Adicet Bio (ACET) 10-Q 12 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 09, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2022
Entity Registrant Name	Adicet Bio, Inc.
Entity Central Index Key	0001720580
Trading Symbol	ACET
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity File Number	001-38359
Entity Tax Identification Number	81-3305277
Entity Address, Address Line One	200 Clarendon Street
Entity Address, Address Line Two	Floor 6
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02116
City Area Code	650
Local Phone Number	503-9095
Entity Common Stock, Shares Outstanding		40,004,357
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 277,883	$ 277,544
Accounts receivable--related party	0	185
Prepaid expenses and other current assets	3,649	4,709
Total current assets	281,532	282,438
Property and equipment, net	17,736	14,643
Operating lease right-of-use asset	19,713	20,358
Goodwill	19,462	19,462
Restricted cash	150	150
Other non-current assets	1,858	1,887
Total assets	340,451	338,938
Current liabilities:
Accounts payable	3,465	3,263
Contract liabilities — related party, current	0	4,805
Accrued and other current liabilities	5,203	6,682
Operating lease liability	1,733	1,567
Total current liabilities	10,401	16,317
Operating lease liability, net of current portion	18,851	19,377
Other non-current liabilities	115	115
Total liabilities	29,367	35,809
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of March 31, 2022 and December 31, 2021, respectively; none issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	0	0
Common stock, $0.0001 par value, 150,000,000 shares authorized as of March 31, 2022 and December 31, 2021, respectively; 39,885,816 and 39,736,914 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	4	4
Additional paid-in capital	474,786	471,449
Accumulated deficit	(163,706)	(168,324)
Accumulated other comprehensive income	0	0
Total stockholders’ equity	311,084	303,129
Total liabilities and stockholders’ equity	$ 340,451	$ 338,938

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (unaudited) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	39,885,816	39,736,914
Common stock, shares outstanding	39,885,816	39,736,914
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

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenue—related party	$ 24,990	$ (3,981)
Operating expenses:
Research and development	13,483	11,743
General and administrative	6,801	5,630
Total operating expenses	20,284	17,373
Income (loss) from operations	4,706	(21,354)
Interest income	32	41
Interest expense	(18)	(50)
Other expense, net	(102)	(4)
Income (loss) before income tax benefit	4,618	(21,367)
Income tax benefit	0	(48)
Net income (loss)	$ 4,618	$ (21,319)
Weighted-average common shares used in computing net income (loss) per share attributable to common stockholders, diluted	45,958,941	26,099,954
Net income (loss) per share attributable to common stockholders, basic	$ 0.12	$ (0.82)
Net income (loss) per share attributable to common stockholders, diluted	$ 0.10	$ (0.82)
Weighted-average common shares used in computing net income (loss) per share attributable to common stockholders, basic	39,823,246	26,099,954
Other comprehensive income (loss):
Unrealized (loss) gain on marketable debt securities, net of tax		$ (22)
Total other comprehensive (loss) income		(22)
Comprehensive loss	$ 4,618	$ (21,341)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Pain In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2020	$ 109,827	$ 2	$ 216,126	$ (106,325)	$ 24
Balance, shares at Dec. 31, 2020		19,677,249
Issuance of common stock upon exercise of stock options	976		976
Issuance of common stock upon exercise of stock options, shares		393,991
Issuance of common stock related to financing	143,754	$ 1	143,753
Issuance of common stock related to financing, shares		11,729,353
Exercise of warrant, shares		1,806
Stock-based compensation expense	3,043		3,043
Net loss	(21,319)			(21,319)
Other comprehensive loss	(22)				(22)
Balance at Mar. 31, 2021	236,259	$ 3	363,898	(127,644)	$ 2
Balance, shares at Mar. 31, 2021		31,802,399
Balance at Dec. 31, 2021	303,129	$ 4	471,449	(168,324)
Balance, shares at Dec. 31, 2021		39,736,914
Issuance of common stock upon exercise of stock options	$ 93		93
Issuance of common stock upon exercise of stock options, shares	10,099	10,099
Issuance of common stock upon vesting of restricted stock, shares		224,000
Stock-based compensation expense	$ 4,350		4,350
Net loss	4,618			4,618
Shares withheld for taxes, shares		(85,197)
Shares withheld for taxes	1,106		(1,106)
Balance at Mar. 31, 2022	$ 311,084	$ 4	$ 474,786	$ (163,706)
Balance, shares at Mar. 31, 2022		39,885,816

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net income (loss)	$ 4,618	$ (21,319)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	352	326
Noncash lease expense	645	686
Stock-based compensation expense	4,350	3,043
Net amortization of premiums and accretion discounts on investments		9
Loss on disposal of property and equipment	18
Amortization of deferred debt issuance costs	18	184
Impairment of in-process research and development	0	460
Reduction to revenue	0	3,981
Remeasurement of contingent consideration liability	0	(380)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,077	36
Accounts receivable - related party	185
Other non-current assets	117	(377)
Accounts payable	(612)	196
Contract liabilities — related party	(4,805)
Operating lease liabilities	(361)	(438)
Accrued and other current liabilities	(1,497)	(1,553)
Net cash used in operating activities	4,105	(15,146)
Cash flows from investing activities
Proceeds from sales of marketable debt securities		7,500
Proceeds from maturities of marketable debt securities		1,000
Purchases of property and equipment	(2,632)	(658)
Net cash provided by (used in) investing activities	(2,632)	7,842
Cash flows from financing activities
Taxes withheld and paid related to net share settlement of equity awards	(1,106)
Proceeds from issuance of common stock, net of issuance costs		143,754
Proceeds from exercise of stock options	94	976
Deferred issuance costs	(122)	(157)
Net cash provided by (used in) financing activities	(1,134)	144,887
Net change in cash, cash equivalents and restricted cash	339	137,583
Cash, cash equivalents and restricted cash, at the beginning of period	277,694	88,857
Cash, cash equivalents and restricted cash, at the end of period	278,033	226,440
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	277,883	221,667
Restricted cash	150	4,773
Cash, cash equivalents and restricted cash, at the end of period	278,033	226,440
Supplemental cash flow information
Cash received from tax refund		158
Supplemental disclosures of noncash investing and financing activities
Purchases of property and equipment included in accounts payable	1,481	67
Adjustment to goodwill		$ 56

Organization and Nature of Busi

Organization and Nature of Business	3 Months Ended
	Mar. 31, 2022
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 cancer. The Company is advancing a pipeline of off-the-shelf gamma delta T cells, engineered with chimeric antigen receptors (CARs) and T cell receptor-like antibodies to enhance selective tumor targeting, facilitate innate and adaptive anti-tumor immune response, and improve persistence for 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 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 another office in Menlo Park, 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 $ 163.7 million as of March 31, 2022. The Company has historically financed its operations primarily through a collaboration and licensing arrangement, through the 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. In February 2021, the Company completed an underwritten public offering of 10,575,513 shares of its common stock at a public offering price of $ 13.00 per share. The Company received aggregate gross proceeds from the offering, before deducting underwriting discounts and commissions and offering expenses of approximately $ 137.5 million. In connection with the offering, the Company also entered into a stock purchase agreement with certain existing investors for $ 15.0 million of shares of the Company’s common stock at a price per share equal to the public offering price, with an initial closing for certain investors held simultaneously with the closing of the offering and a subsequent closing for certain additional investors. In December 2021, the Company closed an underwritten public offering of 7,187,500 shares of its common stock at a public offering price of $ 14.00 per share. The Company received net proceeds from the offering, after deducting underwriting discounts and commissions and offering expenses, of approximately $ 94.2 million. The Company expects that its cash and cash equivalents, including the gross proceeds it received in February 2021 and December 2021 from its underwritten public offerings and the proceeds received from a stock purchase agreement with certain existing investors, 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 interim consolidated financial statements. All of the Company’s revenue to date is 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 manufacturing organizations (CMOs), 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The unaudited interim 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). Significant Accounting Policies The Company’s significant accounting policies are described in Note 2, Summary of Significant Accounting Policies, to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. There have been no material changes to the significant accounting policies during the three months ended March 31, 2022. Unaudited Interim Financial Information The accompanying unaudited consolidated financial statements as of March 31, 2022 and for the three months ended March 31, 2022 and 2021, have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (SEC), for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position as of March 31, 2022 and consolidated results of operations for the three months ended March 31, 2022 and 2021 and consolidated cash flows for the three months ended March 31, 2022 and 2021 have been made. The results of operations for the three months ended March 31, 2022 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2022. 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. 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 all of the Company’s revenue for the three months ended March 31, 2022 and 2021 (see Note 8). 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. The current COVID-19 (coronavirus) pandemic, which is impacting worldwide economic activity, poses the risk that the Company or its employees, contractors, suppliers, and other partners may be prevented from conducting business activities for an indefinite period of time, including due to shutdowns that may be requested or mandated by governmental authorities. The extent to which the coronavirus impacts the Company’s operations will depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration of the outbreak, new information that will emerge concerning the severity of the coronavirus and the actions to contain the coronavirus or treat its impact, among others. COVID-19 may impact the timing of regulatory review and clearance of investigational new drugs (INDs) for clinical trials, the enrollment of any clinical trials that are allowed to proceed, the availability of clinical trial materials and regulatory approval and commercialization of our product candidates. COVID-19 may also impact the Company’s ability to access capital, which could negatively impact short-term and long-term liquidity. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB 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 July 2021, FASB issued ASU No. 2021-05, Lease (Topic 842), Lessors - Certain Leases with Variable Lease Payments (ASU 2021-05). ASU 2021-05 amends the lease classification requirements for lessors when classifying and accounting for a lease with variable lease payments that do not depend on a reference rate index or a rate. The update provides criteria, that if met, the lease would be classified and accounted for as an operating lease. ASU 2021-05 is effective for reporting periods beginning after December 15, 2021, with early adoption permitted. The Company adopted ASU 2021-05 in the first quarter of 2022. The impact on its consolidated financial statements and related disclosures was not material. Accounting Pronouncements Not Yet Adopted 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 plans to adopt the provisions of ASU 2016-13 effective January 1, 2023 and is currently evaluating the impact the adoption of this ASU will have on its consolidated financial statements and related disclosures. 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 plans to adopt the provisions of ASU 2017-04 effective January 1, 2023 and is currently evaluating the impact the adoption of this ASU will have on its consolidated financial statements and related disclosures.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	3. Goodwill and Other Intangible Assets On September 15, 2020, Former Adicet completed its merger with resTORbio. The merger was accounted for as a business combination which requires that assets acquired, and liabilities assumed be recognized at their fair value as of the acquisition date. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to value the assets acquired and liabilities assumed on the acquisition date, its estimates and assumptions are subject to refinement. Fair value estimates are based on a complex series of judgments about future events and uncertainties and rely heavily on estimates and assumptions. The judgments used to determine the estimated fair value assigned to each class of assets acquired and liabilities assumed, as well as asset lives, can materially impact the Company’s results of operations. As part of the transaction the Company recognized goodwill of $ 19.5 million, which is not tax deductible and represents the excess of the consideration paid over the fair value of assets acquired and liabilities assumed. Goodwill is mainly attributable to the enhanced value of the combined company. The fair value of acquired in-process research and development (IPR&D) is related to the research and development of RTB101 for a COVID-19 related indication. The RTB101 compound IPR&D project was valued using an income approach, specifically a projected discounted cash flow method, adjusted for the probability of technical success (PTS). The projected discounted cash flow models used to estimate the Company’s IPR&D reflect significant assumptions regarding the estimates a market participant would make in order to evaluate a drug development asset, including the following: • Estimates of potential cash flows to be generated by the project and resulting asset, which was developed utilizing estimates of total patient population, market penetration rates, demand risk adjustment factors, and product pricing; • Estimates regarding the timing of and the expected costs of goods sold, research and development expenses, selling, general and administrative expenses to advance the clinical programs to commercialization, cash flow adjustments and partner profit split; • The projected cash flows were then adjusted using PTS factors that were selected considering both the current state of clinical development and the nature of the proposed indication, (i.e., respiratory therapeutics); and • Finally, the resulting probability adjusted cash flows were discounted to a present value using a risk-adjusted discount rate, developed considering the market risk present in the forecast and the size of the asset. This IPR&D intangible asset is not amortized, but rather is reviewed for impairment on an annual basis or more frequently if indicators of impairment are present, until the project is completed, abandoned, or transferred to a third party. On July 27, 2021, the Company sent Novartis a termination notice. Termination will automatically take effect as of 60 days from the date of delivery of the termination notice to Novartis, but in no event later than October 1, 2021 without any further notice or action required of either Novartis or the Company. Upon the review of impairment of IPR&D during the second quarter of 2021, the Company concluded that the IPR&D was fully impaired and recorded an impairment charge within research and development expenses in the consolidated statement of operations and comprehensive loss for the remaining balance of the IPR&D intangible asset as of June 30, 2021. The Company recognized IPR&D impairment charges of $ 2.3 million, $ 0.5 million, and $ 0.7 million for the quarters ended as of December 31, 2020, March 31, 2021, and June 30, 2021. In connection with the merger, the Company entered into a Contingent Value Rights Agreement (the CVR Agreement). The contingent consideration for the contingent value right (CVR) was valued using an income approach, leveraging the probability adjusted discounted cash flow used in the valuation of the IPR&D and then deducting the administrative fee to be retained by the combined company and other permitted deductions in order to arrive at the net cash expected to be paid out to the CVR holders. The probability adjusted cash flow includes significant estimates and assumptions pertaining to commercialization events and cash consideration received by the Company for the grant of rights to commercialize RTB101 during the term of the CVR Agreement. These cash flows were then discounted to present value using the same discount rate applied in the valuation of the IPR&D. For additional background on the CVR Agreement and IPR&D, see to Note 3 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The following tables present changes in the Company’s IPR&D and CVR since the merger (in thousands): Acquisition Date Change in As of Change in As of In-process research and development $ 3,490 $ ( 2,300 ) $ 1,190 $ ( 1,190 ) $ — Contingent Value Rights $ 2,880 $ ( 1,900 ) $ 980 $ ( 980 ) $ —

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. 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): March 31, 2022 Level 1 Level 2 Level 3 Total Assets: Money market funds (1) (2) $ 147,075 $ — $ — $ 147,075 Total fair value of assets $ 147,075 $ — $ — $ 147,075 December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds (1) (2) $ 147,071 $ — $ — $ 147,071 Total fair value of assets $ 147,071 $ — $ — $ 147,071 (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 .

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	3 Months Ended
	Mar. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): March 31, December 31, Prepaid insurance $ 1,414 $ 1,021 Prepayments to CROs 1,031 1,658 Prepaid maintenance 1,128 115 Prepayments to CMOs 31 1,884 Other prepaid expenses and current assets 45 31 Total prepaid expenses and other current assets $ 3,649 $ 4,709

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	6. Property and Equipment, net Property and equipment, net consisted of the following (in thousands): Useful life March 31, December 31, Laboratory equipment 3 $ 5,641 $ 5,502 Leasehold improvements Lesser of useful life or lease term 1,606 1,614 Furniture and fixtures 3 303 303 Construction in progress — 16,328 13,014 Computer equipment 3 166 216 Software 3 328 320 24,372 20,969 Less: Accumulated depreciation and amortization ( 6,636 ) ( 6,326 ) Property and equipment, net $ 17,736 $ 14,643 Depreciation and amortization expense was $ 0.4 million and $ 0.3 million for the three months ended March 31, 2022 and 2021 , respectively. Construction in progress has increased by $ 3.3 million during the three months ended March 31, 2022 due to building construction related to the Company's leased space in Redwood City, California. Construction in process is expected to continue to increase through the first half of 2022, until completion of the construction in the third quarter of 2022. On March 18, 2022, the Company's wholly-owned subsidiary Adicet Therapeutics entered into Change Order No. 3 (the Change Order No. 3) to a construction agreement between Adicet Therapeutics and CP Enterprises, Inc. d/b/a CP Construction (CP Construction) (the Construction Agreement). The Construction Agreement provides for pre-construction and construction services at the Company's office and laboratory space in Redwood City, California (1000 Bridge Parkway) for consideration of approximately $ 13.8 million to CP Construction, including previous change orders. The Change Order No. 3 increased the budget for the construction by approximately $ 5.3 million in order to build one GMP cell processing and one vector manufacturing suite in addition to controlled materials warehousing at 1000 Bridge Parkway.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Accrued and Other Current Liabilities	7. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following (in thousands): March 31, December 31, Accrued compensation $ 2,314 $ 4,020 Accrued CMO costs 1,617 1,077 Accrued professional services 783 546 Accrued other research and development expenses 418 504 Accrued other liabilities 53 503 Accrued CRO costs 18 32 Total accrued and other liabilities $ 5,203 $ 6,682

Regeneron License and Collabora

Regeneron License and Collaboration Arrangement	3 Months Ended
	Mar. 31, 2022
Revenue Recognition and Deferred Revenue [Abstract]
Regeneron License and Collaboration Arrangement	. Regeneron License and Collaboration Arrangement Agreement Terms 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 March 31, 2022 . In addition, Regeneron may have to pay the Company additional amounts in the future consisting of up to an aggregate of $ 100.0 million of option exercise fees, as specified in the Regeneron Agreement. Regeneron must also pay the Company high single digit royalties as a percentage of net sales for 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. Equity Investments . In connection with its collaboration, Regeneron and the Company entered into a side letter pursuant to which, among other matters, Regeneron was granted certain stockholder rights and investment rights in connection with the Company’s next equity financing that met certain criteria and in connection with an initial public offering by the Company. Regeneron exercised its investment right and purchased approximately $ 10.0 million of the Company’s Series B redeemable convertible preferred stock in a private placement transaction in July 2019. The remaining obligations under the side letter agreement terminated immediately prior to the closing of the merger with resTORbio. Revenue Recognition The Company identified the following material promises under the Regeneron Agreement: (1) a research license, (2) a collaboration invention license, (3) a trademark license, (4) research and development services during the research term, (5) manufacturing services to manufacture collaboration ICPs for the research programs, (6) participation in the joint research committee, and (7) information sharing during the research term. The Company considered that the licenses granted under the Regeneron Agreement are not capable of being distinct and are not distinct from the research and development and manufacturing services within the context of the Regeneron Agreement, because 1) such licenses are for the research and development effort during the research term, unless Regeneron exercises its option under the Regeneron Agreement, 2) the research and development services significantly increase the utility of such licenses, and 3) research and development services require collaboration ICPs being manufactured. Specifically, the Company’s granted licenses can only provide benefit to Regeneron in combination with the Company’s research and development and manufacturing services to discover the collaboration ICPs. Similarly, the participation in the joint research committee and information sharing are not capable of being distinct and are not distinct from the research and development and manufacturing services within the context of the agreement, because the participation in the joint research committee is for monitoring and governing of the research and development efforts and the information sharing is for sharing results of such research and development efforts. Therefore, all of the promises above are combined into a single performance obligation. The Company also evaluated whether the option provided to Regeneron represents a material right that would require separate deferral and recognition. The option exercise will provide Regeneron with a development and commercial license to develop and commercialize the optioned collaboration ICPs. The Company concluded that the $25.0 million upfront payment to the Company was not negotiated to provide incremental discount for the future option fees payable upon Regeneron’s exercise of the option. Regeneron could decide not to exercise the option at its own discretion. The exercise of the option by Regeneron is not certain and is dependent on many factors, such as progress made on the specific option-eligible collaboration ICP, Regeneron’s overall assessment of commercial feasibility of the further research, development and commercialization of the option products, availability and cost of alternative programs and products. The option provides Regeneron with a license for intellectual property that will be improved from the inception of the Regeneron Agreement. In addition, the option fee is significant compared to the sum total of the upfront payment and research funding fees in the original Regeneron Agreement. Therefore, the Company determined that the option provided to Regeneron does not represent a material right and that any potential exercise of the option should be accounted as a separate contract. Hence, upon the option exercise by Regeneron the option fee would be allocated to the development and commercial license which would be the only performance obligation in that separate contract and recognized as revenue when control of the license rights is transferred to Regeneron. For revenue recognition purposes, the Company determined that the duration of the contract is the same as the research term of five years beginning on the execution of the Regeneron Agreement on July 29, 2016. The contract duration is defined as the period during which parties to the contract have present and enforceable rights and obligations. The Company determined that Regeneron faces significant in-substance penalties were it to terminate the Regeneron Agreement prior to the end of the research term. At contract inception, the Company determined the transaction price of the Regeneron Agreement to be $ 55.0 million, consisting of the $ 25.0 million upfront payment and the aggregate research funding fees of $ 30.0 million payable over the research term. In order to determine the transaction price, the Company evaluated all the payments to be received during the duration of the contract. Per the terms of the original Regeneron Agreement prior to the amendment effective from July 2019, the research funding fees of $ 30.0 million were payable merely due to the passage of time and therefore did not represent a variable consideration. After the amendment became effective in July 2019, $ 20.0 million of these fees became contingent upon meeting certain development and regulatory milestones. Therefore, the Company concluded that after the amendment such potential payments became variable consideration. The receipt of the variable consideration was subject to substantial uncertainty and was therefore excluded from the transaction price upon the effective date of the amendment. Accordingly, the transaction price was reduced to $ 35.0 million in July 2019. The Company re-evaluates the transaction price if there is a significant change in facts and circumstances at least at the end of each reporting period. The Company increased the transaction price by $ 10.0 million in June 2020 to $ 45.0 million when it achieved the milestone for the selection of a clinical candidate to the second collaboration target under the Regeneron Agreement. The Company recorded a $4.0 million revenue reduction in the first quarter of 2021 as a result of an adjustment to cumulative revenue recognized due to a change in overall estimated costs primarily due to an extension of time to fulfill the combined performance obligation. During the three months ended March 31, 2022, the Company recorded $ 25.0 million in revenue, inclusive of a $ 20 million option exercise fee described below. The Company has determined that the combined performance obligation is satisfied over time. ASC 606 requires the Company to select a single revenue recognition method for the performance obligation that depicts the Company’s performance in transferring control of the services. Accordingly, the Company utilizes a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. The Company believes this is the best measure of progress because it reflects how the Company transfers its performance obligation to Regeneron. In applying the cost-based input method of revenue recognition, the Company uses actual costs incurred relative to budgeted costs to fulfill the combined performance obligation. These costs consist primarily of internal full-time equivalent effort and third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligations over the research term of five years. For revenue recognition purposes, the five-year term had been extended to the first quarter of 2022 due to additional time required to complete the performance obligations under the Regeneron Agreement. A cost-based input method of revenue recognition requires management to make estimates of costs to complete the Company’s performance obligations. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete the Company’s performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. The Company's obligations under the combined performance obligation were completed during the three months ended March 31, 2022. The following tables present changes in the Company’s contract liabilities for the three months ended March 31, 2022 and 2021 (in thousands): Three Months Ended March 31, 2022 Balance at Additions (Deductions) Balance at Contract liability $ 4,805 $ ( 4,805 ) $ — Three Months Ended March 31, 2021 Balance at Additions (Deductions) Balance at Contract liability $ 13,980 $ 3,981 $ 17,961 (1) Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period. (2) Additions are the result of a reduction to cumulative revenue recognized as a result of a change in overall estimated costs, primarily due to an extension of time to fulfill the combined performance obligation, which was recorded as a change in estimate during the three months ended March 31, 2021. On January 28, 2022, Regeneron exercised its option to license the exclusive, worldwide rights to ADI-002, an allogeneic gamma delta chimeric antigen receptor (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 by March 31, 2022. Pursuant to the Regeneron Agreement, upon Regeneron’s exercise of the option, the Company had a specified period of time to elect to co-fund future development costs of ADI-002, and to participate in any potential profits with Regeneron up to a specified co-funding percentage in various geographic regions, including on a worldwide basis (Co-Funding Option). The Company elected not to exercise its Co-Funding Option for ADI-002. Accordingly, 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. As of March 31, 2022 , there were no contract liabilities related to the Regeneron Agreement. Additionally, As of March 31, 2022, there were no contract assets which would be reflected as accounts receivable-related party on the consolidated balance sheet. As of March 31, 2021, contract liabilities related to the Regeneron Agreement of $ 18.0 million was comprised of the $ 25.0 million upfront payment and additional $ 5.0 million research funding fees in each of 2017 and 2018, and $ 10.0 million for achievement of the milestone for the selection of a clinical candidate to the second collaboration target in June 2020 less $ 27.0 million of cumulative license and collaboration revenue recognized from the inception of the Regeneron Agreement as of March 31, 2021.

License Funding and Other Agree

License Funding and Other Agreements	3 Months Ended
	Mar. 31, 2022
License Funding And Other Agreements [Abstract]
License, Funding and Other Agreements Related to the CVR	9. License, Funding and Other Agreements National Institute of Health In May 2019, the Company was awarded a 5 -year grant for up to $ 1.5 million from the National Institutes of Health (the NIH) to study RTB101 and the regulation of antiviral immunity in the elderly. The Company is entitled to use the award solely to conduct the research. The Company is solely responsible for commencing and conducting the research and will furnish periodic progress updates to the NIH throughout the term of the award. After completing the research, the Company must provide the NIH with a formal report describing the work performed and the results of the research. For funds received under the NIH funding agreement, the Company recognizes a reduction in research and development expenses in an amount equal to the qualifying expenses incurred in each period up to the amount funded by the NIH. Qualifying expenses incurred by the Company in advance of funding by the NIH are recorded in the consolidated balance sheets as other current assets. For the three months ended March 31, 2022 , no qualifying expenses have been incurred and no thing has been funded by the NIH. On a cumulative basis as of March 31, 2022 , $ 1.3 million has been incurred and $ 1.3 million has been funded by the NIH.

Commitments and Contingences

Commitments and Contingences	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingences	10. Commitments and Contingencies Operating Leases The Company leases office and laboratory space in Menlo Park, CA, Redwood City, CA, and Boston, MA. 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 quarter ended March 31, 2022 (in thousands): March 31, 2022 Lease Cost Operating lease cost $ 1,007 Short-term lease cost 143 Variable lease cost — Sublease Income ( 167 ) Total lease cost $ 983 Other Information Operating cash flows used for lease liabilities $ 511 Operating lease right of use asset obtained in exchange of operating lease liability $ — Weighted-average remaining lease term - operating leases 7.5 Weighted-average discount rate - operating leases 7.1 % On July 19, 2021, the Company entered into a Sublease (the Sublease Agreement) with RFS OPCO LLC (Sublessee), whereby the Company agreed to sublease to Sublessee all of the 9,501 rentable square feet of office space in Boston, MA, currently leased by the Company pursuant to the Company’s lease with 500 Boylston & 222 Berkeley Owner (DE) LLC, dated January 8, 2018, as amended (the Master Lease). The term of the sublease started on September 1, 2021 and ends on July 30, 2026. The aggregate base rent due to the Company under the Sublease is approximately $ 3.5 million which began on October 1, 2021. Upon execution of the Sublease Agreement, the Company received a cash security deposit of $ 0.1 million from the Sublessee which is recorded as other non-current liabilities in the consolidated balance sheets. The expected sublease income as of March 31, 2022 is as follows (in thousands): March 31, 2022 $ 493 2023 671 2024 685 2025 699 2026 416 Total $ 2,964 Further, the Company remains liable for the remaining lease payments under the Master Lease, totaling $ 3.1 million, which is included in future minimum lease payments table below. The future minimum lease payments under all non-cancelable operating lease obligations as of March 31, 2022 were as follows (in thousands): March 31, 2022 $ 2,582 2023 3,428 2024 3,525 2025 3,625 2026 and thereafter 13,747 Total undiscounted lease payments 26,907 Less: imputed interest 6,324 Total operating lease liability 20,583 Less: current portion 1,733 Operating lease liability, net of current maturities $ 18,851

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Stockholders' Equity Note [Abstract]
Stockholders' Equity	11. 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, 2021. Common stockholders are entitled to dividends if and when declared by the Board of Directors subject to the prior rights of the preferred stockholders. As of March 31, 2022 , 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: March 31, December 31, Stock options available for future grant 3,531,453 1,961,338 Stock options issued and outstanding 5,376,145 3,875,317 Unvested restricted stock units 538,660 771,660 Common stock warrants issued and outstanding 220,890 220,890 Total common stock reserved 9,667,148 6,829,205 Warrants to Purchase Shares of Common Stock As of March 31, 2022, the Company’s outstanding warrants to purchase shares of common stock, consisted of the following: Issuance Date Number of Shares of Common Stock Issuable Exercise Price Classification Expiration Date September 15, 2020 101,610 $ 11.3177 Equity July 25, 2026 September 15, 2020 30,924 $ 11.3177 Equity August 21, 2026 September 15, 2020 77,312 $ 11.3177 Equity September 19, 2026 September 15, 2020 11,044 $ 11.3177 Equity September 26, 2026 220,890

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	12. Stock-based Compensation Stock-based Compensation Expense Total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2022 2021 Research and development $ 1,687 $ 1,588 General and administrative 2,663 1,455 Total stock-based compensation $ 4,350 $ 3,043 Stock Options A summary of stock option activity for three months ended March 31, 2022 is set forth below: Number of Weighted- Weighted- Aggregate Outstanding, December 31, 2021 3,875,317 $ 14.08 8.85 $ 13,212 Options authorized — Options granted 1,555,000 $ 14.59 Options exercised ( 10,099 ) $ 9.29 Options forfeited or cancelled ( 44,073 ) $ 14.21 Outstanding, March 31, 2022 5,376,145 $ 14.24 8.89 $ 30,825 Options exercisable, March 31, 2022 1,296,481 $ 13.67 8.45 $ 8,174 Vested and expected to vest, March 31, 2022 5,376,145 $ 14.24 8.89 $ 30,825 The assumptions used in the Black Scholes Model to calculate stock-based compensation are as follows: Three Months Ended March 31, 2022 2021 Fair value of common stock $ 11.93 - $ 19.97 $ 8.33 - $ 11.39 Expected term (years) 5.8 - 6.1 5.9 - 6.1 Volatility 77.4 % - 77.7 % 79.2 % - 79.8 % Risk free rates 1.6 % - 2.4 % 0.7 % - 0.9 % Dividend rate 0.0 % 0.0 % Restricted Stock Units In August 2021, the Company granted 210,750 restricted stock units (RSUs) to employees with a weighted-average grant date fair value of $ 7.12 per share. In October 2021, the Company granted 560,000 RSUs with service and performance conditions to certain employees, 224,000 of which vested during the three months ended March 31, 2022. Vesting of these awards is contingent on the occurrence of certain milestone events and fulfilment of any remaining service condition. As a result, the related compensation cost is recognized as an expense when achievement of the milestone is considered probable. The expense recognized for these awards is based on the grant date fair value of the Company's common stock multiplied by the number of units granted. The Company recognized $ 1.1 million of related expense during the three months ended March 31, 2022. The summary of RSU activity and related information follows: Number of Units Outstanding Weighted- Outstanding, December 31, 2021 771,660 $ 7.84 RSUs granted — - RSUs Vested ( 224,000 ) $ 8.02 RSUs forfeited ( 9,000 ) $ 7.12 Outstanding, March 31, 2022 538,660 $ 7.75 Summary of Plans The Company has a 2014 Share Option Plan (the 2014 Plan), 2015 Stock Incentive Plan (the 2015 Plan), 2017 Stock Incentive Plan (the 2017 Plan), 2018 Stock Incentive Plan (the 2018 Plan), and 2018 Employee Stock Purchase Plan (the 2018 ESPP, and, collectively with the 2014 Plan, the 2015 Plan, the 2017 Plan and the 2018 Plan, the Plans). There have been no material changes in the Plans from those disclosed in Note 18 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The 2017 Plan and 2018 Plan As of March 31, 2022 , the number of shares of common stock available for grant under the 2017 and 2018 Plan is 2,641,835 shares. As of March 31, 2022 , an aggregate of 4,234,328 shares of common stock were issuable upon the exercise of outstanding stock options under the 2017 Plan and 2018 Plans at a weighted average exercise price of $ 15.03 per share. Included in this amount was a grant of 6,410 PSUs, 210,750 RSUs and 560,000 RSUs the Company granted in May 2021, August 2021 and October 2021, respectively. The 2014 Plan and 2015 Plan As of March 31, 2022 , the number of shares of common stock available for grant under the 2014 and 2015 Plans is 13,418 . As of March 31, 2022 , an aggregate of 1,171,193 shares of Former Adicet common stock were issuable upon the exercise of outstanding stock options under the 2015 plan at a weighted average exercise price of $ 11.89 per share and an aggregate of 185,396 shares of Former Adicet common stock were issuable upon the exercise of outstanding stock options under the 2014 Plan at a weighted average exercise price of $ 1.61 per share. 2018 Employee Stock Purchase Plan On January 1, 2022, as a result of the foregoing evergreen provision, the number of shares of common stock available for issuance under the 2018 ESPP automatically increased from 524,775 to 922,144 shares. No shares have been issued under the 2018 ESPP during the three months ended March 31, 2022. Inducement Grant As of March 31, 2022, an aggregate of 486,303 shares of common stock were issuable upon the exercise of inducement grants of stock options approved by the Company in accordance with Nasdaq listing Rule 5635(c)(4) at a weighted average exercise price of $ 14.52 per share.

Net Income (Loss) per Share

Net Income (Loss) per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net Income (Loss) per Share	13. Net Income (Loss) per Share The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share data): Three Months Ended March 31, 2022 2021 Net income (loss) attributable to common stockholders - basic and diluted $ 4,618 $ ( 21,319 ) Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, basic 39,823,246 26,099,954 Effect of dilutive securities: Stock options 5,376,145 — Unvested restricted stock awards 538,660 — Common stock warrants 220,890 — Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, diluted 45,958,941 26,099,954 Net income (loss) per share attributable to common stockholders, basic $ 0.12 $ ( 0.82 ) Net income (loss) per share attributable to common stockholders, diluted $ 0.10 $ ( 0.82 ) For the three months ended March 31, 2021, 4,767,007 options to purchase common stock and 220,890 common stock warrants were excluded from the computation of diluted net loss per share attributable to common stockholders because their effect was antidilutive.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The Company recognized no income tax expense during the three months ended March 31, 2022 , compared to an income tax benefit of $ 48,000 during the three months ended March 31, 2021. The income tax benefit during the three months ended March 31, 2021 was due to the tax effect of the reduction in the deferred tax liability associated with the basis differences from IPR&D. The Company maintains a full valuation allowance against its deferred tax assets due to the Company’s history of losses as of March 31, 2022 .

Related Party

Related Party	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party	15. Related Party As of March 31, 2022 , Regeneron owned 883,568 shares of the Company’s common stock, respectively. Regeneron became a related party in July 2019 as a result of Series B redeemable convertible preferred stock financing. For the three months ended March 31, 2022 , the Company recorded revenue from the Regeneron Agreement of $ 25.0 million. See Note 8 for a discussion of the Regeneron Agreement.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited interim 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).
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited consolidated financial statements as of March 31, 2022 and for the three months ended March 31, 2022 and 2021, have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (SEC), for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position as of March 31, 2022 and consolidated results of operations for the three months ended March 31, 2022 and 2021 and consolidated cash flows for the three months ended March 31, 2022 and 2021 have been made. The results of operations for the three months ended March 31, 2022 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2022.
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. 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 all of the Company’s revenue for the three months ended March 31, 2022 and 2021 (see Note 8).
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. The current COVID-19 (coronavirus) pandemic, which is impacting worldwide economic activity, poses the risk that the Company or its employees, contractors, suppliers, and other partners may be prevented from conducting business activities for an indefinite period of time, including due to shutdowns that may be requested or mandated by governmental authorities. The extent to which the coronavirus impacts the Company’s operations will depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration of the outbreak, new information that will emerge concerning the severity of the coronavirus and the actions to contain the coronavirus or treat its impact, among others. COVID-19 may impact the timing of regulatory review and clearance of investigational new drugs (INDs) for clinical trials, the enrollment of any clinical trials that are allowed to proceed, the availability of clinical trial materials and regulatory approval and commercialization of our product candidates. COVID-19 may also impact the Company’s ability to access capital, which could negatively impact short-term and long-term liquidity.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB 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 July 2021, FASB issued ASU No. 2021-05, Lease (Topic 842), Lessors - Certain Leases with Variable Lease Payments (ASU 2021-05). ASU 2021-05 amends the lease classification requirements for lessors when classifying and accounting for a lease with variable lease payments that do not depend on a reference rate index or a rate. The update provides criteria, that if met, the lease would be classified and accounted for as an operating lease. ASU 2021-05 is effective for reporting periods beginning after December 15, 2021, with early adoption permitted. The Company adopted ASU 2021-05 in the first quarter of 2022. The impact on its consolidated financial statements and related disclosures was not material. Accounting Pronouncements Not Yet Adopted 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 plans to adopt the provisions of ASU 2016-13 effective January 1, 2023 and is currently evaluating the impact the adoption of this ASU will have on its consolidated financial statements and related disclosures. 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 plans to adopt the provisions of ASU 2017-04 effective January 1, 2023 and is currently evaluating the impact the adoption of this ASU will have on its consolidated financial statements and related disclosures.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in the Company’s IPR&D and CVR since the Merger	The following tables present changes in the Company’s IPR&D and CVR since the merger (in thousands): Acquisition Date Change in As of Change in As of In-process research and development $ 3,490 $ ( 2,300 ) $ 1,190 $ ( 1,190 ) $ — Contingent Value Rights $ 2,880 $ ( 1,900 ) $ 980 $ ( 980 ) $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured on Recurring Basis	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): March 31, 2022 Level 1 Level 2 Level 3 Total Assets: Money market funds (1) (2) $ 147,075 $ — $ — $ 147,075 Total fair value of assets $ 147,075 $ — $ — $ 147,075 December 31, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds (1) (2) $ 147,071 $ — $ — $ 147,071 Total fair value of assets $ 147,071 $ — $ — $ 147,071 (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 .

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2022
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): March 31, December 31, Prepaid insurance $ 1,414 $ 1,021 Prepayments to CROs 1,031 1,658 Prepaid maintenance 1,128 115 Prepayments to CMOs 31 1,884 Other prepaid expenses and current assets 45 31 Total prepaid expenses and other current assets $ 3,649 $ 4,709

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): Useful life March 31, December 31, Laboratory equipment 3 $ 5,641 $ 5,502 Leasehold improvements Lesser of useful life or lease term 1,606 1,614 Furniture and fixtures 3 303 303 Construction in progress — 16,328 13,014 Computer equipment 3 166 216 Software 3 328 320 24,372 20,969 Less: Accumulated depreciation and amortization ( 6,636 ) ( 6,326 ) Property and equipment, net $ 17,736 $ 14,643

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Summary of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): March 31, December 31, Accrued compensation $ 2,314 $ 4,020 Accrued CMO costs 1,617 1,077 Accrued professional services 783 546 Accrued other research and development expenses 418 504 Accrued other liabilities 53 503 Accrued CRO costs 18 32 Total accrued and other liabilities $ 5,203 $ 6,682

Regeneron License and Collabo_2

Regeneron License and Collaboration Arrangement (Tables)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Change in Company's Contract Liabilities	The following tables present changes in the Company’s contract liabilities for the three months ended March 31, 2022 and 2021 (in thousands): Three Months Ended March 31, 2022 Balance at Additions (Deductions) Balance at Contract liability $ 4,805 $ ( 4,805 ) $ — Three Months Ended March 31, 2021 Balance at Additions (Deductions) Balance at Contract liability $ 13,980 $ 3,981 $ 17,961 (1) Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period. (2) Additions are the result of a reduction to cumulative revenue recognized as a result of a change in overall estimated costs, primarily due to an extension of time to fulfill the combined performance obligation, which was recorded as a change in estimate during the three months ended March 31, 2021.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
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 quarter ended March 31, 2022 (in thousands): March 31, 2022 Lease Cost Operating lease cost $ 1,007 Short-term lease cost 143 Variable lease cost — Sublease Income ( 167 ) Total lease cost $ 983 Other Information Operating cash flows used for lease liabilities $ 511 Operating lease right of use asset obtained in exchange of operating lease liability $ — Weighted-average remaining lease term - operating leases 7.5 Weighted-average discount rate - operating leases 7.1 %
Schedule Of Sublease Income	The expected sublease income as of March 31, 2022 is as follows (in thousands): March 31, 2022 $ 493 2023 671 2024 685 2025 699 2026 416 Total $ 2,964
Schedule of Future Minimum Lease Payments	The future minimum lease payments under all non-cancelable operating lease obligations as of March 31, 2022 were as follows (in thousands): March 31, 2022 $ 2,582 2023 3,428 2024 3,525 2025 3,625 2026 and thereafter 13,747 Total undiscounted lease payments 26,907 Less: imputed interest 6,324 Total operating lease liability 20,583 Less: current portion 1,733 Operating lease liability, net of current maturities $ 18,851

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Stockholders' Equity Note [Abstract]
Schedule Of Outstanding Warrants To Purchase Shares of Common Stock	As of March 31, 2022, the Company’s outstanding warrants to purchase shares of common stock, consisted of the following: Issuance Date Number of Shares of Common Stock Issuable Exercise Price Classification Expiration Date September 15, 2020 101,610 $ 11.3177 Equity July 25, 2026 September 15, 2020 30,924 $ 11.3177 Equity August 21, 2026 September 15, 2020 77,312 $ 11.3177 Equity September 19, 2026 September 15, 2020 11,044 $ 11.3177 Equity September 26, 2026 220,890
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: March 31, December 31, Stock options available for future grant 3,531,453 1,961,338 Stock options issued and outstanding 5,376,145 3,875,317 Unvested restricted stock units 538,660 771,660 Common stock warrants issued and outstanding 220,890 220,890 Total common stock reserved 9,667,148 6,829,205

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense	Total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2022 2021 Research and development $ 1,687 $ 1,588 General and administrative 2,663 1,455 Total stock-based compensation $ 4,350 $ 3,043
Summary of Stock Option Activity	A summary of stock option activity for three months ended March 31, 2022 is set forth below: Number of Weighted- Weighted- Aggregate Outstanding, December 31, 2021 3,875,317 $ 14.08 8.85 $ 13,212 Options authorized — Options granted 1,555,000 $ 14.59 Options exercised ( 10,099 ) $ 9.29 Options forfeited or cancelled ( 44,073 ) $ 14.21 Outstanding, March 31, 2022 5,376,145 $ 14.24 8.89 $ 30,825 Options exercisable, March 31, 2022 1,296,481 $ 13.67 8.45 $ 8,174 Vested and expected to vest, March 31, 2022 5,376,145 $ 14.24 8.89 $ 30,825
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: Three Months Ended March 31, 2022 2021 Fair value of common stock $ 11.93 - $ 19.97 $ 8.33 - $ 11.39 Expected term (years) 5.8 - 6.1 5.9 - 6.1 Volatility 77.4 % - 77.7 % 79.2 % - 79.8 % Risk free rates 1.6 % - 2.4 % 0.7 % - 0.9 % Dividend rate 0.0 % 0.0 %
Summary of Restricted Stock Unit Activity	The summary of RSU activity and related information follows: Number of Units Outstanding Weighted- Outstanding, December 31, 2021 771,660 $ 7.84 RSUs granted — - RSUs Vested ( 224,000 ) $ 8.02 RSUs forfeited ( 9,000 ) $ 7.12 Outstanding, March 31, 2022 538,660 $ 7.75

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2022
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 attributable to common stockholders (in thousands, except share and per share data): Three Months Ended March 31, 2022 2021 Net income (loss) attributable to common stockholders - basic and diluted $ 4,618 $ ( 21,319 ) Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, basic 39,823,246 26,099,954 Effect of dilutive securities: Stock options 5,376,145 — Unvested restricted stock awards 538,660 — Common stock warrants 220,890 — Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, diluted 45,958,941 26,099,954 Net income (loss) per share attributable to common stockholders, basic $ 0.12 $ ( 0.82 ) Net income (loss) per share attributable to common stockholders, diluted $ 0.10 $ ( 0.82 )

Organization and Nature of the

Organization and Nature of the Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2021	Dec. 31, 2021	Mar. 31, 2022
Schedule Of Equity Method Investments [Line Items]
Accumulated deficit		$ (168,324)	$ (163,706)
Adicet Therapeutics [Member]
Schedule Of Equity Method Investments [Line Items]
Accumulated deficit			$ (163,700)
Initial Public Offering
Schedule Of Equity Method Investments [Line Items]
Number of common stock shares sold	10,575,513	7,187,500
Issuance price per shares	$ 13	$ 14
Underwriting discounts and commissions and other offering expenses	$ 137,500	$ 94,200
Net proceeds received from offering	$ 15,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - Customer	Mar. 31, 2022	Mar. 31, 2021
Accounting Policies [Abstract]
Number of Customer	1	1

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	Jul. 27, 2021	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Impairment charges		$ 500	$ 700	$ 2,300
Goodwill					$ 19,462	$ 19,462
Expiration period termination notice	60 days
resTORbio
Business Acquisition [Line Items]
Goodwill					$ 19,500

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of changes in the Company's IPR&D and CVR since the Merger (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Sep. 15, 2020
In Process Research and Development
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value	$ 0	$ 1,190	$ 3,490
In Process Research and Development | Change in Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value	(1,190)	(2,300)
Contingent Value Rights Agreement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value	0	980	$ 2,880
Contingent Value Rights Agreement | Change in Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value	$ (980)	$ (1,900)

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets		$ 147,075	$ 147,071
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets		147,075	147,071
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets		0	0
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets		0	0
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets	[1],[2]	147,075	147,071
Money Market Funds | Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets	[1],[2]	147,075	147,071
Money Market Funds | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets	[1],[2]	0	0
Money Market Funds | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of assets	[1],[2]	$ 0	$ 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

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid insurance	$ 1,414	$ 1,021
Prepayments to CROs	1,031	1,658
Prepaid maintenance	1,128	115
Prepayments to CMOs	31	1,884
Other prepaid expenses and current assets	45	31
Total prepaid expenses and other current assets	$ 3,649	$ 4,709

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 24,372	$ 20,969
Less: Accumulated depreciation and amortization	(6,636)	(6,326)
Property and equipment, net	17,736	14,643
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 5,641	5,502
Useful life (in years)	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 1,606	1,614
Useful life (in years)	Lesser of useful life or lease term
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	$ 303	303
Useful life (in years)	3 years
Construction In Progress
Property Plant And Equipment [Line Items]
Total property and equipment	$ 16,328	13,014
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 166	216
Useful life (in years)	3 years
Software
Property Plant And Equipment [Line Items]
Total property and equipment	$ 328	$ 320
Useful life (in years)	3 years

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 18, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 352	$ 326
Increase in construction in progress	$ 3,300
Consideration for construction			$ 13,800
Increase in construction budget			$ 5,300

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Summary of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued compensation	$ 2,314	$ 4,020
Accrued CMO costs	1,617	1,077
Accrued professional services	783	546
Accrued other research and development expenses	418	504
Accrued other liabilities	53	503
Accrued CRO costs	18	32
Total accrued and other liabilities	$ 5,203	$ 6,682

Regeneron License and Collabo_3

Regeneron License and Collaboration Arrangement - Additional Information (Details) - USD ($)	Jan. 28, 2022	Jul. 31, 2019	Jul. 29, 2016	Mar. 31, 2022	Mar. 31, 2021	Jun. 30, 2020	Dec. 31, 2018	Dec. 31, 2017
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract Assets				$ 0
Licence agreement cumulative revenue recognised					$ 27,000
Regeneron Pharmaceuticals, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Exercise Fee Paid	$ 20,000,000
Contingent Consideration fees			$ 20,000,000
Option exercise fee				20,000,000
Agreement transaction price			55,000,000
Licence agreement additional revenue recognised				25,000,000
Research funding fee			30,000,000
Non refundable upfront payment received				25,000,000
Additional payment for research funding received			$ 30,000,000	$ 20,000,000			$ 5,000,000	$ 5,000,000
License agreement termination description				twelve years
Contract research term period			5 years
Upfront payment			$ 25,000,000		25,000,000
Licence agreement cumulative revenue recognised						$ 10,000,000
Increase in estimated transaction price		$ 35,000,000
Contract liability				$ 0	$ 18,000,000
Regeneron Pharmaceuticals, Inc. | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Licence agreement additional amount payable of option exercise fees				$ 100,000,000
Increase in estimated transaction price						45,000,000
Regeneron Pharmaceuticals, Inc. | Minimum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Increase in estimated transaction price						$ 10,000,000

Regeneron License and Collabo_4

Regeneron License and Collaboration Arrangement - Summary of Change in Company's Contract Liabilities (Details) - Contract Liability - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Balance at beginning of period		$ 4,805	$ 13,980
Additions (Deductions) (1)	[1],[2]	(4,805)	(3,981)
Balance at end of period		$ 0	$ 17,961
[1]	Additions are the result of a reduction to cumulative revenue recognized as a result of a change in overall estimated costs, primarily due to an extension of time to fulfill the combined performance obligation, which was recorded as a change in estimate during the three months ended March 31, 2021.
[2]	Deductions to contract liabilities relate to deferred revenue recognized as revenue during the reporting period.

License Funding and Other Agr_2

License Funding and Other Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 31, 2019	Mar. 31, 2022
Research And Development Arrangement Contract To Perform For Others [Line Items]
Exercised Investment Right and Purchased		$ 10,000
National Institute of Health
Research And Development Arrangement Contract To Perform For Others [Line Items]
Grant term	5 years
Grants receivable	$ 1,500
Qualifying expenses		0
Qualifying expenses on cumulative basis		1,300
National Institute of Health | Funding Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Qualifying expenses		0
Qualifying expenses on cumulative basis		$ 1,300

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	Jul. 19, 2021USD ($)ft²	Mar. 31, 2022USD ($)
Long Term Purchase Commitment [Line Items]
Operating Lease, Liability		$ 20,583
RFS OPCO LLC [Member]
Long Term Purchase Commitment [Line Items]
Area of Sublease | ft²	9,501
Operating Leases, Rent Expense, Sublease Rentals	$ 3,500
Cash security deposit received	$ 100
Sublease Agreement Description	The term of the sublease started on September 1, 2021 and ends on July 30, 2026. The aggregate base rent due to the Company under the Sublease is approximately $3.5 million which began on October 1, 2021.
Boston Properties, Inc. [Member]
Long Term Purchase Commitment [Line Items]
Operating Lease, Liability		$ 3,100

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Lease Costs and Other Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Lease Cost
Operating lease cost	$ 1,007
Short-term lease cost	143
Variable lease cost	0
Sublease Income	(167)
Lease, Cost, Total	983
Other Information
Operating cash flows used for lease liabilities	511
Operating lease right of use asset obtained in exchange of operating lease liability	$ 0
Weighted-average remaining lease term - operating leases	7 years 6 months
Weighted-average discount rate - operating leases	7.10%

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Sublease Income (Details) $ in Thousands	Mar. 31, 2022USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022	$ 493
2023	671
2024	685
2025	699
2026	416
Total	$ 2,964

Commitments and Contingencies_4

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022	$ 2,582
2023	3,428
2024	3,525
2025	3,625
2026 and thereafter	13,747
Total undiscounted lease payments	26,907
Less: imputed interest	6,324
Total operating lease liability	20,583
Less: current portion	1,733	$ 1,567
Operating lease liability, net of current portion	$ 18,851	$ 19,377

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, shares authorized		150,000,000	150,000,000	150,000,000
Dividends Payable	$ 0
Common stock shares issued, par value		$ 0.0001	$ 0.0001	$ 0.0001

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Outstanding Warrants to Purchase Shares of Common Stock (Details)	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Class Of Stock [Line Items]
Number of Shares of Common Stock Issuable	220,890
September 15, 2020 Warrant One
Class Of Stock [Line Items]
Issuance Date	Sep. 15, 2020
Number of Shares of Common Stock Issuable	101,610
Warrant exercise price | $ / shares	$ 11.3177
Expiration Date	Jul. 25, 2026
September 15, 2020 Warrant Two
Class Of Stock [Line Items]
Issuance Date	Sep. 15, 2020
Number of Shares of Common Stock Issuable	30,924
Warrant exercise price | $ / shares	$ 11.3177
Expiration Date	Aug. 21, 2026
September 15, 2020 Warrant Three
Class Of Stock [Line Items]
Issuance Date	Sep. 15, 2020
Number of Shares of Common Stock Issuable	77,312
Warrant exercise price | $ / shares	$ 11.3177
Expiration Date	Sep. 19, 2026
September 15, 2020 Warrant Four
Class Of Stock [Line Items]
Issuance Date	Sep. 15, 2020
Number of Shares of Common Stock Issuable	11,044
Warrant exercise price | $ / shares	$ 11.3177
Expiration Date	Sep. 26, 2026

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Number of Shares of Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	9,667,148	6,829,205
Unvested Restricted Stock Units
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	538,660	771,660
Stock Options Available for Future Grant
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	3,531,453	1,961,338
Options Issued and Outstanding
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	5,376,145	3,875,317
Common Stock Warrants
Class Of Stock [Line Items]
Number of shares of common stock reserved for future issuance	220,890	220,890

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 4,350	$ 3,043
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	1,687	1,588
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,663	$ 1,455

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Noncash Expense [Abstract]
Number of Shares Underlying Outstanding Options, Beginning balance	3,875,317
Options authorized
Number of Shares Underlying Outstanding Options, Options granted	1,555,000
Number of Shares Underlying Outstanding Options, Options exercised	(10,099)
Number of Shares Underlying Outstanding Options, Options forfeited or cancelled	(44,073)
Number of Shares Underlying Outstanding Options, Ending balance	5,376,145	3,875,317
Number of Shares Underlying Outstanding Options exercisable	1,296,481
Number of Shares Underlying Outstanding Options, Vested and expected to vest	5,376,145
Weighted-Average Exercise Price, Outstanding beginning	$ 14.08
Weighted-Average Exercise Price, Options granted	14.59
Weighted-Average Exercise Price, Options exercised	9.29
Weighted-Average Exercise Price, Options forfeited or cancelled	14.21
Weighted-Average Exercise Price, Outstanding ending	14.24	$ 14.08
Weighted-Average Exercise Price, Options exercisable	13.67
Weighted-Average Exercise Price, Vested and expected to vest	$ 14.24
Weighted-Average Remaining Contract Term, Outstanding	8 years 10 months 20 days	8 years 10 months 6 days
Weighted-Average Remaining Contract Term, Options exercisable	8 years 5 months 12 days
Weighted-Average Remaining Contract Term, Vested and expected to vest	8 years 10 months 20 days
Aggregate Intrinsic Value, Outstanding	$ 30,825	$ 13,212
Aggregate Intrinsic Value, Options exercisable	8,174
Aggregate Intrinsic Value, Vested and expected to vest	$ 30,825

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2022	Jan. 01, 2021	Oct. 31, 2021	Aug. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Oct. 21, 2021	May 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted (includes PSUs)					1,555,000
Expense related to options granted					$ 4,350	$ 3,043
Number of shares of common stock available for grant							560,000
Weighted-Average Exercise Price, Options exercised					$ 9.29
2017 and 2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant					2,641,835
Number of shares reserved for issuance					4,234,328
Weighted-Average Exercise Price, Options exercised					$ 15.03
2014 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					185,396
Weighted-Average Exercise Price, Options exercised					$ 1.61
2015 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant					13,418
Number of shares reserved for issuance					1,171,193
Weighted-Average Exercise Price, Options exercised					$ 11.89
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance	922,144	524,775
Number of shares available for sale under employee stock purchase plan
Inducement Grant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					486,303
Weighted-Average Exercise Price, Options exercised					$ 14.52
Performance Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant								6,410
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted (includes PSUs)			560,000
Expense related to options granted					$ 1,100
Weighted-Average Grant Date Fair Value,Vested					$ 8.02
Number of shares of common stock available for grant				210,750
Weighted-Average Exercise Price, Options exercised				$ 7.12

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model (Details) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	77.40%	79.20%
Expected volatility, maximum	77.70%	79.80%
Risk free rates, minimum	1.60%	0.70%
Risk free rates, maximum	2.40%	0.90%
Dividend rate	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 11.93	$ 8.33
Expected term	5 years 9 months 18 days	5 years 10 months 24 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 19.97	$ 11.39
Expected term	6 years 1 month 6 days	6 years 1 month 6 days

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of Restricted Stock Unit Activity (Details) - RSUs [Member]	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, December 31, 2021 | shares	771,660
RSUs granted | shares
RSUs Vested | shares	224,000
RSUs forfeited | shares	9,000
Outstanding, March 31, 2022 | shares	538,660
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date Fair Value, Beginning | $ / shares	$ 7.84
Weighted-Average Grant Date Fair Value, Granted | $ / shares
Weighted-Average Grant Date Fair Value,Vested | $ / shares	8.02
Weighted-Average Grant Date Fair Value, Forfeited | $ / shares	7.12
Weighted-Average Grant Date Fair Value, Ending | $ / shares	$ 7.75

Net Income (Loss) per Share - S

Net Income (Loss) per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income (loss) attributable to common stockholders - basic and diluted	$ 4,618	$ (21,319)
Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, basic	39,823,246	26,099,954
Effect of dilutive securities:
Stock options	$ 5,376,145	$ 0
Unvested restricted stock awards	538,660	0
Common stock warrants	$ 220,890	$ 0
Weighted-average shares used in computing net income (loss) per share attributable to common shareholders, diluted	45,958,941	26,099,954
Net income (loss) per share attributable to common stockholders, basic	$ 0.12	$ (0.82)
Net income (loss) per share attributable to common stockholders, diluted	$ 0.10	$ (0.82)

Net Income (Loss) per Share (Ad

Net Income (Loss) per Share (Additional Information) (Details)	3 Months Ended
	Mar. 31, 2021shares
Common Stock Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	220,890
Options To Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	4,767,007

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Taxes Disclosure [Line Items]
Income tax benefit	$ 0	$ (48)
COVID-19
Income Taxes Disclosure [Line Items]
Income tax benefit	$ 0	$ 48,000

Related Party - Additional Info

Related Party - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Redeemable convertible preferred stock			0	0
Revenue—related party	$ 24,990	$ (3,981)
Regeneron Pharmaceuticals, Inc.
Related Party Transaction [Line Items]
Revenue—related party	$ 25,000
Regeneron Pharmaceuticals, Inc. | Series B Convertible Preferred Stock [ Member ]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock	883,568