as other product candidates resTORbio may seek to develop or acquire. In addition, while resTORbio may seek one or more collaborators for future development of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, for one or more additional indications beyond PD or in geographies outside of the United States, Europe and key territories, resTORbio may not be able to enter into a collaboration for RTB101 or any other product candidates for such indications or in such geographies on suitable terms, on a timely basis, or at all. In any event, resTORbio’s existing cash, cash equivalents, and marketable securities will not be sufficient to fund all of the efforts that resTORbio plans to undertake or to activities related to the development of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for PD and other indications, and the development of other pipeline candidates. Accordingly, resTORbio will be required to obtain substantial additional funding through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources.

resTORbio cannot be certain that additional funding will be available on acceptable terms, or at all. Other than the funding agreement, resTORbio has no committed source of additional capital and if resTORbio is unable to raise additional capital in sufficient amounts or on terms acceptable to resTORbio, resTORbio may have to significantly delay, scale back or discontinue the development or commercialization of resTORbio’s product candidates or other research and development initiatives. Any of resTORbio’s current or future license agreements may also be terminated if resTORbio is unable to meet the payment or other obligations under the agreements. resTORbio could be required to seek collaborators for product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available or relinquish or license on unfavorable terms resTORbio’s rights to product candidates in markets where resTORbio otherwise would seek to pursue development or commercialization itself.

resTORbio believes resTORbio’s existing cash, cash equivalents and marketable securities, will enable resTORbio to fund its operating expenses and capital expenditure requirements at least into 2022. resTORbio’s estimate may prove to be wrong, and resTORbio could use available capital resources sooner than resTORbio currently expects. Further, changing circumstances, some of which may be beyond resTORbio’s control, could cause resTORbio to consume capital significantly faster than resTORbio currently anticipates, and may need to

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seek additional funds sooner than planned. resTORbio’s future funding requirements, both short- and long-term, will depend on many factors, including:

Raising additional capital may cause dilution to resTORbio stockholders, restrict resTORbio’s operations or require resTORbio to relinquish rights to resTORbio’s technologies or product candidates.

Unless and until resTORbio can generate a substantial amount of revenue from resTORbio’s product candidates, resTORbio expects to finance resTORbio’s future cash needs through public or private equity offerings, debt financings, collaborations, licensing arrangements or other sources, or any combination of the foregoing. In addition, resTORbio may seek additional capital due to favorable market conditions or strategic considerations, even if resTORbio believes that it has sufficient funds for resTORbio’s current or future operating plans.

To the extent that resTORbio raises additional capital through the sale of common stock, convertible securities or other equity securities, your ownership interest may be diluted, and the terms of these securities could include liquidation or other preferences and anti-dilution protections that could adversely affect your rights as a common stockholder. In addition, debt financing, if available, may result in fixed payment obligations and may involve agreements that include restrictive covenants that limit resTORbio’s ability to take specific actions, such as incurring additional debt, making capital expenditures, creating liens, redeeming stock or declaring dividends, that could adversely impact resTORbio’s ability to conduct resTORbio’s business. In addition, securing financing could require a substantial amount of time and attention from resTORbio’s management and may divert a disproportionate amount of their attention away from day-to-day activities, which may adversely affect resTORbio’s management’s ability to oversee the development of resTORbio’s product candidates.

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In April 2020, resTORbio entered into the merger agreement. There is no assurance that the merger will be completed.

If resTORbio raises additional funds through collaborations or marketing, distribution or licensing arrangements with third parties, resTORbio may have to relinquish valuable rights to its technologies, future revenue streams or product candidates or grant licenses on terms that may not be favorable to resTORbio. If resTORbio is unable to raise additional funds when needed, resTORbio may be required to delay, limit, reduce or terminate its product development or future commercialization efforts or grant rights to develop and market product candidates that resTORbio would otherwise prefer to develop and market itself.

Risks Related to the Discovery, Development and Commercialization of resTORbio’s Product Candidates

resTORbio’s business depends virtually entirely upon the success of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus. If resTORbio is unable to successfully develop, obtain regulatory approval for or successfully commercialize RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, resTORbio’s business may be materially harmed.

resTORbio currently has no products approved for sale and is investing the majority of resTORbio’s efforts and financial resources in the development of resTORbio’s lead product candidate, RTB101, either alone or in combination with a rapalog, such as everolimus or sirolimus. Successful continued development and ultimate regulatory approval of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for the treatment of aging-related diseases is critical to the future success of resTORbio’s business. resTORbio will need to raise sufficient funds for, and successfully enroll and complete, resTORbio’s clinical development program for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for indications such as PD and possibly other aging-related diseases. The future regulatory and commercial success of this product candidate is subject to a number of risks, including the following:

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Many of these risks are beyond resTORbio’s control, including the risks related to clinical development, the regulatory submission process, potential threats to resTORbio’s intellectual property rights and the manufacturing, marketing and sales efforts of any future collaborator. If resTORbio is unable to develop, receive regulatory approval for, or successfully commercialize RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or if resTORbio experiences delays as a result of any of these risks or otherwise, resTORbio’s business could be materially harmed.

In addition, of the large number of drugs in development in the pharmaceutical industry, only a small percentage result in the submission of an NDA to the FDA and even fewer are approved for commercialization. Furthermore, even if resTORbio does receive regulatory approval for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, any such approval may be subject to limitations on the indicated uses or patient populations for which resTORbio may market the product. Accordingly, even if resTORbio is able to obtain the requisite financing to continue to fund resTORbio’s development programs, it cannot assure you that it will successfully develop or commercialize RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for PD or any other indications. If resTORbio or any of resTORbio’s future collaborators are unable to develop, or obtain regulatory approval for, or, if approved, successfully commercialize RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for PD or any other indications, resTORbio may not be able to generate sufficient revenue to continue resTORbio’s business.

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resTORbio depends on the successful initiation and completion of clinical trials for RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus. The positive clinical results, if any, obtained in prior or ongoing clinical trials may not be predictive of future results or repeated in later-stage clinical trials.

Before obtaining regulatory approval for the sale of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other potential product candidate, resTORbio must conduct additional clinical trials to demonstrate safety and efficacy in humans. The regulatory requirements for demonstrating efficacy and safety for obtaining approval for RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, may differ. A failure of one or more clinical trials can occur at any stage of testing. For example, in November 2019, resTORbio announced that top line data from the PROTECTOR 1 Phase 3 study, evaluating the safety and efficacy of RTB101 in preventing clinically symptomatic respiratory illness in adults age 65 and older, did not meet its primary endpoint and that resTORbio has stopped the development of RTB101 for clinically symptomatic respiratory illness. A number of companies in the pharmaceutical and biotechnology industries, including those with greater resources and experience than resTORbio, have suffered significant setbacks in late stage clinical development, even after seeing promising results in earlier clinical trials.

resTORbio may experience a number of unforeseen events during, or as a result of, clinical trials for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other potential product candidate that could adversely affect the costs, timing, or successful completion of resTORbio’s clinical trials, including:

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Regulators, IRBs of the institutions in which clinical trials are being conducted or data monitoring committees may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or resTORbio’s clinical protocols, inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, or changes in governmental regulations or administrative actions or resTORbio may have a lack of adequate funding to continue the clinical trial.

Negative or inconclusive results from resTORbio’s clinical trials of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or any other clinical trial or preclinical studies in animals that resTORbio conducts, could mandate repeated or additional clinical trials. resTORbio does not know whether any clinical trials that resTORbio may conduct will demonstrate adequate efficacy and safety to result in regulatory approval to market RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other potential product candidate. If later stage clinical trials do not produce favorable results, resTORbio’s ability to obtain regulatory approval for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other potential product candidate may be adversely impacted.

Clinical trials must be conducted in accordance with the laws and regulations of the FDA, EMA and other applicable regulatory authorities’ laws, and are subject to oversight by these governmental agencies and IRBs at the medical institutions where the clinical trials are conducted. In addition, clinical trials must be conducted with supplies of resTORbio’s product candidates produced under cGMP, requirements and other regulations. Furthermore, resTORbio relies on CROs, and clinical trial sites to ensure the proper and timely conduct of resTORbio’s clinical trials and while resTORbio has agreements governing their committed activities, resTORbio has limited influence over their actual performance. resTORbio depends on resTORbio’s collaborators and on medical institutions and CROs to conduct resTORbio’s clinical trials in compliance with GCP, requirements. To the extent resTORbio’s collaborators or the CROs fail to enroll participants for resTORbio’s clinical trials, fail to conduct the study to GCP standards or are delayed for a significant time in the execution of trials, including achieving full enrollment, resTORbio may be affected by increased costs, program delays or both. In addition, clinical trials that are conducted in countries outside the United States and EU may subject resTORbio to further delays and expenses as a result of increased shipment costs, additional regulatory requirements and the engagement of non-U.S. and non-EU CROs, as well as expose resTORbio to risks associated with clinical investigators who are unknown to the FDA or the EMA, and different standards of diagnosis, screening and medical care.

resTORbio may be subject to additional risks because resTORbio is administering RTB101 in combination with other mTOR inhibitors, including rapalogs, such as everolimus or sirolimus.

resTORbio is evaluating RTB101 in combination with other mTOR inhibitors. The use of RTB101 in combination with other compounds may subject resTORbio to risks that resTORbio would not face if RTB101 were being administered as a monotherapy. For example, other mTOR inhibitors, including rapalogs, such as everolimus or sirolimus, may have safety issues that are improperly attributed to RTB101 or the administration of RTB101 with such

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other therapies may result in safety issues that such other therapies or RTB101 would not have when used alone. In addition, other mTOR inhibitors with which resTORbio may administer RTB101, including a rapalog, such as everolimus or sirolimus, could be removed from the market and thus be unavailable for testing or commercial use concomitantly with RTB101. The outcome and cost of developing a product candidate to be used with other compounds is difficult to predict and dependent on a number of factors that are outside resTORbio’s reasonable control. If resTORbio experiences efficacy or safety issues in resTORbio’s clinical trials in which RTB101 is being administered with a rapalog, such as everolimus or sirolimus, resTORbio may not receive regulatory approval for RTB101, which could prevent resTORbio from ever generating revenue or achieving profitability.

Competitive products may reduce or eliminate the commercial opportunity for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus. If resTORbio’s competitors develop technologies or product candidates more rapidly than resTORbio does, or their technologies are more effective or safer than resTORbio’s, resTORbio’s ability to develop and successfully commercialize RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, may be adversely affected.

The clinical and commercial landscape for aging-related diseases is highly competitive and subject to rapid and significant technological change. New data from competitors’ product candidates continue to emerge. It is possible that these data may alter the current standard of care, completely precluding resTORbio from further developing RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for PD or other aging-related diseases. Further, it is possible that resTORbio may initiate a clinical trial or trials for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other potential product candidate only to find that data from competing products make it impossible for resTORbio to complete enrollment in clinical trials, resulting in resTORbio’s inability to submit applications for regulatory approval with regulatory agencies. Even if RTB101 were approved, alone or in combination with a rapalog, such as everolimus or sirolimus, it may have limited sales due to competition in the specific indications approved.

Competitive therapeutic treatments for aging-related diseases, including PD, include those that are currently in development and any new treatments that enter the market. resTORbio believes that a significant number of product candidates are currently under development, and may become commercially available in the future, for the treatment of conditions for which resTORbio may try to develop product candidates. resTORbio’s potential competitors include large pharmaceutical and biotechnology companies, specialty pharmaceutical and generic drug companies, academic institutions, government agencies and research institutions. resTORbio considers Navitor Pharmaceuticals, Inc. to be resTORbio’s most direct competitor in developing novel therapeutics targeting the TORC1 for aging-related diseases. Additionally, resTORbio is also aware of other companies seeking to develop treatments to prevent or treat aging-related diseases through biological pathways unrelated to mTOR inhibition, including Calico Life Sciences LLC, or Calico, and UNITY Biotechnology, Inc., or Unity. Calico has not yet disclosed any pipeline candidates, and Unity’s most advanced candidate, based on publicly disclosed information, is in Phase 1 clinical trials for osteoarthritis.

resTORbio is also aware of other companies that are potential competitors for prevention or treatment of aging-associated pathologies such as neurodegeneration. Companies pursuing prevention or treatment of aging-associated pathologies such as neurodegeneration in PD include: Denali Therapeutics, Inc., Acorda Therapeutics, Inc., Prothena Biosciences, Inc., Takeda Pharmaceutical Company (formerly Shire plc), Affiris AG, Biogen Inc., Inflazome Ltd., Casma Therapeutics, Inc., Neuropore Therapies, Inc., Caraway Therapeutics, Inc. (previously called Rheostat Therapeutics), Selphagy Therapeutics Inc., and others. Companies pursuing treatments for levodopa-induced dyskinesia in PD include: VistaGen Therapeutics, Inc., Prilienia Therapeutics, Inc., IRLAB Therapeutics AB, Neurolixis Inc, and others.

Many of resTORbio’s competitors have greater financial, technical, manufacturing, marketing, sales and supply resources, and human resources or experience than resTORbio and significantly greater experience in the discovery and development of product candidates, obtaining FDA and other regulatory approvals of products and the commercialization of those products. Accordingly, resTORbio’s competitors may be more successful than it is in obtaining regulatory approval for therapies and achieving widespread market acceptance. resTORbio’s competitors’ products may be more effective, or more effectively marketed and sold, than any product candidate

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resTORbio may commercialize and may render its therapies obsolete or non-competitive before resTORbio can recover development and commercialization expenses. If RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, is approved for the indications resTORbio is currently pursuing, it could compete with a range of therapeutic treatments that are in development. In addition, resTORbio’s competitors may succeed in developing, acquiring or licensing technologies and drug products that are more effective or less costly than RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidates that resTORbio is currently developing or that resTORbio may develop, which could render its product candidates obsolete and noncompetitive.

If resTORbio obtains approval for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other future product candidate, resTORbio may face competition based on many different factors, including the efficacy, safety and tolerability of its products, the ease with which its products can be administered, the timing and scope of regulatory approvals for these products, the availability and cost of manufacturing, marketing and sales capabilities, price, reimbursement coverage and patent position. Existing and future competing products could present superior treatment alternatives, including being more effective, safer, less expensive or marketed and sold more effectively than any products resTORbio may develop. Competitive products may make any products resTORbio develops obsolete or noncompetitive before resTORbio recovers the expense of developing and commercializing resTORbio’s product candidates. Such competitors could also recruit resTORbio’s employees, which could negatively impact resTORbio’s level of expertise and resTORbio’s ability to execute resTORbio’s business plan. Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a small number of competitors.

resTORbio also competes with other clinical stage companies and institutions for clinical trial participants, which could reduce resTORbio’s ability to recruit participants for resTORbio’s clinical trials. Delay in recruiting clinical trial participants could adversely affect resTORbio’s ability to bring a product to market prior to resTORbio’s competitors. Further, research and discoveries by others may result in breakthroughs that render resTORbio’s product candidates obsolete even before they begin to generate any revenue.

In addition, resTORbio’s competitors may obtain patent protection, regulatory exclusivities, or FDA approval and commercialize products more rapidly than resTORbio does, which may impact future approvals or sales of any of resTORbio’s product candidates that receive regulatory approval. If the FDA approves the commercial sale of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate, resTORbio will also be competing with respect to marketing capabilities and manufacturing efficiency. resTORbio expects competition among products will be based on product efficacy and safety, the timing and scope of regulatory approvals, availability of supply, marketing and sales capabilities, product price, reimbursement coverage by government and private third-party payors, regulatory exclusivities and patent position. resTORbio’s profitability and financial position will suffer if resTORbio’s product candidates receive regulatory approval, but cannot compete effectively in the marketplace.

Many of resTORbio’s competitors have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than resTORbio does. Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a smaller number of resTORbio’s competitors. Smaller and other early stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These third parties compete with resTORbio in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites, as well as in acquiring technologies complementary to, or necessary for, resTORbio’s programs.

Furthermore, regulatory authorities’ assessment of the data and results required to demonstrate safety and efficacy can change over time and can be affected by many factors, such as the emergence of new information, including on other products, changing policies and agency funding, staffing and leadership. resTORbio cannot be

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sure whether future changes to the regulatory environment will be favorable or unfavorable to resTORbio’s business prospects. For example, average review times at the FDA for regulatory approval applications can be affected by a variety of factors, including budget and funding levels and statutory, regulatory and policy changes.

The regulatory approval processes of the FDA, the European Medicines Agency (the “EMA”) and comparable foreign authorities are lengthy, time consuming and inherently unpredictable. If clinical trials of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, fail to satisfactorily demonstrate safety and efficacy to the FDA or other regulators, or do not otherwise produce favorable results, resTORbio, or any future collaborators, may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus.

resTORbio, and any future collaborators, are not permitted to commercialize, market, promote or sell any product candidate in the United States without obtaining regulatory approval from the FDA. Foreign regulatory authorities, such as the EMA, impose similar requirements. The time required to obtain approval by the FDA, EMA and comparable foreign authorities is unpredictable, but typically takes many years following the commencement of clinical trials and depends upon numerous factors, including substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions. To date, resTORbio has not submitted an NDA to the FDA or similar drug approval submissions to comparable foreign regulatory authorities for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate. resTORbio, and any future collaborators, must complete additional preclinical or nonclinical studies and clinical trials to demonstrate the safety and efficacy of resTORbio’s product candidates in humans before resTORbio will be able to obtain these approvals.

Clinical testing is expensive, difficult to design and implement, can take many years to complete and is inherently uncertain as to outcome. resTORbio cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, if at all. The clinical development of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or other drugs is susceptible to the risk of failure inherent at any stage of development, including failure to demonstrate efficacy in a clinical trial or across a broad population of patients, the occurrence of adverse events that are severe or medically or commercially unacceptable, failure to comply with protocols or applicable regulatory requirements, and determination by the FDA or any comparable foreign regulatory authority that a product candidate may not continue development or is not approvable. It is possible that even if RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate has a beneficial effect, that effect will not be detected during clinical evaluation as a result of one or more of a variety of factors, including the size, duration, design, measurements, conduct or analysis of resTORbio’s clinical trials. Conversely, as a result of the same factors, resTORbio’s clinical trials may indicate an apparent positive effect of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate that is greater than the actual positive effect, if any. For example, in a topline analysis of resTORbio’s Phase 2b clinical trial, resTORbio observed that certain cohorts responded better to study drug treatment than others, and that certain cohorts did not respond at all. Similarly, in resTORbio’s clinical trials resTORbio may fail to detect toxicity of or intolerability caused by RTB101, everolimus or any other product candidate, or mistakenly believe that resTORbio’s product candidates are toxic or not well tolerated when that is not in fact the case.

Any inability to successfully complete preclinical and clinical development could result in additional costs to resTORbio, or any future collaborators. Moreover, if resTORbio, or any future collaborators, is required to conduct additional clinical trials or other testing of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate beyond the trials and testing that resTORbio or they contemplate, if resTORbio or they are unable to successfully complete clinical trials of resTORbio’s product candidates or other testing or the results of these trials or tests are unfavorable, uncertain or are only modestly

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favorable, or there are unacceptable safety concerns associated with resTORbio’s product candidates, resTORbio, or any future collaborators may:

resTORbio’s failure to successfully initiate and complete clinical trials of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate and to demonstrate the efficacy and safety necessary to obtain regulatory approval to market RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate would significantly harm resTORbio’s business. resTORbio’s product candidate development costs will also increase if resTORbio experiences delays in testing or regulatory approvals and resTORbio may be required to obtain additional funds to complete clinical trials. resTORbio cannot assure you that resTORbio’s clinical trials will begin as planned or be completed on schedule, if at all, or that resTORbio will not need to restructure resTORbio’s trials after they have begun. Significant clinical trial delays also could shorten any periods during which resTORbio may have the exclusive right to commercialize resTORbio’s product candidates or allow resTORbio’s competitors to bring products to market before resTORbio does and impair resTORbio’s ability to successfully commercialize resTORbio’s product candidates, which may harm resTORbio’s business and results of operations. In addition, many of the factors that cause, or lead to, delays of clinical trials may ultimately lead to the denial of regulatory approval of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate.

resTORbio’s product candidates may cause undesirable side effects or have other properties that could delay or prevent their regulatory approval, limit the commercial profile of an approved label, or result in significant negative consequences following regulatory approval, if obtained.

Undesirable side effects caused by RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate could cause resTORbio or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or comparable foreign regulatory authorities. Results of resTORbio’s clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics. In clinical trials of RTB101, alone and in combination with everolimus, to date, there were no observed study drug-related serious adverse events in the Phase 2a clinical trial. In the Phase 2b clinical trial, 4.5% of subjects in the RTB101 10 mg once daily cohort had a serious adverse event, none of which were related to the study drug, though 4.5% of subjects in that arm discontinued the study drug due to an adverse event. The majority of observed study-drug related adverse events were mild or moderate in severity, transient and resolved without stopping the study drug. However, there can be no guarantee that resTORbio would observe a similar tolerability profile of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, in future clinical trials. Many compounds that initially showed promise in clinical or earlier stage testing are later found to cause undesirable or unexpected side effects that prevented further development of the compound.

If unacceptable side effects arise in the development of resTORbio’s product candidates, resTORbio, the FDA or comparable foreign regulatory authorities, the IRBs, or independent ethics committees at the institutions in which resTORbio’s trials are conducted, or the Data Safety Monitoring Board, or DSMB, could suspend or terminate

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resTORbio’s clinical trials or the FDA or comparable foreign regulatory authorities could order resTORbio to cease clinical trials or deny approval of resTORbio’s product candidates for any or all targeted indications. Treatment-emergent side effects that are deemed to be treatment-related could also affect subject recruitment or the ability of enrolled subjects to complete the trial or result in potential product liability claims. In addition, these side effects may not be appropriately recognized or managed by the treating medical staff. resTORbio expects to have to train medical personnel using resTORbio’s product candidates to understand the side effect profiles for resTORbio’s clinical trials and upon any commercialization of any of resTORbio’s product candidates. Inadequate training in recognizing or managing the potential side effects of resTORbio’s product candidates could result in patient injury or death. Any of these occurrences may harm resTORbio’s business, financial condition and prospects significantly.

Moreover, clinical trials of resTORbio’s product candidates are conducted in carefully defined sets of patients who have agreed to enter into clinical trials. Consequently, it is possible that resTORbio’s clinical trials, or those of any future collaborator, may indicate an apparent positive effect of a product candidate that is greater than the actual positive effect, if any, or alternatively fail to identify undesirable side effects. If, following approval of a product candidate, resTORbio, or others, discovers that the product is less effective than previously believed or causes undesirable side effects that were not previously identified, any of the following adverse consequences could occur:

Any of these events could harm resTORbio’s business and operations and could negatively impact resTORbio’s stock price.

If resTORbio fails to develop RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, for additional indications or fail to discover, develop and commercialize other product candidates, resTORbio may be unable to grow resTORbio’s business and resTORbio’s ability to achieve resTORbio’s strategic objectives would be impaired.

As part of resTORbio’s longer-term growth strategy, resTORbio may evaluate RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, in other indications beyond PD, such as COVID-19 related

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indications and develop other product candidates. resTORbio intend to evaluate strategic alternatives and internal opportunities from RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or other product candidates from resTORbio’s TORC1 program, and also may choose to in-license or acquire other product candidates as well as commercial products to treat patients suffering from other disorders with significant unmet medical needs and limited treatment options. These other product candidates will require additional, time-consuming development efforts prior to commercial sale, including preclinical studies, clinical trials and approval by the FDA and/or applicable foreign regulatory authorities. All product candidates are prone to the risks of failure that are inherent in pharmaceutical product development, including the possibility that the product candidate will not be shown to be sufficiently safe and effective for approval by regulatory authorities. In addition, resTORbio cannot assure you that any such products that are approved will be manufactured or produced economically, successfully commercialized or widely accepted in the marketplace or be more effective than other commercially available alternatives.

Research programs to identify product candidates require substantial technical, financial and human resources, whether or not any product candidates are ultimately identified. resTORbio’s research programs may initially show promise in identifying potential product candidates, yet fail to yield product candidates for clinical development for many reasons, including the following:

If resTORbio is unsuccessful in identifying and developing additional product candidates, resTORbio’s potential for growth and achieving resTORbio’s strategic objectives may be impaired.

resTORbio’s preclinical programs may not produce new product candidates that are suitable for clinical trials or that can be successfully commercialized or generate revenue through collaborations.

resTORbio must successfully complete preclinical testing for resTORbio’s preclinical programs, which may include demonstrating activity and comprehensive studies to show the lack of toxicity and other adverse effects in established animal models, before commencing clinical trials for any product candidate. Many pharmaceutical products do not successfully complete preclinical testing and, even if preclinical testing is successfully completed, may fail in clinical trials. In addition, there can be no assurance that positive results from preclinical studies will be predictive of results obtained from subsequent preclinical studies or clinical trials. Many pharmaceutical candidates are not suitable for manufacture on the scale or of the quality required for clinical trials or commercialization. Some pharmaceutical candidates that initially seem suitable may later be found to be insufficiently stable or may generate toxic impurities over time. resTORbio also cannot be certain that any product candidates that do advance into clinical trials will successfully demonstrate safety and efficacy in clinical trials. Even if resTORbio achieves positive results in early preclinical studies or clinical trials, they may not be predictive of the results in later trials.

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Results of preclinical studies and early clinical trials may not be predictive of results of future clinical trials, and such results do not guarantee approval of a product candidate by regulatory authorities.

The outcome of preclinical studies and early clinical trials may not be predictive of the success of later clinical trials, and interim results of clinical trials do not necessarily predict success in the results of completed clinical trials. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials after achieving positive results in earlier development, and resTORbio could face similar setbacks. The design of a clinical trial can determine whether its results will support approval of a product and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. In addition, preclinical and clinical data are often susceptible to varying interpretations and analyses. Many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain the same positive results in later studies or regulatory approval for their product candidates.

For example, in November 2019, resTORbio announced that top line data from the PROTECTOR 1 Phase 3 study, evaluating the safety and efficacy of RTB101 in preventing clinically symptomatic respiratory illness in adults age 65 and older, did not meet its primary endpoint and that resTORbio has stopped the development of RTB101 for clinically symptomatic respiratory illness.

In some instances, there can be significant variability in safety or efficacy results between different clinical trials of the same product candidate due to numerous factors, including changes in trial procedures set forth in protocols, differences in the size and type of the patient populations, changes in and adherence to the dosing regimen and other clinical trial procedures and the rate of dropout among clinical trial participants. If resTORbio fails to receive positive results in clinical trials of resTORbio’s product candidates, the development timeline and regulatory approval and commercialization prospects for resTORbio’s most advanced product candidate, and, correspondingly, resTORbio’s business and financial prospects would be negatively impacted.

resTORbio may expend resTORbio’s resources to pursue a particular product candidate or indication and forgo the opportunity to capitalize on product candidates or indications that may ultimately be more profitable or for which there is a greater likelihood of success.

Because resTORbio has limited financial and managerial resources, resTORbio intends to focus on developing product candidates for specific indications that resTORbio identifies as most likely to succeed, in terms of both their potential for regulatory approval and commercialization. As a result, resTORbio may forego or delay pursuit of opportunities with other product candidates or for other indications that may prove to have greater commercial potential.

resTORbio’s resource allocation decisions may cause resTORbio to fail to capitalize on viable commercial products or profitable market opportunities. resTORbio’s spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable product candidates. If resTORbio does not accurately evaluate the commercial potential or target market for a particular product candidate, resTORbio may relinquish valuable rights to that product candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for resTORbio to retain sole development and commercialization rights to the product candidate.

If the FDA or comparable foreign regulatory authorities approve generic versions of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate of resTORbio’s that receives regulatory approval, or such authorities do not grant resTORbio’s products appropriate periods of non-patent exclusivity before approving generic versions of such products, the sales of such products could be adversely affected.

Once an NDA is approved, the product covered thereby becomes a “listed drug” in the FDA’s publication, “Approved Drug Products with Therapeutic Equivalence Evaluations,” or the Orange Book. Manufacturers may

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seek approval of generic versions of reference listed drugs through submission of abbreviated new drug applications, or AND As, in the United States. In support of an ANDA, a generic manufacturer generally must show that its product has the same active ingredient(s), dosage form, strength, route of administration, conditions of use and labeling as the reference listed drug and that the generic version is bioequivalent to the reference listed drug, meaning, in part, that it is absorbed in the body at the same rate and to the same extent. Generic products may be significantly less costly to bring to market than the reference listed drug and companies that produce generic products are generally able to offer them at lower prices. Moreover, many states allow or require substitution of therapeutically equivalent generic drugs at the pharmacy level even if the branded drug is prescribed. Thus, following the introduction of a generic drug, a significant percentage of the sales of any branded product or reference listed drug may be lost to the generic product.

The FDA may not approve (or in some cases, accept) an ANDA for a generic product until any applicable period of non-patent exclusivity for the reference listed drug has expired. The Federal Food, Drug, and Cosmetic Act, or FDCA, provides a period of five years of non-patent exclusivity for a new drug containing NCE. Specifically, in cases where such exclusivity has been granted, an ANDA may not be filed with the FDA until the expiration of five years unless the submission is accompanied by a Paragraph IV certification that a patent covering the listed drug is invalid, unenforceable or will not be infringed by the generic product, in which case the applicant may submit its application four years following approval of the listed drug. It is unclear whether the FDA will treat the active ingredients in resTORbio’s product candidates as NCEs and, therefore, afford them five years of NCE data exclusivity if they are approved. If any product resTORbio develops does not receive five years of NCE exclusivity, it may nevertheless receive three years of exclusivity if it meets applicable requirements. If so, the FDA may not approve generic versions of such product until three years after its date of approval. Three-year exclusivity is given to a drug if it contains an active moiety that has previously been approved, and the NDA includes reports of one or more new clinical investigations, other than bioavailability or bioequivalence studies, that were conducted by or for the applicant and are essential to the approval of the NDA. If approved, manufacturers may seek to launch these generic products following the expiration of the applicable marketing exclusivity period, even if resTORbio still has patent protection for resTORbio’s product.

Competition that resTORbio’s products, if approved, may face from generic versions of resTORbio’s products could negatively impact resTORbio’s future revenue, profitability and cash flows and substantially limit resTORbio’s ability to obtain a return on resTORbio’s investments in those product candidates.

If resTORbio encounters difficulties enrolling patients in resTORbio’s future clinical trials, resTORbio’s clinical development activities could be delayed or otherwise adversely affected.

resTORbio may experience difficulties in patient enrollment in resTORbio’s clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on resTORbio’s ability to enroll a sufficient number of patients who remain in the study until its conclusion.

Patient enrollment is affected by many factors, including:

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In addition, resTORbio’s clinical trials will compete with other clinical trials for product candidates that are in the same therapeutic areas as resTORbio’s product candidates, and this competition will reduce the number and types of patients available to resTORbio, because some patients who might have opted to enroll in resTORbio’s trials may instead opt to enroll in a trial being conducted by one of resTORbio’s competitors. Since the number of qualified clinical investigators is limited, resTORbio expects to conduct some of resTORbio’s clinical trials at the same clinical trial sites that some of resTORbio’s competitors use, which will reduce the number of patients who are available for resTORbio’s clinical trials in such clinical trial site.

resTORbio’s inability to enroll a sufficient number of patients for resTORbio’s clinical trials would result in significant delays or might require resTORbio to abandon one or more clinical trials altogether. Delays in patient enrollment may result in increased costs, affect the timing or outcome of the planned clinical trials, product candidate development and approval process and jeopardize resTORbio’s ability to seek and obtain the regulatory approval required to commence product sales and generate revenue, which could prevent completion of these trials, adversely affect resTORbio’s ability to advance the development of its product candidates, cause the value of resTORbio to decline and limit resTORbio’s ability to obtain additional financing if needed.

Ingredients, excipients and other materials necessary to manufacture RTB101 or rapalogs, such as everolimus or sirolimus, may not be available on commercially reasonable terms, or at all, which may adversely affect the development and commercialization of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus.

resTORbio and resTORbio’s third-party manufacturers must obtain from other third-party suppliers the active pharmaceutical ingredients, excipients and primary and secondary packaging materials necessary for resTORbio’s contract manufacturers to produce RTB101 or rapalogs, such as everolimus or sirolimus, for resTORbio’s clinical trials and, to the extent approved or commercialized, for commercial distribution. There is no guarantee that resTORbio would be able to enter into all the necessary agreements with third-party suppliers that resTORbio requires for the supply of such materials on commercially reasonable terms, or at all. Even if resTORbio was able to secure such agreements or guarantees, resTORbio’s suppliers may be unable or choose not to provide resTORbio the ingredients, excipients or materials in a timely manner or in the quantities required. If resTORbio’s or its third-party manufacturers is unable to obtain the quantities of these ingredients, excipients or materials that are necessary for the manufacture of commercial supplies of RTB101 or rapalogs, such as everolimus or sirolimus, resTORbio’s ability to generate revenue from the sale of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, would be materially and adversely affected.

Further, if resTORbio or its third-party manufacturers is unable to obtain active pharmaceutical ingredients, excipients and materials as necessary for resTORbio’s clinical trials or for the manufacture of commercial supplies of resTORbio’s product candidates, if approved, potential regulatory approval or commercialization would be delayed, which would materially and adversely affect resTORbio’s ability to generate revenue from the sale of resTORbio’s product candidates. As a result of these and other factors, the cost of manufacturing drug material may not support continued development or commercialization or may materially reduce revenue. resTORbio is also unable to predict how changing global economic conditions or potential global health concerns such as the coronavirus will affect resTORbio’s third-party suppliers and manufacturers. Any negative impact of such matters on resTORbio’s third-party suppliers and manufacturers may also have an adverse impact on resTORbio’s results of operations or financial condition.

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Even if RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate of resTORbio’s receives regulatory approval, it may fail to achieve the degree of market acceptance by physicians, patients, third-party payors and others in the medical community necessary for commercial success, in which case resTORbio may not generate significant revenues or become profitable.

resTORbio has never commercialized a product, and even if RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate of resTORbio’s is approved by the appropriate regulatory authorities for marketing and sale, it may nonetheless fail to gain sufficient market acceptance by physicians, patients, third-party payors and others in the medical community. The market for therapies targeting PD with a TORC1 inhibitor is novel, and physicians may be reluctant to adopt novel therapies. In addition, patients and their physicians may not desire to add RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, even if approved, to their existing treatment regime. Further, patients often acclimate to the treatment regime that they are currently taking and do not want to switch unless their physicians recommend switching products or they are required to switch due to lack of coverage and reimbursement. In addition, even if resTORbio is able to demonstrate resTORbio’s product candidates’ safety and efficacy to the FDA and other regulators, safety or efficacy concerns in the medical community may hinder market acceptance.

Efforts to educate the medical community and third-party payors on the benefits of resTORbio’s product candidates may require significant resources, including management time and financial resources, and may not be successful. If RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate is approved but does not achieve an adequate level of market acceptance, resTORbio may not generate significant revenues and resTORbio may not become profitable. The degree of market acceptance of resTORbio’s product candidates, if approved for commercial sale, will depend on a number of factors, including:

Any failure by RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate of resTORbio’s that obtains regulatory approval to achieve market acceptance or commercial success would adversely affect resTORbio’s business prospects.

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Even if resTORbio, or any future collaborators, is able to commercialize any product candidate that resTORbio, or they, develop, the product may become subject to unfavorable pricing regulations or third-party payor coverage and reimbursement policies, any of which could harm resTORbio’s business.

Patients who are provided medical treatment for their conditions generally rely on third party payors to reimburse all or part of the costs associated with their treatment. Therefore, resTORbio’s ability, and the ability of any future collaborators to commercialize any of resTORbio’s product candidates will depend in part on the extent to which coverage and reimbursement for these products and related treatments will be available from third-party payors including government health administration authorities and private health coverage insurers. Third-party payors decide which medications they will cover and establish reimbursement levels. resTORbio cannot be certain that coverage will be available and that reimbursement will be adequate for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any of resTORbio’s other product candidates. Also, resTORbio cannot be certain that reimbursement policies will not reduce the demand for, or the price paid for, resTORbio’s products.

If coverage and reimbursement are not available, or reimbursement is available only to limited levels, resTORbio, or any future collaborators, may be limited in resTORbio’s ability to successfully commercialize resTORbio’s product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow resTORbio, or any future collaborators, to establish or maintain pricing to realize a sufficient return on resTORbio’s or their investment. In the United States, no uniform policy of coverage and reimbursement for products exists among third-party payors and coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that will require resTORbio to provide scientific and clinical support for the use of resTORbio’s products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.

There is significant uncertainty related to third-party payor coverage and reimbursement of newly approved drugs. Regulatory approvals, pricing and reimbursement for new drug products vary widely from country to country. Some countries require approval of the sale price of a drug before it can be marketed. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. As a result, resTORbio, or any future collaborators, might obtain regulatory approval for a product in a particular country, but then be subject to price regulations that delay commercial launch of the product, which may negatively impact the revenues resTORbio is able to generate from the sale of the product in that country. Adverse pricing limitations may hinder resTORbio’s ability or the ability of any future collaborators to recoup resTORbio’s or their investment in one or more product candidates, even if resTORbio’s product candidates obtain regulatory approval.

The healthcare industry is acutely focused on cost containment, both in the United States and elsewhere. Government authorities and other third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for certain medications, which could affect resTORbio’s ability or that of any future collaborators to sell resTORbio’s product candidates profitably. These payors may not view resTORbio’s products, if any, as cost-effective, and coverage and reimbursement may not be available to resTORbio’s customers, or those of any future collaborators, or may not be sufficient to allow resTORbio’s products, if any, to be marketed on a competitive basis. Cost-control initiatives could cause resTORbio, or any future collaborators, to decrease the price resTORbio, or they, might establish for products, which could result in lower than anticipated product revenues. If the prices for resTORbio’s products, if any, decrease or if governmental and other third-party payors do not provide coverage or adequate reimbursement, resTORbio’s prospects for revenue and profitability will suffer.

There may also be delays in obtaining coverage and reimbursement for newly approved drugs, and coverage may be more limited than the indications for which the drug is approved by the FDA or comparable foreign regulatory authorities. Moreover, eligibility for reimbursement does not imply that any drug will be paid for in all cases or

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at a rate that covers resTORbio’s costs, including research, development, manufacture, sale and distribution. Reimbursement rates may vary, by way of example, according to the use of the product and the clinical setting in which it is used. Reimbursement rates may also be based on reimbursement levels already set for lower cost drugs or may be incorporated into existing payments for other services.

In addition, increasingly, third-party payors are requiring higher levels of evidence of the benefits and clinical outcomes of new technologies and are challenging prices. resTORbio cannot be sure that coverage will be available for any product candidate that resTORbio, or any future collaborator, commercializes and, if available, that the reimbursement rates will be adequate. Further, the net reimbursement for drug products may be subject to additional reductions if there are changes to laws that presently restrict imports of drugs from one country to another. An inability to promptly obtain coverage and adequate payment rates from both government-funded and private payors for any of resTORbio’s product candidates for which resTORbio, or any future collaborator, obtains regulatory approval could significantly harm resTORbio’s operating results, resTORbio’s ability to raise capital needed to commercialize products and resTORbio’s overall financial condition.

Product liability lawsuits against resTORbio or any of resTORbio’s future collaborators could divert resTORbio’s resources and attention, cause resTORbio to incur substantial liabilities and limit commercialization of resTORbio’s product candidates.

resTORbio is exposed to potential product liability and professional indemnity risks that are inherent in the research, development, manufacturing, marketing and use of pharmaceutical products. Currently, resTORbio has no products that have been approved for commercial sale; however, the current and future use of resTORbio’s product candidates by resTORbio and any collaborators in clinical trials, and the sale of these product candidates, if approved, in the future, may expose resTORbio to liability claims. resTORbio faces an inherent risk of product liability lawsuits related to the use of resTORbio’s product candidates in elderly patients and will face an even greater risk if product candidates are approved by regulatory authorities and introduced commercially. Product liability claims may be brought against resTORbio or resTORbio’s partners by participants enrolled in resTORbio’s clinical trials, patients, health care providers, pharmaceutical companies, resTORbio’s collaborators or others using, administering or selling any of resTORbio’s future approved products. If resTORbio cannot successfully defend itself against any such claims, resTORbio may incur substantial liabilities or be required to limit commercialization of resTORbio’s product candidates. Regardless of the merits or eventual outcome, liability claims may result in:

Although the clinical trial process is designed to identify and assess potential side effects, clinical development does not always fully characterize the safety and efficacy profile of a new medicine, and it is always possible that a drug, even after regulatory approval, may exhibit unforeseen side effects. If resTORbio’s product candidates were to cause adverse side effects during clinical trials or after approval, resTORbio may be exposed to

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substantial liabilities. Physicians and patients may not comply with any warnings that identify known potential adverse effects and patients who should not use resTORbio’s product candidates. If any of resTORbio’s product candidates are approved for commercial sale, resTORbio will be highly dependent upon consumer perceptions of resTORbio and the safety and quality of resTORbio’s products. resTORbio could be adversely affected if resTORbio is subject to negative publicity associated with illness or other adverse effects resulting from patients’ use or misuse of resTORbio’s products or any similar products distributed by other companies.

Although resTORbio maintains product liability insurance coverage in the amount of up to $10.0 million in the aggregate, including clinical trial liability, this insurance may not fully cover potential liabilities that resTORbio may incur. The cost of any product liability litigation or other proceeding, even if resolved in resTORbio’s favor, could be substantial. resTORbio will need to increase resTORbio’s insurance coverage if resTORbio commercializes any product that receives regulatory approval. In addition, insurance coverage is becoming increasingly expensive. If resTORbio is unable to maintain sufficient insurance coverage at an acceptable cost or to otherwise protect against potential product liability claims, it could prevent or inhibit the development and commercial production and sale of resTORbio’s product candidates, which could harm resTORbio’s business, financial condition, results of operations and prospects.

resTORbio currently has limited marketing, sales or distribution infrastructure. If resTORbio is unable to develop its sales, marketing and distribution capability on its own or through collaborations with marketing partners, resTORbio will not be successful in commercializing its product candidates.

resTORbio currently has limited marketing, sales or distribution infrastructure. Factors that may inhibit resTORbio’s efforts to commercialize its products on its own include:

With respect to resTORbio’s existing and future product candidates, resTORbio may choose to collaborate with third parties that have direct sales forces and established distribution systems to serve as an alternative to resTORbio’s own sales force and distribution systems. resTORbio’s product revenue may be lower than if resTORbio directly marketed or sold resTORbio’s products, if approved. In addition, any revenue resTORbio receives will depend in whole or in part upon the efforts of these third parties, which may not be successful and are generally not within resTORbio’s control. If resTORbio is not successful in commercializing any approved products, resTORbio’s future product revenue will suffer, and resTORbio may incur significant additional losses.

If resTORbio does not establish sales and marketing capabilities successfully, either on resTORbio’s own or in collaboration with third parties, resTORbio will not be successful in commercializing resTORbio’s product candidates.

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If resTORbio, or any future collaborators, experiences any of a number of possible unforeseen events in connection with clinical trials of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate, potential clinical development, regulatory approval or commercialization of resTORbio’s product candidates could be delayed or prevented.

resTORbio, or any future collaborators, may experience numerous unforeseen events during, or as a result of, clinical trials that could delay or prevent clinical development, regulatory approval or commercialization of resTORbio’s product candidates, including:

Further, conducting clinical trials in foreign countries, as resTORbio has done and plan to do for resTORbio’s product candidates, presents additional risks that may delay completion of resTORbio’s clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs, managing additional administrative burdens associated with foreign regulatory schemes, as well as political and economic risks relevant to such foreign countries.

Product development costs for resTORbio, or any future collaborators, will increase if resTORbio, or they, experiences delays in testing or pursuing regulatory approvals and resTORbio, or they, may be required to obtain

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additional funds to complete clinical trials and prepare for possible commercialization of resTORbio’s product candidates. resTORbio does not know whether any preclinical studies or clinical trials will begin as planned, will need to be restructured, or will be completed on schedule, or at all. Significant preclinical study or clinical trial delays also could shorten any periods during which resTORbio, or any future collaborators, may have the exclusive right to commercialize resTORbio’s product candidates or allow resTORbio’s competitors, or the competitors of any future collaborators, to bring products to market before resTORbio, or any future collaborators, does and impair resTORbio’s ability, or the ability of any future collaborators, to successfully commercialize resTORbio’s product candidates and may harm resTORbio’s business and results of operations. In addition, many of the factors that lead to clinical trial delays may ultimately lead to the denial of regulatory approval of any of resTORbio’s product candidates.

Business interruptions resulting from the coronavirus disease (COVID-19) outbreak or similar public health crises could cause a disruption of the development of resTORbio’s product candidates and adversely impact resTORbio’s business.

Public health crises such as pandemics or similar outbreaks could adversely impact resTORbio’s business. In December 2019, a novel strain of a virus named SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), or coronavirus, which causes coronavirus disease, or COVID-19, surfaced in Wuhan, China and has reached multiple other regions and countries, including Boston, Massachusetts where resTORbio’s primary office and laboratory space are located. The coronavirus pandemic is evolving, and to date has led to the implementation of various responses, including government-imposed quarantines, travel restrictions and other public health safety measures. The extent to which the coronavirus impacts resTORbio’s operations or those of resTORbio’s third party partners will depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration of the outbreak, new information that will emerge concerning the severity of the coronavirus and the actions to contain the coronavirus or treat its impact, among others.

Additionally, timely enrollment in planned clinical trials is dependent upon clinical trial sites which will be adversely affected by global health matters, such as pandemics. resTORbio plans to conduct clinical trials for resTORbio’s product candidates in geographies which are currently being affected by the coronavirus. Some factors from the coronavirus outbreak that will delay or otherwise adversely affect enrollment in the clinical trials of resTORbio’s product candidates, as well as resTORbio’s business generally, include:

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Risks Related to Regulatory Approval and Marketing of resTORbio’s Product Candidates and Other Legal Compliance Matters

Even if resTORbio completes the necessary preclinical studies and clinical trials, the regulatory approval process for product candidates is expensive, time consuming and uncertain and may prevent resTORbio or any future collaborators from obtaining approvals for the commercialization of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate. As a result, resTORbio cannot predict when or if, and in which territories, resTORbio, or any future collaborators, will obtain regulatory approval to commercialize a product candidate.

The research, testing, manufacturing, labeling, approval, selling, marketing, promotion and distribution of products are subject to extensive regulation by the FDA and comparable foreign regulatory authorities. resTORbio, and any future collaborators, are not permitted to market RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate in the United States or in other countries until resTORbio, or any future collaborators, or they, receive approval of an NDA from the FDA or regulatory approval from applicable regulatory authorities outside the United States. RTB101 is in clinical development and is subject to the risks of failure inherent in drug development. resTORbio has not submitted an application for or received regulatory approval for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidate in the United States or in any other jurisdiction. resTORbio has limited experience in conducting and managing the clinical trials necessary to obtain regulatory approvals, including obtaining FDA approval of an NDA.

The process of obtaining regulatory approvals, both in the United States and abroad, is lengthy, expensive and uncertain. It may take many years, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Securing regulatory approval requires the submission of extensive preclinical and clinical data and supporting information to regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing regulatory approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities by, the regulatory authorities. The FDA or other regulatory authorities may determine that RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidates are not safe and effective, only moderately effective or have undesirable or unintended side effects, toxicities or other characteristics that preclude resTORbio’s obtaining regulatory approval or prevent or limit commercial use. Any regulatory approval resTORbio ultimately obtains may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable.

In addition, changes in regulatory approval policies during the development period, changes in or the enactment or promulgation of additional statutes, regulations or guidance or changes in regulatory review for each submitted product application, may cause delays in the approval or rejection of an application. Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that resTORbio’s data are insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent regulatory approval of a product candidate. Any regulatory approval resTORbio, or any future collaborators, ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable.

Moreover, principal investigators for resTORbio’s clinical trials may serve as scientific advisors or consultants to resTORbio from time to time and receive compensation in connection with such services. Under certain circumstances, resTORbio may be required to report some of these relationships to the FDA or other regulatory authority. The FDA or other regulatory authority may conclude that a financial relationship between resTORbio and a principal investigator has created a conflict of interest or otherwise affected interpretation of the study. The FDA or other regulatory authority may therefore question the integrity of the data generated at the applicable clinical trial site and the utility of the clinical trial itself may be jeopardized. This could result in a delay in

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approval, or rejection, of resTORbio’s marketing applications by the FDA or other regulatory authority, as the case may be, and may ultimately lead to the denial of regulatory approval of one or more of resTORbio’s product candidates.

Any delay in obtaining or failure to obtain required approvals could negatively impact resTORbio’s ability or that of any future collaborators to generate revenue from the particular product candidate, which likely would result in significant harm to resTORbio’s business and adversely impact resTORbio’s stock price.

resTORbio’s failure to obtain regulatory approval in foreign jurisdictions would prevent resTORbio’s product candidates from being marketed abroad, and any approval resTORbio is granted for RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any of resTORbio’s other product candidates in the United States would not assure approval of product candidates in foreign jurisdictions.

In order to market any products outside of the United States, resTORbio must establish and comply with numerous and varying regulatory requirements of other countries regarding clinical trial design, safety and efficacy. Clinical trials conducted in one country may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not mean that regulatory approval will be obtained in any other country. Approval procedures vary among countries and can involve additional product testing and validation and additional administrative review periods. Seeking foreign regulatory approvals could result in significant delays, difficulties and costs for resTORbio and may require additional preclinical studies or clinical trials which would be costly and time consuming and could delay or prevent introduction of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any of resTORbio’s other product candidates in those countries. resTORbio does not have experience in obtaining regulatory approval in international markets. If resTORbio or resTORbio’s partners fail to comply with regulatory requirements or to obtain and maintain required approvals, resTORbio’s target market will be reduced and resTORbio’s ability to realize the full market potential of resTORbio’s product candidates will be harmed.

The exit of the United Kingdom, or the UK, from the European Union, or the EU, may materially affect the regulatory regime that governs resTORbio’s handling of EU personal data and expose resTORbio to legal and business risks under European data privacy and protection law.

On June 23, 2016, the UK held a referendum in which a majority of the eligible members of the electorate voted to leave the EU. The UK’s withdrawal from the EU is commonly referred to as Brexit. Pursuant to Article 50 of the Treaty on European Union, the UK ceased being a Member State of the EU on January 31, 2020. However, the terms of the withdrawal have yet to be fully negotiated. The implementation period began February 1, 2020 and will continue until December 31, 2020. During this 11-month period, the UK will continue to follow all of the EU’s rules and its trading relationship will remain the same. However, regulations (including data protection laws, health and safety laws and regulations and medicine licensing and regulations), have yet to be addressed. This lack of clarity on future UK laws and regulations and their interaction with EU laws and regulations could add legal risk, uncertainty, complexity and cost to resTORbio’s handling of EU personal information and resTORbio’s privacy and data security compliance programs. It is possible that over time the UK Data Protection Act could become less aligned with the EU General Data Protection Regulation, or GDPR, which could require resTORbio to implement different compliance measures for the UK and the European Union and result in potentially enhanced compliance obligations for EU personal data. This risk would apply more immediately in the event of a “no-deal” Brexit (including no transition period).

It is unclear whether the European Commission, or EC, will grant an adequacy finding to the UK (a finding that the UK privacy legal framework provides an adequate level of privacy protection to EU individuals). Absent an adequacy finding, transfers of personal data from the EU to the UK would be impermissible without adequate safeguards provided for under EC-approved mechanisms, such as current standard contractual clauses or, if approved in the future, an EU—UK privacy shield similar to the current framework in place between the EU and the U.S. The extensive authority of UK intelligence and law enforcement agencies, including to conduct

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surveillance on personal data flows, could reduce the likelihood that the EC would give the UK an adequacy finding, and reduce the likelihood that the EC would approve an EU—UK privacy shield. Accordingly, resTORbio would be exposed to legal risk for any of resTORbio’s EU-UK personal data transfers, including those that involve sensitive data such as patient and genetic data.

Even if resTORbio, or any future collaborators, obtain regulatory approvals for resTORbio’s product candidates, the terms of approvals and ongoing regulation of resTORbio’s products may limit how resTORbio manufactures and markets resTORbio’s products, which could impair resTORbio’s ability to generate revenue.

Once regulatory approval has been granted, an approved product and its manufacturer and marketer are subject to ongoing review and extensive regulation. resTORbio, and any future collaborators, must therefore comply with requirements concerning advertising and promotion for any of resTORbio’s product candidates for which resTORbio or its future collaborators obtain regulatory approval. Promotional communications with respect to prescription drugs are subject to a variety of legal and regulatory restrictions and must be consistent with the information in the product’s approved labeling. Thus, resTORbio and any future collaborators will not be able to promote any products resTORbio develops for indications or uses for which they are not approved.

In addition, manufacturers of approved products and those manufacturers’ facilities are required to comply with extensive FDA requirements, including ensuring that quality control and manufacturing procedures conform to cGMPs, which include requirements relating to quality control and quality assurance as well as the corresponding maintenance of records and documentation and reporting requirements. resTORbio, resTORbio’s contract manufacturers, any future collaborators and their contract manufacturers could be subject to periodic unannounced inspections by the FDA to monitor and ensure compliance with cGMPs. Despite resTORbio’s efforts to inspect and verify regulatory compliance, one or more of resTORbio’s third-party manufacturing vendors may be found on regulatory inspection by FDA or other authorities to be not in compliance with cGMP regulations, which may result in shutdown of the third-party vendor or invalidation of drug product lots or processes. In some cases, a product recall may be warranted or required, which would materially affect resTORbio’s ability to supply and market resTORbio’s drug products.

Accordingly, assuming resTORbio, or any future collaborators, receive regulatory approval for one or more of resTORbio’s product candidates, resTORbio, and any future collaborators, and resTORbio and their contract manufacturers will continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production, product surveillance and quality control.

If resTORbio, and any future collaborators, are not able to comply with post-approval regulatory requirements, resTORbio, and any future collaborators, could have the regulatory approvals for resTORbio’s products withdrawn by regulatory authorities and resTORbio’s, or any future collaborators’, ability to market any future products could be limited, which could adversely affect resTORbio’s ability to achieve or sustain profitability. Further, the cost of compliance with post-approval regulations may have a negative effect on resTORbio’s operating results and financial condition.

resTORbio is subject to extensive government regulation and the failure to comply with these regulations may have a material adverse effect on resTORbio’s operations and business.

Both before and after approval of any product, resTORbio and its suppliers, contract manufacturers and clinical investigators are subject to extensive regulation by governmental authorities in the United States and other countries, covering, among other things, testing, manufacturing, quality control, clinical trials, post-marketing studies, labeling, advertising, promotion, distribution, import and export, governmental pricing, price reporting and rebate requirements. Failure to comply with applicable requirements could result in one or more of the following actions: warning or untitled letters; unanticipated expenditures; delays in approval or refusal to approve a product candidate; voluntary product recall; product seizure; interruption of manufacturing or clinical

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trials; operating or marketing restrictions; injunctions; criminal prosecution and civil or criminal penalties including fines and other monetary penalties; exclusion from federal health care programs such as Medicare and Medicaid; adverse publicity; and disruptions to resTORbio’s business. Further, government investigations into potential violations of these laws would require resTORbio to expend considerable resources and face adverse publicity and the potential disruption of resTORbio’s business even if resTORbio is ultimately found not to have committed a violation.

Obtaining FDA approval of resTORbio’s product candidates requires substantial time, effort and financial resources and may be subject to both expected and unforeseen delays, and there can be no assurance that any approval will be granted for any of resTORbio’s product candidates on a timely basis, if at all. The FDA may decide that resTORbio’s data are insufficient for approval of resTORbio’s product candidates and require additional preclinical, clinical or other studies or additional work related to chemistry, manufacturing and controls. In addition, resTORbio, the FDA, IRBs or independent ethics committees may suspend or terminate human clinical trials at any time on various grounds, including a finding that the patients are or would be exposed to an unacceptable health risk or because of the way in which the investigators on which resTORbio relies to carry out the trials. If resTORbio is required to conduct additional trials or to conduct other testing of resTORbio’s product candidates beyond that which resTORbio currently contemplates for regulatory approval, if resTORbio is unable to complete successfully its clinical trials or other testing, or if the results of these and other trials or tests fail to demonstrate efficacy or raise safety concerns, resTORbio may face substantial additional expenses, be delayed in obtaining regulatory approval for its product candidates or may never obtain regulatory approval.

resTORbio is also required to comply with extensive governmental regulatory requirements after a product has received marketing authorization. Governing regulatory authorities may require post-marketing studies that may negatively impact the commercial viability of a product. Once on the market, a product may become associated with previously undetected adverse effects and/or may experience manufacturing or other commercial difficulties. As a result of any of these or other problems, a product’s regulatory approval could be withdrawn, suspended or modified which could harm resTORbio’s business and operating results.

Any of resTORbio’s product candidates for which resTORbio, or any future collaborators, obtain regulatory approval in the future will be subject to ongoing obligations and continued regulatory review, which may result in significant additional expense. If approved, resTORbio’s product candidates could be subject to post-marketing restrictions or withdrawal from the market and resTORbio, or any future collaborators, may be subject to substantial penalties if resTORbio, or future collaborators, fail to comply with regulatory requirements or if resTORbio, or future collaborators, experience unanticipated problems with resTORbio’s products following approval.

Any of resTORbio’s product candidates for which resTORbio, or any future collaborators, obtain regulatory approval, as well as the manufacturing processes, post-approval studies, labeling, advertising and promotional activities for such product, among other things, will be subject to ongoing requirements of and review by the FDA, EMA and other regulatory authorities. These requirements include submissions of safety and other post-marketing information and reports, registration and listing requirements, requirements relating to manufacturing, quality control, quality assurance and corresponding maintenance of records and documents, requirements regarding the distribution of samples to physicians and recordkeeping. resTORbio and resTORbio’s contract manufacturers will also be subject to user fees and periodic inspection by the FDA, EMA and other regulatory authorities to monitor compliance with these requirements and the terms of any product approval resTORbio may obtain. Even if regulatory approval of a product candidate is granted, the approval may be subject to limitations on the indicated uses for which the product may be marketed or to the conditions of approval, including the requirement to implement a REMS.

The FDA, EMA and other regulatory authorities may also impose requirements for costly post-marketing studies or clinical trials and surveillance to monitor the safety or efficacy of a product. The FDA and other agencies,

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including the Department of Justice, closely regulate and monitor the post-approval marketing and promotion of products to ensure that they are manufactured, marketed and distributed only for the approved indications and in accordance with the provisions of the approved labeling. The FDA imposes stringent restrictions on manufacturers’ communications regarding off-label use and if resTORbio, or any future collaborators, do not market any of resTORbio’s product candidates for which resTORbio, or they, receive regulatory approval for only their approved indications, resTORbio, or they, may be subject to warnings or enforcement action for off-label marketing if it is alleged that resTORbio is doing so. Violation of the Federal Food, Drug and Cosmetic Act, or FDCA, and other statutes relating to the promotion and advertising of prescription drugs may lead to investigations or allegations of violations of federal and state health care fraud and abuse laws and state consumer protection laws, including the False Claims Act.

In addition, later discovery of previously unknown adverse events or other problems with resTORbio’s products or their manufacturers or manufacturing processes, or failure to comply with regulatory requirements, may yield various results, including:

The efforts of the current administration to pursue regulatory reform may limit FDA’s ability to engage in oversight and implementation activities in the normal course, and that could negatively impact resTORbio’s business.

The policies of the FDA and of other regulatory authorities may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of resTORbio’s product candidates. resTORbio cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative or executive action, either in the United States or abroad. For example, certain policies of the current administration may impact resTORbio’s business and industry. Namely, the current administration has taken several executive actions, including the issuance of a number of executive orders, that could impose significant burdens on, or otherwise materially delay, the FDA’s ability to engage in routine regulatory and oversight activities such as implementing statutes through rulemaking, issuance of guidance, and review and approval of marketing applications. On January 30, 2017, President Trump issued an executive order,

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applicable to all executive agencies, including the FDA, that requires that for each notice of proposed rulemaking or final regulation to be issued in fiscal year 2017, the agency shall identify at least two existing regulations to be repealed, unless prohibited by law. These requirements are referred to as the “two-for-one” provisions. This executive order includes a budget neutrality provision that requires the total incremental cost of all new regulations in the 2017 fiscal year, including repealed regulations, to be no greater than zero, except in limited circumstances. For fiscal years 2018 and beyond, the executive order requires agencies to identify regulations to offset any incremental cost of a new regulation. In interim guidance issued by the Office of Information and Regulatory Affairs within OMB on February 2, 2017, the administration indicates that the “two-for-one” provisions may apply not only to agency regulations, but also to significant agency guidance documents, and on September 8, 2017, the FDA published notices in the Federal Register soliciting broad public comment to identify regulations that could be modified in compliance with these Executive Orders. It is difficult to predict how these requirements will be implemented, and the extent to which they will impact the FDA’s ability to exercise its regulatory authority. If these executive actions impose constraints on FDA’s ability to engage in oversight and implementation activities in the normal course, resTORbio’s business may be negatively impacted.

resTORbio’s relationships with healthcare providers, physicians and third-party payors will be subject to applicable anti-kickback, fraud and abuse, privacy and transparency and other healthcare laws and regulations, which could expose resTORbio to criminal sanctions, civil penalties, exclusion from government healthcare programs, contractual damages, reputational harm and diminished profits and future earnings.

Healthcare providers, physicians and third-party payors will play a primary role in the recommendation and prescription of any products for which resTORbio obtains regulatory approval. resTORbio’s future arrangements with third party payors, healthcare providers and physicians may expose resTORbio to broadly applicable fraud and abuse and other healthcare laws and regulations, in addition to legal obligations related to privacy, data protection and information security, that may constrain the business or financial arrangements and relationships through which resTORbio conducts its operations, including how resTORbio researches, markets, sells and distributes any products for which resTORbio obtains regulatory approval. These include the following:

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Some state laws require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government and require manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures and pricing information. State and foreign laws also govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not pre-empted by HIPAA, thus complicating compliance efforts.

Efforts to ensure that resTORbio’s business arrangements with third parties, and resTORbio’s business generally, will comply with applicable healthcare laws and regulations will involve substantial costs. It is possible that governmental authorities will conclude that resTORbio’s business practices may not comply with current or future statutes, regulations, agency guidance or case law involving applicable fraud and abuse or other healthcare laws and regulations. If resTORbio’s operations are found to be in violation of any of these laws or any other governmental regulations that may apply to resTORbio, resTORbio may be subject to significant civil, criminal and administrative penalties, damages, fines, imprisonment, exclusion from government funded healthcare programs, such as Medicare and Medicaid, and the curtailment or restructuring of resTORbio’s operations. Defending against any such actions can be costly, time-consuming and may require significant financial and personnel resources. Therefore, even if resTORbio is successful in defending against any such actions that may be brought against resTORbio, resTORbio’s business may be impaired. If any of the physicians or other healthcare providers or entities with whom resTORbio expects to do business is found to be not in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs.

The provision of benefits or advantages to physicians to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is generally not permitted in the countries that form part of the EU. Some EU Member States, like the United Kingdom, through the United Kingdom Bribery Act 2010, have enacted laws explicitly prohibiting the provision of these type of benefits and advantages. Infringements of these laws can result in substantial fines and imprisonment.

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Payments made to physicians in certain EU Member States (e.g., France or Belgium) must be publicly disclosed. Moreover, agreements with physicians often must be the subject of prior notification and approval by the physician’s employer, his or her competent professional organization and/or the regulatory authorities of the individual EU Member States. These requirements are provided in the EU Member State national laws, industry codes (e.g. the European Federation of Pharmaceutical Industries and Associations Disclosure and Healthcare Professionals Codes) or professional codes of conduct. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.

resTORbio is subject to governmental regulation and other legal obligations, particularly related to privacy, data protection and information security, and resTORbio is subject to consumer protection laws that regulate resTORbio’s marketing practices and prohibit unfair or deceptive acts or practices. resTORbio’s actual or perceived failure to comply with such obligations could harm resTORbio’s business.

The EU General Data Protection Regulation, or GDPR, imposes strict requirements on controllers and processors of personal data, including special protections for “special category data,” which includes health, biometric and genetic information of data subjects located in the EU. Further, GDPR provides a broad right for EU Member States to create supplemental national laws, such as laws relating to the processing of health, genetic and biometric data, which could further limit resTORbio’s ability to use and share such data or could cause resTORbio’s costs to increase, and harm resTORbio’s business and financial condition. GDPR grants individuals the opportunity to object to the processing of their personal information, allows them to request deletion of personal information in certain circumstances, and provides the individual with an express right to seek legal remedies in the event the individual believes his or her rights have been violated. Further, the GDPR imposes strict rules on the transfer of personal data out of the EU to the United States or other regions that have not been deemed to offer “adequate” privacy protections.

Failure to comply with the requirements of the GDPR and the related national data protection laws of the EU Member States, which may deviate slightly from the GDPR, may result in fines of up to 4% of global revenues, or €20,000,000, whichever is greater, and in addition to such fines, resTORbio may be the subject of litigation and/or adverse publicity, which could have material adverse effect on resTORbio’s reputation and business. As a result of the implementation of the GDPR, resTORbio is required to put in place additional mechanisms to ensure compliance with the new data protection rules. For example, the GDPR requires resTORbio to make more detailed disclosures to data subjects, requires disclosure of the legal basis on which resTORbio can process personal data, may make it harder for resTORbio to obtain valid consent for processing, will require the appointment of a data protection officer where sensitive personal data (i.e., health data) is processed on a large scale, introduces mandatory data breach notification requirements throughout the EU, imposes additional obligations on resTORbio when resTORbio is contracting with service providers and requires resTORbio to adopt appropriate privacy governance including policies, procedures, training and data audit.

resTORbio is subject to the supervision of local data protection authorities in those jurisdictions where resTORbio monitors the behavior of individuals in the EU (i.e., undertaking clinical trials).

resTORbio is also subject to evolving European privacy laws on electronic marketing and cookies. The EU is in the process of replacing the e-Privacy Directive (2002/58/EC) with a new set of rules taking the form of a regulation, which will be directly implemented in the laws of each EU state, without the need for further enactment. While the e-Privacy Regulation was originally intended to be adopted on May 25, 2018 (alongside the GDPR), it is still going through the European legislative process. Draft regulations were rejected by the Permanent Representatives Committee of the Council of EU on November 22, 2019; it is not clear when new regulations will be adopted.

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Current and future legislation may increase the difficulty and cost for resTORbio and any collaborators to obtain regulatory approval of and commercialize resTORbio’s product candidates and affect the prices resTORbio, or future collaborators, may obtain.

In the United States and foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay regulatory approval of resTORbio’s product candidates, restrict or regulate post-approval activities and affect resTORbio’s ability to profitably sell any product candidates for which resTORbio obtains regulatory approval. resTORbio expects that current laws, as well as other healthcare reform measures that may be adopted in the future, may result in additional reductions in Medicare and other healthcare funding, more rigorous coverage criteria, new payment methodologies and additional downward pressure on the price that resTORbio, or any collaborators, may receive for any approved products.

In March 2010, President Obama signed into law the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, or collectively the Affordable Care Act. Among the provisions of the Affordable Care Act of potential importance to resTORbio’s business and resTORbio’s product candidates are the following:

Since its enactment, there have been numerous judicial, administrative, executive, and legislative challenges to certain aspects of the Affordable Care Act, and resTORbio expects there will be additional challenges and

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amendments to the Affordable Care Act in the future. Various portions of the Affordable Care Act are currently undergoing legal and constitutional challenges in the Fifth Circuit Court and the United States Supreme Court; the Trump Administration has issued various Executive Orders which eliminated cost sharing subsidies and various provisions that would impose a fiscal burden on states or a cost, fee, tax, penalty or regulatory burden on individuals, healthcare providers, health insurers, or manufacturers of pharmaceuticals or medical devices; and Congress has introduced several pieces of legislation aimed at significantly revising or repealing the Affordable Care Act. It is unclear whether the Affordable Care Act will be overturned, repealed, replaced, or further amended. resTORbio cannot predict what affect further changes to the Affordable Care Act would have on resTORbio’s business.

In addition, other legislative changes have been proposed and adopted since the Affordable Care Act was enacted. In August 2011, the Budget Control Act of 2011, among other things, included aggregate reductions to Medicare payments to providers of 2% per fiscal year, which went into effect in April 2013 and will remain in effect through 2029 unless additional Congressional action is taken. The American Taxpayer Relief Act of 2012, among other things, reduced Medicare payments to several providers and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. These laws may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices resTORbio may obtain for any of resTORbio’s product candidates for which resTORbio may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used.

The costs of prescription pharmaceuticals in the United States has also been the subject of considerable discussion in the United States, and members of Congress and the Trump Administration have stated that they will address such costs through new legislative and administrative measures. There have been several U.S. Congressional inquiries and proposed and enacted state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, reduce the costs of drugs under Medicare and reform government program reimbursement methodologies for drug products. At the federal level, Congress and the Trump administration have each indicated that it will continue to pursue new legislative and/or administrative measures to control drug costs. The Trump administration recently released a plan, or Blueprint, to reduce the cost of drugs. The Trump administrations’ Blueprint contains certain measures that the U.S. Department of Health and Human Services is already working to implement.

Individual state legislatures have become increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing. Some of these measures include price or patient reimbursement constraints, discounts, restrictions on certain product access, marketing cost disclosure and transparency measures, and, in some cases, measures designed to encourage importation from other countries and bulk purchasing. In addition, regional health care authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other health care programs. These measures could reduce the ultimate demand for resTORbio’s products, once approved, or put pressure on resTORbio’s product pricing.

In addition, individual states in the United States have also become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access, and to encourage importation from other countries and bulk purchasing.

The pricing of prescription pharmaceuticals is also subject to governmental control outside the United States. In these countries, pricing negotiations with governmental authorities can take considerable time after the receipt of regulatory approval for a product. To obtain reimbursement or pricing approval in some countries, resTORbio may be required to conduct a clinical trial that compares the cost-effectiveness of resTORbio’s product candidates to other available therapies. If reimbursement of resTORbio’s products is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, resTORbio’s ability to generate revenues and become profitable could be impaired.

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Governments outside the United States may impose strict price controls, which may adversely affect resTORbio’s revenues, if any.

In some countries, including Member States of the EU, the pricing of prescription drugs is subject to governmental control. Additional countries may adopt similar approaches to the pricing of prescription drugs. In such countries, pricing negotiations with governmental authorities can take considerable time after receipt of regulatory approval for a product. In addition, there can be considerable pressure by governments and other stakeholders on prices and reimbursement levels, including as part of cost containment measures. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after coverage and reimbursement have been obtained. Reference pricing used by various countries and parallel distribution, or arbitrage between low-priced and high-priced countries, can further reduce prices. In some countries, resTORbio may be required to conduct a clinical study or other studies that compare the cost-effectiveness of any of resTORbio’s product candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval, which is time-consuming and costly. resTORbio cannot be sure that such prices and reimbursement will be acceptable to resTORbio or resTORbio’s strategic partners. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If pricing is set at unsatisfactory levels or if reimbursement of resTORbio’s products is unavailable or limited in scope or amount, resTORbio’s revenues from sales by resTORbio or resTORbio’s strategic partners and the potential profitability of any of resTORbio’s product candidates in those countries would be negatively affected.

Laws and regulations governing any international operations resTORbio may have in the future may preclude resTORbio from developing, manufacturing and selling certain products outside of the United States and require resTORbio to develop and implement costly compliance programs.

If resTORbio further expands its operations outside of the United States, resTORbio must dedicate additional resources to comply with numerous laws and regulations in each jurisdiction in which resTORbio plans to operate. The Foreign Corrupt Practices Act, or FCPA, prohibits any U.S. individual or business from paying, offering, authorizing payment or offering of anything of value, directly or indirectly, to any foreign official, political party or candidate for the purpose of influencing any act or decision of the foreign entity in order to assist the individual or business in obtaining or retaining business. The FCPA also obligates companies whose securities are listed in the United States to comply with certain accounting provisions requiring resTORbio to maintain books and records that accurately and fairly reflect all transactions of the corporation, including international subsidiaries, and to devise and maintain an adequate system of internal accounting controls for international operations.

Compliance with the FCPA is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, the FCPA presents particular challenges in the pharmaceutical industry, because, in many countries, hospitals are operated by the government, and doctors and other hospital employees are considered foreign officials. Certain payments to hospitals in connection with clinical trials and other work have been deemed to be improper payments to government officials and have led to FCPA enforcement actions.

Various laws, regulations and executive orders also restrict the use and dissemination outside of the United States, or the sharing with certain non-U.S. nationals, of information classified for national security purposes, as well as certain products and technical data relating to those products. If resTORbio expands its presence outside of the United States, it will require resTORbio to dedicate additional resources to comply with these laws, and these laws may preclude resTORbio from developing, manufacturing, or selling certain products and product candidates outside of the United States, which could limit resTORbio’s growth potential and increase resTORbio’s development costs.

The failure to comply with laws governing international business practices may result in substantial civil and criminal penalties and suspension or debarment from government contracting. The Securities and Exchange

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Commission, or SEC, also may suspend or bar issuers from trading securities on U.S. exchanges for violations of the FCPA’s accounting provisions.

If resTORbio fails to comply with environmental, health and safety laws and regulations, resTORbio could become subject to fines or penalties or incur costs that could harm resTORbio’s business.

resTORbio is subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. From time to time and in the future, resTORbio’s operations may involve the use of hazardous and flammable materials, including chemicals and biological materials, and may also produce hazardous waste products. Even if resTORbio contracts with third parties for the disposal of these materials and waste products, resTORbio cannot completely eliminate the risk of contamination or injury resulting from these materials. In the event of contamination or injury resulting from the use or disposal of resTORbio’s hazardous materials, resTORbio could be held liable for any resulting damages, and any liability could exceed resTORbio’s resources. resTORbio also could incur significant costs associated with civil or criminal fines and penalties for failure to comply with such laws and regulations.

resTORbio maintains workers’ compensation insurance to cover resTORbio for costs and expenses resTORbio may incur due to injuries to its employees, but this insurance may not provide adequate coverage against potential liabilities. However, resTORbio does not maintain insurance for environmental liability or toxic tort claims that may be asserted against resTORbio.

In addition, resTORbio may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. Current or future environmental laws and regulations may impair resTORbio’s research, development or production efforts. In addition, failure to comply with these laws and regulations may result in substantial fines, penalties or other sanctions.

The anticipated phasing out of LIBOR in the future may adversely affect the value of any outstanding debt instruments.

National and international regulators and law enforcement agencies have conducted investigations into a number of rates or indices known as “reference rates.” Actions by such regulators and law enforcement agencies may result in changes to the manner in which certain reference rates are determined, their discontinuance, or the establishment of alternative reference rates. In particular, in July 2017, the Chief Executive of the U.K. Financial Conduct Authority, or FCA, which regulates LIBOR, announced that the FCA will no longer persuade or compel banks to submit rates for the calculation of LIBOR after 2021. Such announcement indicates that the continuation of LIBOR on the current basis cannot and will not be guaranteed after 2021. As a result, it appears highly likely that LIBOR will be discontinued or modified by 2021.

At this time, it is not possible to predict the effect that these developments, any discontinuance, modification or other reforms to LIBOR or any other reference rate, or the establishment of alternative reference rates may have on LIBOR, other benchmarks, or LIBOR-based debt instruments. Uncertainty as to the nature of such potential discontinuance, modification, alternative reference rates or other reforms may materially adversely affect the trading market for securities linked to such benchmarks. Furthermore, the use of alternative reference rates or other reforms could cause the interest rate calculated for the LIBOR-based debt instruments to be materially different than expected.

Risks Related to resTORbio’s Intellectual Property

resTORbio’s commercial success depends on resTORbio’s ability to protect resTORbio’s intellectual property and proprietary technology.

resTORbio’s commercial success depends in large part on resTORbio’s ability to obtain and maintain intellectual property rights protection through patents, trademarks, and trade secrets in the United States and other countries

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with respect to resTORbio’s proprietary product candidates. If resTORbio does not adequately protect resTORbio’s intellectual property rights, competitors may be able to erode, negate or preempt any competitive advantage resTORbio may have, which could harm resTORbio’s business and ability to achieve profitability. To protect resTORbio’s proprietary position, resTORbio has patent applications and may file other patent applications in the United States or abroad related to resTORbio’s product candidates that are important to resTORbio’s business; resTORbio may also license or purchase patent applications filed by others. The patent application and approval process is expensive and time-consuming. resTORbio may not be able to file and prosecute all necessary or desirable patent applications at a reasonable cost or in a timely manner.

Agreements through which resTORbio licenses patent rights may not give resTORbio control over patent prosecution or maintenance, so that resTORbio may not be able to control which claims or arguments are presented, how claims are amended, and may not be able to secure, maintain, or successfully enforce necessary or desirable patent protection from those patent rights. resTORbio has not had and do not have primary control over patent prosecution and maintenance for certain of the patents and patent applications resTORbio licenses, and therefore cannot guarantee that these patents and applications will be prosecuted or maintained in a manner consistent with the best interests of resTORbio’s business. resTORbio cannot be certain that patent prosecution and maintenance activities by resTORbio’s licensors have been or will be conducted in compliance with applicable laws and regulations or will result in valid and enforceable patents.

If the scope of the patent protection resTORbio or its licensors obtain is not sufficiently broad, resTORbio may not be able to prevent others from developing and commercializing technology and products similar or identical to ours. The degree of patent protection resTORbio requires to successfully compete in the marketplace may be unavailable or severely limited in some cases and may not adequately protect resTORbio’s rights or permit resTORbio to gain or keep any competitive advantage. resTORbio cannot provide any assurances that any of resTORbio’s licensed patents have, or that any of resTORbio’s pending owned or licensed patent applications that mature into issued patents will include, claims with a scope sufficient to protect resTORbio’s proprietary platform or otherwise provide any competitive advantage, nor can resTORbio assure you that resTORbio’s licenses are or will remain in force. Other parties have developed or may develop technologies that may be related or competitive with resTORbio’s approach, and may have filed or may file patent applications and may have been issued or may be issued patents with claims that overlap or conflict with resTORbio’s patent applications, either by claiming the same compounds, formulations or methods or by claiming subject matter that could dominate resTORbio’s patent position. In addition, the laws of foreign countries may not protect resTORbio’s rights to the same extent as the laws of the United States. Furthermore, patents have a limited lifespan. In the United States, the natural expiration of a patent is generally twenty years after it is filed. Various extensions may be available; however, the life of a patent, and the protection it affords, is limited. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, resTORbio’s patent portfolio may not provide resTORbio with adequate and continuing patent protection sufficient to exclude others from commercializing products similar to resTORbio’s product candidates. In addition, the patent portfolio licensed to resTORbio is, or may be, licensed to third parties, such as outside resTORbio’s field, and such third parties may have certain enforcement rights. Thus, patents licensed to resTORbio could be put at risk of being invalidated or interpreted narrowly in litigation filed by or against another licensee or in administrative proceedings brought by or against another licensee in response to such litigation or for other reasons.

Even if they are unchallenged, resTORbio’s owned and licensed patents and pending patent applications, if issued, may not provide resTORbio with any meaningful protection or prevent competitors from designing around resTORbio’s patent claims to circumvent resTORbio’s patents by developing similar or alternative technologies or therapeutics in a non-infringing manner. For example, a third party may develop a competitive therapy that provides benefits similar to one or more of resTORbio’s product candidates but falls outside the scope of resTORbio’s patent protection or license rights. If the patent protection provided by the patents and patent applications resTORbio holds or pursues with respect to its product candidates is not sufficiently broad to

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impede such competition, resTORbio’s ability to successfully commercialize resTORbio’s product candidates could be negatively affected, which would harm resTORbio’s business. Currently, a significant portion of resTORbio’s patents and patent applications are in-licensed, though similar risks would apply to any patents or patent applications that resTORbio now owns or may own or in-license in the future.

resTORbio, or any future partners, collaborators, or licensees, may fail to identify patentable aspects of inventions made in the course of development and commercialization activities before it is too late to obtain patent protection on them. Therefore, resTORbio may miss potential opportunities to strengthen its patent position.

It is possible that defects of form in the preparation or filing of resTORbio’s patents or patent applications may exist, or may arise in the future, for example with respect to proper priority claims, inventorship, claim scope, or requests for patent term adjustments. If resTORbio or its partners, collaborators, licensees, or licensors, whether current or future, fail to establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If resTORbio’s partners, collaborators, licensees, or licensors, are not fully cooperative or disagree with resTORbio as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised. If there are material defects in the form, preparation, prosecution, or enforcement of resTORbio’s patents or patent applications, such patents may be invalid and/or unenforceable, and such applications may never result in valid, enforceable patents. Any of these outcomes could impair resTORbio’s ability to prevent competition from third parties, which may have an adverse impact on resTORbio’s business.

The patent position of biotechnology and pharmaceutical companies carries uncertainty. In addition, the determination of patent rights with respect to pharmaceutical compounds commonly involves complex legal and factual questions, which are dependent upon the current legal and intellectual property context, extant legal precedent and interpretations of the law by individuals. As a result, the issuance, scope, validity, enforceability and commercial value of resTORbio’s patent rights are characterized by uncertainty.

Pending patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless and until a patent issues from such applications. Assuming the other requirements for patentability are met, currently, the first to file a patent application is generally entitled to the patent. However, prior to March 16, 2013, in the United States, the first to invent was entitled to the patent. Publications of discoveries in the scientific literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are not published until 18 months after filing, or in some cases not at all. Therefore, resTORbio cannot be certain that resTORbio was the first to make the inventions claimed in resTORbio’s patents or pending patent applications, or that resTORbio was the first to file for patent protection of such inventions. Similarly, resTORbio cannot be certain that parties from whom resTORbio does or may license or purchase patent rights were the first to make relevant claimed inventions, or were the first to file for patent protection for them. If third parties have filed prior patent applications on inventions claimed in resTORbio’s patents or applications that were filed on or before March 15, 2013, an interference proceeding in the United States can be initiated by such third parties to determine who was the first to invent any of the subject matter covered by the patent claims of resTORbio’s applications. If third parties have filed such prior applications after March 15, 2013, a derivation proceeding in the United States can be initiated by such third parties to determine whether resTORbio’s invention was derived from theirs.

Moreover, because the issuance of a patent is not conclusive as to its inventorship, scope, validity or enforceability, resTORbio’s patents or pending patent applications may be challenged in the courts or patent offices in the United States and abroad. There is no assurance that all of the potentially relevant prior art relating to resTORbio’s patents and patent applications has been found. If such prior art exists, it may be used to invalidate a patent, or may prevent a patent from issuing from a pending patent application. For example, such patent filings may be subject to a third-party submission of prior art to the U.S. Patent and Trademark Office, or USPTO, or to other patent offices around the world. Alternately or additionally, resTORbio may become

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involved in post-grant review procedures, oppositions, derivation proceedings, ex parte reexaminations, inter partes review, supplemental examinations, or interference proceedings or challenges in district court, in the United States or in various foreign patent offices, including both national and regional, challenging patents or patent applications in which resTORbio has rights, including patents on which resTORbio relies to protect its business. An adverse determination in any such challenges may result in loss of the patent or in patent or patent application claims being narrowed, invalidated or held unenforceable, in whole or in part, or in denial of the patent application or loss or reduction in the scope of one or more claims of the patent or patent application, any of which could limit resTORbio’s ability to stop others from using or commercializing similar or identical technology and products, or limit the duration of the patent protection of resTORbio’s technology and products. In addition, given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized.

Pending and future patent applications may not result in patents being issued that protect resTORbio’s business, in whole or in part, or which effectively prevent others from commercializing competitive products. Competitors may also be able to design around resTORbio’s patents. Changes in either the patent laws or interpretation of the patent laws in the United States and other countries may diminish the value of resTORbio’s patents or narrow the scope of resTORbio’s patent protection. In addition, the laws of foreign countries may not protect resTORbio’s rights to the same extent or in the same manner as the laws of the United States. For example, patent laws in various jurisdictions, including significant commercial markets such as Europe, restrict the patentability of methods of treatment of the human body more than United States law does. If these developments were to occur, they could have a material adverse effect on resTORbio’s ability to generate revenue.

The patent application process is subject to numerous risks and uncertainties, and there can be no assurance that resTORbio or any of its future development partners will be successful in protecting resTORbio’s product candidates by obtaining and defending patents. These risks and uncertainties include the following:

Issued patents that resTORbio has or may obtain or license may not provide resTORbio with any meaningful protection, prevent competitors from competing with resTORbio or otherwise provide resTORbio with any competitive advantage. resTORbio’s competitors may be able to circumvent resTORbio’s patents by developing similar or alternative technologies or products in a non-infringing manner. resTORbio’s competitors may also

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seek approval to market their own products similar to or otherwise competitive with resTORbio’s products. Alternatively, resTORbio’s competitors may seek to market generic versions of any approved products by submitting ANDAs to the FDA in which they claim that patents owned or licensed by resTORbio are invalid, unenforceable or not infringed. In these circumstances, resTORbio may need to defend or assert its patents, or both, including by filing lawsuits alleging patent infringement. In any of these types of proceedings, a court or other agency with jurisdiction may find resTORbio’s patents invalid or unenforceable, or that resTORbio’s competitors are competing in a non-infringing manner. Thus, even if resTORbio has valid and enforceable patents, these patents still may not provide protection against competing products or processes sufficient to achieve resTORbio’s business objectives.

In addition, resTORbio relies on the protection of its trade secrets and proprietary, unpatented know-how. Although resTORbio has taken steps to protect its trade secrets and unpatented know-how, including entering into confidentiality agreements with third parties, and confidential information and invention assignment agreements with employees, consultants, collaborators, vendors, and advisors, resTORbio cannot provide any assurances that all such agreements have been duly executed, and third parties may still obtain this information or may come upon this or similar information independently. It is possible that technology relevant to resTORbio’s business will be independently developed by a person who is not a party to such a confidentiality or invention assignment agreement. resTORbio may not be able to prevent the unauthorized disclosure or use of resTORbio’s technical knowledge or trade secrets by consultants, collaborators, vendors, advisors, former employees and current employees. Furthermore, if the parties to resTORbio’s confidentiality agreements breach or violate the terms of these agreement, resTORbio may not have adequate remedies for any such breach or violation, and resTORbio could lose its trade secrets as a consequence of such breaches or violations. resTORbio’s trade secrets could otherwise become known or be independently discovered by resTORbio’s competitors. Additionally, if the steps taken to maintain resTORbio’s trade secrets are deemed inadequate, resTORbio may have insufficient recourse against third parties for misappropriating resTORbio’s trade secrets. If any of these events occurs or if resTORbio otherwise loses protection for resTORbio’s trade secrets or proprietary know-how, resTORbio’s business may be harmed.

resTORbio depends on intellectual property licensed from third parties and termination of any of these licenses could result in the loss of significant rights, which would harm resTORbio’s business.

In March 2017, resTORbio entered into a license agreement with Novartis, or the Novartis License, pursuant to which resTORbio was granted an exclusive, field-restricted, worldwide license to certain intellectual property rights owned or controlled by Novartis, including patents, patent applications, proprietary information, know-how and other intellectual property, to develop, commercialize and sell one or more therapeutic products comprising RTB101 or RTB101 and everolimus in a fixed dose combination.

resTORbio is dependent on these patents, know-how and proprietary technology, licensed from Novartis. Any termination of this license, or a finding that such intellectual property lacks legal effect, could result in the loss of significant rights and could harm resTORbio’s ability to commercialize any product candidates. Please see the section entitled “resTORbio Business—resTORbio Intellectual Property” on page 262 of this proxy statement/prospectus/information statement for additional information regarding resTORbio’s license agreements.

Disputes may also arise between resTORbio and resTORbio’s licensor, resTORbio’s licensor and its licensors, or resTORbio and third parties that co-own intellectual property with resTORbio’s licensor or its licensors, regarding intellectual property subject to a license agreement, including those relating to:

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If disputes over intellectual property that resTORbio has licensed prevent or impair its ability to maintain resTORbio’s current licensing arrangements on acceptable terms, or are insufficient to provide resTORbio the necessary rights to use the intellectual property, resTORbio may be unable to successfully develop and commercialize the affected product candidates. If resTORbio or any such licensors fail to adequately protect this intellectual property, resTORbio’s ability to commercialize resTORbio’s products could suffer.

Novartis may partially terminate the license agreement with respect to everolimus if resTORbio fails or ceases for three years to use commercially reasonable efforts to research, develop and commercialize a product using everolimus, provided that resTORbio’s license related to RTB101 and Novartis’s license to resTORbio’s improvements related to everolimus will continue. Additionally, either party may terminate the Novartis License if the other party commits a material breach and fails to cure such breach within 60 days after written notice. If Novartis unilaterally terminates the Novartis License, the research and development of RTB101 or RTB101 and everolimus in a fixed dose combination would be suspended, and resTORbio may be unable to research, develop and license future product candidates.

resTORbio may be required to pay certain milestones and royalties under resTORbio’s license agreements with third-party licensors.

Under resTORbio’s current and future license agreements, resTORbio may be required to pay milestones and royalties based on resTORbio’s revenues from sales of resTORbio’s products utilizing the technologies licensed or sublicensed from Novartis or other licensors and these royalty payments could adversely affect the overall profitability for resTORbio of any products that resTORbio may seek to commercialize. In order to maintain resTORbio’s license rights under current and future license agreements, resTORbio may need to meet certain specified milestones, subject to certain cure provisions, in the development of resTORbio’s product candidates and in the raising of funding. In addition, these agreements may contain diligence milestones and resTORbio may not be successful in meeting all of the milestones in the future on a timely basis, or at all, which could result in termination of resTORbio’s rights under such agreements. resTORbio may need to outsource and rely on third parties for many aspects of the clinical development, sales and marketing of resTORbio’s products covered under resTORbio’s current and future license agreements. Delay or failure by these third parties could adversely affect the continuation of resTORbio’s license agreements with their third-party licensors.

It is difficult and costly to protect resTORbio’s intellectual property and resTORbio’s proprietary technologies, and resTORbio may not be able to ensure their protection.

resTORbio’s commercial success will depend in part on obtaining and maintaining patent protection and trade secret protection for the use, formulation and structure of resTORbio’s products and product candidates, the methods used to manufacture them, the related therapeutic targets and associated methods of treatment as well as

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on successfully defending these patents against potential third-party challenges. resTORbio’s ability to protect resTORbio’s products and product candidates from unauthorized making, using, selling, offering to sell or importing by third parties is dependent on the extent to which resTORbio has rights under valid and enforceable patents that cover these activities.

The patent positions of pharmaceutical, biotechnology and other life sciences companies can be highly uncertain and involve complex legal and factual questions for which important legal principles remain unresolved. Changes in either the patent laws or in interpretations of patent laws in the United States and other countries may diminish the value of resTORbio’s intellectual property. Further, the determination that a patent application or patent claim meets all of the requirements for patentability is a subjective determination based on the application of law and jurisprudence. The ultimate determination by the USPTO or by a court or other trier of fact in the United States, or corresponding foreign national patent offices or courts, on whether a claim meets all requirements of patentability cannot be assured. Although resTORbio has conducted searches for third-party publications, patents and other information that may affect the patentability of claims in its various patent applications and patents, resTORbio cannot be certain that all relevant information has been identified. Accordingly, resTORbio cannot predict the breadth of claims that may be allowed or enforced in resTORbio’s owned patents or patent applications, in resTORbio’s licensed patents or patent applications or in third-party patents.

resTORbio cannot provide assurances that any of resTORbio’s patent applications will be found to be patentable, including over resTORbio’s own or resTORbio’s licensors’ prior art publications or patent literature, or will issue as patents. Neither can resTORbio make assurances as to the scope of any claims that may issue from resTORbio’s pending and future patent applications nor to the outcome of any proceedings by any potential third parties that could challenge the patentability, validity or enforceability of resTORbio’s patents and patent applications in the United States or foreign jurisdictions. Any such challenge, if successful, could limit patent protection for resTORbio’s products and product candidates and/or materially harm resTORbio’s business.

The degree of future protection for resTORbio’s proprietary rights is uncertain because legal means afford only limited protection and may not adequately protect resTORbio’s rights or permit resTORbio to gain or keep resTORbio’s competitive advantage. For example:

In addition, to the extent that resTORbio is unable to obtain and maintain patent protection for one of resTORbio’s products or product candidates or in the event that such patent protection expires, it may no longer be cost-effective to extend resTORbio’s portfolio by pursuing additional development of a product or product candidate for follow-on indications.

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resTORbio also may rely on trade secrets to protect resTORbio’s technologies or products, especially where resTORbio does not believe patent protection is appropriate or obtainable. Also, resTORbio cannot provide any assurances that any of resTORbio’s licensed patents have claims with a scope sufficient to protect resTORbio’s technology or otherwise provide any competitive advantage, nor can resTORbio assure you that resTORbio’s licenses are or will remain in full force or effect, in which case resTORbio would similarly rely on trade secrets. However, trade secrets are difficult to protect. Although resTORbio uses reasonable efforts to protect its trade secrets, resTORbio’s employees, consultants, contractors, outside scientific collaborators and other advisers may unintentionally or willfully disclose resTORbio’s information to competitors. Enforcing a claim that a third-party entity illegally obtained and is using any of resTORbio’s trade secrets is expensive and time-consuming, and the outcome is unpredictable. In addition, courts outside the United States are sometimes less willing to protect trade secrets. Moreover, resTORbio’s competitors may independently develop equivalent knowledge, methods and know-how. Notably, proprietary technology protected by a trade secret does not preempt the patenting of independently developed equivalent technology, even if such equivalent technology is invented subsequent to the technology protected by a trade secret.

Obtaining and maintaining patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and resTORbio’s patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance fees, renewal fees, annuity fees and various other governmental fees on patents and applications are required to be paid to the USPTO and various governmental patent agencies outside of the United States in several stages over the lifetime of the patents and applications. The USPTO and various non-U.S. governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process and after a patent has issued. There are situations in which non-compliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such a circumstance, competitors may be able to enter the market earlier than otherwise would be the case. Under the terms of some of resTORbio’s current and future licenses, resTORbio may not have the ability to maintain patents or prosecute patent applications in the portfolio and may therefore have to rely on third parties to comply with these requirements.

Patent terms may be inadequate to protect resTORbio’s competitive position on resTORbio’s products for an adequate amount of time.

Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. resTORbio expects to seek extensions of patent terms in the United States and, if available, in other countries where resTORbio is prosecuting patents. In the United States, the Drug Price Competition and Patent Term Restoration Act of 1984 permits a patent term extension of up to five years beyond the normal expiration of the patent, which is limited to the approved indication (or any additional indications approved during the period of extension). resTORbio might not be granted an extension because of, for example, failure to apply within applicable periods, failure to apply prior to the expiration of relevant patents or otherwise failure to satisfy any of the numerous applicable requirements. Moreover, the applicable authorities, including the FDA and the USPTO in the United States, and any equivalent regulatory authority in other countries, may not agree with resTORbio’s assessment of whether such extensions are available, and may refuse to grant extensions to resTORbio’s patents, or may grant more limited extensions than resTORbio requests. If this occurs, resTORbio’s competitors may be able to obtain approval of competing products following resTORbio’s patent expiration by referencing resTORbio’s clinical and preclinical data and launch their product earlier than might otherwise be the case. If this were to occur, it could have a material adverse effect on resTORbio’s ability to generate revenue.

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Changes to patent law in the United States and other jurisdictions could diminish the value of patents in general, thereby impairing resTORbio’s ability to protect resTORbio’s products.

As is the case with other biopharmaceutical companies, resTORbio’s commercial success is heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biopharmaceutical industry involves both technological and legal complexity and is therefore costly, time consuming and inherently uncertain. Recent wide-ranging patent reform legislation in the United States, including the Leahy-Smith America Invents Act, or the America Invents Act, could increase those uncertainties and costs. The America Invents Act was signed into law on September 16, 2011, and many of the substantive changes became effective on March 16, 2013. The America Invents Act reforms United States patent law in part by changing the U.S. patent system from a “first to invent” system to a “first inventor to file” system, expanding the definition of prior art, and developing a post-grant review system. This legislation changes United States patent law in a way that may weaken resTORbio’s ability to obtain patent protection in the United States for those applications filed after March 16, 2013.

Further, the America Invents Act created new procedures to challenge the validity of issued patents in the United States, including post-grant review and inter partes review proceedings, which some third parties have been using to cause the cancellation of selected or all claims of issued patents of competitors. For a patent with an effective filing date of March 16, 2013 or later, a petition for post-grant review can be filed by a third party in a nine-month window from issuance of the patent. A petition for inter partes review can be filed immediately following the issuance of a patent if the patent has an effective filing date prior to March 16, 2013. A petition for inter partes review can be filed after the nine-month period for filing a post-grant review petition has expired for a patent with an effective filing date of March 16, 2013 or later. Post-grant review proceedings can be brought on any ground of invalidity, whereas inter partes review proceedings can only raise an invalidity challenge based on published prior art and patents. These adversarial actions at the USPTO review patent claims without the presumption of validity afforded to U.S. patents in lawsuits in U.S. federal courts and use a lower burden of proof than used in litigation in U.S. federal courts. Therefore, it is generally considered easier for a competitor or third party to have a U.S. patent invalidated in a USPTO post-grant review or inter partes review proceeding than invalidated in a litigation in a U.S. federal court. If any of resTORbio’s patents are challenged by a third party in such a USPTO proceeding, there is no guarantee that resTORbio or its licensors or collaborators will be successful in defending the patent, which may result in a loss of the challenged patent right to resTORbio.

In addition, recent court rulings in cases such as Association for Molecular Pathology v. Myriad Genetics, Inc., BRCA1- & BRCA2-Based Hereditary Cancer Test Patent Litigation, and Promega Corp. v. Life Technologies Corp. have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. In addition to increasing uncertainty with regard to resTORbio’s ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents once obtained. Depending on future actions by the U.S. Congress, the U.S. courts, the USPTO and the relevant law-making bodies in other countries, the laws and regulations governing patents could change in unpredictable ways that would weaken resTORbio’s ability to obtain new patents or to enforce its existing patents and patents that it might obtain in the future.

resTORbio may not be able to enforce resTORbio’s intellectual property rights throughout the world.

Filing, prosecuting, enforcing and defending patents on resTORbio’s product candidates in all countries throughout the world would be prohibitively expensive, and resTORbio’s intellectual property rights in some countries outside the United States can be less extensive than those in the United States. The requirements for patentability may differ in certain countries, particularly in developing countries; thus, even in countries where resTORbio does pursue patent protection, there can be no assurance that any patents will issue with claims that cover resTORbio’s products.

Moreover, resTORbio’s ability to protect and enforce resTORbio’s intellectual property rights may be adversely affected by unforeseen changes in foreign intellectual property laws. Additionally, laws of some countries

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outside of the United States and Europe do not afford intellectual property protection to the same extent as the laws of the United States and Europe. Many companies have encountered significant problems in protecting and defending intellectual property rights in certain foreign jurisdictions. The legal systems of some countries, including India, China and other developing countries, do not favor the enforcement of patents and other intellectual property rights. This could make it difficult for resTORbio to stop the infringement of resTORbio’s patents or the misappropriation of resTORbio’s other intellectual property rights. For example, many foreign countries have compulsory licensing laws under which a patent owner must grant licenses to third parties. Consequently, resTORbio may not be able to prevent third parties from practicing resTORbio’s inventions in certain countries outside the United States and Europe or from selling or importing products made from resTORbio’s inventions in and into the United States or other jurisdictions. Competitors may use resTORbio’s technologies in jurisdictions where resTORbio has not obtained patent protection to develop and market their own products and, further, may export otherwise infringing products to territories where resTORbio has patent protection, if resTORbio’s ability to enforce resTORbio’s patents to stop infringing activities is inadequate. These products may compete with resTORbio’s products, and resTORbio’s patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Agreements through which resTORbio licenses patent rights may not give resTORbio sufficient rights to permit resTORbio to pursue enforcement of resTORbio’s licensed patents or defense of any claims asserting the invalidity of these patents (or control of such enforcement or defense) of such patent rights in all relevant jurisdictions as requirements may vary.

Proceedings to enforce resTORbio’s patent rights, whether or not successful, could result in substantial costs and divert resTORbio’s efforts and resources from other aspects of resTORbio’s business. Moreover, such proceedings could put resTORbio’s patents at risk of being invalidated or interpreted narrowly and resTORbio’s patent applications at risk of not issuing and could provoke third parties to assert claims against resTORbio. resTORbio may not prevail in any lawsuits that it initiates and the damages or other remedies awarded, if any, may not be commercially meaningful. Furthermore, while resTORbio intends to protect its intellectual property rights in major markets for resTORbio’s products, resTORbio cannot ensure that it will be able to initiate or maintain similar efforts in all jurisdictions in which resTORbio may wish to market its products, if approved. Accordingly, resTORbio’s efforts to protect its intellectual property rights in such countries may be inadequate.

Others may challenge inventorship or claim an ownership interest in resTORbio’s intellectual property which could expose it to litigation and have a significant adverse effect on its prospects.

A third party or former employee or collaborator may claim an ownership interest in one or more of resTORbio’s or resTORbio’s licensors’ patents or other proprietary or intellectual property rights. A third party could bring legal actions against resTORbio and seek monetary damages and/or enjoin clinical testing, manufacturing and marketing of the affected product or products. While resTORbio is presently unaware of any claims or assertions by third-parties with respect to resTORbio’s patents or other intellectual property, resTORbio cannot guarantee that a third party will not assert a claim or an interest in any of such patents or intellectual property. If resTORbio becomes involved in any litigation, it could consume a substantial portion of resTORbio’s resources, and cause a significant diversion of effort by resTORbio’s technical and management personnel.

If resTORbio is sued for infringing intellectual property rights of third parties, such litigation could be costly and time consuming and could prevent or delay resTORbio from developing or commercializing resTORbio’s product candidates.

resTORbio’s commercial success depends, in part, on resTORbio’s ability to develop, manufacture, market and sell resTORbio’s product candidates without infringing the intellectual property and other proprietary rights of third parties. Third parties may have U.S. and non-U.S. issued patents and pending patent applications relating to compounds, methods of manufacturing compounds and/or methods of use for the treatment of the disease indications for which resTORbio is developing resTORbio’s product candidates. If any third-party patents or

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patent applications are found to cover resTORbio’s product candidates or its methods of use or manufacture, resTORbio may not be free to manufacture or market resTORbio’s product candidates as planned without obtaining a license, which may not be available on commercially reasonable terms, or at all.

There is a substantial amount of intellectual property litigation in the biotechnology and pharmaceutical industries, and resTORbio may become party to, or threatened with, litigation or other adversarial proceedings regarding intellectual property rights with respect to resTORbio’s products candidates, including interference and post-grant proceedings before the USPTO. There may be third-party patents or patent applications with claims to materials, formulations, methods of manufacture or methods for treatment related to the composition, use or manufacture of resTORbio’s product candidates. resTORbio cannot guarantee that any of resTORbio’s patent searches or analyses including, but not limited to, the identification of relevant patents, the scope of patent claims or the expiration of relevant patents are complete or thorough, nor can resTORbio be certain that it has identified each and every patent and pending application in the United States and abroad that is relevant to or necessary for the commercialization of resTORbio’s product candidates in any jurisdiction. Because patent applications can take many years to issue, there may be currently pending patent applications which may later result in issued patents that resTORbio’s product candidates may be accused of infringing. In addition, third parties may obtain patents in the future and claim that use of resTORbio’s technologies infringes upon these patents. Accordingly, third parties may assert infringement claims against resTORbio based on intellectual property rights that exist now or arise in the future. The outcome of intellectual property litigation is subject to uncertainties that cannot be adequately quantified in advance. The pharmaceutical and biotechnology industries have produced a significant number of patents, and it may not always be clear to industry participants, including resTORbio, which patents cover various types of products or methods of use or manufacture. The scope of protection afforded by a patent is subject to interpretation by the courts, and the interpretation is not always uniform. If resTORbio was sued for patent infringement, resTORbio would need to demonstrate that its product candidates, products or methods either do not infringe the patent claims of the relevant patent or that the patent claims are invalid or unenforceable, and resTORbio may not be able to do this. Proving invalidity is difficult. For example, in the United States, proving invalidity requires a showing of clear and convincing evidence to overcome the presumption of validity enjoyed by issued patents. Even if resTORbio is successful in these proceedings, resTORbio may incur substantial costs and the time and attention of its management and scientific personnel could be diverted in pursuing these proceedings, which could significantly harm resTORbio’s business and operating results. In addition, resTORbio may not have sufficient resources to bring these actions to a successful conclusion.

If resTORbio is found to infringe a third party’s intellectual property rights, resTORbio could be forced, including by court order, to cease developing, manufacturing or commercializing the infringing product candidate or product. Alternatively, resTORbio may be required to obtain a license from such third party in order to use the infringing technology and continue developing, manufacturing or marketing the infringing product candidate or product. If resTORbio was required to obtain a license to continue to manufacture or market the affected product, resTORbio may be required to pay substantial royalties or grant cross-licenses to resTORbio’s patents. resTORbio cannot, however, assure you that any such license will be available on acceptable terms, if at all. Ultimately, resTORbio could be prevented from commercializing a product, or be forced to cease some aspect of resTORbio’s business operations as a result of claims of patent infringement or violation of other intellectual property rights, Further, the outcome of intellectual property litigation is subject to uncertainties that cannot be adequately quantified in advance, including the demeanor and credibility of witnesses and the identity of any adverse party. This is especially true in intellectual property cases that may turn on the testimony of experts as to technical facts upon which experts may reasonably disagree. Furthermore, resTORbio may not be able to obtain any required license on commercially reasonable terms, or at all. Even if resTORbio was able to obtain a license, it could be non-exclusive, thereby giving resTORbio’s competitors access to the same technologies licensed to resTORbio; alternatively or additionally it could include terms that impede or destroy resTORbio’s ability to compete successfully in the commercial marketplace. In addition, resTORbio could be found liable for monetary damages, including treble damages and attorneys’ fees if resTORbio is found to have willfully infringed a patent. A finding of infringement could prevent resTORbio from commercializing

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resTORbio’s product candidates or force resTORbio to cease some of resTORbio’s business operations, which could harm resTORbio’s business. Claims that resTORbio has misappropriated the confidential information or trade secrets of third parties could have a similar negative impact on resTORbio’s business.

resTORbio may be subject to claims by third parties asserting that resTORbio’s employees or resTORbio has misappropriated their intellectual property, or claiming ownership of what resTORbio regards as its own intellectual property.

Many of resTORbio’s current and former employees and resTORbio’s licensors’ current and former employees, including resTORbio’s senior management, were previously employed at universities or at other biotechnology or pharmaceutical companies, including some which may be competitors or potential competitors. Some of these employees, including members of resTORbio’s senior management, may have executed proprietary rights, non-disclosure and non-competition agreements, or similar agreements, in connection with such previous employment. Although resTORbio tries to ensure that its employees do not use the proprietary information or know-how of others in their work for resTORbio, resTORbio may be subject to claims that resTORbio or these employees have used or disclosed intellectual property, including trade secrets or other proprietary information, of any such third party. Litigation may be necessary to defend against such claims. If resTORbio fails in defending any such claims, in addition to paying monetary damages, resTORbio may sustain damages or lose key personnel, valuable intellectual property rights or the personnel’s work product, which could hamper or prevent commercialization of resTORbio’s technology, which could materially affect resTORbio’s commercial development efforts. Such intellectual property rights could be awarded to a third party, and resTORbio could be required to obtain a license from such third party to commercialize resTORbio’s technology or products. Such a license may not be available on commercially reasonable terms, or at all. Even if resTORbio is successful in defending against such claims, litigation could result in substantial costs and be a distraction to management.

In addition, while resTORbio typically requires its employees, consultants and contractors who may be involved in the development of intellectual property to execute agreements assigning such intellectual property to resTORbio, resTORbio may be unsuccessful in executing such an agreement with each party who in fact develops intellectual property that resTORbio regards as its own, which may result in claims by or against resTORbio related to the ownership of such intellectual property. If resTORbio fails in prosecuting or defending any such claims, in addition to paying monetary damages, resTORbio may lose valuable intellectual property rights. Even if resTORbio is successful in prosecuting or defending against such claims, litigation could result in substantial costs and be a distraction to resTORbio’s senior management and scientific personnel.

resTORbio may become involved in lawsuits to protect or enforce resTORbio’s patents or other intellectual property, which could be expensive, time consuming and unsuccessful.

Competitors may infringe resTORbio’s patents, trademarks, copyrights or other intellectual property. To counter infringement or unauthorized use, resTORbio may be required to file infringement claims, which can be expensive and time consuming and divert the time and attention of resTORbio’s management and scientific personnel. Any claims resTORbio asserts against perceived infringers could provoke these parties to assert counterclaims against resTORbio alleging that resTORbio infringes their patents, in addition to counterclaims asserting that resTORbio’s patents are invalid or unenforceable, or both. In any patent infringement proceeding, there is a risk that a court will decide that a patent of ours is invalid or unenforceable, in whole or in part, and that resTORbio does not have the right to stop the other party from using the invention at issue. There is also a risk that, even if the validity of such patents is upheld, the court will construe the patent’s claims narrowly or decide that resTORbio does not have the right to stop the other party from using the invention at issue on the grounds that resTORbio’s patent claims do not cover the invention. An adverse outcome in a litigation or proceeding involving one or more of resTORbio’s patents could limit resTORbio’s ability to assert those patents against those parties or other competitors, and may curtail or preclude resTORbio’s ability to exclude third parties from making and selling similar or competitive products. Similarly, if resTORbio asserts trademark infringement claims, a court may determine that the marks resTORbio has asserted are invalid or unenforceable, or that the

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party against whom resTORbio has asserted trademark infringement has superior rights to the trademarks in question. In this case, resTORbio could ultimately be forced to cease use of such trademarks.

Even if resTORbio establishes infringement, the court may decide not to grant an injunction against further infringing activity and instead award only monetary damages, which may or may not be an adequate remedy. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of resTORbio’s confidential information could be compromised by disclosure during litigation. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it could adversely affect the price of shares of resTORbio common stock. Moreover, there can be no assurance that resTORbio will have sufficient financial or other resources to file and pursue such infringement claims, which typically last for years before they are concluded. Even if resTORbio ultimately prevails in such claims, the monetary cost of such litigation and the diversion of the attention of resTORbio’s management and scientific personnel could outweigh any benefit resTORbio receives as a result of the proceedings.

Additionally, for certain of resTORbio’s existing and future in-licensed patent rights, resTORbio may not have the right to bring suit for infringement and may have to rely on third parties to enforce these rights for resTORbio. If resTORbio cannot or choose not to take action against those resTORbio believes infringe its intellectual property rights, resTORbio may have difficulty competing in certain markets where such potential infringers conduct their business, and resTORbio’s commercialization efforts may suffer as a result.

If resTORbio’s trademarks and trade names are not adequately protected, then resTORbio may not be able to build name recognition in resTORbio’s trademarks of interest and resTORbio’s business may be adversely affected.

resTORbio’s trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks. resTORbio relies on both registration and common law protection for resTORbio’s trademarks. resTORbio may not be able to protect resTORbio’s rights to these trademarks and trade names or may be forced to stop using these names, which resTORbio needs for name recognition by potential partners or customers in resTORbio’s markets of interest. During trademark registration proceedings, resTORbio may receive rejections. Although resTORbio would be given an opportunity to respond to those rejections, resTORbio may be unable to overcome such rejections. In addition, in the USPTO and in comparable agencies in many foreign jurisdictions, third parties are given an opportunity to oppose pending trademark applications and to seek to cancel registered trademarks. Opposition or cancellation proceedings may be filed against resTORbio’s trademarks, and resTORbio’s trademarks may not survive such proceedings. Moreover, any name resTORbio proposes to use for its products in the United States must be approved by the FDA, regardless of whether resTORbio has registered it, or applied to register it, as a trademark. The FDA typically conducts a review of proposed product names, including an evaluation of potential for confusion with other product names. If the FDA objects to any of resTORbio’s proposed product names, resTORbio may be required to expend significant additional resources in an effort to identify a usable substitute name that would qualify under applicable trademark laws, not infringe the existing rights of third parties and be acceptable to the FDA. If resTORbio is unable to establish name recognition based on its trademarks and trade names, resTORbio may not be able to compete effectively and resTORbio’s business may be adversely affected.

Risks Related to resTORbio’s Dependence on Third Parties

resTORbio relies on third parties to assist in conducting resTORbio’s clinical trials. If they do not perform satisfactorily, resTORbio may not be able to obtain regulatory approval or commercialize resTORbio’s product candidates, or such approval or commercialization may be delayed, and resTORbio’s business could be substantially harmed.

resTORbio does not independently conduct clinical trials of any of resTORbio’s product candidates. resTORbio has relied upon and plan to continue to rely on third parties, such as CROs, clinical data management

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organizations, medical institutions and clinical investigators, to conduct these clinical trials and expect to rely on these third parties to conduct clinical trials of any other product candidate that resTORbio develops. Any of these third parties may terminate their engagements with resTORbio under certain circumstances. resTORbio may not be able to enter into alternative arrangements or do so on commercially reasonable terms. In addition, there is a natural transition period when a new CRO begins work. As a result, delays may occur, which could negatively impact resTORbio’s ability to meet resTORbio’s expected clinical development timelines and harm resTORbio’s business, financial condition and prospects. For example, in April 2020, resTORbio announced that it would postpone enrollment in the fifth cohort of its ongoing Phase 1b/2a trial of RTB 101 in patients with PD due to the COVID-19 level 4 alert in New Zealand. While resTORbio plans to analyze the data from the four completed dosing arms and completed cohorts, resTORbio subsequently elected to terminate the study and not to dose patients in the fifth dosing arm.

Further, although resTORbio’s reliance on these third parties for clinical development activities limits its control over these activities, resTORbio remains responsible for ensuring that each of its trials is conducted in accordance with the applicable protocol, legal and regulatory requirements and scientific standards. For example, notwithstanding the obligations of a CRO for a trial of one of resTORbio’s product candidates, resTORbio remains responsible for ensuring that each of resTORbio’s clinical trials is conducted in accordance with the general investigational plan and protocols for the trial. Moreover, the FDA requires resTORbio to comply with requirements, commonly referred to as GCPs, for conducting, recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. The FDA enforces these GCPs through periodic inspections of trial sponsors, principal investigators, clinical trial sites and IRBs. If resTORbio or its third-party contractors fail to comply with applicable GCPs, the clinical data generated in resTORbio’s clinical trials may be deemed unreliable and the FDA may require resTORbio to perform additional clinical trials before approving resTORbio’s product candidates, which would delay the regulatory approval process. resTORbio cannot be certain that, upon inspection, the FDA will determine that any of resTORbio’s clinical trials comply with GCPs. resTORbio is also required to register certain clinical trials and post the results of completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within certain timeframes. Failure to do so can result in fines, adverse publicity and civil and criminal sanctions.

Furthermore, the third parties conducting clinical trials on resTORbio’s behalf are not resTORbio’s employees, and except for remedies available to resTORbio under resTORbio’s agreements with such contractors, resTORbio cannot control whether or not they devote sufficient time, skill and resources to resTORbio’s ongoing development programs. These contractors may also have relationships with other commercial entities, including resTORbio’s competitors, for whom they may also be conducting clinical trials or other drug development activities, which could impede their ability to devote appropriate time to resTORbio’s clinical programs. If these third parties, including clinical investigators, do not successfully carry out their contractual duties, meet expected deadlines or conduct resTORbio’s clinical trials in accordance with regulatory requirements or resTORbio’s stated protocols, resTORbio may not be able to obtain, or may be delayed in obtaining, regulatory approvals for resTORbio’s product candidates. If that occurs, resTORbio will not be able to, or may be delayed in its efforts to, successfully commercialize resTORbio’s product candidates. In such an event, resTORbio’s financial results and the commercial prospects for any product candidates that resTORbio seeks to develop could be harmed, its costs could increase and its ability to generate revenues could be delayed, impaired or foreclosed.

resTORbio also relies on other third parties to store and distribute drug supplies for resTORbio’s clinical trials. Any performance failure on the part of resTORbio’s distributors could delay clinical development or regulatory approval of resTORbio’s product candidates or commercialization of any resulting products, producing additional losses and depriving resTORbio of potential product revenue.

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resTORbio’s use of third parties to manufacture resTORbio’s product candidates and products which resTORbio is studying in combination with resTORbio’s product candidates may increase the risk that resTORbio will not have sufficient quantities of resTORbio’s product candidates, products, or necessary quantities of such materials on time or at an acceptable cost.

resTORbio does not own or operate manufacturing facilities for the production of clinical or commercial quantities of resTORbio’s product candidates, and resTORbio lacks the resources and the capabilities to do so. As a result, resTORbio currently relies on third parties for the manufacture and supply of the active pharmaceutical ingredients, or API, in resTORbio’s product candidates. resTORbio’s current strategy is to outsource all manufacturing of resTORbio’s product candidates to third parties.

resTORbio currently engages one third-party manufacturer to provide the active pharmaceutical ingredient, or API, and two other third-party manufacturers to provide services for the final drug product formulation of RTB101 that is being used in resTORbio’s clinical trials. Although resTORbio believes that there are several potential alternative manufacturers who could manufacture RTB101 and rapalogs, such as everolimus or sirolimus, resTORbio may incur added costs and delays in identifying and qualifying any such replacement. In addition, resTORbio typically orders raw materials and services on a purchase order basis and do not enter into long-term dedicated capacity or minimum supply arrangements with any commercial manufacturer. There is no assurance that resTORbio will be able to timely secure needed supply arrangements on satisfactory terms, or at all. resTORbio’s failure to secure these arrangements as needed could have a material adverse effect on resTORbio’s ability to complete the development of resTORbio’s product candidates or, to commercialize them, if approved. resTORbio may be unable to conclude agreements for commercial supply with third-party manufacturers, or may be unable to do so on acceptable terms. There may be difficulties in scaling up to commercial quantities and formulation of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, and the costs of manufacturing could be prohibitive.

Even if resTORbio is able to establish and maintain arrangements with third-party manufacturers, reliance on third-party manufacturers entails additional risks, including:

If resTORbio does not maintain its key manufacturing relationships, resTORbio may fail to find replacement manufacturers or develop its own manufacturing capabilities, which could delay or impair resTORbio’s ability to obtain regulatory approval for resTORbio’s products. If resTORbio does find replacement manufacturers, resTORbio may not be able to enter into agreements with them on terms and conditions favorable to resTORbio and there could be a substantial delay before new facilities could be qualified and registered with the FDA and other foreign regulatory authorities.

If any of resTORbio’s product candidates are approved by any regulatory agency, resTORbio intends to utilize arrangements with third-party contract manufacturers for the commercial production of those products. This

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process is difficult and time consuming and resTORbio may face competition for access to manufacturing facilities as there are a limited number of contract manufacturers operating under cGMPs that are capable of manufacturing resTORbio’s product candidates. Consequently, resTORbio may not be able to reach agreement with third-party manufacturers on satisfactory terms, which could delay resTORbio’s commercialization.

resTORbio’s failure, or the failure of resTORbio’s third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on resTORbio, including clinical holds, fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, seizures or voluntary recalls of product candidates, operating restrictions and criminal prosecutions, any of which could significantly affect supplies of resTORbio’s product candidates. resTORbio does not control the manufacturing process of, and are completely dependent on, resTORbio’s contract manufacturing partners for compliance with cGMPs. If resTORbio’s contract manufacturers cannot successfully manufacture material that conforms to resTORbio’s specifications and the strict regulatory requirements of the FDA or others, resTORbio may not be able to secure and/or maintain regulatory approval for its product manufactured at these facilities. In addition, resTORbio has no control over the ability of resTORbio’s contract manufacturers to maintain adequate quality control, quality assurance and qualified personnel. If the FDA finds deficiencies or a comparable foreign regulatory authority does not approve these facilities for the manufacture of resTORbio’s product candidates or if it withdraws any such approval in the future, resTORbio may need to find alternative manufacturing facilities, which would significantly impact resTORbio’s ability to develop, obtain regulatory approval for or market resTORbio’s product candidates, if approved. Contract manufacturers may face manufacturing or quality control problems causing drug substance production and shipment delays or a situation where the contractor may not be able to maintain compliance with the applicable cGMP requirements. Any failure to comply with cGMP requirements or other FDA, EMA and comparable foreign regulatory requirements could adversely affect resTORbio’s clinical research activities and resTORbio’s ability to develop resTORbio’s product candidates and market resTORbio’s products, if approved.

The FDA and other foreign regulatory authorities require manufacturers to register manufacturing facilities. The FDA and corresponding foreign regulators also inspect these facilities to confirm compliance with cGMPs. Contract manufacturers may face manufacturing or quality control problems causing drug substance production and shipment delays or a situation where the contractor may not be able to maintain compliance with the applicable cGMP requirements. Any failure to comply with cGMP requirements or other FDA, EMA and comparable foreign regulatory requirements could adversely affect resTORbio’s clinical research activities and resTORbio’s ability to develop resTORbio’s product candidates and market resTORbio’s products following approval.

If any third-party manufacturer of resTORbio’s product candidates is unable to increase the scale of its production of resTORbio’s product candidates, and/or increase the product yield of its manufacturing, then resTORbio’s costs to manufacture the product may increase and commercialization may be delayed.

In order to produce sufficient quantities to meet the demand for clinical trials and, if approved, subsequent commercialization of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, or any other product candidates that resTORbio may develop, resTORbio’s third-party manufacturer will be required to increase its production and optimize its manufacturing processes while maintaining the quality of the product. The transition to larger scale production could prove difficult. In addition, if resTORbio’s third-party manufacturer is not able to optimize its manufacturing process to increase the product yield for resTORbio’s product candidates, or if it is unable to produce increased amounts of resTORbio’s product candidates while maintaining the quality of the product, then resTORbio may not be able to meet the demands of clinical trials or market demands, which could decrease resTORbio’s ability to generate profits and have a material adverse impact on resTORbio’s business and results of operation.

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resTORbio may need to maintain licenses for active ingredients from third parties to develop and commercialize some of resTORbio’s product candidates, which could increase resTORbio’s development costs and delay resTORbio’s ability to commercialize those product candidates.

Should resTORbio decide to use active pharmaceutical ingredients in any of its product candidates that are proprietary to one or more third parties, resTORbio would need to maintain licenses to those active ingredients from those third parties. If resTORbio is unable to gain or continue to access rights to these active ingredients prior to conducting preclinical toxicology studies intended to support clinical trials, resTORbio may need to develop alternate product candidates for these programs by either accessing or developing alternate active ingredients, resulting in increased development costs and delays in commercialization of these product candidates. If resTORbio is unable to gain or maintain continued access rights to the desired active ingredients on commercially reasonable terms or develop suitable alternate active ingredients, resTORbio may not be able to commercialize product candidates from these programs.

Use of third parties to conduct testing of resTORbio’s product candidates in tissues or animals may increase the risk that resTORbio will have unsuitable or invalidated data for regulatory submissions and approval.

resTORbio currently do not own or operate laboratory facilities in which to conduct preclinical testing of resTORbio’s product candidates in tissues or animals. Preclinical studies regulated by FDA, EMA and most other health authorities are governed by GLP. Additionally, studies involving animals may be subject to further regulation by institutional, private or government animal welfare authorities that may vary by territory. Studies involving human tissues may also be subject to institutional and government human subject privacy policies that may vary by territory. Third-party vendors conducting tissue and/or animal studies on resTORbio’s behalf may be found to be in violation of one or more of these regulations or policies and may be subject to closure, censure or other penalties. In some cases, these penalties could materially impact the performance, availability, or validity of studies conducted on resTORbio’s behalf. Even in the absence of violations resulting in penalties, regulatory and other authorities may refuse to authorize the conduct or to accept the results of studies for regulatory or ethical reasons.

resTORbio enters into various contracts in the normal course of resTORbio’s business in which resTORbio indemnifies the other party to the contract. In the event resTORbio has to perform under these indemnification provisions, it could have a material adverse effect on resTORbio’s business, financial condition and results of operations.

In the normal course of business, resTORbio periodically enters into academic, commercial, service, collaboration, licensing, consulting and other agreements that contain indemnification provisions. With respect to resTORbio’s academic and other research agreements, resTORbio typically indemnifies the institution and related parties from losses arising from claims relating to the products, processes or services made, used, sold or performed pursuant to the agreements for which resTORbio has secured licenses, and from claims arising from resTORbio’s exercise of rights under the agreement. With respect to resTORbio’s commercial agreements, resTORbio indemnifies its vendors from any third-party product liability claims that could result from the production, use or consumption of the product, as well as for alleged infringements of any patent or other intellectual property right by a third party.

Should resTORbio’s obligation under an indemnification provision exceed applicable insurance coverage or if resTORbio was denied insurance coverage, resTORbio’s business, financial condition and results of operations could be adversely affected. Similarly, if resTORbio is relying on a collaborator to indemnify resTORbio and the collaborator is denied insurance coverage or the indemnification obligation exceeds the applicable insurance coverage and does not have other assets available to indemnify resTORbio, resTORbio’s business, financial condition and results of operations could be adversely affected.

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resTORbio may seek to establish collaborations and, if resTORbio is not able to establish them on commercially reasonable terms, resTORbio may have to alter its development and commercialization plans.

resTORbio may seek one or more collaborators for the development and commercialization of one or more of resTORbio’s product candidates. Likely collaborators may include large and mid-size pharmaceutical companies, regional and national pharmaceutical companies and biotechnology companies. In addition, if resTORbio is able to obtain regulatory approval for product candidates from foreign regulatory authorities, resTORbio may enter into collaborations with international biotechnology or pharmaceutical companies for the commercialization of such product candidates.

resTORbio faces significant competition in seeking appropriate collaborators. Whether resTORbio reaches a definitive agreement for a collaboration will depend, among other things, upon resTORbio’s assessment of the collaborator’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator’s evaluation of a number of factors. Those factors may include the potential differentiation of resTORbio’s product candidate from competing product candidates, design or results of clinical trials, the likelihood of approval by the FDA, the EMA or comparable foreign regulatory authorities and the regulatory pathway for any such approval, the potential market for the product candidate, the costs and complexities of manufacturing and delivering the product to patients and the potential of competing products. The collaborator may also consider alternative product candidates or technologies for similar indications that may be available for collaboration and whether such a collaboration could be more attractive than the one with resTORbio for resTORbio’s product candidate. If resTORbio elects to increase its expenditures to fund development or commercialization activities on resTORbio’s own, resTORbio may need to obtain additional capital, which may not be available to resTORbio on acceptable terms, or at all. If resTORbio does not have sufficient funds, resTORbio may not be able to further develop its product candidates or bring them to market and generate product revenue.

Collaborations are complex and time-consuming to negotiate and document. Further, there have been a significant number of recent business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators. Any collaboration agreements that resTORbio enters into in the future may contain restrictions on resTORbio’s ability to enter into potential collaborations or to otherwise develop specified product candidates. resTORbio may not be able to negotiate collaborations on a timely basis, on acceptable terms, or at all. If resTORbio is unable to do so, resTORbio may have to curtail the development of the product candidate for which resTORbio is seeking to collaborate, reduce or delay its development program or one or more of resTORbio’s other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, or increase resTORbio’s expenditures and undertake development or commercialization activities at resTORbio’s own expense.

If resTORbio enters into collaborations with third parties for the development and commercialization of its product candidates, resTORbio’s prospects with respect to those product candidates will depend in significant part on the success of those collaborations.

resTORbio may enter into collaborations for the development and commercialization of certain of resTORbio’s product candidates. If resTORbio enters into such collaborations, resTORbio will have limited control over the amount and timing of resources that resTORbio’s collaborators will dedicate to the development or commercialization of resTORbio’s product candidates. resTORbio’s ability to generate revenues from these arrangements will depend on any future collaborators’ abilities to successfully perform the functions assigned to them in these arrangements. In addition, any future collaborators may have the right to abandon research or development projects and terminate applicable agreements, including funding obligations, prior to or upon the expiration of the agreed upon terms.

Collaborations involving resTORbio’s product candidates pose a number of risks, including the following:

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Collaboration agreements may not lead to development or commercialization of product candidates in the most efficient manner, or at all. If any future collaborator of ours is involved in a business combination, it could decide to delay, diminish or terminate the development or commercialization of any product candidate licensed to it by resTORbio.

resTORbio may have to alter resTORbio’s development and commercialization plans if resTORbio is not able to establish collaborations.

resTORbio will require additional funds to complete the development and potential commercialization of RTB101 alone or in combination with a rapalog, such as everolimus or sirolimus, and other product candidates. For some of resTORbio’s product candidates, resTORbio may decide to collaborate with pharmaceutical and biotechnology companies for the development and potential commercialization of those product candidates.

resTORbio faces significant competition in seeking and obtaining appropriate collaborators. Whether resTORbio reaches a definitive agreement for a collaboration will depend, among other things, upon resTORbio’s assessment of the collaborator’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator’s evaluation of a number of factors. Those factors may include:

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The collaborator may also consider alternative product candidates or technologies for similar indications that may be available for collaboration and whether such a collaboration could be more attractive than the one with resTORbio for resTORbio’s product candidate. resTORbio may also be restricted under future license agreements from entering into agreements on certain terms with potential collaborators. In addition, there have been a significant number of recent business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators.

If resTORbio is unable to reach agreements with suitable collaborators on a timely basis, on acceptable terms, or at all, resTORbio may have to curtail the development of a product candidate, reduce or delay its development program or one or more of resTORbio’s other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, or increase resTORbio’s expenditures and undertake development or commercialization activities at resTORbio’s own expense. If resTORbio elects to fund and undertake development or commercialization activities on its own, resTORbio may need to obtain additional expertise and additional capital, which may not be available to resTORbio on acceptable terms, or at all. If resTORbio fails to enter into collaborations and do not have sufficient funds or expertise to undertake the necessary development and commercialization activities, resTORbio may not be able to further develop its product candidates or bring them to market and resTORbio’s business may be materially and adversely affected.

Business or economic disruptions or global health concerns could seriously harm resTORbio’s development efforts and increase resTORbio’s costs and expenses.

Broad-based business or economic disruptions could adversely affect resTORbio’s ongoing or planned research and development activities. For example, in December 2019 an outbreak of a novel strain of coronavirus originated in Wuhan, China, and has since spread to a number of other countries, including the United States and several countries in the EU. To date, this outbreak has already resulted in extended shutdowns of certain businesses in the Wuhan region and has had ripple effects to businesses around the world. Global health concerns, such as coronavirus, could also result in social, economic, and labor instability in the countries in which resTORbio or the third parties with whom resTORbio engages operate. resTORbio cannot presently predict the scope and severity of any potential business shutdowns or disruptions, but if resTORbio or any of the third parties with whom resTORbio engages, including the suppliers, clinical trial sites, regulators and other third parties with whom resTORbio conducts business, were to experience shutdowns or other business disruptions, resTORbio’s ability to conduct resTORbio’s business in the manner and on the timelines presently planned could be materially and negatively impacted. It is also possible that global health concerns such as this one could disproportionately impact the hospitals and clinical sites in which resTORbio conducts any of its clinical trials, which could have a material adverse effect on resTORbio’s business and resTORbio’s results of operation and financial condition.

Risks Related to Employee Matters and Managing Growth

resTORbio only has a limited number of employees to manage and operate resTORbio’s business.

As of August 4, 2020, resTORbio had nine full-time employees and no part-time employees. resTORbio’s focus on the development of RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus,

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requires resTORbio to optimize cash utilization and to manage and operate resTORbio’s business in a highly efficient manner. resTORbio cannot assure you that it will be able to hire and/or retain adequate staffing levels to develop RTB101, alone or in combination with a rapalog, such as everolimus or sirolimus, meet resTORbio’s obligations as a public company, run resTORbio’s operations and/or accomplish all of the objectives that it otherwise would seek to accomplish.

resTORbio’s internal computer systems, or those used by resTORbio’s CROs or other independent organizations, advisors, contractors or consultants, may be subject to cyber-attacks, fail or suffer security breaches.

Despite the implementation of security measures, resTORbio’s internal computer systems and those of resTORbio’s CROs and other independent organizations, advisors, contractors and consultants are vulnerable to damage from computer viruses and unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. Because information systems, networks and other technologies are critical to many of resTORbio’s operating activities, shutdowns or service disruptions at the company or vendors that provide information systems, networks or other services to resTORbio pose increasing risks. Disruptions of this nature may be caused by events such as computer hacking, phishing attacks, ransomware, dissemination of computer viruses, worms and other destructive or disruptive software, denial of service attacks and other malicious activity, as well as power outages, natural disasters (including extreme weather), terrorist attacks or other similar events. In addition, outside parties may attempt to penetrate resTORbio’s systems or those of resTORbio’s vendors or fraudulently induce resTORbio’s personnel or the personnel of resTORbio’s vendors to disclose sensitive information in order to gain access to resTORbio’s data and/or systems. Like other companies, resTORbio has on occasion experienced, and will continue to experience, threats and incursions to resTORbio’s data and systems, including malicious codes and viruses, phishing, business email compromise attacks or other cyber-attacks. The number and complexity of these threats continue to increase over time. While resTORbio has not experienced any material system failure or security breach to date, if an event of that nature were to occur and cause interruptions in resTORbio’s operations, it could result in a material disruption of resTORbio’s development programs and resTORbio’s business operations. For example, the loss of clinical trial data from completed or future clinical trials could result in delays in resTORbio’s regulatory approval efforts and significantly increase resTORbio’s costs to recover or reproduce the data. resTORbio currently, and may in the future continue to, rely on third parties for the manufacture of resTORbio’s product candidates and to conduct clinical trials and similar events relating to their computer systems could also have a material adverse effect on resTORbio’s business. To the extent that any disruption or security breach were to result in a loss of, or damage to, resTORbio’s internal computer systems or those used by resTORbio’s CROs or other independent organizations, advisors, contractors or consultants, resTORbio’s data or applications, or inappropriate disclosure of confidential or proprietary information, resTORbio could incur liability, suffer reputational harm and experience delays in the further development and commercialization of resTORbio’s product candidates.

resTORbio could be required to expend significant amounts of money and other resources to respond to these threats or breaches and to repair or replace information systems or networks. resTORbio also could suffer financial loss or the loss of valuable confidential information. In addition, resTORbio could be subject to regulatory actions and/or claims made by individuals and groups in private litigation involving privacy issues related to data collection and use practices and other data privacy laws and regulations, including claims for misuse or inappropriate disclosure of data, as well as unfair or deceptive practices. Although resTORbio develops and maintains systems and controls designed to prevent these events from occurring and resTORbio has a process to identify and mitigate threats, the development and maintenance of these systems, controls and processes is costly and requires ongoing monitoring and updating as technologies change and efforts to overcome security measures become increasingly sophisticated. Moreover, despite resTORbio’s efforts, the possibility of these events occurring cannot be eliminated entirely and there can be no assurance that any measures resTORbio take will prevent cyber-attacks or security breaches that could adversely affect resTORbio’s business.

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resTORbio depends heavily on resTORbio’s executive officers, principal consultants and others and the loss of their services would materially harm resTORbio’s business.

resTORbio’s success depends, and will likely continue to depend, upon resTORbio’s ability to hire, retain the services of resTORbio’s current executive officers, principal consultants and others, including Chen Schor, resTORbio’s president and chief executive officer, Joan Mannick, resTORbio’s chief medical officer, and Lloyd Klickstein, resTORbio’s chief scientific officer. resTORbio has entered into employment agreements with Mr. Schor, Dr. Mannick, and Dr. Klickstein, but they may terminate their employment with resTORbio at any time. Although resTORbio does not have any reason to believe that resTORbio will lose the services of Mr. Schor, Dr. Mannick, and Dr. Klickstein in the foreseeable future, the loss of their services might impede the achievement of resTORbio’s research, development and commercialization objectives.

resTORbio’s ability to compete in the biotechnology and pharmaceuticals industries depends upon resTORbio’s ability to attract and retain highly qualified managerial, scientific and medical personnel. resTORbio’s industry has experienced a high rate of turnover of management personnel in recent years. Replacing executive officers or other key employees may be difficult and may take an extended period of time because of the limited number of individuals in resTORbio’s industry with the breadth of skills and experience required to develop, gain regulatory approval of and commercialize products successfully.

Competition to hire from this limited pool is intense, and resTORbio may be unable to hire, train, retain or motivate these additional key employees on acceptable terms given the competition among numerous pharmaceutical and biotechnology companies for similar personnel. resTORbio also experience competition for the hiring of scientific and clinical personnel from universities and research institutions.

resTORbio relies on consultants and advisors, including scientific and clinical advisors, to assist resTORbio in formulating resTORbio’s research and development and commercialization strategy. resTORbio’s consultants and advisors may be employed by other entities and may have commitments under consulting or advisory contracts with those entities that may limit their availability to resTORbio. If resTORbio is unable to continue to attract and retain highly qualified personnel, resTORbio’s ability to develop and commercialize resTORbio’s product candidates will be limited.

resTORbio’s employees, independent contractors, consultants, collaborators and contract research organizations may engage in misconduct or other improper activities, including non-compliance with regulatory standards and requirements, which could cause significant liability for resTORbio and harm resTORbio’s reputation.

resTORbio is exposed to the risk that resTORbio’s employees, independent contractors, consultants, collaborators and CROs may engage in fraudulent conduct or other illegal activity. Misconduct by those parties could include intentional, reckless and/or negligent conduct or disclosure of unauthorized activities to resTORbio that violates:

Activities subject to these laws also involve the improper use or misrepresentation of information obtained in the course of clinical trials, creating fraudulent data in resTORbio’s preclinical studies or clinical trials or illegal misappropriation of product materials, which could result in regulatory sanctions and serious harm to

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resTORbio’s reputation. It is not always possible to identify and deter misconduct, and the precautions resTORbio takes to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting resTORbio from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws, standards or regulations. Additionally, resTORbio is subject to the risk that a person or government could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against resTORbio, and resTORbio is not successful in defending itself or asserting resTORbio’s rights, those actions could have a significant impact on resTORbio’s business and results of operations, including the imposition of civil, criminal and administrative penalties, damages, monetary fines, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, contractual damages, reputational harm, diminished profits and future earnings, and curtailment of resTORbio’s operations, any of which could have a material adverse effect on resTORbio’s ability to operate resTORbio’s business and resTORbio’s results of operations.

resTORbio’s current operations are concentrated primarily in a single location and any events affecting resTORbio’s headquarters may have material adverse consequences.

resTORbio’s current operations are primarily located in resTORbio’s principal office in Boston, Massachusetts. Any unplanned event, such as flood, fire, explosion, earthquake, extreme weather condition, medical epidemics, power shortage, telecommunication failure or other natural or manmade accidents or incidents that result in resTORbio being unable to fully utilize the office may have a material adverse effect on resTORbio’s ability to operate resTORbio’s business, and have significant negative consequences on resTORbio’s financial and operating conditions. Loss of access to this office may result in increased costs, delays in the development of resTORbio’s product candidates or interruption of resTORbio’s business operations. As part of resTORbio’s risk management policy, resTORbio maintains insurance coverage at levels that resTORbio believes are appropriate for its business. However, in the event of an accident or incident at resTORbio’s office, resTORbio’s insurance coverage may not be sufficient to satisfy all of resTORbio’s damages and losses. If resTORbio’s office is unable to operate because of an accident or incident or for any other reason, even for a short period of time, any or all of resTORbio’s research and development programs may be harmed.

If resTORbio fails to maintain an effective system of internal control over financial reporting, resTORbio may not be able to accurately report its financial results or prevent fraud. As a result, stockholders could lose confidence in resTORbio’s financial and other public reporting, which would harm resTORbio’s business and the trading price of resTORbio common stock.

Effective internal controls over financial reporting are necessary for resTORbio to provide reliable financial reports and, together with adequate disclosure controls and procedures, are designed to prevent fraud. resTORbio currently have a limited number of employees performing resTORbio’s accounting functions, including monitoring and maintaining effective internal control over financial reporting. Any failure to implement required new or improved controls, or difficulties encountered in their implementation could cause resTORbio to fail to meet resTORbio’s reporting obligations. In addition, any testing by resTORbio conducted in connection with Section 404 of the Sarbanes-Oxley Act of 2002, or Section 404, or any subsequent testing by resTORbio’s independent registered public accounting firm, may reveal deficiencies in resTORbio’s internal controls over financial reporting that are deemed to be material weaknesses or that may require prospective or retroactive changes to resTORbio’s consolidated financial statements or identify other areas for further attention or improvement. Inferior internal controls could also cause investors to lose confidence in resTORbio’s reported financial information, which could have a negative effect on the trading price of resTORbio’s stock.

resTORbio will be required to disclose changes made in resTORbio’s internal controls and procedures on a quarterly basis and resTORbio’s management will be required to assess the effectiveness of these controls annually. However, for as long as resTORbio is an “emerging growth company” under the JOBS Act, resTORbio’s independent registered public accounting firm will not be required to attest to the effectiveness of resTORbio’s internal controls over financial reporting pursuant to Section 404. resTORbio could be an

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“emerging growth company” for up to five years. An independent assessment of the effectiveness of resTORbio’s internal controls over financial reporting could detect problems that resTORbio’s management’s assessment might not. Undetected material weaknesses in resTORbio’s internal controls over financial reporting could lead to financial statement restatements and require resTORbio to incur the expense of remediation.

resTORbio’s disclosure controls and procedures may not prevent or detect all errors or acts of fraud.

resTORbio’s disclosure controls and procedures are designed to reasonably assure that information required to be disclosed by resTORbio in reports resTORbio files or submits under the Securities Exchange Act of 1934, as amended (referred to as the “Exchange Act”) is accumulated and communicated to management, recorded, processed, summarized and reported within the time periods specified in the rules and forms of the SEC. resTORbio believes that any disclosure controls and procedures or internal controls and procedures, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in resTORbio’s control system, misstatements or insufficient disclosures due to error or fraud may occur and not be detected.

resTORbio has conducted and expect to continue to conduct resTORbio’s operations in jurisdictions outside of the United States, and such foreign operations subject resTORbio to additional risks.

A portion of resTORbio’s operations, including resTORbio’s clinical research and development efforts, have been undertaken outside of the United States, and resTORbio expects to continue to conduct a portion of its business in foreign countries. For example, resTORbio conducted resTORbio’s Phase 2b clinical trial across two hemispheres. In addition, resTORbio may utilize third party contract organizations, some of which may be located in foreign jurisdictions, for the conduct of resTORbio’s clinical trials, the manufacturing of resTORbio’s product candidates and the commercialization of resTORbio’s product candidates, if approved. Such operations subject resTORbio to additional risks related to international business operations, including:

These and other risks may materially adversely affect resTORbio’s ability to conduct resTORbio’s business in international markets.

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resTORbio may engage in acquisitions that could disrupt resTORbio’s business, cause dilution to resTORbio stockholders or reduce resTORbio’s financial resources.

In the future, resTORbio may enter into transactions to acquire other businesses, products or technologies. If resTORbio does identify suitable candidates, resTORbio may not be able to make such acquisitions on favorable terms, or at all. Any acquisitions resTORbio makes may not strengthen resTORbio’s competitive position, and these transactions may be viewed negatively by customers or investors. resTORbio may decide to incur debt in connection with an acquisition or issue resTORbio common stock or other equity securities to the stockholders of the acquired company, which would reduce the percentage ownership of resTORbio’s existing stockholders. resTORbio could incur losses resulting from undiscovered liabilities of the acquired business that are not covered by the indemnification resTORbio may obtain from the seller. In addition, resTORbio may not be able to successfully integrate the acquired personnel, technologies and operations into resTORbio’s existing business in an effective, timely and nondisruptive manner. Acquisitions may also divert management attention from day-to-day responsibilities, increase resTORbio’s expenses and reduce resTORbio’s cash available for operations and other uses. resTORbio cannot predict the number, timing or size of future acquisitions or the effect that any such transactions might have on resTORbio’s operating results.

Risks Related to resTORbio’s Common Stock

An active trading market for resTORbio common stock may not be sustained. If an active trading market is not sustained, resTORbio’s ability to raise capital in the future may be impaired.

resTORbio’s shares began trading on The Nasdaq Global Select Market on January 26, 2018. Given the limited trading history of resTORbio common stock, there is a risk that an active trading market for resTORbio’s shares may not be sustained, which could put downward pressure on the market price of resTORbio common stock and thereby affect your ability to sell shares you purchased. An inactive trading market for resTORbio common stock may also impair resTORbio’s ability to raise capital to continue to fund resTORbio’s operations by selling shares and impair resTORbio’s ability to acquire other companies or technologies by using resTORbio’s shares as consideration.

The trading price of resTORbio common stock is highly volatile, which could result in substantial losses for purchasers of resTORbio common stock. Securities class action or other litigation involving resTORbio or members of its management team could also substantially harm its business, financial condition and results of operations.

resTORbio’s stock price is highly volatile. The stock market in general and the market for smaller pharmaceutical and biotechnology companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, you may not be able to sell your common stock at or above the purchase price and you may lose some or all of your investment. The market price for resTORbio common stock may be influenced by many factors, including:

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In the past, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for biopharmaceutical companies, which have experienced significant stock price volatility in recent years.

resTORbio is an “emerging growth company,” and the reduced disclosure requirements applicable to emerging growth companies may make resTORbio common stock less attractive to investors.

resTORbio is an emerging growth company, and, for as long as resTORbio continues to be an emerging growth company, resTORbio may choose to take advantage of exemptions from various reporting requirements applicable to other public companies but not to “emerging growth companies.” resTORbio could remain an “emerging growth company” for up to five years following resTORbio’s IPO, or until the earliest of (1) the last day of the first fiscal year in which resTORbio’s annual gross revenue exceeds $1.07 billion, (2) the date that resTORbio becomes a “large accelerated filer” as defined in Rule 12b-2 under the Exchange Act, which would occur if the market value of resTORbio common stock that is held by non-affiliates exceeds $700.0 million as of the last business day of resTORbio’s most recently completed second fiscal quarter or (3) the date on which resTORbio has issued more than $1.0 billion in non-convertible debt during the preceding three-year period. So long as resTORbio remains an “emerging growth company,” resTORbio expects to avail itself of the exemption from the requirement that resTORbio’s independent registered public accounting firm attest to the effectiveness of resTORbio’s internal control over financial reporting under Section 404. When resTORbio’s independent registered public accounting firm is required to undertake an assessment of resTORbio’s internal control over financial reporting, the cost of resTORbio’s compliance with Section 404 will correspondingly increase. Moreover, if resTORbio is not able to comply with the requirements of Section 404 applicable to resTORbio in a timely manner, or if resTORbio or its independent registered public accounting firm identifies deficiencies in resTORbio’s internal control over financial reporting that are deemed to be material weaknesses, the market price of resTORbio’s stock could decline and resTORbio could be subject to sanctions or investigations by the SEC or other regulatory authorities, which would require additional financial and management resources.

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In addition, the JOBS Act also provides that an “emerging growth company” can take advantage of an extended transition period for complying with new or revised accounting standards. resTORbio has elected to take advantage of this extended transition period under the JOBS Act. As a result, resTORbio’s operating results and financial statements may not be comparable to the operating results and financial statements of other companies who have adopted the new or revised accounting standards. It is possible that some investors will find resTORbio’s common stock less attractive as a result, which may result in a less active trading market for resTORbio’s common stock and higher volatility in resTORbio’s stock price.

resTORbio is also a “smaller reporting company,” and the reduced disclosure requirements applicable to smaller reporting companies may make resTORbio common stock less attractive to investors.

resTORbio is considered a “smaller reporting company” under Rule 12b-2 of the Exchange Act. resTORbio is therefore entitled to rely on certain reduced disclosure requirements, such as an exemption from providing selected financial data and executive compensation information. These exemptions and reduced disclosures in resTORbio’s SEC filings due to resTORbio’s status as a smaller reporting company also mean resTORbio’s auditors are not required to review resTORbio’s internal control over financial reporting and may make it harder for investors to analyze resTORbio’s results of operations and financial prospects. resTORbio cannot predict if investors will find resTORbio common stock less attractive because resTORbio may rely on these exemptions. If some investors find resTORbio common stock less attractive as a result, there may be a less active trading market for resTORbio common stock and resTORbio common stock prices may be more volatile. resTORbio will remain a smaller reporting company until resTORbio’s public float exceeds $250 million or resTORbio’s annual revenues exceed $100 million with a public float greater than $700 million.

resTORbio has and will incur increased costs as a result of operating as a public company, and resTORbio’s management will be required to devote substantial time to new compliance initiatives and corporate governance practices.

As a public company, and particularly after resTORbio is no longer an “emerging growth company,” resTORbio has and will incur significant legal, accounting and other expenses that resTORbio did not incur as a private company, including costs associated with public company reporting requirements. resTORbio has and will incur costs associated with relatively recently adopted corporate governance requirements, including requirements of the Securities and Exchange Commission, or SEC, and The Nasdaq Global Select Market. resTORbio expects these rules and regulations to increase resTORbio’s legal and financial compliance costs and to make some activities more time-consuming and costly. resTORbio also expect that these rules and regulations may make it more difficult and more expensive for resTORbio to obtain director and officer liability insurance and resTORbio may be required to accept reduced policy limits and coverage or incur substantially higher costs to obtain the same or similar coverage. As a result, it may be more difficult for resTORbio to attract and retain qualified individuals to serve on the resTORbio Board or as executive officers.

resTORbio is currently evaluating and monitoring developments with respect to these rules, and resTORbio cannot predict or estimate the amount of additional costs resTORbio may incur or the timing of such costs. These rules and regulations are often subject to varying interpretations, in many cases due to their lack of specificity, and, as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies. This could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices.

Pursuant to Section 404, resTORbio is required to furnish a report by resTORbio’s management on resTORbio’s internal control over financial reporting in annual financial statements with the Securities and Exchange Commission, or the SEC. However, while resTORbio remains an emerging growth company, resTORbio will not be required to include an attestation report on internal control over financial reporting issued by resTORbio’s independent registered public accounting firm. To achieve compliance with Section 404 within the prescribed period, resTORbio has engaged in a process to document and evaluate resTORbio’s internal control over

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financial reporting, which is both costly and challenging. In this regard, resTORbio will need to continue to dedicate internal resources, engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting. resTORbio will continue steps to improve control processes as appropriate, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. Despite resTORbio’s efforts, there is a risk that resTORbio will not be able to conclude, within the prescribed timeframe, or at all, that resTORbio’s internal control over financial reporting is effective as required by Section 404. If resTORbio identifies one or more material weaknesses, it could result in an adverse reaction in the financial markets due to a loss of confidence in the reliability of resTORbio’s consolidated financial statements.

resTORbio has broad discretion over the use of its cash, cash equivalents, and marketable securities and may not use them effectively.

resTORbio’s management has broad discretion to use its cash, cash equivalents, and marketable securities to fund resTORbio’s operations and could spend these funds in ways that do not improve resTORbio’s results of operations or enhance the value of resTORbio common stock. The failure by resTORbio’s management to apply these funds effectively could result in financial losses that could have a material adverse effect on resTORbio’s business, cause the price of resTORbio common stock to decline and delay the development of resTORbio’s product candidates. Pending resTORbio’s use to fund operations, resTORbio may invest its cash, cash equivalents, and marketable securities in a manner that does not produce income or that loses value.

Future sales and issuances of resTORbio common stock or rights to purchase common stock, including pursuant to resTORbio’s equity incentive plans, could result in additional dilution of the percentage ownership of stockholders and could cause resTORbio’s stock price to fall.

resTORbio will need additional capital in the future to continue resTORbio’s planned operations. To the extent resTORbio raises additional capital by issuing equity securities, resTORbio stockholders may experience substantial dilution. resTORbio may sell common stock, convertible securities or other equity securities in one or more transactions at prices and in a manner resTORbio determines from time to time. If resTORbio sells common stock, convertible securities or other equity securities in more than one transaction, investors may be materially diluted by subsequent sales. These sales may also result in material dilution to resTORbio’s existing stockholders, and new investors could gain rights superior to resTORbio’s existing stockholders.

On February 1, 2019, resTORbio filed a registration statement on Form S-3 (File No. 333-229499) with the SEC, which was declared effective on February 12, 2019 (referred to as the “Shelf Registration Statement”), in relation to the registration of common stock, preferred stock, warrants and/or units of any combination thereof for the purposes of selling, from time to time, resTORbio common stock, convertible securities or other equity securities in one or more offerings. The Shelf Registration Statement also registered for resale from time to time up to 12,445,646 shares of common stock held by the selling stockholders named therein. resTORbio also simultaneously entered into a Controlled Equity Offering Sales Agreement (referred to as the “Sales Agreement”) with SVB Leerink LLC and Cantor Fitzgerald & Co., (referred to as the “Sales Agents”), to provide for the offering, issuance and sale of up to an aggregate amount of $50.0 million of resTORbio common stock from time to time in “at-the-market” offerings under the Shelf Registration Statement and subject to the limitations thereof. As of June 30, 2020, approximately $43.0 million in shares of common stock remain eligible for sale under the Sales Agreement. resTORbio will pay to the Sales Agent cash commissions of 3.0 percent of the aggregate gross proceeds of sales of common stock under the Sales Agreement. Sales of common stock, convertible securities or other equity securities by resTORbio or resTORbio stockholders under the Shelf Registration Statement may represent a significant percentage of resTORbio common stock currently outstanding. If resTORbio or resTORbio stockholders sell, or the market perceives that resTORbio or resTORbio stockholders intend to sell, substantial amounts of resTORbio common stock under the Shelf Registration Statement or otherwise, the market price of resTORbio common stock could decline significantly.

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In addition, sales of a substantial number of shares of resTORbio’s outstanding common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares of common stock intend to sell shares, could reduce the market price of resTORbio common stock. Persons who were resTORbio stockholders prior to resTORbio’s IPO continue to hold a substantial number of shares of resTORbio common stock that many of them are now able to sell in the public market. Significant portions of these shares are held by a relatively small number of stockholders. Sales by resTORbio stockholders of a substantial number of shares, or the expectation that such sales may occur, could significantly reduce the market price of resTORbio common stock.

resTORbio does not anticipate paying any cash dividends on resTORbio’s capital stock in the foreseeable future. Accordingly, stockholders must rely on capital appreciation, if any, for any return on their investment.

resTORbio has never declared nor paid cash dividends on resTORbio’s capital stock. resTORbio currently plan to retain all of resTORbio’s future earnings, if any, to finance the operation, development and growth of resTORbio’s business. In addition, the terms of any future debt or credit agreements may preclude resTORbio from paying dividends. As a result, capital appreciation, if any, of resTORbio common stock will be your sole source of gain for the foreseeable future.

resTORbio’s principal stockholders and management own a significant percentage of resTORbio’s stock and, if they choose to act together, will be able to control or exercise significant influence over matters subject to stockholder approval.

As of August 4, 2020, resTORbio’s executive officers, directors, five percent or greater stockholders and their affiliates own approximately 29.2% of resTORbio’s outstanding voting stock. These stockholders may have the ability to influence resTORbio through their ownership positions. These stockholders may be able to determine all matters requiring stockholder approval. For example, these stockholders, acting together, may be able to control elections of directors or approval of any merger, sale of assets or other major corporate transaction. This may prevent or discourage unsolicited acquisition proposals or offers for resTORbio common stock that you may believe are in your best interest as one of resTORbio stockholders.

Provisions in the resTORbio certificate of incorporation documents and under Delaware law may prevent or frustrate attempts by resTORbio stockholders to change resTORbio’s management or hinder efforts to acquire a controlling interest in resTORbio.

Provisions in the resTORbio certificate of incorporation and the resTORbio bylaws may discourage, delay or prevent a merger, acquisition or other change in control of resTORbio that stockholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of resTORbio common stock, thereby depressing the market price of resTORbio common stock. In addition, because the resTORbio Board is responsible for appointing the members of resTORbio’s management team, these provisions may frustrate or prevent any attempts by resTORbio stockholders to replace or remove resTORbio’s current management by making it more difficult for stockholders to replace members of the resTORbio Board. Among other things, these provisions:

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Moreover, because resTORbio is incorporated in Delaware, resTORbio is governed by the provisions of Section 203 of the General Corporation Law of the State of Delaware, which prohibits a person who owns in excess of 15% of resTORbio’s outstanding voting stock from merging or combining with resTORbio for a period of three years after the date of the transaction in which the person acquired in excess of 15% of resTORbio’s outstanding voting stock, unless the merger or combination is approved in a prescribed manner. This could discourage, delay or prevent someone from acquiring resTORbio or merging with resTORbio, whether or not it is desired by, or beneficial to, resTORbio stockholders. This could also have the effect of discouraging others from making tender offers for resTORbio common stock, including transactions that may be in your best interests. These provisions may also prevent changes in resTORbio’s management or limit the price that investors are willing to pay for resTORbio’s stock.

The resTORbio bylaws provide that, unless resTORbio consents in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for most legal actions between resTORbio and resTORbio stockholders, which could limit resTORbio stockholders’ ability to obtain a favorable judicial forum for disputes with resTORbio or resTORbio’s directors, officers, employees or agents.

The resTORbio bylaws specify that, unless resTORbio consents in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of resTORbio, (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of resTORbio to resTORbio or resTORbio stockholders, (iii) any action asserting a claim arising pursuant to any provision of the Delaware General Corporation Law or the resTORbio certificate of incorporation or the resTORbio bylaws, or (iv) any action asserting a claim against resTORbio governed by the internal affairs doctrine provided, that these choice of forum provisions do not apply to suits brought to enforce a duty or liability created by the Securities Act of 1933, as amended (referred to as the Securities Act), the Exchange Act, or any other claim for which the federal courts have exclusive jurisdiction. Any person or entity purchasing or otherwise acquiring any interest in shares of resTORbio’s capital stock shall be deemed to have notice of and to have consented to the provisions of the resTORbio bylaws described above.

resTORbio believes this provision benefits resTORbio by providing increased consistency in the application of Delaware law by chancellors particularly experienced in resolving corporate disputes, efficient administration of cases on a more expedited schedule relative to other forums and protection against the burdens of multi-forum litigation. However, the provision may have the effect of discouraging lawsuits against resTORbio’s directors, officers, employees and agents as it may limit any stockholder’s ability to bring a claim in a judicial forum that such stockholder finds favorable for disputes with resTORbio or resTORbio’s directors, officers, employees or agents. The enforceability of similar choice of forum provisions in other companies’ bylaws or certificates of incorporation has been challenged in legal proceedings, and it is possible that, in connection with any applicable action brought against resTORbio, a court could find the choice of forum provisions contained in the resTORbio bylaws to be inapplicable or unenforceable in such action. If a court were to find the choice of forum provision contained in the resTORbio bylaws to be inapplicable or unenforceable in an action, resTORbio may incur additional costs associated with resolving such action in other jurisdictions, which could adversely affect resTORbio’s business, financial condition or results of operations.

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If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about resTORbio’s business, resTORbio’s share price and trading volume could decline.

The trading market for resTORbio common stock will be influenced by the research and reports that industry or securities analysts publish about resTORbio or resTORbio’s business. If one or more of the analysts who cover resTORbio issues an adverse opinion about the company, resTORbio’s stock price would likely decline. If one or more of these analysts ceases research coverage of resTORbio or fails to regularly publish reports on resTORbio, resTORbio could lose visibility in the financial markets, which in turn could cause resTORbio’s stock price or trading volume to decline.

resTORbio’s ability to use net operating losses and research and development credits to offset future taxable income may be subject to certain limitations as a result of the merger.

As of December 31, 2019, resTORbio had federal net operating loss carryforwards of $127.0 million, of which $14.0 million will begin to expire in 2036 and $113.0 million can be carried forward indefinitely. As of December 31, 2019, resTORbio had state net operating loss carryforwards of $130.8 million, which begin to expire in various amounts in 2036. As of December 31, 2019, resTORbio also had federal research and development tax credit carryforwards of $3.8 million, which begin to expire in 2037. These net operating loss and tax credit carryforwards could expire unused and be unavailable to offset future income tax liabilities. In addition, in general, under Sections 382 and 383 of the Code, a corporation that undergoes an “ownership change” is subject to limitations on its ability to utilize its pre-change net operating losses or tax credits, or NOLs or credits, to offset future taxable income or taxes. For these purposes, an ownership change generally occurs where the aggregate stock ownership of one or more stockholders or groups of stockholders who owns at least 5% of a corporation’s stock increases its ownership by more than 50 percentage points over its lowest ownership percentage within a specified testing period. resTORbio’s existing NOLs or credits may be subject to limitations arising from previous ownership changes. resTORbio has not completed a study to determine whether resTORbio’s public offerings, private placements and other transactions that have occurred over the past three years may have triggered an ownership change limitation. In addition, the merger, if consummated, is expected to constitute an ownership change under Sections 382 and 383 of the Code. resTORbio’s NOLs or credits may also be impaired under state law. Accordingly, resTORbio may not be able to utilize a material portion of resTORbio’s NOLs or credits.

The ability of the combined company to utilize resTORbio’s NOLs or credits following the merger is conditioned upon the combined company attaining profitability and generating U.S. federal and state taxable income. As described under the sections entitled “Risk Factors—Risks Related to resTORbio’s Financial Position and Need for Capital” and “Risk Factors—Risks Related to Adicet’s Business and Industry” on pages 36 and 100, respectively, of this proxy statement/prospectus/information statement, each of resTORbio and Adicet has incurred significant net losses since inception and it is anticipated that each will continue to incur significant losses for the foreseeable future; and therefore, resTORbio does not know whether or when the combined company will generate the U.S. federal or state taxable income necessary to utilize resTORbio’s NOL or credit carryforwards that are, or become, subject to limitation by Sections 382 and 383 of the Code.

Risks Related to Adicet

Risks Related to Adicet’s Business and Industry

Adicet has a limited operating history and faces significant challenges and expense as it builds its capabilities.

Biopharmaceutical product development is a highly speculative undertaking and involves a substantial degree of risk. Adicet began operation in November 2014. Adicet has a limited operating history upon which you can evaluate Adicet’s business and prospects and is subject to the risks inherent in any early stage company, including, among other things, risks that Adicet may not be able to hire sufficient qualified personnel and establish operating controls and procedures. Adicet currently does not have complete in-house resources to

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enable its gamma delta T cell platform. As Adicet builds its own capabilities, it expects to encounter risks and uncertainties frequently experienced by growing companies in new and rapidly evolving fields, including the risks and uncertainties described herein. Consequently, any predictions made about Adicet’s future success or viability may not be as accurate as they could be if Adicet had a history of successfully developing and commercializing biopharmaceutical products.

Adicet has incurred net losses in every period since its inception and anticipates that it will incur substantial net losses in the future.

Adicet is a pre-clinical stage biopharmaceutical company. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate effect or an acceptable safety profile, gain regulatory approval and become commercially viable. Adicet’s programs, including ADI-001 and ADI-002, remain in the pre-clinical stage. Adicet has no products approved for commercial sale and has not generated any revenue from product sales to date, and it will continue to incur significant research and development and other expenses related to its ongoing operations. As a result, Adicet is not profitable and has incurred net losses in each period since Adicet’s inception. For the years ended December 31, 2019 and 2018, Adicet reported net losses of $28.1 million and $9.3 million, respectively. As of June 30, 2020, Adicet had an accumulated deficit of $82.6 million.

Adicet expects to incur significant expenditures for the foreseeable future, and it expects these expenditures to increase as it continues its research and development of, and seek regulatory approvals for, product candidates based on its gamma delta T cell platform, including ADI-001 and ADI-002. Even if Adicet succeeds in commercializing one or more of its product candidates, it will continue to incur substantial research and development and other expenditures to develop and market additional product candidates. Adicet may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect its business. The size of Adicet’s future net losses will depend, in part, on the rate of future growth of its expenses and its ability to generate revenue. Adicet’s prior losses and expected future losses have had and will continue to have an adverse effect on its stockholders’ equity and working capital. Further, even if Adicet does achieve profitability, it may not be able to sustain or increase profitability on a quarterly or annual basis. Adicet’s failure to become and remain profitable would depress the value of the combined company and could impair its ability to raise capital, expand its business, maintain its research and development efforts, diversify its product candidates or even continue its operations, any of which could have a material adverse effect on Adicet’s business, financial condition, results of operations, and prospects and cause you to lose all or part of your investment.

Adicet’s history of recurring losses and anticipated expenditures raise substantial doubts about its ability to continue as a going concern. Adicet’s ability to continue as a going concern requires that it obtain sufficient funding to finance its operations.

Adicet has incurred operating losses to date and it is possible Adicet will never generate a profit. Adicet has concluded that substantial doubt exists regarding its ability to continue as a going concern. Adicet’s financial statements included elsewhere in this proxy statement/prospectus/information statement have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. These financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of these uncertainties related to Adicet’s ability to operate on a going concern basis.

The report of Adicet’s independent registered public accounting firm on its financial statements as of and for the years ended December 31, 2019 and 2018 includes an explanatory paragraph indicating that there is substantial doubt about Adicet’s ability to continue as a going concern. If Adicet is unable to raise sufficient capital when needed, Adicet’s business, financial condition and results of operations will be harmed, and Adicet will need to significantly modify its operational plans to continue as a going concern. If Adicet is unable to continue as a going concern, Adicet might have to liquidate its assets and the values it receives for its assets in liquidation or

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dissolution could be significantly lower than the values reflected in its financial statements. The inclusion of a going concern explanatory paragraph by Adicet’s auditors, its lack of cash resources and its potential inability to continue as a going concern may negatively impact Adicet’s share price and its ability to raise new capital or to enter into critical contractual relations with third parties due to concerns about its ability to meet its contractual obligations.

Adicet’s gamma delta T cell candidates represent a novel approach to cancer treatment that creates significant challenges for Adicet.

Adicet is developing a pipeline of gamma delta T cell product candidates and a novel antibody platform that are intended for use in patient with certain cancers. Advancing these novel product candidates creates significant challenges for Adicet, including:

The success of Adicet’s business, including its ability to obtain financing and generate any revenue in the future, will primarily depend on the successful development, manufacturing, positive efficacy and safety profile in its clinical trials, regulatory approval and commercialization of Adicet’s novel product candidates, which may never occur. Adicet has not yet succeeded and may not succeed in demonstrating efficacy and safety for any of its product candidates in clinical trials or in obtaining marketing approval thereafter. Given Adicet’s early stage of development, it may be several years, if at all, before Adicet has demonstrated the safety and efficacy of a product candidate sufficient to warrant approval for commercialization. If Adicet is unable to develop, or obtain regulatory approval for, or, if approved, successfully commercialize its product candidates, Adicet may not be able to generate sufficient revenue to continue its business, which could have a material adverse effect on Adicet’s results of operations and prospects.

Adicet’s product candidates are based on novel technologies, which makes it difficult to predict the likely success of such product candidates and the time and cost of product candidate development and obtaining regulatory approval.

Adicet has concentrated its research and development efforts on its allogeneic gamma delta T cell therapy and Adicet’s future success depends on the successful development of this therapeutic approach. Adicet is in the

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early stages of developing its platform and product candidates and there can be no assurance that any development problems Adicet has experienced or may experience in the future will not cause significant delays or result in unforeseen issues or unanticipated costs, or that any such development problems or issues can be overcome. Adicet may also experience delays in developing a sustainable, reproducible and scalable manufacturing process or transferring that process to commercial partners, which may prevent it from completing Adicet’s future clinical studies or commercializing its products on a timely or profitable basis, if at all. In addition, Adicet’s expectations with regard to the advantages of an allogenic gamma delta T cell therapy platform relative to other therapies may not materialize or materialize to the degree Adicet anticipates. Further, Adicet’s scalability and costs of manufacturing may vary significantly as Adicet develops its product candidates and understands these critical factors.

In addition, the clinical study requirements of the FDA, EMA and other regulatory agencies and the criteria these regulators use to determine the safety and efficacy of a product candidate are determined according to the type, complexity, novelty and intended use and market of the potential products. The regulatory approval process for novel product candidates such as Adicet’s can be more complex and consequently more expensive and take longer than for other, better known or extensively studied pharmaceutical or other product candidates. Approvals by the EMA and FDA for existing autologous CAR-T therapies, such as Kymriah^® and Yescarta^®, may not be indicative of what these regulators may require for approval of Adicet’s therapies. Also, while Adicet expects reduced variability in its products candidates compared to autologous products, Adicet does not have significant clinical data supporting any benefit of lower variability. More generally, approvals by any regulatory agency may not be indicative of what any other regulatory agency may require for approval or what such regulatory agencies may require for approval in connection with new product candidates.