0000950170-24-033482 | 10-K | XBRL Viewer

Stock-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

11. Stock-Based Compensation

Stock-based Compensation Expense

The following table presents stock-based compensation expense as reflected in the Company's consolidated statements of operations (in thousands):


	Year Ended December 31,
	2023		2022
Research and development	$	9,143	$	7,225
General and administrative		11,116		9,901
Total stock-based compensation	$	20,259	$	17,126

The following table presents stock-based compensation expense by type of award (in thousands):


	Year Ended December 31,
	2023		2022
Stock options	$	18,060	$	14,054
Restricted stock units (including performance-based RSUs)		2,023		2,878
Employee Stock Purchase Plan		176		194
Total	$	20,259	$	17,126

Stock Options

A summary of stock option activity for the year ended December 31, 2023 is set forth below (in thousands, except share and per share data):


	Number of Shares Underlying Outstanding Options			Weighted Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022		6,203,020		$	14.44		8.4	$	780
Options granted		4,293,442		$	5.36
Options exercised		(946	)	$	4.76
Options forfeited or cancelled		(1,112,411	)	$	10.59
Outstanding, December 31, 2023		9,383,105		$	10.64		8.2	$	45
Options exercisable, December 31, 2023		3,984,821		$	13.65		7.4	$	6
Vested and expected to vest, December 31, 2023		9,383,105		$	10.64		8.2	$	45

The assumptions used in the Black Scholes Model to calculate stock-based compensation are as follows:


	Year Ended December 31,
	2023	2022
Fair value of common stock	$1.32 - $9.15	$8.94 - $19.97
Expected term (years)	5.5 - 6.1 years	5.5 - 6.1 years
Volatility	83.25% - 92.87%	77.4% - 81.7%
Risk free rates	3.5% - 4.86%	1.6% - 4.22%
Dividend rate	0.0%	0.0%

The fair value of each stock option was estimated at the date of grant using a Black-Scholes option-pricing model using the following assumptions:

The assumptions are as follows:

•

Expected volatility. The Company has limited trading history. As such, the expected volatility was determined by examining the historical volatilities for comparable publicly traded companies within the biotechnology and pharmaceutical industry using an average of historical volatilities of the Company’s industry peers.

•

Risk-free interest rate. The risk-free interest rate is based on the United States Treasury yield with a maturity equal to the expected term of the option in effect at the time of grant.

•

Dividend yield. The expected dividend is assumed to be zero as dividends have never been paid and there are no current plans to pay dividends on common stock.

•

Expected term. The expected term represents the period that the stock-based awards are expected to be outstanding. The expected term is calculated using the simplified method which is used when there is insufficient historical data about exercise patterns and post-vesting employment termination behavior. The simplified method is based on the vesting period and the contractual term for each grant, or for each vesting-tranche for awards with graded vesting. The mid-point between the vesting date and the maximum contractual expiration date is used as the expected term under this method. For awards with multiple vesting-tranches, the times from grant until the mid-points for each of the tranches may be averaged to provide an overall expected term.

The Company will continue to use judgment in evaluating the expected volatility, risk-free interest rates, dividend yield and expected term, utilized for stock-based compensation on a prospective basis.

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock options and the fair value of the Company’s common stock for stock options that were in-the-money at December 31, 2023 and 2022. The aggregate intrinsic value of stock options exercised during the years ended on December 31, 2023 and 2022 was less than $0.1 million and $1.0 million, respectively.

The total fair value of options that vested during the years ended December 31, 2023 and 2022 was $17.9 million and $13.4 million, respectively. The options granted during the years ended December 31, 2023 and 2022 had a weighted-average per share grant-date fair value of $3.94 per share and $10.07 per share, respectively.

As of December 31, 2023, the total unrecognized stock-based compensation expense related to unvested stock options was $31.7 million, which is expected to be recognized over the remaining weighted-average vesting period of 2.3 years.

Restricted Stock Units

The summary of RSU activity and related information for the year ended December 31, 2023 is set forth below:


	Number of Units Outstanding			Weighted Average Grant Date Fair Value
Outstanding, December 31, 2022		197,580		$	7.80
RSUs granted		513,700		$	7.47
RSUs vested		(194,455	)	$	7.43
RSUs forfeited		(62,625	)	$	7.07
Outstanding, December 31, 2023		454,200		$	7.69

The Company granted 513,700 RSU's in the year ended December 31, 2023. The Company did not grant any RSU's in the year ended December 31, 2022. The weighted-average grant date fair value of RSUs granted during the year ended December 31, 2023 was $7.69.

As of December 31, 2023, there was approximately $2.4 million of unrecognized compensation cost related to unvested RSUs that the Company expects to recognize over a remaining weighted-average period of approximately 2.1 years.

Option repricing

On August 8, 2023, the board of directors approved a stock option repricing (the Option Repricing) to be effective on August 14, 2023 (the Effective Date) in accordance with the terms of the Company’s 2015 Stock Incentive Plan and 2018 Plan (together, the Plans). Pursuant to the Option Repricing, and subject to a one year cliff period, the exercise price of each stock

option previously granted under the Plans, totaling 6,431,910 options, was amended to reduce the exercise price of such options to $2.14 per share, the closing price of the Company’s common stock on the Nasdaq Global Market on the Effective Date. Under the terms of the Option Repricing, a repriced option will revert to its original exercise price if, prior to the one year anniversary of the Effective Date, (a) the option holder’s employment is terminated by the Company with cause or by the option holder or (b) the option is exercised.

The repriced options otherwise retained their existing terms and conditions as set forth in the Plans and applicable award agreements. The stock option modification resulted in an incremental compensation cost of approximately $4.6 million, which was calculated based on the difference between the fair value of the stock options before the repricing and the fair value as of the Effective Date, using the Black-Scholes option-pricing model. Of the incremental compensation cost, $1.3 million was recognized in the year ended December 31, 2023, and the remaining amount, less any employee terminations, will be recognized on the straight-line basis over the remaining vesting period of the repriced options. The incremental cost is included in general and administrative expense and research and development expense on the consolidated statements of operations.

In addition, as of the Effective Date, the Company issued 1,418,042 options to purchase shares of common stock under the 2018 Plan to eligible employees who held inducement awards as of August 8, 2023. These new options were issued to eligible employees because their inducement awards granted under Nasdaq Listing Rule 5635(c)(4) are not eligible for repricing. The prior inducement awards remain outstanding under their original terms.

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Common stock, shares issued	43,270,386	42,954,820
Preferred Stock, Shares Issued	0	0
Regeneron Pharmaceuticals, Inc.
Related Party Transaction [Line Items]
Common stock, shares issued	883,568
Revenue from related party	$ 0

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Schedule of Number of Shares of Common Stock Reserved for Future Issuance

The Company has the following shares of common stock reserved for future issuance:


	December 31, 2023		December 31, 2022
Stock options and restricted stock units available for future grant		2,473,485		2,871,705
Stock options issued and outstanding		9,383,105		6,203,020
Unvested restricted stock units		454,200		197,580
Total common stock reserved		12,310,790		9,272,305

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 159,711	$ 257,656
Prepaid expenses and other current assets	2,561	3,382
Total current assets	162,272	261,038
Property and equipment, net	26,777	28,710
Operating lease right-of-use asset	17,424	20,269
Goodwill	0	19,462
Other non-current assets	822	1,211
Total assets	207,295	330,690
Current liabilities:
Accounts payable	2,625	4,404
Accrued and other current liabilities	13,441	12,811
Operating lease liability	3,221	2,492
Total current liabilities	19,287	19,707
Operating lease liability, net of current portion	17,703	18,531
Other non-current liabilities	130	114
Total liabilities	37,120	38,352
Commitments and contingencies (Note 9)
Stockholders’ equity (deficit):
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of December 31, 2023 and December 31, 2022, respectively; none issued and outstanding as of December 31, 2023 and December 31, 2022, respectively	0	0
Common stock, $0.0001 par value, 150,000,000 shares authorized as of December 31, 2023 and December 31, 2022, respectively; 43,270,386 and 42,954,820 shares issued and outstanding as of December 31, 2023 and December 31, 2022, respectively	4	4
Additional paid-in capital	550,943	530,448
Accumulated deficit	(380,772)	(238,114)
Total stockholders' equity	170,175	292,338
Total liabilities and stockholders' equity	$ 207,295	$ 330,690

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Stock issuance cost	$ 1.6

License, Funding and Other Agreements - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement termination description	twelve (12) years

Net Loss Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Net Loss per Share

12. Net Loss Per Share

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data):


	Year Ended December 31,
	2023			2022
Net loss - basic and diluted	$	(142,658	)	$	(69,790	)
Weighted-average shares used in computing net loss per share, basic and diluted		43,042,405			41,080,286
Net loss per share, basic and diluted		(3.31	)		(1.70	)

The Company's potentially dilutive shares as of December 31, 2023 and 2022, which include outstanding stock options and unvested RSUs, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.

The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share for the period presented because including them would have been antidilutive:


	As of December 31,
	2023		2022
Options to purchase common stock		9,383,105		6,203,020
Unvested restricted stock units		454,200		197,580
Total		9,837,305		6,400,600

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Deferred Tax Assets:
Net operating loss carryforwards	$ 65,601	$ 68,499
Operating lease right-of-use asset liability	4,414	5,641
Deferred revenue	0	0
Stock-based compensation	2,285	1,846
Intangible assets	704	1,060
Fixed Assets	768	574
Accruals and reserves	1,074	1,480
Sec 174 Capitalized R&D	27,871	15,803
Research and development credit carryforwards		26
Tax credits	28
Gross deferred tax assets	102,745	94,928
Less: Valuation allowance	(99,069)	(89,490)
Deferred tax assets, net of valuation allowance	3,676	5,439
Deferred tax liabilities:
Fixed assets	0	0
Basis Difference IPR&D	0	0
Operating lease right-of-use asset	(3,676)	(5,439)
Net deferred tax asset	$ 0	$ 0

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes Disclosure [Line Items]
Income tax provision	$ 0	$ 0
Increase in valuation allowance	9,600	16,300
Net operating loss carryforwards	$ 65,601	68,499
Ownership change plan description	In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50% over a three-year period.
Unrecognized tax benefits	$ 18,462	9,759	$ 4,040
Intellectual Property
Income Taxes Disclosure [Line Items]
Unrecognized tax benefits	800
California Research And Development
Income Taxes Disclosure [Line Items]
Tax credit carryforward, amount	6,400
Federal and state research and development [Member]
Income Taxes Disclosure [Line Items]
Tax credit carryforward, amount	11,300
Unrecognized tax benefits	17,700
Domestic Tax Authority
Income Taxes Disclosure [Line Items]
Operating loss carryforwards	$ 294,800
Operating loss carryforwards, expiration date	Dec. 31, 2037
Net operating loss carryforwards	$ 7,500
Operating loss carryforwards indefinitely	287,300
State
Income Taxes Disclosure [Line Items]
Operating loss carryforwards	$ 12,100
Operating loss carryforwards, expiration date	Dec. 31, 2035
Foreign Tax Authority
Income Taxes Disclosure [Line Items]
Operating loss carryforwards	$ 16,100
COVID-19
Income Taxes Disclosure [Line Items]
Income tax provision	$ 0	$ 0

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements and related disclosures have been prepared in conformity with accounting principles generally accepted in the United States of America (United States GAAP or GAAP). Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The United States dollar is the functional and reporting currency of the Company and its subsidiaries. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent liabilities at the date of the consolidated financial statements as well as the reported amounts of revenues and expenses during the reporting period. Such estimates include deferred tax assets, useful lives of property and equipment, accruals for research and development activities, revenue recognition and stock-based compensation and the Company’s incremental borrowing rate. Actual results could differ from those estimates. Goodwill Goodwill represents the excess of the purchase price over the fair value of net tangible and identified intangible assets acquired in a business combination. Goodwill is not amortized but is evaluated at least annually for impairment or when a change in facts and circumstances indicate that the fair value of the goodwill may be below the carrying value. Goodwill is tested for impairment at the reporting unit level annually in the fourth quarter, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition. The Company has determined that it operates in a single operating segment and has a single reporting unit. Prior to performing the impairment test, the Company assesses qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that the fair value of the reporting unit was less than the carrying amount. If after assessing the totality of events or circumstances, the Company were to determine that it is more likely than not that the fair value of the reporting unit is less than the carrying amount, then the Company would perform a quantitative impairment test. The quantitative impairment test involves comparing the fair value of the reporting unit to the carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets, goodwill is not impaired, and no further testing is required. If the fair value of the reporting unit is less than the carrying value, the Company measures the amount of impairment loss, if any, as the excess of the carrying value over the fair value of the reporting unit. The Company performed an interim test for goodwill impairment in the third quarter of the fiscal year ended December 31, 2023 and determined that goodwill was impaired. For additional information regarding this assessment, refer to Note 16. Goodwill to our consolidated financial statements. Segments The Company operates and manages its business as one reportable and operating segment, which is the business of research and development of allogeneic gamma delta T cell therapies for autoimmune diseases and cancer. The Company’s Chief Executive Officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and cash equivalents. The Company’s cash and cash equivalents are held at two financial institutions in the U.S. and one financial institution in Israel and such amounts may, at times, exceed insured limits. The Company invests its cash equivalents in money market funds and treasury securities. The Company limits its credit risk associated with cash equivalents by placing them with banks and institutions it believes are highly creditworthy and in highly rated investments. The Company has not experienced any losses on its deposits of cash and cash equivalents to date. The Company has one customer, Regeneron, which represents 100% of the Company’s total revenue during the year ended December 31, 2022 (see Note 8). The Company did not have any revenue for the year ended December 31, 2023. Risks and Uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies, clinical trials, and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting. The Company’s product candidates are still in development and, to date, none of the Company’s product candidates have been approved for sale and, therefore, the Company has not generated any revenue from product sales. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained or maintained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from other pharmaceutical and biotechnology companies. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with maturities of three months or less from the purchase date to be cash equivalents. As of December 31, 2023 and 2022, cash and cash equivalents consist of cash deposited with banks, investments in money market funds with maturities of three months or less from the date of purchase, and overnight treasury securities. Fair Value of Financial Instruments The carrying amounts of certain financial instruments of the Company, including cash equivalents, accounts receivable, accounts payable and accrued and other current liabilities approximate fair value due to their relatively short maturities. Property and Equipment, Net Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed on a straight-line basis over the estimated useful lives of the related assets, generally three years. Leasehold improvements are amortized using the straight-line method over the lesser of the assets’ estimated useful lives or the remaining term of the lease. Maintenance and repairs are charged to operations as incurred. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in the consolidated statements of operations in the period realized. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. Recoverability is measured by comparison of the carrying amount of the asset or asset group to the future net cash flows which the asset or asset group is expected to generate. If such asset or asset group is considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset or asset group exceeds the fair value of the asset or asset group. The Company performed a long-lived asset impairment test in conjunction with its goodwill impairment test in the third quarter of 2023 and concluded that there was no impairment of long-lived assets. There was also no impairment of long-lived assets for the year ended December 31, 2022. Revenue Recognition Under ASC 606, Revenue from Contracts with Customers (ASC 606), the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps as prescribed by ASC 606: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. A contract with a customer exists when (i) the Company enters into a legally enforceable contract with a customer that defines each party’s rights regarding the products or services to be transferred and identifies the payment terms related to these products or services, (ii) the contract has commercial substance and (iii) the Company determines that collection of substantially all consideration for products or services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company identifies the goods or services promised and determines the performance obligations by assessing whether each promised good or service is distinct. Goods or services that are not distinct are bundled with other goods or services in the contract until a bundle of goods or services that is distinct is created. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. All of the Company’s revenues for the year ended December 31, 2022 are derived through a license and collaboration agreement with Regeneron (see Note 8). The Company did not have any revenue for the year ended December 31, 2023. For revenue recognition purposes, the Company determines the term of its license or collaboration agreements by evaluating the period during which present and enforceable rights and obligations exist. This determination is impacted by the existence of substantive termination penalties, among other factors. The Company recognizes revenue under the Company’s license or collaboration agreements that are within the scope of ASC 606. These agreements include promises related to licenses to intellectual property and research and development services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Accordingly, the transaction price is generally comprised of a fixed fee due at contract inception and at specified future dates, variable consideration in the form of milestone payments due upon the achievement of specified events and tiered royalties earned when customers recognize net sales of licensed products. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes the “most likely amount” method to estimate the amount of variable consideration to which it will be entitled for the contract. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. At the inception of each arrangement that includes development and regulatory milestone payments, the Company evaluates whether the associated event is considered most likely to be achieved and estimates the amount to be included in the transaction price. Payments or reimbursements for the Company’s research and development efforts where such efforts are considered part of or a single performance obligation are recognized over time using a measure of progress that best reflects the Company’s performance in satisfying the obligation. Upfront payments are recorded as contract liabilities upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligation under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from its collaboration arrangement. Research and Development Expenses Research and development expenses include costs directly attributable to the conduct of research and development programs, including payroll and related expenses, costs for CDMOs, costs for CROs, materials, supplies, depreciation on and maintenance of research equipment, consulting costs, and the allocated portions of facility costs, such as rent, utilities, insurance, repairs and maintenance, depreciation, information technology costs and general support services. All costs associated with research and development are expensed within the consolidated statements of operations as incurred. Costs incurred in obtaining technology licenses are charged to research and development expense as acquired in-process research and development if the technology licensed has not reached technological feasibility and has no alternative future use. Accrued CRO, CDMO, and Research and Development Expenses The Company has entered into various agreements with CDMOs and CROs. The Company’s research and development accruals are estimated based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. The estimated costs of research and development provided, but not yet invoiced are included in accrued and other current liabilities on the consolidated balance sheets. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to CDMOs and CROs under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and other current assets on the consolidated balance sheets until the services are rendered. Through December 31, 2023 there had been no material adjustments to the Company’s prior period estimates of accrued research and development expenses. Leases Consistent with ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02), the Company determines if an arrangement is a lease, or contains a lease, at inception. Leases with a term greater than 12 months are recognized on the balance sheet as Right-of-Use (ROU) assets and current and long-term operating lease liabilities, as applicable. The Company has elected not to recognize on the balance sheet leases with terms of 12 months or less. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. The Company monitors its plan to renew its leases no less than on a quarterly basis. In addition, the Company’s lease agreements generally do not contain any residual value guarantees or restrictive covenants. In accordance with ASU 2016-02, the ROU assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate (IBR), which is the estimated rate the Company would be required to pay for a fully collateralized borrowing equal to the total lease payments over the term of the lease, to determine the present value of future minimum lease payments. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASU 2016-02, the Company does not combine lease and non-lease components. Variable lease payments are expenses as incurred. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. Stock-Based Compensation The Company accounts for stock-based compensation arrangements with employees and non-employees using a fair value method which requires the recognition of compensation expense for costs related to all stock-based payments including stock options. The fair value method requires the Company to estimate the fair value of stock-based payment awards on the date of grant using an option-pricing model. The Company uses the Black-Scholes option-pricing model to estimate the fair value of options granted that are expensed on a straight-line basis over the requisite service period, which is generally the vesting period. The Company accounts for forfeitures as they occur. Option valuation models, including the Black-Scholes option-pricing model, require the input of several assumptions. Changes in the assumptions used can materially affect the grant-date fair value of an award. These assumptions include the risk-free rate of interest, expected dividend yield, expected volatility and the expected life of the award. For awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved, using an accelerated attribution model, over the explicit or implicit service period. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences attributable to differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax reporting purposes and for operating loss and tax credit carryforwards. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company’s deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the years in which these temporary differences are expected to be recovered or settled. A valuation allowance is recorded to reduce deferred tax assets if it is determined that it is more likely than not that all or a portion of the deferred tax asset will not be realized. The Company considers many factors when assessing the likelihood of future realization of deferred tax assets, including recent earnings results, expectations of future taxable income, carryforward periods available and other relevant factors. The Company records changes in the required valuation allowance in the period that the determination is made. The Company assesses its income tax positions and records tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances and information available as of the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company records the largest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority having full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be sustained, the Company does not recognize a tax benefit in the consolidated financial statements. The Company records interest and penalties related to uncertain tax positions, if applicable, as a component of income tax expense (benefit). Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. The Company’s potentially dilutive shares, which include outstanding stock options, Employee Stock Purchase Plan (ESPP) awards and unvested restricted stock units (RSUs), are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Basic and diluted net loss per share is presented in conformity with the two-class method required for participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income (loss) available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in undistributed earnings as if all income (loss) for the period had been distributed. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss is attributed entirely to common stockholders. Since the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. Subsequent Events Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure, other than as disclosed in these notes to the consolidated financial statements. Refer to Note 17. Subsequent Events. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB under its ASC or other standard setting bodies and adopted by the Company as of the specified effective date, unless otherwise discussed below. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. This ASU replaces the existing incurred loss impairment model with an expected loss model. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. These changes will result in earlier recognition of credit losses. For SEC filers that are eligible to be smaller reporting companies, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted ASU 2016-13 in the first quarter of 2023. The impact on its consolidated financial statements and related disclosures was not material. In January 2017, the FASB issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (ASU 2017-04). The new guidance simplifies the subsequent measurement of goodwill by removing the second step of the two-step impairment test. The amendment requires an entity to perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. SEC filers that are eligible to be smaller reporting companies should adopt the amendments in this update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2022. The amendment should be applied on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company adopted ASU 2017-04 in the first quarter of 2023. The impact on its consolidated financial statements and related disclosures was not material. Accounting Pronouncements Not Yet Adopted In September 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances the transparency and usefulness of income tax disclosures. This amendment requires public issuers to disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income, or loss, by the applicable statutory income tax rate. Additionally, this amendment requires issuers to disclose the amount of income taxes paid (net of refunds received) disaggregated by federal (national), state, and foreign taxes as well as the amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which income taxes paid (net of refunds received) is equal to or greater than 5 percent of total income taxes paid (net of refunds received). For SEC filers, this ASU is effective for fiscal years beginning after December 15, 2025. Early adoption is permitted. The Company is currently evaluating the impact the adoption that this ASU will have on its consolidated financial statements and related disclosures.

Commitment and Contingencies - Schedule Of Future Minimum Rental Payments For Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2024	$ 5,015
2025	4,662
2026	4,009
2027 and thereafter	12,090
Total undiscounted lease payments	25,776
Less: imputed interest	4,852
Total operating lease liability	20,924
Less: current portion	3,221	$ 2,492
Operating lease liability, net of current maturities	$ 17,703	$ 18,531

Stockholders' Equity - Schedule of Number of Shares of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	12,310,790	9,272,305
Stock options issued and outstanding
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	9,383,105	6,203,020
Stock options and restricted stock units available for future grant
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	2,473,485	2,871,705
Unvested restricted stock units
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	454,200	197,580

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Organization and Nature of the Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Aug. 31, 2022	Mar. 12, 2021	Jan. 31, 2024	Nov. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Equity Method Investments [Line Items]
Accumulated deficit					$ 380,772	$ 238,114
Proceeds from issuance of common stock pursuant to at-the-market offering, net of issuance costs					0	$ 43,360
aggregate net proceed					19,300
Public Offering Underwritten					$ 91,800
Common stock, shares outstanding					43,270,386	42,954,820
Sales Agreement [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from issuance of common stock pursuant to at-the-market offering, net of issuance costs				$ 100,000
Aggregate number of shares sold	2,611,723
Sale of Stock, Price Per Share	$ 17.23
Sales agent commissions and expenses	$ 43,400
Common Stock not sold				30,000
Additional Common Stock not sold				$ 70,000
ATM Program [Member]
Schedule Of Equity Method Investments [Line Items]
Number of common stock shares sold					0
Subsequent Event \| ATM Program [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from issuance of common stock pursuant to at-the-market offering, net of issuance costs			$ 19,300
Maximum [Member] \| Sales Agreement [Member]
Schedule Of Equity Method Investments [Line Items]
Proceeds from issuance of common stock pursuant to at-the-market offering, net of issuance costs		$ 75,000
Adicet Therapeutics [Member]
Schedule Of Equity Method Investments [Line Items]
Accumulated deficit					$ (380,800)

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Summary of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Prepaid insurance	$	1,014	$	1,251
Prepaid software subscription and licensing fees		582		529
Prepaid maintenance		373		295
Prepaid professional services		82		44
Prepayments to CROs and CDMOs		53		492
Interest receivable		—		435
Other prepaid expenses and current assets		457		336
Total prepaid expenses and other current assets	$	2,561	$	3,382

Property and Equipment, net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement [Table]
Depreciation and amortization expense	$ 6,098	$ 2,575
Loss on disposition of fixed assets	4	$ (55)
Equipment [Member]
Statement [Table]
Construction in progress remaining	300
Construction in Progress [Member]
Statement [Table]
Decrease in construction in progress	$ 9,000

- Definition

Schedule reflecting a Statement of Income, Statement of Cash Flows, Statement of Financial Position, Statement of Shareholders' Equity and Other Comprehensive Income, or other statement as needed.

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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Topic 946
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 38: http://www.xbrl.org/2003/role/disclosureRef
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Reference 39: http://www.xbrl.org/2003/role/disclosureRef
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Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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Reference 41: http://www.xbrl.org/2003/role/disclosureRef
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Reference 43: http://www.xbrl.org/2003/role/disclosureRef
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Reference 44: http://www.xbrl.org/2003/role/disclosureRef
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Reference 45: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

+ Details

Subsequent Events

12 Months Ended

Dec. 31, 2023

Subsequent Events [Abstract]

Subsequent Events

17. Subsequent Events

ATM Program

In January 2024, 6,350,000 shares of common stock were issued in a series of sales in accordance with the ATM Program, at an average price of $3.13 per share for aggregate net proceeds of approximately $19.3 million, after deducting sales agent commissions, but before deducting any expenses related to such sales.

Underwritten Public Offering

On January 22, 2024, Adicet entered into an Underwriting Agreement (the Underwriting Agreement) with Jefferies LLC and Guggenheim Securities, LLC (the Underwriters) related to an underwritten public offering (the Offering) of 27,054,667 shares (the Shares) of common stock of the Company, par value $0.0001 per share (the Common Stock), and, in lieu of Common Stock to an investor, pre-funded warrants (the Pre-Funded Warrants) to purchase 8,445,333 shares of Common Stock (the Warrant Shares). The Shares were sold at a public offering price of $2.40 per share and the Pre-Funded Warrants were sold at a public offering price of $2.3999 per underlying share, which represents the per share public offering price of each share of common stock minus the $0.0001 per share exercise price for each pre-funded warrant. The purchase price paid by the

Underwriters to the Company was $2.256 per Share and $2.2559 per Pre-Funded Warrant, representing a discount to the Underwriters of 6.0%. In addition, the Company granted the Underwriters an option exercisable for 30 days from the date of the Underwriting Agreement to purchase, at the public offering price less underwriting discounts and commissions, up to an additional 5,325,000 shares of Common Stock. On January 23, 2024, the Underwriters exercised this option in full. The Company received net proceeds from the Offering, after deducting the underwriting discount and commissions and other estimated offering expenses, of approximately $91.8 million. The Company may receive nominal proceeds, if any, from the exercise of the Pre-Funded Warrants.

Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The Company determines the fair value of financial and non-financial assets and liabilities using the fair value hierarchy which establishes three level of inputs that may be used to measure fair value, as follows:

Level 1 — Observable inputs, such as quoted prices in active markets for identical assets or liabilities.

Level 2 — Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 — Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability.

The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands):


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Treasury securities (1) (2)	$	115,143	$	—	$	—	$	115,143
Total fair value of assets	$	115,143	$	—	$	—	$	115,143


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds (1) (3)	$	75,701	$	—	$	—	$	75,701
Total fair value of assets	$	75,701	$	—	$	—	$	75,701

(1)

Included in cash and cash equivalents in the consolidated balance sheets.

(2)

Treasury securities are included within Level 1 of the fair value hierarchy because they are actively traded and valued using quoted market prices.

(3)

Money market funds are included within Level 1 of the fair value hierarchy because they are valued using quoted market prices.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value Recurring [Member] - USD ($)
$ in Thousands

Dec. 31, 2023

Dec. 31, 2022

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

$ 115,143

$ 75,701

Money Market Funds

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[2]

75,701

Treasury Securities

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[3]

115,143

Fair Value Level 1

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

115,143

75,701

Fair Value Level 1 | Money Market Funds

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[2]

75,701

Fair Value Level 1 | Treasury Securities

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[3]

115,143

Fair Value Level 2

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

Fair Value Level 2 | Money Market Funds

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[2]

Fair Value Level 2 | Treasury Securities

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[3]

Fair Value Level 3

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

Fair Value Level 3 | Money Market Funds

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[2]

$ 0

Fair Value Level 3 | Treasury Securities

Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]

Total fair value of assets

^[1],[3]

$ 0

[1]	Included in cash and cash equivalents in the consolidated balance sheets.
[2]	Money market funds are included within Level 1 of the fair value hierarchy because they are valued using quoted market prices.
[3]	Treasury securities are included within Level 1 of the fair value hierarchy because they are actively traded and valued using quoted market prices.

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2023	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Common stock, shares authorized			150,000,000	150,000,000
Common stock shares issued, par value			$ 0.0001	$ 0.0001
Dividends Payable			$ 0
Common stock dividends declared \| $ / shares	$ 0	$ 0

Third Party Agreements - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 28, 2022	Dec. 31, 2023	Dec. 31, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development in process 1		$ 1,000
License agreement termination description		twelve (12) years
Payment from Regeneron for exercise of its option to license exclusive rights		$ 4	$ 1,315
Regeneron Pharmaceuticals, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non refundable upfront payment received		25,000
Additional payment for research funding received		20,000
Exercise Fee Paid	$ 20,000	20,000
Revenue recognized		5,000
Licence agreement additional revenue recognised		25,000
Regeneron Pharmaceuticals, Inc. \| Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Licence agreement additional amount payable of option exercise fees		$ 80,000

Commitment and Contingencies - Summary of Lease Costs and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Lease Cost
Operating lease cost	$ 4,510	$ 4,508
Short-term lease cost	195	133
Sublease Income	(714)	(704)
Total lease cost	3,991	3,937
Other Information
Operating cash flows used for lease payments	1,700
Operating cash flows used for lease liabilities	$ (99)	$ 2,264
Weighted-average remaining lease term - operating leases	5 years 8 months 12 days	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	7.10%	7.10%
Operating lease right of use asset obtained in exchange of operating lease liability	$ 0	$ 2,329

Goodwill

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

16. Goodwill

In connection with the annual goodwill impairment analysis performed during the fourth quarter of 2022, the Company determined that the fair value of its sole reporting unit exceeded its book value, and therefore no goodwill impairment charge was recorded in 2022. During the first and second quarters of 2023, the Company concluded that no events or changes in circumstances had occurred that indicated goodwill was more likely than not impaired.

During the third quarter of 2023, the Company experienced a significant decline in its stock price. As of September 30, 2023, the Company’s stock price declined 44% from its closing stock price on June 30, 2023, and the decline in stock price was sustained. The Company determined that this decline in stock price and market capitalization of the Company constituted a substantive change in circumstances that would more likely than not reduce the fair value of the Company’s single reporting unit below its carrying amount. Accordingly, the Company tested its goodwill for impairment as of September 30, 2023 (the Interim Testing Date).

In determining the fair value of the Company’s sole reporting unit for the interim impairment analysis as of the Interim Testing Date, the Company used a market-based approach, and the primary input in this approach was a quoted market price in an active market. To determine the estimated fair value of the Company’s single reporting unit, the Company calculated its market capitalization based on its stock price. Based on the Company’s interim impairment analysis as of the Interim Testing Date, the carrying value of the Company’s single reporting unit exceeded its fair value. Accordingly, step two of the goodwill impairment test was performed. In performing step two of the goodwill impairment test, the Company utilized observable inputs and concluded that an impairment charge was necessary for the full amount of goodwill. As a result of the step two evaluation, the Company recorded a goodwill impairment charge of $19.5 million during the three month period ended September 30, 2023. This impairment charge reduced the balance of goodwill to $0.

Net Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	9,837,305	6,400,600
Stock options issued and outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	9,383,105	6,203,020
Unvested restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	454,200	197,580

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (142,658)	$ (69,790)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	6,098	2,575
Noncash lease expense	2,844	2,434
Stock-based compensation expense	20,259	17,126
Loss on disposal of property, plant, and equipment	(4)	55
Goodwill impairment	19,462	0
Loss on disposal of lease assets	0	(1)
Amortization of deferred debt issuance costs	30	92
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	926	1,343
Other non-current assets	358	929
Accounts payable	(1,683)	1,710
Contract liabilities—related party	0	(4,805)
Operating lease liability	(99)	(2,264)
Accrued and other current and non-current liabilities	750	5,831
Net cash used in operating activities	(93,717)	(44,765)
Cash flows from investing activities
Purchase of property and equipment	(4,464)	(16,782)
Net cash used in investing activities	(4,464)	(16,782)
Cash flows from financing activities
Proceeds from issuance of common stock pursuant to at-the-market offering, net of issuance costs	0	43,360
Proceeds from exercise of stock options	4	1,315
Proceeds from Employee Stock Purchase Plan	382	432
Taxes withheld and paid related to net share settlement of equity awards	(150)	(3,234)
Deferred issuance costs	0	(364)
Net cash provided by financing activities	236	41,509
Net change in cash, cash equivalents	(97,945)	(20,038)
Cash, cash equivalents at the beginning of the period	257,656	277,694
Cash, cash equivalents at the end of the period	159,711	257,656
Reconciliation of cash, cash equivalents and restricted cash:
Cash, cash equivalents and restricted cash	159,711	257,656
Supplemental disclosures of noncash investing and financing activities
Purchases of property and equipment included in accounts payable and accrued expenses	279	565
Operating right-of-use asset obtained in exchange for operating lease liability	$ 0	$ 2,329

Term Loan - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	May 30, 2023	Mar. 13, 2023	Apr. 28, 2020
Class Of Warrant Or Right [Line Items]
Available under the Loan Agreement	$ 12.7
Pacific western bank
Class Of Warrant Or Right [Line Items]
Total loan accounts outside		$ 2.5
Banc of California
Class Of Warrant Or Right [Line Items]
Term loan to finance leasehold improvements				$ 5.5
Demand Deposit Accounts		35.0
Term Loan cash maintain		$ 35.0
Combined balances in demand deposit accounts			$ 200.0
Maximum [Member] \| Banc of California
Class Of Warrant Or Right [Line Items]
Term loan to finance leasehold improvements				15.0
Minimum [Member] \| Banc of California
Class Of Warrant Or Right [Line Items]
Term loan to finance leasehold improvements				$ 1.0

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
	Aug. 08, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate intrinsic value of options exercised				$ 1,000
RSUs granted (includes PSUs)			4,293,442
Total stock-based compensation expense			$ 20,259	17,126
RSUs granted			4,293,442
Options Issued and Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total fair value of options vested			$ 17,900	$ 13,400
Weighted-Average Grant Date Fair Value,Vested			$ 3.94	$ 10.07
Unrecognized compensation expense		$ 31,700	$ 31,700
Unrecognized compensation expense, estimated weighted-average period for recognition			2 years 3 months 18 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value,Vested			$ 7.43
Unrecognized compensation expense		$ 2,400	$ 2,400
Unrecognized compensation expense, estimated weighted-average period for recognition			2 years 1 month 6 days
RSUs granted (includes PSUs)			513,700	0
RSUs Vested			194,455
RSUs granted			513,700	0
weighted-average grant date fair value		$ 7.69	$ 7.69	$ 7.8
Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Shares Granted	$ 2.14
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate intrinsic value of options exercised			$ 100
2015 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares Available for Grant, Options granted	(6,431,910)
Inducement Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance		1,418,042	1,418,042
Black Scholes Option Pricing Model [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-Based Payment Arrangement, Plan Modification, Incremental Cost	$ 4,600
Share-Based Payment Arrangement, Incremental Cost, Amount Recognized Over The Remaining Vesting Period Of Repriced Options		$ 1,300

At-The-Market (ATM) Offering - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Common Stock, Shares, Issued		43,270,386	42,954,820
Common Stock, Par or Stated Value Per Share		$ 0.0001	$ 0.0001
Common stock issued		$ 4	$ 4
Additional paid-in capital		$ 550,943	$ 530,448
Sales Agreement [Member]
Class Of Stock [Line Items]
Sales agent commissions and expenses	$ 43,400

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Prepaid Expenses and Other Current Assets

4. Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Prepaid insurance	$	1,014	$	1,251
Prepaid software subscription and licensing fees		582		529
Prepaid maintenance		373		295
Prepaid professional services		82		44
Prepayments to CROs and CDMOs		53		492
Interest receivable		—		435
Other prepaid expenses and current assets		457		336
Total prepaid expenses and other current assets	$	2,561	$	3,382

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data):


	Year Ended December 31,
	2023			2022
Net loss - basic and diluted	$	(142,658	)	$	(69,790	)
Weighted-average shares used in computing net loss per share, basic and diluted		43,042,405			41,080,286
Net loss per share, basic and diluted		(3.31	)		(1.70	)

Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share


	As of December 31,
	2023		2022
Options to purchase common stock		9,383,105		6,203,020
Unvested restricted stock units		454,200		197,580
Total		9,837,305		6,400,600

Commitments and Contingences (Tables)

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Schedule Of Future Lease payments

The future minimum lease payments under all non-cancelable operating lease obligations as of December 31, 2023 were as follows (in thousands):


	December 31, 2023
2024		5,015
2025		4,662
2026		4,009
2027 and thereafter		12,090
Total undiscounted lease payments		25,776
Less: imputed interest		4,852
Total operating lease liability		20,924
Less: current portion		3,221
Operating lease liability, net of current maturities	$	17,703

Schedule Of Sublease Income

The expected undiscounted cash flows to be received from the sublease as of December 31, 2023 is as follows (in thousands):


	December 31, 2023
2024		722
2025		736
2026		438
2027 and thereafter		—
Total	$	1,896

Schedule of Weighted Average IBR and Remaining Lease Term

The IBR and the remaining lease terms of our facilities and their weighted average IBR and remaining terms are as follows as of December 31, 2023:


Lease Locations	IBR	Remaining Terms (in years)
Redwood City, CA (1000 Bridge Parkway)	6.90%		6.20
Redwood City, CA (1200 Bridge Parkway)	6.80%		1.50
Boston, MA	9.30%		2.60
Weighted Average	7.10%		5.70

Summary of Lease Costs and Other Information

The following table presents the operating lease cost and information related to the operating lease right-of-use assets, net and operating lease liabilities for the year ended December 31, 2023 (in thousands):


	Twelve Months Ended December 31,
	2023			2022
Lease Cost
Operating lease cost	$	4,510		$	4,508
Short-term lease cost		195			133
Sublease income		(714	)		(704	)
Total lease cost	$	3,991		$	3,937
Other Information
Operating cash flows used for lease liabilities	$	(99	)	$	2,264
Weighted-average remaining lease term - operating leases		5.7			6.5
Weighted-average discount rate - operating leases		7.1	%		7.1	%

Third Party Agreements - Summary of Change in Company's Contract Liabilities (Details) - Contract Liability - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]

Balance at beginning of period

$ 0

$ 4,805

Additions (Deductions)

(4,805)

^[1]

Balance at end of period

$ 0

[1]	Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Stock-Based Compensation Expense

The following table presents stock-based compensation expense as reflected in the Company's consolidated statements of operations (in thousands):


	Year Ended December 31,
	2023		2022
Research and development	$	9,143	$	7,225
General and administrative		11,116		9,901
Total stock-based compensation	$	20,259	$	17,126

The following table presents stock-based compensation expense by type of award (in thousands):


	Year Ended December 31,
	2023		2022
Stock options	$	18,060	$	14,054
Restricted stock units (including performance-based RSUs)		2,023		2,878
Employee Stock Purchase Plan		176		194
Total	$	20,259	$	17,126

Summary of Stock Option Activity

A summary of stock option activity for the year ended December 31, 2023 is set forth below (in thousands, except share and per share data):


	Number of Shares Underlying Outstanding Options			Weighted Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022		6,203,020		$	14.44		8.4	$	780
Options granted		4,293,442		$	5.36
Options exercised		(946	)	$	4.76
Options forfeited or cancelled		(1,112,411	)	$	10.59
Outstanding, December 31, 2023		9,383,105		$	10.64		8.2	$	45
Options exercisable, December 31, 2023		3,984,821		$	13.65		7.4	$	6
Vested and expected to vest, December 31, 2023		9,383,105		$	10.64		8.2	$	45

Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model

The assumptions used in the Black Scholes Model to calculate stock-based compensation are as follows:


	Year Ended December 31,
	2023	2022
Fair value of common stock	$1.32 - $9.15	$8.94 - $19.97
Expected term (years)	5.5 - 6.1 years	5.5 - 6.1 years
Volatility	83.25% - 92.87%	77.4% - 81.7%
Risk free rates	3.5% - 4.86%	1.6% - 4.22%
Dividend rate	0.0%	0.0%

Summary of Restricted Stock Unit Activity

The summary of RSU activity and related information for the year ended December 31, 2023 is set forth below:


	Number of Units Outstanding			Weighted Average Grant Date Fair Value
Outstanding, December 31, 2022		197,580		$	7.80
RSUs granted		513,700		$	7.47
RSUs vested		(194,455	)	$	7.43
RSUs forfeited		(62,625	)	$	7.07
Outstanding, December 31, 2023		454,200		$	7.69

Stockholders' Equity

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Common Stock

10. Stockholders' Equity

Common Stock

The Company’s Certificate of Incorporation, as amended, authorized the Company to issue 150,000,000 shares of $0.0001 par value common stock as of December 31, 2023.

Common stockholders are entitled to dividends if and when declared by the Board of Directors of the Company subject to the prior rights of the preferred stockholders. As of December 31, 2023, no dividends on common stock had been declared by the Board of Directors.

The Company has the following shares of common stock reserved for future issuance:


	December 31, 2023		December 31, 2022
Stock options and restricted stock units available for future grant		2,473,485		2,871,705
Stock options issued and outstanding		9,383,105		6,203,020
Unvested restricted stock units		454,200		197,580
Total common stock reserved		12,310,790		9,272,305

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481004/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Subparagraph (c)
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Publisher FASB
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
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-Section 50
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-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Stock-Based Compensation - Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	83.25%	77.40%
Expected volatility, maximum	92.87%	81.70%
Risk-free interest rate, minimum	3.50%	1.60%
Risk-free interest rate, maximum	4.86%	4.22%
Dividend yield	0.00%	0.00%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 1.32	$ 8.94
Expected term (in years)	5 years 6 months	5 years 6 months
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 9.15	$ 19.97
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2021	$ 303,129	$ 4	$ 471,449	$ (168,324)
Beginning Balance, shares at Dec. 31, 2021		39,736,914
Issuance of common stock upon exercise of stock options	1,315		1,315
Issuance of common stock upon exercise of stock options, shares		126,176
Issuance of common stock for cashless exercise of warrants, shares		100,731
Issuance of common stock upon vesting of restricted stock		548,580
Shares withheld for taxes		(215,901)
Shares withheld for taxes, Value	(3,234)		(3,234)
Purchase of common stock under Employee Stock Purchase Plan	432		432
Purchase of common stock under Employee Stock Purchase Plan, shares		46,597
Issuance of common stock pursuant to at-the-market offering, net of issuance costs of $1.6 million,shares		2,611,723
issuance of common stock pursuant to at-the-market offering, net of issuance costs of $1.6 million,value	43,360		43,360
Stock-based compensation expense	17,126		17,126
Net loss	(69,790)			(69,790)
Ending Balance at Dec. 31, 2022	292,338	$ 4	530,448	(238,114)
Ending Balance, shares at Dec. 31, 2022		42,954,820
Issuance of common stock upon exercise of stock options	$ 4		4
Issuance of common stock upon exercise of stock options, shares	946	946
Issuance of common stock upon vesting of restricted stock		194,455
Shares withheld for taxes		(86,145)
Shares withheld for taxes, Value	$ (150)		(150)
Purchase of common stock under Employee Stock Purchase Plan	382		382
Purchase of common stock under Employee Stock Purchase Plan, shares		206,310
Stock-based compensation expense	20,259		20,259
Net loss	(142,658)			(142,658)
Ending Balance at Dec. 31, 2023	$ 170,175	$ 4	$ 550,943	$ (380,772)
Ending Balance, shares at Dec. 31, 2023		43,270,386

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Number of Shares Underlying Outstanding Options, Beginning balance	6,203,020
RSUs granted	4,293,442
Number of Shares Underlying Outstanding Options, Options exercised	(946)
Number of Shares Underlying Outstanding Options, Options forfeited or cancelled	(1,112,411)
Number of Shares Underlying Outstanding Options, Ending balance	9,383,105	6,203,020
Number of Shares Underlying Outstanding Options, Shares exercisable	3,984,821
Number of Shares Underlying Outstanding Options, Vested and expected to vest	9,383,105
Weighted-Average Exercise Price, Outstanding beginning	$ 14.44
Weighted-Average Exercise Price, Options granted	5.36
Weighted-Average Exercise Price, Options exercised	4.76
Weighted-Average Exercise Price, Options forfeited or cancelled	10.59
Weighted-Average Exercise Price, Outstanding ending	10.64	$ 14.44
Weighted-Average Exercise Price, Shares exercisable	13.65
Weighted-Average Exercise Price, Vested and expected to vest	$ 10.64
Weighted-Average Remaining Contract Term, Outstanding	8 years 2 months 12 days	8 years 4 months 24 days
Weighted-Average Remaining Contract Term, Shares exercisable	7 years 4 months 24 days
Weighted-Average Remaining Contract Term, Vested and expected to vest	8 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding	$ 45	$ 780
Aggregate Intrinsic Value, Shares exercisable	6
Aggregate Intrinsic Value, Vested and expected to vest	$ 45

Property and Equipment, net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Total property and equipment	$ 41,624	$ 37,463
Less: Accumulated depreciation and amortization	(14,847)	(8,753)
Property and equipment, net	$ 26,777	28,710
Lesser of useful life or lease term	Property and equipment, net
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 13,165	7,503
Useful life (in years)	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 26,643	19,959
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	$ 951	184
Useful life (in years)	3 years
Construction In Progress
Property Plant And Equipment [Line Items]
Total property and equipment	$ 265	9,292
Useful life (in years)
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 189	172
Useful life (in years)	3 years
Software
Property Plant And Equipment [Line Items]
Total property and equipment	$ 411	$ 353
Useful life (in years)	3 years

Third Party Agreements (Tables)

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Change in Company's Contract Liabilities

As of December 31, 2023 and 2022, there were no contract assets related to the Regeneron Agreement. The following tables present changes in the Company’s contract liabilities for the years ended December 31, 2023 and 2022 (in thousands):

        Twelve Months Ended December 31, 2023

        Balance at
Beginning 
of Period

        Deductions

        Balance at
End of Period

Contract liability

—

—

—


Twelve Months Ended December 31, 2022	Balance at Beginning of Period		Deductions (1)			Balance at End of Period
Contract liability	$	4,805	$	(4,805	)	$	—

Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period.

Property and Equipment, net (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):


	Useful life (in years)	December 31, 2023			December 31, 2022
Leasehold improvements	Lesser of useful life or lease term	$	26,643		$	19,959
Laboratory equipment	3		13,165			7,503
Furniture and fixtures	3		951			184
Software	3		411			353
Construction in progress	—		265			9,292
Computer equipment	3		189			172
Property and equipment, gross			41,624			37,463
Less: Accumulated depreciation and amortization			(14,847	)		(8,753	)
Property and equipment, net		$	26,777		$	28,710

Organization and Nature of Business

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Nature of Business

1. Organization and Nature of the Business

Adicet Bio, Inc. (formerly resTORbio, Inc. (resTORbio)), together with its subsidiaries, (the Company) is a clinical stage biotechnology company discovering and developing allogeneic gamma delta T cell therapies for autoimmune diseases and cancer. The Company is advancing a pipeline of “off-the-shelf” gamma delta T cells, engineered with chimeric antigen receptors (CARs), to facilitate durable activity in patients. The Company's approach to activate, engineer, and manufacture allogeneic gamma delta T cell product candidates derived from the peripheral blood cells of unrelated donors allows it to generate new product candidates in a rapid and cost-efficient manner.

Adicet Bio, Inc. (when referred to prior to the merger, Former Adicet) was incorporated in November 2014 in Delaware. On September 15, 2020, Former Adicet completed a merger (Merger) with resTORbio, pursuant to which Former Adicet merged with a wholly owned subsidiary of resTORbio in an all-stock transaction with Former Adicet surviving as a wholly owned subsidiary of resTORbio and changing its name to “Adicet Therapeutics, Inc.” (Adicet Therapeutics). In connection with the Merger, the Company changed its name from “resTORbio, Inc.” to “Adicet Bio, Inc.” The Company’s principal executive offices are located in Boston, Massachusetts. The Company also has offices in Redwood City, California.

Adicet Bio Israel Ltd. (formerly Applied Immune Technologies Ltd.) (Adicet Israel) is a wholly owned subsidiary of the Company and is located in Haifa, Israel. Adicet Israel was founded in 2006. During 2019, the Company consolidated its operations, including research and development activities, in the United States and as a result, substantially reduced its operations in Israel.

Liquidity

The Company has incurred significant net operating losses and negative cash flows from operations and has an accumulated deficit of $380.8 million as of December 31, 2023. The Company has historically financed its operations primarily through a collaboration and licensing arrangement, public and private placements of equity securities and debt, and cash received in the Merger with resTORbio. To date, none of the Company’s product candidates have been approved for sale and therefore the Company has not generated any revenue from product sales. Management expects operating losses and negative cash flows to continue for the foreseeable future, until such time, if ever, that it can generate significant sales of its product candidates currently in development.

On March 12, 2021, the Company entered into a Capital On Demand™ Sales Agreement (the Sales Agreement) with JonesTrading Institutional Services LLC, as sales agent, to provide for the offering, issuance and sale of up to an aggregate amount of $75.0 million of shares of common stock from time to time in “at-the-market” (ATM) offerings under a registration statement on Form S-3 (File No. 333-254193) (2021 Shelf Registration Statement) filed with the U.S. Securities and Exchange Commission (the SEC), which was declared effective on March 30, 2021. In August 2022, pursuant to the Sales Agreement and subject to the limitations thereof, the Company sold an aggregate of 2,611,723 shares of common stock at $17.23 per share resulting in net proceeds to the Company of $43.4 million after deducting sales agent commissions and expenses. In November 2022, the Company filed a new prospectus supplement to the 2021 Shelf Registration Statement for the offer and sale of up to $100.0 million of shares of common stock from time to time through the sales agent, which includes the $30.0 million of shares of common stock not sold under the original prospectus and up to an additional $70.0 million of shares of common stock (the ATM Program). During the year ended December 31, 2023, no shares were sold under the ATM Program.

Subsequent to December 31, 2023, the Company raised aggregate net proceeds of approximately $19.3 million through its ATM Program and approximately $91.8 million through an underwritten public offering (the Offering). Refer to Note 19. Subsequent Events for additional details on these financings subsequent to December 31, 2023.

The Company expects that its cash and cash equivalents, together with the proceeds raised subsequent to year-end through our ATM Program and the Offering, will be sufficient to fund its forecasted operating expenses, capital expenditure requirements and debt service payments for at least the next twelve months from the issuance of these consolidated financial statements.

All of the Company’s revenue to date has been generated from a collaboration and license agreement with Regeneron Pharmaceuticals Inc, (Regeneron). The Company does not expect to generate any significant product revenue until it obtains regulatory approval of and commercializes any of the Company’s product candidates or enters into additional collaborative agreements with third parties, and it does not know when, or if, either will occur. The Company expects to continue to incur significant losses for the foreseeable future, and it expects the losses to increase as the Company continues the development of, and seeks regulatory approvals for, its product candidates and begins to commercialize any approved products. The Company is subject to all of the risks typically related to the development of new product candidates, including, but not limited to, raising additional capital, development by its competitors of new technological innovations, risk of failure in preclinical and clinical

studies, safety and efficacy of its product candidates in clinical trials, the risk of relying on external parties such as contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs), the regulatory approval process, market acceptance of the Company’s products once approved, lack of marketing and sales history, dependence on key personnel and protection of proprietary technology and it may encounter unforeseen expenses, difficulties, complications, delays, and other unknown factors that may adversely affect its business.

Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through the sale of equity, debt financings, collaborative or other arrangements with corporate or other sources of financing. Adequate funding may not be available to the Company on acceptable terms or at all. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and the Company’s ability to pursue its business strategies. Although the Company continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member]	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Beginning Balance \| shares	197,580
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance \| shares	454,200
RSUs granted \| shares	513,700
RSUs Vested \| shares	(194,455)
RSUs forfeited \| shares	(62,625)
Weighted- Average Grant Date Fair Value, beginning balance \| $ / shares	$ 7.8
Weighted-Average Grant Date Fair Value,Granted \| $ / shares	7.47
Weighted-Average Grant Date Fair Value,Vested \| $ / shares	7.43
Weighted Average Grant Date Fair Value, RSUs forfeited \| $ / shares	7.07
Weighted- Average Grant Date Fair Value, ending balance \| $ / shares	$ 7.69

Accrued and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

Summary of Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Accrued compensation	$	6,514	$	5,703
Accrued CDMO costs		5,679		4,390
Accrued professional services		625		1,356
Accrued other research and development expenses		354		674
Accrued CRO costs		257		657
Accrued other liabilities		12		31
Total accrued and other liabilities	$	13,441	$	12,811

Related Party Transactions

12 Months Ended

Dec. 31, 2023

Related Party Transactions

14. Related Party Transactions

As of December 31, 2023, Regeneron owned 883,568 shares of the Company’s common stock. Regeneron became a related party in July 2019 as a result of Series B redeemable convertible preferred stock financing which was subsequently converted into common stock. For the year ended December 31, 2023, the Company recorded no revenue from the Regeneron Agreement. See Note 8 for a discussion of the Regeneron Agreement.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Name Accounting Standards Codification
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
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-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (SX 210.6-07(2)(e))
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-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Paragraph 1
-Subparagraph (a)
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
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-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

13. Income Taxes

The components of the provision for (benefit from) income taxes are as follows (in thousands):


	December 31,
	2023		2022
Current:
Federal	$	—	$	—
State		—		—
Foreign		—		—
Total current		—		—
Deferred:
Federal		—		—
State		—		—
Foreign		—		—
Total deferred		—		—
Provision for (benefit from) income taxes	$	—	$	—

There was no income tax expense nor benefit for the years ended December 31, 2023 and 2022.

For the rate table below the (provision for) benefit from income taxes differ from the amount expected by applying the federal statutory rate to the loss before taxes as follows:


	Year Ended December 31,
	2023			2022
Federal statutory income tax rate		21.0	%		21.0	%
Tax credits		—			(2.5	)%
State income taxes		(8.3	)%		8.5	%
Change in valuation allowance		(7.0	)%		(23.2	)%
162m limitation		—			(1.5	)%
Stock-based compensation		(2.7	)%		(2.3	)%
Goodwill Impairment		(2.9	)%		—
Other permanent differences		(0.1	)%		(0.2	)%
Provision for income taxes		(0.0	)%		(0.0	)%

The tax effects of temporary differences and carryforwards of the deferred tax assets are presented below (in thousands):


	December 31,
	2023			2022
Deferred Tax Assets:
Net operating loss carryforwards	$	65,601		$	68,499
Operating lease right-of-use asset liability		4,414			5,641
Deferred revenue		—			—
Stock-based compensation		2,285			1,846
Intangible assets		704			1,060
Fixed assets		768			574
Accruals and reserves		1,074			1,480
Sec 174 Capitalized R&D		27,871			15,803
Research and development credit carryforwards					26
Tax credits		28
Gross deferred tax assets		102,745			94,928
Less: Valuation allowance		(99,069	)		(89,490	)
Deferred tax assets, net of valuation allowance		3,676			5,439
Deferred tax liabilities:
Fixed assets		—			—
Basis Difference IPR&D		—			—
Operating lease right-of-use asset		(3,676	)		(5,439	)
Net deferred tax assets	$	—		$	—

On September 15, 2020 Adicet Bio and resTORbio completed the Merger upon which Adicet Bio became the parent company of the consolidated group. The Merger did not create a step up in basis for tax basis of the asset as it was considered a tax-free merger. The above deferred tax table includes deferred related to resTORbio.

The Company has established a valuation allowance against its deferred tax assets due to the uncertainty surrounding the realization of such assets. IRC Section 174, as modified by the Tax Cuts and Jobs Act of 2017, no longer permit an immediate deduction for research and development expenditures in the tax year that such costs are incurred. As a result the Company capitalized such costs in its 2023 income tax provision, resulting in an increase in deferred tax assets.

ASC 740 requires that the tax benefit of net operating losses, temporary differences and credit carryforwards be recorded as an asset to the extent that management assesses that realization is “more likely than not.” Realization of the future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Because of the Company’s recent history of operating losses, management believes that recognition of the deferred tax assets arising from the above-mentioned future tax benefits is currently not likely to be realized and, accordingly, has provided a valuation allowance.

The valuation allowance increased by $9.6 million and by $16.3 million during the years ended December 31, 2023 and 2022, respectively.

As of December 31, 2023, the Company had net operating loss carryforwards of $294.8 million, $12.1 million, and $16.1 million to reduce future taxable income, if any, for federal, state and foreign income tax purposes, respectively. Of the federal net operating loss carryforwards, $7.5 million will begin to expire in 2036 if not utilized, and $287.3 million can be carried forward indefinitely. The state carryforwards will begin to expire in 2035.

The Company also had approximately $11.3 million of federal and $6.4 million of California research and development tax credit carryforwards available to offset future taxable income as of December 31, 2023. The federal credits begin to expire in 2041 and the California research credits can be carried forward indefinitely.

Utilization of the net operating loss carryforwards and research and development tax credit carryforwards may be subject to an annual limitation under Section 382 of the Internal Revenue Code of 1986, and corresponding provisions of state law, due to ownership changes that have occurred previously or that could occur in the future. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50% over a three-year period. If the Company has experienced an ownership change, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation. As of December 31, 2023, the ownership change analysis has not been completed, however no material tax attributes are expected to be limited for full use before their respective carryforward periods expires.

The Company files income tax returns in the United States federal jurisdiction, California, Massachusetts and Israel. The tax years 2016 to 2023 remains open to United States federal and state examination to the extent of the utilization of net operating loss and credit carryovers. Additionally, the Company is currently undergoing an audit with California’s Franchise Tax Board (FTB) regarding the apportionment of revenue for the tax year 2017 and may be obligated to make future payments to the state related to this tax year depending on the outcome of the examination. The Company is evaluating the FTB's proposal and assessing its course of action.

As of December 31, 2023, the Company had unrecognized tax benefits of $0.8 million related to the transfer of certain intellectual property from its Israeli subsidiary. In addition, as of December 31, 2023, the Company had unrecognized tax benefits of $17.7 million related to the federal and state research and development credits as a result of no formal research credit study performed.

A reconciliation of the beginning and ending unrecognized tax benefit amount is as follows (in thousands):


	Year Ended December 31,
	2023		2022
Balance at the beginning of the year	$	9,759	$	4,040
Adjustment based on tax positions related to prior year		5		(2	)
Adjustment based on tax positions related to current year		8,698		5,721
Balance at the end of the year	$	18,462	$	9,759

The Company recognizes interest expense and penalties related to the above unrecognized tax benefits within income tax expense (benefit). Management determined that no accrual for interest and penalties was required as of December 31, 2023.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended
	Jan. 23, 2024	Jan. 31, 2024	Jan. 22, 2024	Dec. 31, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Issuance of common stock				43,270,386	42,954,820
Common stock price per share				$ 0.0001	$ 0.0001
Subsequent Event
Subsequent Event [Line Items]
Estimated offering expenses	$ 91.8
Subsequent Event \| Jefferies LLC [Member]
Subsequent Event [Line Items]
Shares Issued, Price Per Share			$ 2.256
Subsequent Event \| ATM Program [Member]
Subsequent Event [Line Items]
Aggregate net proceeds		$ 19.3
Subsequent Event \| Common Stock [Member]
Subsequent Event [Line Items]
Issuance of common stock			5,325,000
Subsequent Event \| Common Stock [Member] \| Jefferies LLC [Member]
Subsequent Event [Line Items]
Exercise price			$ 2.4
Warrants outstanding			8,445,333
Issuance of common stock			27,054,667
Common stock price per share		$ 0.0001
Subsequent Event \| Common Stock [Member] \| ATM Program [Member]
Subsequent Event [Line Items]
Issuance of common stock		6,350,000
Common stock price per share		$ 3.13
Subsequent Event \| Pre Funded Warrant [Member] \| Jefferies LLC [Member]
Subsequent Event [Line Items]
Underwriting Commitments		30
Discount On Underwriters Warrant			6.00%
Shares Issued, Price Per Share			$ 2.2559
Exercise price			2.3999
Subsequent Event \| Pre Funded Warrant [Member] \| Jefferies LLC [Member] \| Initial Public Offering
Subsequent Event [Line Items]
Exercise price			$ 0.0001

Defined Contribution Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Company contribution in the plan	$ 1.2	$ 0.8

Income Taxes - Schedule of Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Balance at the beginning of the year	$ 9,759	$ 4,040
Adjustment based on tax positions related to prior years	5
Adjustment based on tax positions related to prior years		(2)
Adjustment based on tax positions related to current year	8,698	5,721
Balance at the end of the year	$ 18,462	$ 9,759

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2023	Mar. 14, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Entity Registrant Name	Adicet Bio, Inc
Entity Central Index Key	0001720580
Entity File Number	001-38359
Trading Symbol	ACET
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Public Float			$ 76.7
Entity Common Stock, Shares Outstanding		82,153,984
Document Annual Report	true
Document Transition Report	false
Entity Tax Identification Number	81-3305277
Entity Incorporation, State or Country Code	DE
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Entity Address, Address Line One	131 Dartmouth Street
Entity Address, Address Line Two	3rd Floor
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
City Area Code	650
Local Phone Number	503-9095
Entity Address, Postal Zip Code	02116
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	Boston, Massachusetts
Documents Incorporated by Reference	Part III of this Annual Report on Form 10-K incorporates by reference certain information from the registrant’s definitive Proxy Statement for its 2024 annual meeting of shareholders, scheduled to be held on June 5, 2024, which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year end of December 31, 2023. Except with respect to information specifically incorporated by reference in this Form 10-K, the Proxy Statement is not deemed to be filed as part of this Form 10-K.

Business Combination - Schedule of Summarizes the Allocation of the Purchase Price to the Net Tangible and Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Net assets acquired:
Goodwill	$ 0	$ 19,462

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References + Details

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Common stock price per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	43,270,386	42,954,820
Common stock, shares outstanding	43,270,386	42,954,820
Preferred Stock, par value	$ 0.0001	$ 0.0001
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0

Accrued and Other Current Liabilities - Summary of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued compensation	$ 6,514	$ 5,703
Accrued CDMO costs	5,679	4,390
Accrued professional services	625	1,356
Accrued research and development expenses	354	674
Accrued CRO costs	257	657
Accrued other liabilities	12	31
Total	$ 13,441	$ 12,811

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Revenue related party	$ 0	$ 24,990
Operating expenses:
Research and development	106,043	71,246
General and administrative	26,533	26,295
Goodwill impairment	19,462	0
Total operating expenses	152,038	97,541
Loss from operations	(152,038)	(72,551)
Interest income	9,978	3,760
Interest expense	(25)	(80)
Other expense, net	(573)	(919)
Loss before income tax provision	(142,658)	(69,790)
Income tax provision	0	0
Net loss	$ (142,658)	$ (69,790)
Net loss per share attributable to common stockholders, basic	$ (3.31)	$ (1.7)
Net loss per share attributable to common stockholders, diluted	$ (3.31)	$ (1.7)
Weighted-average common shares used in computing net income (loss) per share attributable to common stockholders, basic	43,042,405	41,080,286
Weighted-average common shares used in computing net income (loss) per share attributable to common stockholders, diluted	43,042,405	41,080,286

Commitments And Contingencies - Schedule of Sublease Income (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024	$ 722
2025	736
2026	438
Total	$ 1,896

Goodwill (Additional Information) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill Impairement charges	$ 19.5	$ 0.0	$ 0.0
Stock price declined	44.00%

Property and Equipment, net

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

5. Property and Equipment, net

Property and equipment, net consisted of the following (in thousands):


	Useful life (in years)	December 31, 2023			December 31, 2022
Leasehold improvements	Lesser of useful life or lease term	$	26,643		$	19,959
Laboratory equipment	3		13,165			7,503
Furniture and fixtures	3		951			184
Software	3		411			353
Construction in progress	—		265			9,292
Computer equipment	3		189			172
Property and equipment, gross			41,624			37,463
Less: Accumulated depreciation and amortization			(14,847	)		(8,753	)
Property and equipment, net		$	26,777		$	28,710

All of the Company’s property and equipment as of December 31, 2023 and 2022 is located in the U.S. Depreciation and amortization expense for the years ended December 31, 2023 and 2022 was $6.1 million and $2.6 million, respectively. The increase in expense is primarily due to the completion and subsequent depreciation of the Company's good manufacturing practice (GMP) cell processing and vector manufacturing suite at the Company's office in Redwood City, California (1000 Bridge Parkway) which was completed in February 2023.

Construction in progress has decreased by $9.0 million during the year ended December 31, 2023, compared to the balance at December 31, 2022, due to the Company's completion of the Company's GMP cell processing and vector manufacturing suite in February 2023. The remaining $0.3 million in construction in progress as of December 31, 2023 is primarily related to lab and computer equipment not yet placed into service.

Commitment and Contingencies - Schedule of Weighted Average IBR and Remaining Lease Term (Details)	Dec. 31, 2023	Dec. 31, 2022
Long Term Purchase Commitment [Line Items]
Weighted Average IBR	7.10%	7.10%
Remaining Terms (in years)	5 years 8 months 12 days	6 years 6 months
Redwood City, CA (1000 Bridge Parkway)
Long Term Purchase Commitment [Line Items]
Weighted Average IBR	6.90%
Remaining Terms (in years)	6 years 2 months 12 days
Redwood City, CA (1200 Bridge Parkway)
Long Term Purchase Commitment [Line Items]
Weighted Average IBR	6.80%
Remaining Terms (in years)	1 year 6 months
Boston, MA
Long Term Purchase Commitment [Line Items]
Weighted Average IBR	9.30%
Remaining Terms (in years)	2 years 7 months 6 days

Income Taxes - Schedule of (Provision for) Benefit from Income Taxes Differs from Federal Statutory Rate to the Loss Before Taxes (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory income tax rate, percent	21.00%	21.00%
Tax credits	0.00%	(2.50%)
State income taxes	(8.30%)	8.50%
Change in valuation allowance	(7.00%)	(23.20%)
162m limitation	0.00%	(1.50%)
Stock-based compensation	(2.70%)	(2.30%)
Goodwill Impairment	(2.90%)	0.00%
Other permanent differences	(0.10%)	(0.20%)
Provision for income taxes	(0.00%)	(0.00%)

Commitments and Contingences

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingences

9. Commitments and Contingencies

Operating Leases

The Company leases office and laboratory space in Redwood City, California, and Boston, Massachusetts.

Redwood City

In 2018, Adicet Therapeutics executed a non-cancelable lease agreement, as amended in 2022, pursuant to which the Company leases office and laboratory facility at 1000 Bridge Parkway and a portion of 1200 Bridge Parkway in Redwood City, California (the Redwood City Lease).

On January 9, 2023, Adicet Therapeutics entered into a third lease amendment with Westport Office Park, LLC (the Third Amendment). The Third Amendment further amends the Redwood City Lease and increases the tenant improvement allowance as of January 1, 2023 by an additional $3.0 million. The Company fully utilized the allowance for the continued buildout of office and laboratory space at 1000 Bridge Parkway in 2023. Per the terms of this amendment, this additional allowance will be repaid through equal monthly payments of principal amortization and interest on a monthly basis over the term of the lease at an interest rate of eight percent (8%) per annum. The Company received the allowance on February 21, 2023 and increased the operating lease liability accordingly.

On August 7, 2023, Adicet Therapeutics entered into a fourth lease amendment with Westport Office Park, LLC (the Fourth Amendment). The Fourth Amendment amends the period over which the tenant improvement allowance received in the Third Amendment will be amortized and identifies the monthly amortization payable by the Company.

On September 1, 2023, Adicet Therapeutics amended its letter of credit with Westport Office Park, LLC. The amendment reduced the amount of the letter of credit associated with 1000 Bridge Parkway by $2.1 million resulting in an updated letter of credit amount of $2.1 million.

Boston

In 2018, the Company entered into a lease agreement, as amended in 2019, for office space at 500 Boylston St, Boston, Massachusetts (500 Boylston Lease). Under the terms of the 500 Boylston Lease, the Company was permitted to assign, sublease or transfer this lease, with the consent of the landlord.

On July 19, 2021, the Company entered into a sublease agreement with RFS OPCO LLC (Sublessee), whereby the Company agreed to sublease to Sublessee all of the 9,501 rentable square feet of 500 Boylston St. The expected undiscounted cash flows to be received from the sublease as of December 31, 2023 is as follows (in thousands):


	December 31, 2023
2024		722
2025		736
2026		438
2027 and thereafter		—
Total	$	1,896

The Company recognized rent expense, net of sublease income, of $4.0 million and $3.9 million for the years ended December 31, 2023 and 2022, respectively.

Further, the Company remains liable for the remaining lease payments under the 500 Boylston Lease, totaling $1.7 million, which is included in the future minimum lease payments table below.

The future minimum lease payments under all non-cancelable operating lease obligations as of December 31, 2023 were as follows (in thousands):


	December 31, 2023
2024		5,015
2025		4,662
2026		4,009
2027 and thereafter		12,090
Total undiscounted lease payments		25,776
Less: imputed interest		4,852
Total operating lease liability		20,924
Less: current portion		3,221
Operating lease liability, net of current maturities	$	17,703

The IBR and the remaining lease terms of our facilities and their weighted average IBR and remaining terms are as follows as of December 31, 2023:


Lease Locations	IBR	Remaining Terms (in years)
Redwood City, CA (1000 Bridge Parkway)	6.90%		6.20
Redwood City, CA (1200 Bridge Parkway)	6.80%		1.50
Boston, MA	9.30%		2.60
Weighted Average	7.10%		5.70


	Twelve Months Ended December 31,
	2023			2022
Lease Cost
Operating lease cost	$	4,510		$	4,508
Short-term lease cost		195			133
Sublease income		(714	)		(704	)
Total lease cost	$	3,991		$	3,937
Other Information
Operating cash flows used for lease liabilities	$	(99	)	$	2,264
Weighted-average remaining lease term - operating leases		5.7			6.5
Weighted-average discount rate - operating leases		7.1	%		7.1	%

As of December 31, 2023, operating right-of-use assets were $17.4 million and operating lease liabilities were $20.9 million. The Company has no material finance leases.

The Company maintains letters of credit of $2.1 million and $0.2 million in connection with the Company’s office leases in Redwood City, CA and Boston, MA, respectively.

Indemnification Agreements

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ liability insurance.

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 20,259	$ 17,126
Research And Development Expenses
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	9,143	7,225
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	11,116	9,901
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	18,060	14,054
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	176	194
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,023	$ 2,878

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss attributable to common stockholders	$ (142,658)	$ (69,790)
Weighted-average shares used in computing net loss per share, basic	43,042,405	41,080,286
Weighted-average shares used in computing net loss per share, diluted	43,042,405	41,080,286
Net loss per share attributable to common stockholders, basic	$ (3.31)	$ (1.7)
Net loss per share attributable to common stockholders, diluted	$ (3.31)	$ (1.7)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured on Recurring Basis


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Treasury securities (1) (2)	$	115,143	$	—	$	—	$	115,143
Total fair value of assets	$	115,143	$	—	$	—	$	115,143


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds (1) (3)	$	75,701	$	—	$	—	$	75,701
Total fair value of assets	$	75,701	$	—	$	—	$	75,701

(1)

Included in cash and cash equivalents in the consolidated balance sheets.

(2)

Treasury securities are included within Level 1 of the fair value hierarchy because they are actively traded and valued using quoted market prices.

(3)

Money market funds are included within Level 1 of the fair value hierarchy because they are valued using quoted market prices.

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Customer Segment	Dec. 31, 2022 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Impairment charges	$ 0	$ 0
Number of customer \| Customer	1
Customers percentage of total revenue	100.00%	100.00%
Number of Reportable Segments \| Segment	1
Accrued research and development	$ 0

Accrued and Other Current Liabilities

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

Accrued and Other Current Liabilities

6. Accrued and Other Current Liabilities

Accrued and other current liabilities consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Accrued compensation	$	6,514	$	5,703
Accrued CDMO costs		5,679		4,390
Accrued professional services		625		1,356
Accrued other research and development expenses		354		674
Accrued CRO costs		257		657
Accrued other liabilities		12		31
Total accrued and other liabilities	$	13,441	$	12,811

Third Party Agreements

12 Months Ended

Dec. 31, 2023

Revenue Recognition and Deferred Revenue [Abstract]

Third Party Agreements

8. Third Party Agreements

Regeneron

On July 29, 2016, the Company entered into a license and collaboration agreement with Regeneron, which was amended in April 2019, with such amendment becoming effective in connection with Regeneron’s investment in the Company’s Series B redeemable convertible preferred stock private placement transaction in July 2019 (as amended, the Regeneron Agreement).

Financial Terms. The Company received a non-refundable upfront payment of $25.0 million from Regeneron upon execution of the Regeneron Agreement and an aggregate of $20.0 million of additional payments for research funding from Regeneron as of December 31, 2023. In addition, Regeneron may have to pay the Company additional amounts in the future consisting of up to an aggregate of $80.0 million of option exercise fees, as specified in the Regeneron Agreement. Per the terms of the agreement, Regeneron must pay the Company high single digit royalties as a percentage of net sales for immune cell products (ICPs) to targets for which it has exclusive rights, and low single digit royalties as a percentage of net sales on any non-ICP product comprising a targeting moiety generated by the Company through the use of Regeneron’s proprietary mice. The Company must pay Regeneron mid-single to low double digit, but less than teens, of royalties as a percentage of net sales of ICPs to targets for which the Company has exercised exclusive rights, and low to mid-single digit of royalties as a percentage of net sales of targeting moieties generated from the Company’s license to use Regeneron’s proprietary mice. Royalties are payable until the longer of the expiration or invalidity of the licensed patent rights or twelve (12) years from first commercial sale. No royalties have been earned or paid under the Regeneron Agreement through December 31, 2023.

On January 28, 2022, Regeneron exercised its option to license the exclusive, worldwide rights to ADI-002, an allogeneic gamma delta CAR T cell therapy directed against Glypican-3, pursuant to the Regeneron Agreement. In conjunction with the exercise of the option, Regeneron paid an exercise fee of $20.0 million to the Company on January 28, 2022, and the Company completed the transfer of the associated license rights to Regeneron during the first quarter of 2022. The $20.0 million option exercise fee, plus $5.0 million of revenue recognized relating to the combined performance obligation, resulted in an aggregate of $25.0 million recorded as revenue for the year ended December 31, 2022. The Company's obligations under the combined performance obligation were completed during the year ended December 31, 2022.

Regeneron is responsible, at its sole cost, for all development, manufacturing and commercialization of ADI-002 and must pay the Company high single digit royalties as a percentage of any net sales of ADI-002 for a period commencing on the first commercial sale until the longer of (i) the expiration or invalidity of the licensed patent rights or (ii) a low double digit amount of years from first commercial sale.

        Twelve Months Ended December 31, 2023

        Balance at
Beginning 
of Period

        Deductions

        Balance at
End of Period

Contract liability

—

—

—


Twelve Months Ended December 31, 2022	Balance at Beginning of Period		Deductions (1)			Balance at End of Period
Contract liability	$	4,805	$	(4,805	)	$	—

(1)

Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period.

Twist Bioscience

In March 2021, the Company entered into an Antibody Discovery Agreement (the Twist Agreement) with Twist Bioscience Corporation (Twist). Under the terms of the Twist Agreement, Twist will utilize its proprietary platform technology to assist the Company with the discovery of novel antibodies related to target antigens selected by the Company. The Company maintains the sole and exclusive rights to any program antibodies discovered under the Twist Agreement and has the right to patent, assign, license or transfer any work product under the agreement. Furthermore, the Company has the right to sublicense its rights to program antibodies to third parties. The Company may terminate the Twist Agreement at any time, with or without cause, upon a specified period advance written notice.

Per the terms of the agreement, the Company will pay Twist an upfront, non-refundable project initiation fee, a technology access fee, as well as a project fee for each project entered into under the agreement. Additionally, the Company will pay fees for development and regulatory milestones in the tens of millions of dollars and low single digit royalties on net sales to Twist for programs initiated under the agreement. In November 2022, the Company entered into an amendment to the Twist Agreement (the Twist Amendment). The Twist Amendment updates the language associated with Twist's audit rights as well as the amounts associated with technology access fees.

On a cumulative basis as of December 31, 2023, the Company has incurred and expensed $1.0 million related to project initiation fees, technology access fees and projects fees as research and development expense related to this agreement.

Defined Contribution Plan

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Defined Contribution Plan

15. Defined Contribution Plan

The Company maintains a defined contribution plan under Section 401(k) of the Internal Revenue Code covering substantially all full-time United States employees. Employee contributions are voluntary and are determined on an individual basis subject to the maximum allowable under federal tax regulations. During the years ended December 31, 2023 and 2022, the Company made aggregate matching contributions of $1.2 million and $0.8 million, respectively.

Commitment and Contingencies - Additional Information (Details) $ in Thousands		12 Months Ended
	Jan. 09, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 01, 2023 USD ($)	Jul. 19, 2021 ft²
Long Term Purchase Commitment [Line Items]
Area of Sublease \| ft²					9,501
Total operating lease liability		$ 20,924
Sublease income		714	$ 704
Lease payments		1,700
Operating lease right-of-use asset		17,424	20,269
Operating lease liability		20,924
Operating lease right-of-use asset		17,424	20,269
Topic 842
Long Term Purchase Commitment [Line Items]
Lease payments		4,000	$ 3,900
Westport Office Park, LLC
Long Term Purchase Commitment [Line Items]
Tenant improvements	$ 3,000
Interest rate	8.00%
Letters of Credit issued amount				$ 2,100
Redwood City Lease Agreement [Member]
Long Term Purchase Commitment [Line Items]
Letters of Credit issued amount		2,100
Boston, Massachusetts [Member]
Long Term Purchase Commitment [Line Items]
Letters of Credit issued amount		$ 200

Income Taxes - Schedule of Components of Provision for (benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Current:
Federal	$ 0	$ 0
State	0	0
Foreign	0	0
Total current	0	0
Deferred:
Federal	0	0
State	0	0
Foreign	0	0
Total deferred	0	0
Provision for (benefit from) income taxes	$ 0	$ 0

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements and related disclosures have been prepared in conformity with accounting principles generally accepted in the United States of America (United States GAAP or GAAP).
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The United States dollar is the functional and reporting currency of the Company and its subsidiaries.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent liabilities at the date of the consolidated financial statements as well as the reported amounts of revenues and expenses during the reporting period. Such estimates include deferred tax assets, useful lives of property and equipment, accruals for research and development activities, revenue recognition and stock-based compensation and the Company’s incremental borrowing rate. Actual results could differ from those estimates.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of net tangible and identified intangible assets acquired in a business combination. Goodwill is not amortized but is evaluated at least annually for impairment or when a change in facts and circumstances indicate that the fair value of the goodwill may be below the carrying value. Goodwill is tested for impairment at the reporting unit level annually in the fourth quarter, or more frequently when events or changes in circumstances indicate that the asset might be impaired. Examples of such events or circumstances include, but are not limited to, a significant adverse change in legal or business climate, an adverse regulatory action or unanticipated competition. The Company has determined that it operates in a single operating segment and has a single reporting unit. Prior to performing the impairment test, the Company assesses qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that the fair value of the reporting unit was less than the carrying amount. If after assessing the totality of events or circumstances, the Company were to determine that it is more likely than not that the fair value of the reporting unit is less than the carrying amount, then the Company would perform a quantitative impairment test. The quantitative impairment test involves comparing the fair value of the reporting unit to the carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets, goodwill is not impaired, and no further testing is required. If the fair value of the reporting unit is less than the carrying value, the Company measures the amount of impairment loss, if any, as the excess of the carrying value over the fair value of the reporting unit. The Company performed an interim test for goodwill impairment in the third quarter of the fiscal year ended December 31, 2023 and determined that goodwill was impaired. For additional information regarding this assessment, refer to Note 16. Goodwill to our consolidated financial statements.
Segments	Segments The Company operates and manages its business as one reportable and operating segment, which is the business of research and development of allogeneic gamma delta T cell therapies for autoimmune diseases and cancer. The Company’s Chief Executive Officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash and cash equivalents. The Company’s cash and cash equivalents are held at two financial institutions in the U.S. and one financial institution in Israel and such amounts may, at times, exceed insured limits. The Company invests its cash equivalents in money market funds and treasury securities. The Company limits its credit risk associated with cash equivalents by placing them with banks and institutions it believes are highly creditworthy and in highly rated investments. The Company has not experienced any losses on its deposits of cash and cash equivalents to date. The Company has one customer, Regeneron, which represents 100% of the Company’s total revenue during the year ended December 31, 2022 (see Note 8). The Company did not have any revenue for the year ended December 31, 2023.
Risks and Uncertainties	Risks and Uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies, clinical trials, and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting. The Company’s product candidates are still in development and, to date, none of the Company’s product candidates have been approved for sale and, therefore, the Company has not generated any revenue from product sales. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained or maintained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from other pharmaceutical and biotechnology companies.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with maturities of three months or less from the purchase date to be cash equivalents. As of December 31, 2023 and 2022, cash and cash equivalents consist of cash deposited with banks, investments in money market funds with maturities of three months or less from the date of purchase, and overnight treasury securities.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of certain financial instruments of the Company, including cash equivalents, accounts receivable, accounts payable and accrued and other current liabilities approximate fair value due to their relatively short maturities.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed on a straight-line basis over the estimated useful lives of the related assets, generally three years. Leasehold improvements are amortized using the straight-line method over the lesser of the assets’ estimated useful lives or the remaining term of the lease. Maintenance and repairs are charged to operations as incurred. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the consolidated balance sheet and any resulting gain or loss is reflected in the consolidated statements of operations in the period realized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. Recoverability is measured by comparison of the carrying amount of the asset or asset group to the future net cash flows which the asset or asset group is expected to generate. If such asset or asset group is considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset or asset group exceeds the fair value of the asset or asset group. The Company performed a long-lived asset impairment test in conjunction with its goodwill impairment test in the third quarter of 2023 and concluded that there was no impairment of long-lived assets. There was also no impairment of long-lived assets for the year ended December 31, 2022.
Revenue Recognition	Revenue Recognition Under ASC 606, Revenue from Contracts with Customers (ASC 606), the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the Company performs the following five steps as prescribed by ASC 606: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. A contract with a customer exists when (i) the Company enters into a legally enforceable contract with a customer that defines each party’s rights regarding the products or services to be transferred and identifies the payment terms related to these products or services, (ii) the contract has commercial substance and (iii) the Company determines that collection of substantially all consideration for products or services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company identifies the goods or services promised and determines the performance obligations by assessing whether each promised good or service is distinct. Goods or services that are not distinct are bundled with other goods or services in the contract until a bundle of goods or services that is distinct is created. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. All of the Company’s revenues for the year ended December 31, 2022 are derived through a license and collaboration agreement with Regeneron (see Note 8). The Company did not have any revenue for the year ended December 31, 2023. For revenue recognition purposes, the Company determines the term of its license or collaboration agreements by evaluating the period during which present and enforceable rights and obligations exist. This determination is impacted by the existence of substantive termination penalties, among other factors. The Company recognizes revenue under the Company’s license or collaboration agreements that are within the scope of ASC 606. These agreements include promises related to licenses to intellectual property and research and development services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Accordingly, the transaction price is generally comprised of a fixed fee due at contract inception and at specified future dates, variable consideration in the form of milestone payments due upon the achievement of specified events and tiered royalties earned when customers recognize net sales of licensed products. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes the “most likely amount” method to estimate the amount of variable consideration to which it will be entitled for the contract. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. At the inception of each arrangement that includes development and regulatory milestone payments, the Company evaluates whether the associated event is considered most likely to be achieved and estimates the amount to be included in the transaction price. Payments or reimbursements for the Company’s research and development efforts where such efforts are considered part of or a single performance obligation are recognized over time using a measure of progress that best reflects the Company’s performance in satisfying the obligation. Upfront payments are recorded as contract liabilities upon receipt or when due and may require deferral of revenue recognition to a future period until the Company performs its obligation under these arrangements. Amounts payable to the Company are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from its collaboration arrangement.
Research and Development Expenses	Research and Development Expenses Research and development expenses include costs directly attributable to the conduct of research and development programs, including payroll and related expenses, costs for CDMOs, costs for CROs, materials, supplies, depreciation on and maintenance of research equipment, consulting costs, and the allocated portions of facility costs, such as rent, utilities, insurance, repairs and maintenance, depreciation, information technology costs and general support services. All costs associated with research and development are expensed within the consolidated statements of operations as incurred. Costs incurred in obtaining technology licenses are charged to research and development expense as acquired in-process research and development if the technology licensed has not reached technological feasibility and has no alternative future use.
Accrued CRO, CMO, and Research and Development Expenses	Accrued CRO, CDMO, and Research and Development Expenses The Company has entered into various agreements with CDMOs and CROs. The Company’s research and development accruals are estimated based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. The estimated costs of research and development provided, but not yet invoiced are included in accrued and other current liabilities on the consolidated balance sheets. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to CDMOs and CROs under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and other current assets on the consolidated balance sheets until the services are rendered. Through December 31, 2023 there had been no material adjustments to the Company’s prior period estimates of accrued research and development expenses.
Leases	Leases Consistent with ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02), the Company determines if an arrangement is a lease, or contains a lease, at inception. Leases with a term greater than 12 months are recognized on the balance sheet as Right-of-Use (ROU) assets and current and long-term operating lease liabilities, as applicable. The Company has elected not to recognize on the balance sheet leases with terms of 12 months or less. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. The Company monitors its plan to renew its leases no less than on a quarterly basis. In addition, the Company’s lease agreements generally do not contain any residual value guarantees or restrictive covenants. In accordance with ASU 2016-02, the ROU assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate (IBR), which is the estimated rate the Company would be required to pay for a fully collateralized borrowing equal to the total lease payments over the term of the lease, to determine the present value of future minimum lease payments. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASU 2016-02, the Company does not combine lease and non-lease components. Variable lease payments are expenses as incurred. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation arrangements with employees and non-employees using a fair value method which requires the recognition of compensation expense for costs related to all stock-based payments including stock options. The fair value method requires the Company to estimate the fair value of stock-based payment awards on the date of grant using an option-pricing model. The Company uses the Black-Scholes option-pricing model to estimate the fair value of options granted that are expensed on a straight-line basis over the requisite service period, which is generally the vesting period. The Company accounts for forfeitures as they occur. Option valuation models, including the Black-Scholes option-pricing model, require the input of several assumptions. Changes in the assumptions used can materially affect the grant-date fair value of an award. These assumptions include the risk-free rate of interest, expected dividend yield, expected volatility and the expected life of the award. For awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved, using an accelerated attribution model, over the explicit or implicit service period.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences attributable to differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax reporting purposes and for operating loss and tax credit carryforwards. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company’s deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the years in which these temporary differences are expected to be recovered or settled. A valuation allowance is recorded to reduce deferred tax assets if it is determined that it is more likely than not that all or a portion of the deferred tax asset will not be realized. The Company considers many factors when assessing the likelihood of future realization of deferred tax assets, including recent earnings results, expectations of future taxable income, carryforward periods available and other relevant factors. The Company records changes in the required valuation allowance in the period that the determination is made. The Company assesses its income tax positions and records tax benefits for all years subject to examination based upon management’s evaluation of the facts, circumstances and information available as of the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company records the largest amount of tax benefit with a greater than 50% likelihood of being realized upon ultimate settlement with a taxing authority having full knowledge of all relevant information. For those income tax positions where it is not more likely than not that a tax benefit will be sustained, the Company does not recognize a tax benefit in the consolidated financial statements. The Company records interest and penalties related to uncertain tax positions, if applicable, as a component of income tax expense (benefit).
Net Loss per Share Attributable to Common Stockholders	Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. The Company’s potentially dilutive shares, which include outstanding stock options, Employee Stock Purchase Plan (ESPP) awards and unvested restricted stock units (RSUs), are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Basic and diluted net loss per share is presented in conformity with the two-class method required for participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income (loss) available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in undistributed earnings as if all income (loss) for the period had been distributed. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss is attributed entirely to common stockholders. Since the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.
Subsequent Events Considerations	Subsequent Events Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. The Company has evaluated all subsequent events and determined that there are no material recognized or unrecognized subsequent events requiring disclosure, other than as disclosed in these notes to the consolidated financial statements. Refer to Note 17. Subsequent Events.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB under its ASC or other standard setting bodies and adopted by the Company as of the specified effective date, unless otherwise discussed below. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. This ASU replaces the existing incurred loss impairment model with an expected loss model. It also eliminates the concept of other-than-temporary impairment and requires credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. These changes will result in earlier recognition of credit losses. For SEC filers that are eligible to be smaller reporting companies, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted ASU 2016-13 in the first quarter of 2023. The impact on its consolidated financial statements and related disclosures was not material. In January 2017, the FASB issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (ASU 2017-04). The new guidance simplifies the subsequent measurement of goodwill by removing the second step of the two-step impairment test. The amendment requires an entity to perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. SEC filers that are eligible to be smaller reporting companies should adopt the amendments in this update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2022. The amendment should be applied on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company adopted ASU 2017-04 in the first quarter of 2023. The impact on its consolidated financial statements and related disclosures was not material. Accounting Pronouncements Not Yet Adopted In September 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances the transparency and usefulness of income tax disclosures. This amendment requires public issuers to disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income, or loss, by the applicable statutory income tax rate. Additionally, this amendment requires issuers to disclose the amount of income taxes paid (net of refunds received) disaggregated by federal (national), state, and foreign taxes as well as the amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which income taxes paid (net of refunds received) is equal to or greater than 5 percent of total income taxes paid (net of refunds received). For SEC filers, this ASU is effective for fiscal years beginning after December 15, 2025. Early adoption is permitted. The Company is currently evaluating the impact the adoption that this ASU will have on its consolidated financial statements and related disclosures.

Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 1,014	$ 1,251
Prepaid software subscription and licensing fees	582	529
Prepaid maintenance	373	295
Prepayments to CROs and CDMOs	53	492
Prepaid professional services	82	44
Interest receivable	0	435
Other prepaid expenses and current assets	457	336
Total prepaid expenses and other current assets	$ 2,561	$ 3,382

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Components of Provision for (Benefit from) Income Taxes

The components of the provision for (benefit from) income taxes are as follows (in thousands):


	December 31,
	2023		2022
Current:
Federal	$	—	$	—
State		—		—
Foreign		—		—
Total current		—		—
Deferred:
Federal		—		—
State		—		—
Foreign		—		—
Total deferred		—		—
Provision for (benefit from) income taxes	$	—	$	—

Schedule of (Provision for) Benefit from Income Taxes Differs from Federal Statutory Rate to the Loss Before Taxes

For the rate table below the (provision for) benefit from income taxes differ from the amount expected by applying the federal statutory rate to the loss before taxes as follows:


	Year Ended December 31,
	2023			2022
Federal statutory income tax rate		21.0	%		21.0	%
Tax credits		—			(2.5	)%
State income taxes		(8.3	)%		8.5	%
Change in valuation allowance		(7.0	)%		(23.2	)%
162m limitation		—			(1.5	)%
Stock-based compensation		(2.7	)%		(2.3	)%
Goodwill Impairment		(2.9	)%		—
Other permanent differences		(0.1	)%		(0.2	)%
Provision for income taxes		(0.0	)%		(0.0	)%

Schedule of Deferred Tax Assets and Liabilities

The tax effects of temporary differences and carryforwards of the deferred tax assets are presented below (in thousands):


	December 31,
	2023			2022
Deferred Tax Assets:
Net operating loss carryforwards	$	65,601		$	68,499
Operating lease right-of-use asset liability		4,414			5,641
Deferred revenue		—			—
Stock-based compensation		2,285			1,846
Intangible assets		704			1,060
Fixed assets		768			574
Accruals and reserves		1,074			1,480
Sec 174 Capitalized R&D		27,871			15,803
Research and development credit carryforwards					26
Tax credits		28
Gross deferred tax assets		102,745			94,928
Less: Valuation allowance		(99,069	)		(89,490	)
Deferred tax assets, net of valuation allowance		3,676			5,439
Deferred tax liabilities:
Fixed assets		—			—
Basis Difference IPR&D		—			—
Operating lease right-of-use asset		(3,676	)		(5,439	)
Net deferred tax assets	$	—		$	—

Schedule of Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending unrecognized tax benefit amount is as follows (in thousands):


	Year Ended December 31,
	2023		2022
Balance at the beginning of the year	$	9,759	$	4,040
Adjustment based on tax positions related to prior year		5		(2	)
Adjustment based on tax positions related to current year		8,698		5,721
Balance at the end of the year	$	18,462	$	9,759

Business Combination - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Goodwill	$ 0	$ 19,462

- Definition

+ References + Details

Term Loan

12 Months Ended

Dec. 31, 2023

Term Loan [Abstract]

Term Loan

7. Term Loan

On April 28, 2020, the Company entered into a Loan and Security Agreement (the Loan Agreement) as amended on July 8, 2020, September 14, 2020, September 15, 2020, October 21, 2021, December 2, 2022 (the 2022 Loan Amendment) and May 30, 2023 with Banc of California (formerly known as Pacific Western Bank) to finance leasehold improvements for the facilities in Redwood City, CA and other purposes permitted under the Loan Agreement. Under the October 21, 2021 amendment, Banc of California will provide one or more Term Loans (as defined in the 2021 Loan Amendment), as well as Non-Formula Ancillary Services which shall not exceed $5.5 million in the aggregate. Non-Formula Ancillary Services are defined as automated clearinghouse transactions, corporate credit card services, letters of credit, or other treasury management services. The aggregate sum of the outstanding Term Loans and Non-Formula Ancillary Services shall at no time exceed $15.0 million, which each Term Loan to be in an amount of not less than $1.0 million.

On March 13, 2023, the Company and Banc of California executed a letter agreeing that, notwithstanding the covenants included in the 2022 Loan Amendment, until June 30, 2023 (i) the Company and its subsidiaries will not be required to maintain the lesser of $200 million or seventy percent (70%) of its combined balances in demand deposit accounts, money

market funds and/or insured cash sweep (ICS) accounts with Banc of California and (ii) the Company must maintain its combined balances at Banc of California or its affiliates, including Pacific Western Asset Management (the Letter).

On May 30, 2023, the Company further amended its Loan Agreement with Banc of California (the 2023 Loan Amendment). Pursuant to the 2023 Loan Amendment, the Company must maintain the lesser of (i) $35.0 million or (ii) all of the Company’s combined balances in demand deposit accounts, money market accounts, and/or insured cash sweep accounts with Banc of California. If the Company’s total cash and investments drop to less than $35.0 million, the 2023 Loan Amendment permits the Company to maintain cash and/or investments in one or more accounts outside of Banc of California up to a total of $2.5 million.

As of December 31, 2023, the Company has $12.7 million available under the Loan Agreement. Additionally, as of December 31, 2023, the Company is in compliance with such covenants as stated in the 2023 Loan Amendment and had no indebtedness outstanding under the Loan Agreement.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
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-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

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-Topic 470
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-Section 50
-Paragraph 1I
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details