0001785530-23-000009 | 10-K | XBRL Viewer | Werewolf Therapeutics INC

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Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Mar. 17, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-40366
Entity Registrant Name	WEREWOLF THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3523180
Entity Address, Address Line One	200 Talcott Ave
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	Watertown
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02472
City Area Code	617
Local Phone Number	952‑0555
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	HOWL
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 59,285,867
Entity Common Stock, Shares Outstanding		35,279,820
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement on Schedule 14A relating to its 2023 Annual Meeting of Stockholders to be filed within 120 days of the registrant’s fiscal year ended December 31, 2022 are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.
Entity Central Index Key	0001785530
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Audit Information [Line Items]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	Boston, Massachusetts
Deloitte & Touche LLP
Audit Information [Line Items]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Boston, Massachusetts

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 129,315	$ 157,531
Prepaid expenses and other current assets	3,957	3,537
Other receivables (due from collaborations)	6,928	0
Total current assets	140,200	161,068
Property and equipment, net	8,988	2,913
Restricted cash	1,214	1,208
Operating lease right of use asset	8,463	13,412
Other non-current assets	1,380	649
Total assets	160,245	179,250
Current liabilities:
Accounts payable	1,221	2,037
Accrued expenses and other current liabilities	14,152	8,765
Operating lease liability, current	2,084	1,072
Deferred revenue, current	6,532	0
Total current liabilities	23,989	11,874
Operating lease liability, net of current portion	12,600	14,589
Deferred revenue, net of current portion	1,128	0
Other liabilities	191	0
Total liabilities	37,908	26,463
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value, 5,000 shares authorized as of December 31, 2022 and December 31, 2021; no shares issued or outstanding as of December 31, 2022 or December 31, 2021	0	0
Common stock, $0.0001 par value, 200,000 shares authorized as of December 31, 2022 and December 31, 2021; 31,515 and 27,608 shares issued as of December 31, 2022 and December 31, 2021, respectively; 31,434 and 27,313 shares outstanding as of December 31, 2022 and December 31, 2021, respectively	3	2
Additional paid-in capital	429,039	405,680
Accumulated deficit	(306,705)	(252,895)
Total stockholders’ equity	122,337	152,787
Total liabilities and stockholders’ equity	$ 160,245	$ 179,250

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (shares)	5,000,000
Preferred stock issued (shares)	0	0
Preferred stock outstanding (shares)	0	0
Common stock par value (usd per share)	$ 0.0001	$ 0.0001
Common stock authorized (shares)	200,000,000
Common stock issued (shares)	31,515,000	27,608,000
Common stock outstanding (shares)	31,434,000	27,313,000

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue:
Collaboration revenue	$ 16,401	$ 0
Operating expenses:
Research and development	53,761	35,269
General and administrative	18,696	14,818
Total operating expenses	72,457	50,087
Operating loss	(56,056)	(50,087)
Other income:
Other income, net	338	0
Interest income	1,908	104
Total other income	2,246	104
Net loss	(53,810)	(49,983)
Accretion of redeemable convertible preferred stock to redemption value	0	(151,942)
Net loss attributable to common stockholders	(53,810)	(201,925)
Net loss attributable to common stockholders	$ (53,810)	$ (201,925)
Net loss per share attributable to common stockholders, basic and diluted
Net loss per share attributable to common stockholders, basic (usd per share)	$ (1.86)	$ (10.94)
Net loss per share attributable to common stockholders, diluted (usd per share)	$ (1.86)	$ (10.94)
Weighted-average common shares outstanding, basic and diluted
Weighted average common shares outstanding, basic (shares)	28,864	18,455
Weighted average common shares outstanding, diluted (shares)	28,864	18,455

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity - USD ($) shares in Thousands, $ in Thousands	Total	Series A Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock	Common Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Redeemable convertible preferred stock outstanding, beginning balance (shares) at Dec. 31, 2020		80,247	78,222
Redeemable convertible preferred stock outstanding, beginning balance at Dec. 31, 2020		$ 69,012	$ 72,070
Increase (Decrease) in Temporary Equity [Roll Forward]
Accretion of redeemable convertible preferred stock to redemption value		$ 79,372	$ 72,570
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering (in shares)		(80,247)	(78,222)
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering		$ (148,384)	$ (144,640)
Redeemable convertible preferred stock outstanding, ending balance (shares) at Dec. 31, 2021		0	0
Redeemable convertible preferred stock outstanding, ending balance at Dec. 31, 2021		$ 0	$ 0
Stockholders' equity, beginning balance (shares) at Dec. 31, 2020					1,746
Stockholders' equity, beginning balance at Dec. 31, 2020	$ (51,863)				$ 2	$ 0	$ (51,865)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from initial public offering, net of issuance costs (shares)				7,500
Issuance of common stock from at the market offering, net of issuance costs	109,221					109,221
Accretion of redeemable convertible preferred stock to redemption value	(151,942)					(895)	(151,047)
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering (shares)				18,280
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering	293,024					293,024
Stock-based compensation expense	4,095					4,095
Stock option exercises (shares)					82
Stock option exercises	235					235
Net loss	(49,983)						(49,983)
Stockholders' equity, ending balance (shares) at Dec. 31, 2021					27,608
Stockholders' equity, ending balance at Dec. 31, 2021	152,787				$ 2	405,680	(252,895)
Redeemable convertible preferred stock outstanding, ending balance (shares) at Dec. 31, 2022		0	0
Redeemable convertible preferred stock outstanding, ending balance at Dec. 31, 2022		$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from initial public offering, net of issuance costs (shares)					3,827
Issuance of common stock from at the market offering, net of issuance costs	15,736					15,735
Stock-based compensation expense	7,400					7,400
Stock option exercises (shares)					80
Stock option exercises	224					224
Net loss	(53,810)						(53,810)
Stockholders' equity, ending balance (shares) at Dec. 31, 2022					31,515
Stockholders' equity, ending balance at Dec. 31, 2022	$ 122,337				$ 3	$ 429,039	$ (306,705)

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ (Deficit) Equity (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 455	$ 2,379

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating activities:
Net loss	$ (53,810)	$ (49,983)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	7,400	4,095
Depreciation expense	1,104	216
Non-cash lease expense	1,406	519
Change in fair value of success payment liability	555	0
Amortization of debt issuance costs	203	0
Loss on disposal of property and equipment	7	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(541)	(3,072)
Other receivables	(6,928)	0
Other non-current assets	279	(649)
Accounts payable	(883)	1,007
Accrued expenses and other current liabilities	3,738	5,263
Deferred revenue	7,660	0
Right of use assets and operating lease liability	(977)	(241)
Other liabilities	191	(31)
Net cash used in operating activities	(40,596)	(42,876)
Investing activities:
Purchases of property and equipment	(3,611)	(498)
Net cash used in investing activities	(3,611)	(498)
Financing activities:
Proceeds from at the market offering of common stock	16,191	0
Proceeds from initial public offering of common stock	0	111,600
Payment of equity issuance costs	(451)	(2,378)
Deferred financing costs	(88)	0
Proceeds from stock option exercises	254	205
Net cash provided by financing activities	15,906	109,427
Net (decrease) increase in cash and cash equivalents	(28,301)	66,053
Cash, cash equivalents and restricted cash—beginning of period	158,830	92,777
Cash, cash equivalents and restricted cash—end of period	130,529	158,830
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Cash paid for lease liabilities	1,806	1,035
Supplemental disclosure of non-cash investing and financing activities:
Stock option exercise receivables in prepaid expenses and other current assets	0	30
Purchases of property and equipment in accounts payable and accrued expenses	111	79
Issuance costs in accounts payable and accrued expenses	4	0
Right of use assets obtained in exchange for lease liabilities	0	13,658
Accretion of Series A and Series B redeemable convertible preferred stock	$ 0	$ 151,942

Nature of Business	12 Months Ended
Nature of Business	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Werewolf Therapeutics, Inc. (“Werewolf” or the “Company”) was incorporated in the state of Delaware in October 2017. The Company is an innovative biopharmaceutical company pioneering the development of therapeutics engineered to stimulate the body’s immune system for the treatment of cancer. The Company’s headquarters are located in Watertown, Massachusetts. Since inception, the Company has devoted substantially all of its time and efforts to performing research and development activities, raising capital and recruiting management and technical staff to support these operations. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The Company had cash and cash equivalents of $129.3 million at December 31, 2022. The Company expects that its cash and cash equivalents will enable it to fund its operating expenses and capital expenditure requirements for at least twelve months from the filing date of this Annual Report on Form 10-K.

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and generally accepted accounting principles in the United States of America (“GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying consolidated financial statements include the accounts of Werewolf Therapeutics, Inc. and its wholly-owned subsidiary, Werewolf Therapeutics Mass Securities, Inc. All intercompany transactions and balances have been eliminated in consolidation. Segment Information Operating segments are identified as components of an enterprise for which separate discrete financial information is available for evaluation by the Company’s Chief Operating Decision Maker (“CODM”) to make decisions with respect to resource allocation and assessment of performance. The CODM is the Company’s Chief Executive Officer. The CODM manages the Company’s operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular concentration is focused on the discovery and development of cancer therapeutics by advancing a novel class of conditionally activated proinflammatory immune modulators. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, estimates related to the application of Revenue from Contracts with Customers (Topic 606) (“ASC 606”) to the Company’s collaboration agreement with Jazz Pharmaceuticals Ireland Limited, the accrual of research and development expenses, the expected future lives of property and equipment, the valuation of stock-based awards, and the success based fee associated with the Company’s debt agreement. Actual results could differ from those estimates. Fair Value of Financial Instruments ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure for Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following: •Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. •Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. •Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Cash and Cash Equivalents The Company’s cash and cash equivalents consist of cash maintained within a standard checking account. The Company also maintains a cash sweep account in which cash from its main operating cash account is invested overnight in highly liquid, short-term investments. The Company considers all highly liquid investments with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Property and Equipment Property and equipment is recorded at cost and consists of laboratory equipment, furniture and office equipment, computer equipment, and leasehold improvements. The Company capitalizes property and equipment that is acquired for research and development activities and that has alternate future use. Expenditures for maintenance and repairs are recorded to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. Leasehold improvements are depreciated over the lesser of their useful life or the term of the lease. Depreciation is calculated over the estimated useful lives of the assets using the straight-line method. Impairment of Long-lived Assets Long-lived assets consist of property and equipment. The Company reviews its property and equipment whenever events or changes in circumstances indicate that the carrying value of certain assets might not be recoverable. If such events or changes in circumstances arise, the Company compares the carrying amount of the long-lived assets to the estimated future undiscounted cash flows expected to be generated by the long-lived assets. If the estimated aggregate undiscounted cash flows are less than the carrying amount of the long-lived assets, an impairment charge, calculated as the amount by which the carrying amount of the assets exceeds the fair value of the assets, is recorded. The fair value of the long-lived assets is determined based on the estimated discounted cash flows expected to be generated from the long-lived assets. The Company has not recorded any material impairment charges during the years presented. Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and short-term and long-term lease liabilities, as applicable. The Company does not recognize leases with terms of one year or less on the balance sheet. Options to renew a lease are not included in the Company’s initial lease term assessment unless there is reasonable certainty that the Company will renew. The Company monitors its plans to renew its material leases on a quarterly basis. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate (“IBR”), which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, and in a similar economic environment. The Company subsequently measures its lease liability at the present value of remaining lease payments, discounted using the IBR for the lease. The right-of-use asset is subsequently measured at the amount of the lease liability, adjusted for prepaid or accrued lease payments and the remaining balance of lease incentives received. The Company recognizes operating lease expense on a straight-line basis over the lease term. Revenue Recognition The Company analyzes its collaborations to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”). For elements of collaboration arrangements that are accounted for pursuant to Topic 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election. For those elements of the arrangement that are accounted for pursuant to ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. In applying ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the promises and performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. As part of the assessment, the Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include reimbursement rates for personnel costs, development timelines and probabilities of regulatory success. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of promised goods or services to the customer will be one year or less. Arrangements that include upfront payments may require deferral of revenue recognition to a future period until obligations under these arrangements are fulfilled. The event-based milestone payments represent variable consideration, and the Company uses the “most likely amount” method to estimate this variable consideration. Given the high degree of uncertainty around the occurrence of these events, the Company determined the milestone and other contingent amounts to be fully constrained until the uncertainty associated with these payments is resolved. Revenue will be recognized from sales-based royalty payments when or as the sales occur. The Company will re-evaluate the transaction price in each reporting period as uncertain events are resolved and other changes in circumstances occur. Research and Development Expenses Expenditures relating to research and development are expensed as incurred. Research and development expenses include external expenses incurred under arrangements with third parties, academic and non-profit institutions and consultants; salaries and personnel-related costs, including non-cash stock-based compensation expense; license fees to acquire in-process technology and other expenses, which include direct and allocated expenses for laboratory, facilities and other costs. Non‑refundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. As part of the process of preparing the consolidated financial statements, the Company is required to estimate its accrued research and development expenses as of each balance sheet date. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. This process involves reviewing open contracts and purchase orders, communicating with internal personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The Company periodically confirms the accuracy of its estimates with its service providers and makes adjustments if necessary. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The financial terms of agreements with these service providers are subject to negotiation, vary from contract to contract and may result in uneven payment flows. In circumstances where amounts have been paid in excess of costs incurred, the Company records a prepaid expense. Intellectual Property Expenses The Company expenses costs associated with intellectual property-related matters as incurred and classifies such costs as general and administrative expenses within the consolidated statements of operations. Stock-based Compensation The Company accounts for stock-based payments in accordance with ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASC 718”). This guidance requires all stock-based payments to employees, including grants of employee stock options and restricted stock awards (“RSAs”), to be recognized as expense in the consolidated statements of operations and comprehensive (loss) income based on their grant date fair values. For stock options granted to employees and to members of the Company’s board of directors for their services on the board of directors, the Company estimates the grant date fair value of each stock option using the Black-Scholes option-pricing model. For restricted stock units (“RSUs”) and RSAs granted to employees, the Company estimates the grant date fair value of each award using intrinsic value, which is based on the value of the underlying common stock less any purchase price. For stock-based payments subject to service-based vesting conditions, the Company recognizes stock-based compensation expense equal to the grant date fair value of stock-based payment on a straight-line basis over the requisite service period. The Black‑Scholes option pricing model requires the input of certain subjective assumptions, including (i) the calculation of expected term of the stock-based payment, (ii) the risk‑free interest rate, (iii) the expected stock price volatility and (iv) the expected dividend yield. The Company uses the simplified method as proscribed by SEC Staff Accounting Bulletin No. 107 to calculate the expected term for stock options granted to employees as the Company does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. The Company determines the risk‑free interest rate based on a treasury instrument whose term is consistent with the expected term of the stock options. Because there had been no public market for the Company’s common stock prior to the Company’s IPO, there is a lack of Company‑specific historical and implied volatility data. Accordingly, the Company bases its estimates of expected volatility on the historical volatility of a group of publicly-traded companies with similar characteristics to itself, including stage of product development and therapeutic focus within the life sciences industry. Historical volatility is calculated over a period of time commensurate with the expected term of the stock-based payment. The Company uses an assumed dividend yield of zero as the Company has never paid dividends on its common stock, nor does it expect to pay dividends on its common stock in the foreseeable future. The Company accounts for forfeitures of all stock-based payments when such forfeitures occur. Income Taxes Income taxes are recorded in accordance with ASU No. 2019-12, Income Taxes (Topic 740) (“ASC 740”) which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a more-likely-than-not threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors, including, but not limited to, changes in the law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. Comprehensive Loss The Company does not have items of other comprehensive loss for the years ended December 31, 2022 and 2021, and therefore does not present a consolidated statement of comprehensive loss. The Company’s comprehensive loss equals its net loss. Net Loss per Common Share Basic net loss per share is calculated based upon the weighted-average number of common shares outstanding during the period, excluding outstanding stock options and RSUs that have been issued but are not yet vested. Diluted net loss per share is calculated based upon the weighted-average number of common shares outstanding during the period plus the dilutive impact of weighted-average common equivalent shares outstanding during the period. The potentially dilutive shares of common stock resulting from the assumed exercise of outstanding stock options and the assumed vesting of RSUs are determined under the treasury stock method. Concentration of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist of cash and cash equivalents. Cash is held in a checking account at two financial institutions. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company has no significant off-balance sheet concentrations of credit risk, such as foreign currency exchange contracts, option contracts or other hedging arrangements. Recent Accounting Pronouncements Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s consolidated financial statements upon adoption. Subsequent Events The Company has evaluated subsequent events and transactions that occurred after the balance sheet date up to the date that the financial statements were issued. Other than as described in these financial statements, the Company did not identify any subsequent events that would have required adjustment to or disclosure in the financial statements.

Jazz Collaboration Agreement

12 Months Ended

Dec. 31, 2022

Business Combination and Asset Acquisition [Abstract]

Jazz Collaboration Agreement

Jazz Collaboration and License Agreement

In April 2022, the Company entered into an exclusive global collaboration and license agreement (the “Collaboration Agreement”) with Jazz Pharmaceuticals Ireland Limited (“Jazz”) pursuant to which the Company granted Jazz certain licenses to develop and commercialize products containing the Company’s Interferon alpha (“IFNα”) INDUKINE™ molecule, JZP898 (formerly WTX-613), as well as products containing certain isolated recombinant polypeptides comprising IFNα that meet specified criteria (each such product, a “Licensed Product”). Under the Collaboration Agreement, the Company is responsible for certain pre-clinical development activities with respect to JZP898 (formerly WTX-613) and other development activities specified in mutually agreed upon development plans. Jazz will generally reimburse the Company for the cost of such activities. Jazz will be responsible for all other development and commercialization activities conducted to exploit the Licensed Products, including submission of an investigational new drug application (“IND”) to the U.S. Food and Drug Administration (the “FDA”).

Under the terms of the Collaboration Agreement, the Company received a non-refundable upfront cash payment of $15.0 million in April 2022.

Milestones and Royalties

The Company is eligible to receive up to $520.0 million in development and regulatory milestones, and up to $740.0 million in sales-based milestones for all Licensed Products. In addition, the Company is eligible to receive tiered mid-single digit royalties based on Jazz’s, and any of its affiliates’ and sublicensees’ annual net sales of Licensed Products, subject to reduction in specified circumstances.

Accounting Analysis under ASC 606

Identification of the Contract(s)

The Company assessed the Collaboration Agreement and concluded that it represents a contract with a customer within the scope of ASC Topic 606, Revenue from Contracts with Customers.

Identification of Promises and Performance Obligations

The Company has concluded that the exclusive license to its intellectual property, JZP898 (formerly WTX-613), and the non-exclusive corresponding “know-how” are not capable of being distinct from the other promises within the contract, and as such, the Company has determined that the license and “know-how” combined with the other research and development services and supply represent a single combined performance obligation.

Determination of Transaction Price

The overall transaction price as of the inception of the contract was determined to be $33.5 million, which is comprised of the nonrefundable upfront payment of $15.0 million and the estimated costs for research services of $18.5 million. Outside of the estimated costs for research services, there is no other variable consideration included in the transaction price at inception. The Company used the most likely amount method to estimate variable consideration and estimated that the most likely amount for each potential development and regulatory milestone payment under this agreement is zero, as achievement of those milestones is uncertain and highly susceptible to factors outside the Company’s control. Accordingly, all such milestone payments were excluded from the transaction price. Management will reevaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, will adjust the transaction price as necessary. Sales based royalties, including milestones based on the level of sales, were also excluded from the transaction price, as the license is deemed to be the predominant item to which the royalties relate. The Company will recognize such revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

The upfront payment of $15.0 million was recorded as deferred revenue and, along with payments related to the Company’s conduct of research services under the Collaboration Agreement, will be recognized as revenue over approximately 3.7 years using an input-based measurement of actual costs incurred as a percentage of the estimated total costs expected to be incurred over the expected term of conduct of the research services. The Company believes this input-based method to recognize revenue best reflects the transfer of value to Jazz.

Recognition of Revenue

For the year ended December 31, 2022, using the cost-to-cost input method, which best depicts the research services performed for the customer, the Company recognized $16.4 million of revenue related to the Collaboration Agreement, of which $7.3 million related to the upfront payment and $9.1 million related to costs incurred for research services. As of December 31, 2022, there is $6.5 million and $1.1 million of current and long-term deferred revenue, respectively, related to the Collaboration Agreement. All costs associated with the Collaboration Agreement are recorded in research and development expense in the consolidated statements of operations.

“Unbilled receivables” of $4.1 million was included within “Other receivables” in the accompanying consolidated balance sheets as of December 31, 2022.

The following table presents changes in the Company’s contract liabilities during the year ended December 31, 2022 (in thousands):


	Balance as of						Balance as of
	December 31, 2021		Additions		Reductions		December 31, 2022
Contract liabilities:
Deferred revenue	$	—	$	15,000	$	(7,340)	$	7,660
Totals	$	—	$	15,000	$	(7,340)	$	7,660

As of December 31, 2022, the Company had not received any milestone or royalty payments under the Collaboration Agreement.

Financial Instruments and Fair Value Measurements

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Financial Instruments and Fair Value Measurements

The Company’s financial instruments that are measured at fair value on a recurring basis consist of money market funds and a success payment liability pursuant to an amended and restated loan and security agreement (the “Loan Agreement”) with Pacific Western Bank (“PWB”) (see Note 8, Term Loan).

The carrying amounts reflected in the consolidated balance sheets for cash, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values, due to their short-term nature.

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2022 were as follows (in thousands):


	Quoted Price in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market funds	$	128,812	$	—	$	—	$	128,812
Total assets	$	128,812	$	—	$	—	$	128,812
Liabilities
Success payment liability	$	—	$	—	$	570	$	570
Total liabilities	$	—	$	—	$	570	$	570

The success payment liability was included within “Accrued expenses and other current liabilities” in the accompanying consolidated balance sheets as of December 31, 2022. There were no changes in valuation techniques during the year ended December 31, 2022.

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2021 were as follows (in thousands):


	Quoted Price in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market funds	$	157,531	$	—	$	—	$	157,531
Total assets	$	157,531	$	—	$	—	$	157,531

There were no liabilities measured at fair value on a recurring basis as of December 31, 2021.

Success Payment Liability

The Company is obligated to pay to PWB a one-time success payment upon the occurrence of the Company achieving certain conditions defined in the Loan Agreement. The maximum aggregate success payment that could be payable by the Company is $1.6 million.

The following table reconciles the change in fair value of the success payment liability during the year ended December 31, 2022 based on Level 3 inputs (in thousands):


	Year Ended December 31, 2022
Balance at December 31, 2021	$	—
Additions	1,125
Change in fair value	(555)
Balance at December 31, 2022	$	570

The success payment liability is stated at fair value and is considered Level 3 because its fair value measurement is based, in part, on significant inputs not observed in the market. The Company models the value of the liability based on several key variables, including probability of event occurrence and timing of event occurrence.

The fair value of the success payment liability was determined using a probability weighted expected return method, in which the probability and timing of potential future events is considered in order to estimate the fair value of the success payment liability as of each valuation date. Management determined the fair value of the success payment liability as of December 31, 2022 using the following significant unobservable inputs:


	As of December 31, 2022
Probability of Success Fee Event	75	%
Expected term (in years)	0.33 - 0.75
Discount rate	7.1	%

Significant increases (decreases) in these inputs could result in a significantly lower or higher fair value measurement. The Company remeasured the liability at fair value with a corresponding decrease of $0.6 million recorded to other income, net for the year ended December 31, 2022.

- Definition

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

+ References + Details

Restricted Cash

12 Months Ended

Dec. 31, 2022

Cash and Cash Equivalents [Abstract]

Restricted Cash

The Company maintained restricted cash of $1.2 million and $1.3 million at December 31, 2022 and December 31, 2021, respectively. At December 31, 2021, $0.1 million of the Company’s restricted cash balance was included within “Prepaid expenses and other current assets” in the accompanying consolidated balance sheets. These amounts are comprised solely of letters of credit required pursuant to the Company’s leased office spaces.


	Year Ended December 31, 2022				Year Ended December 31, 2021
	Beginning of Period		End of Period		Beginning of Period		End of Period
Cash and cash equivalents	$	157,531	$	129,315	$	92,570	$	157,531
Restricted cash	1,299		1,214		207		1,299
Cash, cash equivalents and restricted cash	$	158,830	$	130,529	$	92,777	$	158,830

Property and Equipment, Net

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

Property and equipment, net as of December 31, 2022 and 2021 was comprised as follows (in thousands):


		December 31,
	Estimated Useful Life (in years)	2022		2021
Laboratory equipment	5	$	1,635	$	839
Furniture and office equipment	5	264		9
Computer equipment	3	418		221
Leasehold improvements	Shorter of 7 years or remaining lease term	7,971		274
Construction in progress		106		1,961
Total property and equipment, gross		10,394		3,304
Less: accumulated depreciation		(1,406)		(391)
Total property and equipment, net		$	8,988	$	2,913

Depreciation expense for the years ended December 31, 2022 and 2021 was $1.1 million and $0.2 million, respectively.

Accrued Expenses and Other Current Liabilities

12 Months Ended

Dec. 31, 2022

Payables and Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities as of December 31, 2022 and 2021 were comprised as follows (in thousands):


	December 31,
	2022		2021
Manufacturing	$	6,674	$	3,427
Employee compensation and benefits	3,135		2,200
Professional fees	613		433
Contract research	2,990		2,542
Success payment liability	570		—
Other	170		163
Total accrued expenses and other current liabilities	$	14,152	$	8,765

Term Loan	12 Months Ended
Term Loan	Dec. 31, 2022
Debt Disclosure [Abstract]
Term Loan	Term Loan In April 2022, the Company entered into the Loan Agreement with PWB. Under the terms of the Loan Agreement, PWB made available a term loan in an aggregate principal amount of up to $20.0 million (“Tranche I Loan”) available at any time after the closing date until February 28, 2024 as extended to August 31, 2024 upon the satisfaction of certain conditions set forth in the Loan Agreement (such date, the “Amortization Date”). Based on the satisfaction of certain conditions defined in the Loan Agreement, PWB is also obligated to make available an additional term loan in the aggregate principal amount of up to $20.0 million (“Tranche II Loan”, or collectively with the Tranche I Loan, the “Term Loans”) available at any time after the closing date until the Amortization Date upon the acceptance by the U.S. Food and Drug Administration (the “FDA”) of two investigational new drug (“IND”) submissions on or before March 31, 2023. Although the Tranche I Loan and Tranche II Loan are now available to the Company, as of December 31, 2022, the Company has elected to defer making a draw. As of December 31, 2022, the Company had not drawn down any Term Loans and had no outstanding borrowings under the Loan Agreement. The Term Loans will bear interest on the outstanding daily balance at a floating annual rate equal to greater of: (i) 0.5% above the prime rate then in effect or (ii) 4.5%. If the prime rate changes throughout the term, the interest rate will be adjusted effective on the date of the prime rate change. All interest chargeable under the Loan Agreement is computed on a 360-day year for the actual number of days elapsed, with interest payable monthly. The Company is obligated to pay PWB a fee in the event of certain corporate transactions equal to either (i) the greater of (a) $0.2 million and (b) 2.0% of the amount drawn under the Term Loans, for a transaction occurring on or before March 31, 2023, or (ii) for any transaction occurring thereafter, the greater of (a) $0.4 million and (b) 4.0% of the amount drawn under the Term Loans (the “Success Fee”). The Success Fee will survive ten years from the date of payment of the Term Loans in full, such that, if the Loan Agreement is terminated prior to the payment of the Success Fee the Company will remain obligated to pay the Success Fee upon the occurrence of a Success Fee Event (as defined in the Loan Agreement) during such ten-year period. The Company determined that the Success Fee constitutes a freestanding financial instrument and should be accounted for as a liability in connection with ASC 815, Derivatives and Hedging. The Company determined the fair value of the Success Fee upon the closing date of the Loan Agreement and then marked to market the fair value of the Success Fee as of December 31, 2022. All outstanding obligations under the Loan Agreement are secured by the Company’s personal property (exclusive of any intellectual property) and are subject to acceleration in the event of default. In the event of a late payment or default, the Company is obligated to pay a fee equal to 5.0% of such unpaid amounts. In connection with the Loan Agreement, the Company is required to comply with certain negative covenants, which among other things, restrict the Company from (i) incurring future debt or granting liens, (ii) effectuating a merger or consolidation with or into any other business organization, (iii) paying dividends or making certain other distributions, (iv) selling or otherwise transferring its assets, (v) making investments in any entities or instruments other than certain investments specified in the Loan Agreement and (vi) making capitalized expenditures in excess of 125% of the amount provided for in the annual budget approved by the board of directors. The Loan Agreement also contains standard affirmative covenants, including with respect to the issuance of audited consolidated financial statements, insurance, and maintenance of good standing and government compliance in the Company’s state of formation. On or before September 30, 2023, the Company is required to raise aggregate gross cash process of at least $50.0 million from the sale or issuance of its equity or from strategic partnerships or any similar transaction. From after receipt of those proceeds, the Company is required to maintain at all times at least $20.0 million of unrestricted cash in accounts with PWB. PWB has the right to accelerate all outstanding obligations of the Company under the Loan Agreement or terminate any remaining Term Loan commitments in the event of a material adverse effect on (i) the operations, business or financial condition of the Company, (ii) the Company’s ability to repay any portion of the Term Loans or perform any of its other obligations under the Loan Agreement, and (iii) the Company’s interest in, or the value, perfection or priority of PWB’s security interest in the collateral. As of December 31, 2022, the Company had $40.0 million available to draw on the Term Loans and had no outstanding principal. In connection with the Loan Agreement, the Company recorded a total of $1.1 million as a success fee liability that is contingent upon the occurrence of future events and will be payable to PWB upon the occurrence of those events. The initial valuation of the success fee recorded in connection with the Loan Agreement was recorded as a deferred asset on the Company’s balance sheet until the Company draws down on the Term Loans. Upon drawdown of the Term Loans the initial value of the success fee will be reclassified as a discount to the term loan payable. The unamortized balance of the success fee will be charged to interest expense over the remainder of the borrowing term.

- Definition

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

+ References

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+ Details

Common and Preferred Stock

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Common and Preferred Stock

Common Stock

The Company is authorized to issue 200.0 million shares of common stock. Common stockholders are entitled to dividends if and when declared by the Company’s board of directors. As of December 31, 2022, no dividends on common stock had been declared by the Company.

On May 10, 2022, the Company entered into a Sales Agreement (the “Sales Agreement”) with SVB Securities LLC (“SVB”), pursuant to which the Company may offer and sell shares of its common stock with an aggregate offering price of up to $50.0 million (the “ATM Offering”). The Sales Agreement provides that SVB will be entitled to a sales commission equal to 3.0% of the gross sales price per share of all shares sold under the ATM Offering. As of December 31, 2022, the Company had sold an aggregate of 3,827,567 shares under the ATM Offering at an average price of $4.36 per share for net proceeds of $15.7 million after deducting sales commissions and offering expenses.

The Company had reserved shares of common stock for issuance as follows (in thousands):


	As of December 31,
	2022	2021
Shares reserved for exercises of outstanding stock options	5,244	3,266
Shares reserved for vesting of restricted stock units	323	—
Shares reserved for exercises of warrants	59	59
Shares reserved for future issuance under the 2021 Stock Incentive Plan	939	1,939
Total shares reserved for future issuance	6,565	5,264

Preferred Stock

The Company is authorized to issue 5.0 million shares of undesignated preferred stock in one or more series. As of December 31, 2022, no shares of preferred stock were issued or outstanding.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

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+ Details

Stock-based Compensation

12 Months Ended

Dec. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-based Compensation

2017 Stock Incentive Plan

In December 2017, the Company adopted the 2017 Stock Incentive Plan (the “2017 Plan”), as amended and restated, under which it could grant incentive stock options (“ISOs”), non-qualified stock options, RSAs, RSUs, stock appreciation rights and other stock-based awards to eligible employees, officers, directors and consultants. The terms of stock options and RSAs, including vesting requirements, are determined by the board of directors, subject to the provisions of the 2017 Plan.

2021 Stock Incentive Plan

In April 2021, the board of directors adopted and the Company’s stockholders approved the 2021 Stock Incentive Plan (the “2021 Plan”), which became effective immediately prior to the effectiveness of the Company’s IPO. As a result of the adoption of the 2021 Plan, no further awards will be made under the 2017 Plan.

The 2021 Plan provides for the grant of ISOs, non-qualified stock options, RSAs, RSUs, stock appreciation rights and other stock-based awards. The Company’s employees, officers, directors, consultants and advisors are eligible to receive awards under the 2021 Plan. The terms of awards, including vesting requirements, are determined by the board of directors, subject to the provisions of the 2021 Plan.

The Company initially registered 3,352,725 shares of common stock under the 2021 Plan, pursuant to a Registration Statement on Form S-8 filed with the SEC on April 30, 2021, which was comprised of (i) 2,843,116 shares of common stock reserved for issuance under the 2021 Plan, (ii) 31,884 shares of common stock originally reserved for issuance under the 2017 Plan that became available for issuance under the 2021 Plan upon the completion of the Company’s IPO, and (iii) 477,725 shares of unvested restricted stock subject to repurchase by us that

may become issuable under the 2021 Stock Incentive Plan following such repurchase. The 2021 Plan also provides that an additional number of shares will be added annually to the shares authorized for issuance under the 2021 Plan on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2022 and continuing until, and including, the fiscal year ended December 31, 2031. The number of shares added each year will be equal to the lesser of (i) 5% of the number of outstanding common stock on such date and (ii) such amount as determined by the board of directors. Effective January 1, 2022, 1,380,397 additional shares were automatically added to the shares authorized for issuance under the 2021 Plan.

As of December 31, 2022, there were 938,587 shares available for future issuance under the 2021 Plan.

2021 Employee Stock Purchase Plan

In April 2021, the board of directors adopted and the Company’s stockholders approved the 2021 Employee Stock Purchase Plan (the “2021 ESPP”), which became effective immediately prior to the effectiveness of the Company’s IPO. The Company initially reserved 244,000 shares of common stock for future issuance under the 2021 ESPP. The 2021 ESPP provides that an additional number of shares will automatically be added to the shares reserved for issuance on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2022 and continuing for each fiscal year until, and including, the fiscal year ending on December 31, 2032. The number of shares added each year will be equal to the lowest of (i) 488,000 shares of common stock, (ii) 1% of the number of shares of outstanding common stock on such date, and (iii) such amount as determined by the board of directors. The Company initiated its first offering period under the 2021 ESPP in December 2022.

The 2021 ESPP provides that eligible employees may contribute up to 15% of their eligible earnings toward the semi-annual purchase of the Company’s common stock. The 2021 ESPP is qualified under Section 423 of the Internal Revenue Code. The employee’s purchase price is derived from a formula based on the closing price of the common stock on the first day of the offering period versus the closing price on the last date of purchase (or, if not a trading day, on the immediately preceding trading day). The offering period under the 2021 ESPP has a duration of six months, and the purchase price with respect to each offering period beginning on or after such date is, until otherwise amended, equal to 85% of the lesser of (i) the fair market value of the Company’s common stock at the commencement of the applicable six-month offering period or (ii) the fair market value of the Company’s common stock on the purchase date. The Company estimate the fair value of the common stock under the 2021 ESPP using a Black-Scholes valuation model. The fair value was estimate on the date of grant using the Black-Scholes option valuation model and the straight-line attribution approach with the following assumptions: risk-free interest rate (4.7%); expected term (0.5 years); expected volatility (77.0%); and an expected dividend yield (0%). The Company recorded less than $0.1 million of stock-based compensation under the 2021 ESPP for the year ended December 31, 2022. As of December 31, 2022, there was unrecognized stock-based compensation expense of less than $0.1 million related to the current ESPP offering period, which ends May 31, 2023.

Stock-Based Compensation Expense

Total stock-based compensation expense recognized in the consolidated statements of operations for the years ended December 31, 2022 and 2021 was as follows (in thousands):


	Year Ended December 31,
	2022		2021
Research and development	$	3,410	$	1,524
General and administrative	3,990		2,571
Total stock-based compensation	$	7,400	$	4,095

RSA Activity

The Company may, at its discretion, repurchase unvested shares of restricted stock issued pursuant to the 2017 Plan at the initial purchase price if the employees or non-employees terminate their service relationship with the Company. The shares are recorded in stockholders’ deficit as they vest.

The following table summarizes restricted stock award activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2021	295	$	1.35
Granted	—	$	—
Vested	(214)	$	1.34
Forfeited	—	$	—
Unvested at December 31, 2022	81	$	1.38

As of December 31, 2022, there was unrecognized stock-based compensation expense related to unvested restricted stock awards of $0.1 million, which the Company expects to recognize over a weighted-average period of approximately 0.4 years.

The aggregate fair value of restricted stock awards that vested during the years ended December 31, 2022 and 2021, based upon the fair values of the stock underlying the restricted stock awards on the day of vesting, was $1.2 million and $3.6 million, respectively.

RSU Activity

The Company has also granted RSUs to its employees under the 2021 Plan. The following table summarizes RSU activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2021	—	$	—
Granted	364	$	4.39
Vested	—	$	—
Forfeited	(41)	$	4.97
Unvested at December 31, 2022	323	$	4.32

As of December 31, 2022, there was unrecognized stock-based compensation expense related to unvested RSUs of $1.0 million, which the Company expects to recognize over a weighted-average period of approximately 1.24 years.

No RSUs vested during the years ended December 31, 2022 or 2021.

Stock Option Activity

During the year ended December 31, 2022, the Company granted performance-based stock options to certain executive officers for the purchase of an aggregate of 883,352 shares of common stock with a grant date fair value of $3.36 per share. These stock options vest only upon achievement of specified performance targets related to certain business objectives. As of December 31, 2022, none of these options were vested because none of the specified performance targets had been achieved. Because achievement of the specified performance targets was not deemed probable as of December 31, 2022, the Company did not record any expense for these stock options from the date of issuance through December 31, 2022.

The fair value of stock options granted during the years ended December 31, 2022 and 2021 was calculated on the date of grant using the following weighted-average assumptions:


	Year Ended December 31,
	2022		2021
Risk-free interest rate	2.3	%	1.0	%
Expected term (in years)	6.0		6.0
Dividend yield	—	%	—	%
Expected volatility	77.0	%	78.7	%

Using the Black-Scholes option pricing model, the weighted-average grant date fair value of stock options granted during the years ended December 31, 2022 and 2021 was $5.98 and $9.72 per share, respectively.

The following table summarizes stock option activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Options Outstanding
	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (in years)
Outstanding at December 31, 2021	3,266	$	8.24	9.02
Granted	2,183	$	7.14
Exercised	(80)	$	2.82
Cancelled	(125)	$	8.55
Outstanding, December 31, 2022	5,244	$	7.86	8.34
Exercisable at December 31, 2022	1,683	$	8.00	8.09

The aggregate intrinsic fair value of stock options exercised during the years ended December 31, 2022 and 2021 was $0.4 million and $0.8 million, respectively.

As of December 31, 2022, there was unrecognized stock-based compensation expense related to unvested stock options of $18.3 million, which the Company expects to recognize over a weighted-average period of approximately 2.2 years.

Commitment and Contingencies

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Leases

The Company’s leases are as follows:

•An April 2019 operating lease for approximately 9,949 square feet of office and laboratory space which commenced in April 2019 and terminates in March 2024. The lease is subject to fixed-rate rent escalations and provided for a term extension option, which was not reasonably certain of exercise. In May 2022, the Company entered into a sublease agreement with Crossbow Therapeutics, Inc. (“Crossbow”), to sublease the entirety of this space. The annual rent for the subleased premises will be approximately $1.1 million in the first year and $1.0 million in the second year, which is greater than the annual rent paid by the Company to the landlord for the leased premises. Crossbow is obligated to pay all real estate taxes and costs related to the subleased premises, including cost of operations, maintenance, repair, replacement, and property management.

•A March 2021 short-term lease for approximately 7,500 square feet of office and laboratory space which commenced in April 2021 and terminated in May 2022. The Company did not recognize an operating lease right of use asset or a lease liability upon lease commencement. Rent expense for the short-term lease was recognized as incurred.

•A June 2021 operating lease for approximately 25,778 square feet of office and laboratory space, which commenced in May 2022 and terminates in May 2030. The lease is subject to fixed-rate rent escalations and provided for $5.7 million in tenant improvements, which the Company fully utilized, and a term extension option, which was not reasonably certain of exercise. The Company provided the landlord with a security deposit in the form of a letter of credit in the amount of $1.0 million upon signing, which is included in restricted cash as of December 31, 2022.

Accounting under ASC 842:

•Expected lease term: The expected lease term includes noncancelable lease periods and, when applicable, periods covered by an option to extend the lease if the Company is reasonably certain to exercise that option, as well as periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise that option.

•Incremental borrowing rate: As the discount rates in the Company’s lease are not implicit, management estimated the incremental borrowing rate based on the rate of interest the Company would have to pay to borrow a similar amount on a collateralized basis over a similar term.

•Lease and non-lease components: The Company is required to pay fees for operating expenses in addition to monthly base rent for certain operating leases (non-lease components). The Company has elected the practical expedient which allows non-lease components to be combined with lease components for all asset classes. Variable non-lease components are not included within the lease right-of-use asset and lease liability on the consolidated balance sheet, and instead are reflected as expense in the period they are paid.

The following table summarizes operating lease costs (in thousands):


	Year Ended December 31,
	2022		2021
Operating lease costs	$	2,537	$	1,312
Variable lease costs	837		398
Short-term lease costs	228		411
Sublease income	(834)		—
Total	$	2,768	$	2,121

The following table summarizes the lease term and discount rate for operating leases:


	As of December 31,
	2022		2021
Weighted-average remaining lease term (years)	7.0		7.6
Weighted-average discount rate	8.1	%	8.1	%

As of December 31, 2022, the future minimum lease payments due under the Company’s leases are as follows (in thousands):


	Amount
2023	$	3,133
2024	2,505
2025	2,337
2026	2,403
2027	2,472
Thereafter	6,258
Total remaining minimum rental payments	19,108
Less: effect of discounting	(4,424)
Total lease liability	$	14,684

License Agreements

Harpoon License

In March 2018, the Company entered into a Patent Assignment and License Agreement (the “Harpoon Agreement”) with Harpoon Therapeutics, Inc. (“Harpoon”), a clinical-stage immune-oncology company developing a novel class of T-cell engagers to fight cancer and other diseases. Under the terms of the Harpoon Agreement, Harpoon granted the Company a license to use its intellectual property, solely to make, have made, use, sell, offer for sale and import covered products in the licensed field and Harpoon sold, assigned and transferred other specific patents to the Company (the “Harpoon License”).

On October 19, 2018, the Company and Harpoon entered into the First Amended and Restated Assignment and License Agreement which amended certain terms of the original agreement, but did not change the terms of the license to the Company, patent assignments between the parties or payments due to Harpoon. Further, on December 20, 2019, the companies entered into the Second Amended and Restated Assignment and License Agreement, which also amended certain terms of the original agreement to expand the licenses and assignments for specific patents granted to the Company or by the Company to Harpoon. In exchange for these additional terms, Harpoon agreed to reimburse up to $75,000 of the Company’s legal costs. Additionally, the Company agreed to pay to Harpoon royalties on future net sales and pay minimum annual royalties of $250,000 upon achievement of its first commercial sale.

Under the terms of the Harpoon License, the Company paid an upfront fee of $500,000 in 2018 and is obligated to reimburse Harpoon for certain legal costs incurred by Harpoon. In addition, the Company is obligated to pay Harpoon royalties based on future net sales and has agreed to pay a minimum annual royalty payment at an amount in the low hundreds of thousands of dollars upon achievement of its first commercial sale. In 2018, the Company recorded the upfront fee as research and development expense upon payment as the intellectual property was acquired prior to regulatory approval and does not have an alternative future use. The royalty payments are contingent upon sales and, as such, the royalty payments made to Harpoon will be considered probable and estimable and treated as cost of sales when incurred. Accordingly, at the commencement of sales, the Company will account for the royalty payments as cost of sales equal to the greater of a percentage in the low-single digits of the net sales of the patent-covered products or a minimum annual royalty payment at an amount in the low hundreds of thousands of dollars. Any legal fees incurred in connection with the Harpoon Agreement will be expensed as incurred.

The Harpoon License will expire on a country-by-country basis upon the expiration of the last to expire patent or patent application included in the licensed patents within the applicable country. The Company has the right to terminate the Harpoon License upon 30 days prior written notice to Harpoon, and either party may terminate for a material breach if such breach is not cured within a specified number of days.

Adimab 2018 License

In March 2018, the Company entered into a Development and Option Agreement (the “Adimab Agreement”) with Adimab LLC (“Adimab”), a company specializing in antibody discovery, humanization and optimization. Under the terms of the Adimab Agreement, Adimab granted the Company the rights to initiate certain research initiatives on a specified number of targets. Adimab also granted to the Company a license to certain Adimab core technologies, antibodies and products applicable to certain targets (“Adimab License”).

In August 2020, the Company and Adimab entered into Amendment One to the Development and Option Agreement, which extended the period of time for the Company to evaluate candidate antibodies in advance of electing to exercise the option to acquire exclusive rights to licensed antibodies (the “Evaluation Term”), but did not otherwise change the terms of the Adimab License. The Evaluation Term was then further extended in December 2020 by entering into Amendment Two to the Development and Option Agreement, through delivery of a non-refundable payment of $100,000 by the Company to Adimab, which was creditable toward the option fee. The non-refundable payment was recorded immediately as research and development expense in the consolidated statements of operations. In July 2021, the Company and Adimab entered into the First Amended and Restated Development and Option Agreement to extend the target selection time period and to allow for the Company to add additional antibody discovery programs to be covered under the agreement, but otherwise retaining all other material provisions of the Adimab License.

Under the terms of the Adimab License, the Company must pay both an upfront fee and final fee of $200,000 for all research programs. The Company must also pay Adimab milestone fees with respect to each research program ranging from $150,000 to $200,000 based on the achievement of technical milestones by Adimab for the applicable research program. In order to exercise any options in the Adimab Agreement, the Company must pay a $500,000 fee for each target option exercised.

For each target option exercised, the Company is also obligated to pay certain milestones ranging from $1.0 million to $4.0 million for certain clinical and commercialization achievements. Additionally, for licensed products sold during the applicable royalty term, the Company must pay Adimab royalties at percentages in the low-to-mid single digits.

The Adimab Agreement will expire upon the expiration of any options or if an option is exercised, on a country-by-country and licensed product-by-licensed product basis on the expiration of the last royalty term for a licensed product in the particular country. As of December 31, 2022, the Company has not exercised any target options or recorded any milestone or royalty payments for exercised options pursuant to the Adimab Agreement.

Adimab 2022 Collaboration

In November 2022, the Company entered into a Collaboration Agreement (the “Adimab Collaboration Agreement”) with Adimab. Under the terms of the Adimab Collaboration Agreement, Adimab has agreed to provide the Company with services to help discover, generate, optimize and/or engineer specified proteins. In addition, Adimab will provide the Company with a license to certain Adimab core technologies, patents and products applicable to certain targets (“Adimab Collaboration License”), separate from those provided in the 2018 Adimab Agreement.

Under the terms of the Adimab Collaboration Agreement, the Company must pay Adimab milestone fees with respect to each research program ranging from $500,000 to $1.5 million based on the achievement of certain clinical milestones by the Company. The Adimab Collaboration Agreement provides the Company with an option to obtain any development and commercialization licenses from Adimab used in products. To exercise an option, the Company must pay a $500,000 fee for each product option exercised.

For each product sold, the Company is also obligated to pay certain milestones ranging from $1.0 million to $2.0 million based on the achievement of the first commercial sale in certain countries. Additionally, for licensed products sold during the applicable royalty term, the Company must pay Adimab royalties at percentages in the low-to-mid single digits.

The Adimab Collaboration Agreement will expire upon the expiration of any options or if an option is exercised, on a country-by-country and licensed product-by-licensed product basis on the expiration of the last royalty term for a licensed product in the particular country. As of December 31, 2022, the Company has not exercised any options and has not made any payments for clinical or sales-based milestones or royalties pursuant to the Adimab Collaboration Agreement.

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

During the years ended December 31, 2022 and 2021, the Company recorded no current or deferred income tax expenses or benefits as the Company has incurred losses since inception and has provided a full valuation allowance against its deferred tax assets.

A reconciliation of the expected income tax (benefit) computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows:


	Year Ended December 31,
	2022		2021
Income tax computed at federal statutory rate	21.0	%	21.0	%
State taxes	8.3		5.7
Change in valuation allowance	(30.4)		(27.2)
R&D credit carryovers	2.4		1.8

Stock-based compensation	(1.5)		(0.9)

Permanent differences	0.2		(0.4)
Effective income tax rate	0.0	%	0.0	%

The Company’s deferred tax assets consist of the following (in thousands):


	As of December 31,
	2022		2021
Deferred tax assets:
Net operating losses	$	26,234	$	22,831
Tax credit carryforwards	3,819		1,918
Lease liability	4,180		4,393
Other capitalized costs—net of amortization	103		111
Reserves and accruals	950		658
Stock-based compensation	1,448		500
Capitalized research and experimental expenditures—net of amortization	9,474		—
Deferred tax assets	46,208		30,411
Valuation allowance	(42,417)		(26,110)
Deferred tax assets recognized	3,791		4,301
Deferred tax liabilities:
Right of use asset	(2,358)		(3,762)
Fixed assets and depreciation	(1,433)		(6)
Construction in progress	—		(533)

Deferred tax liabilities	(3,791)		(4,301)
Net deferred tax assets	$	—	$	—

The Tax Cuts and Jobs Act (“TCJA”) requires taxpayers to capitalize and amortize research and experimental (“R&E”) expenditures under Section 174 for tax years beginning after December 31, 2021. This rule became effective for the Company during 2022 and resulted in the capitalization of R&E expenditures of $36.1 million. The Company will amortize these costs for tax purposes over 5 years if the research and development (“R&D”) was performed in the U.S. and over 15 years if the R&D was performed outside the U.S.

The Company evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets as of December 31, 2022 and 2021. Management considered the Company’s cumulative net losses and concluded as of December 31, 2022 and 2021, that it was more likely than not that the Company would not realize the benefits of the deferred tax assets. Accordingly, a full valuation allowance was established against the net deferred tax assets as of December 31, 2022 and 2021. The valuation allowance increased by $16.3 million and $14.3 million for the years ended December 31, 2022 and 2021, respectively, primarily as a result of operating losses generated with no corresponding financial statement benefit.

The Company has incurred net operating losses (“NOL”) since inception. As of December 31, 2022 and 2021, the Company had federal net operating loss carryforwards of $92.1 million and $80.3 million, respectively, available to reduce future federal taxable income. The carryforwards generated in 2017 expire in 2037. $92.0 million of carryforwards generated post 2017 do not expire. The TCJA enacted on December 22, 2017 limits a taxpayer’s ability to utilize NOL deduction in a year to 80% taxable income for federal net operating losses arising in tax years beginning after 2017. As of December 31, 2022 and 2021, the Company had state net operating loss carryforwards of $86.1 million and $74.5 million, respectively, available to reduce future state taxable income, which expire at various dates beginning in 2037.

As of December 31, 2022 and 2021, the Company had federal research and development tax credit carryforwards of $2.6 million and $1.3 million, respectively, available to reduce future federal tax liabilities, which expire at various dates beginning in 2038. The Company also had state research and development tax credit carryforwards as of December 31, 2022 and 2021 of $1.2 million and $0.6 million, respectively, available to reduce future state tax liabilities, which expire at various dates beginning in 2034.

Utilization of the Company’s net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50% over a three-year period.

The Company is in the process of completing a Section 382 study for the period of January 22, 2018, through December 31, 2022. As part of the first phase in the study, the Company completed testing date analysis through December 31, 2022, and identified three ownership changes that occurred on June 10, 2019, August 2, 2019, and August 31, 2022 for Section 382 purposes. As the Company experienced these ownership changes, all pre-change net operating loss and research and development tax credit carryforwards are subject to limitation. Due to the unlimited carryover period for post-2017 generated net operating losses, none of the Company’s net operating losses will expire unused. A portion of the Company’s research and development tax credits will expire unused. The exact amount of the research and development tax credits that will expire unused will be determined upon the completion of the Section 382 study.

The Company is currently in a full valuation allowance and will not make any limitation adjustment to the net operating loss and research and development tax credit carryforwards until the Section 382 study is completed. Further, until the Section 382 study is completed, no amounts are being presented as an uncertain tax position.

The Company has not recorded any reserves for uncertain tax positions as of December 31, 2022 and 2021. The Company has conducted a study of research and development tax credit for tax years 2018 - 2020. The amounts of federal and state research and development tax credit carryforwards presented above have reflected the results from the study. A full valuation allowance has been provided against the Company’s research and development credits.

The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending tax examinations. The Company’s tax years are still open under statute from inception to the present.

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI http://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Related Parties	12 Months Ended
Related Parties	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Parties	Related Parties In May 2022, the Company entered into a sublease agreement with Crossbow, for which entities affiliated with MPM Capital (“MPM Capital”) are also beneficial owners, to sublease the entirety of its office and laboratory space in Cambridge, Massachusetts. Luke Evnin, Ph.D., the chair of the Company’s board of directors, co-founded MPM Capital and serves as Managing Director of MPM Capital. Briggs Morrison, who serves on the Company’s board of directors, serves as Executive Partner of MPM Capital. The term of the sublease agreement commenced in June 2022 and ends in March 2024, with no option to extend (see Note 11, Commitments and Contingencies). The Company received cash payments under its sublease of approximately $0.8 million during the year ended December 31, 2022. In addition, the Company received $0.2 million from Crossbow in June 2022 as a security deposit that is included within “Other liabilities” in the accompanying consolidated balance sheets as of December 31, 2022.

401(k) Savings Plan	12 Months Ended
401(k) Savings Plan	Dec. 31, 2022
Retirement Benefits [Abstract]
401(k) Savings Plan	401(k) Savings PlanThe Company has a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code (the "401(k) Plan"). The 401(k) Plan covers all employees who meet defined minimum age and service requirements, and allows participants to defer a portion of their annual compensation on a pretax basis. Beginning in 2022, the Company will match 50% of each participant’s contribution up to a maximum of 6% of the participant’s eligible compensation paid during the period. During the year ended December 31, 2022, the Company recognized expense of $0.2 million related to matching contributions.

Net Loss Attributable to Common Stockholders per Share

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Net Loss Attributable to Common Stockholders per Share

For purposes of the diluted net loss attributable to common stockholders per share calculation, outstanding stock options, unvested RSAs, unvested RSUs and warrants to purchase common stock are considered to be potentially dilutive securities, however the following weighted-average amounts were excluded from the calculation of diluted net loss attributable to common stockholders per share because their effect would be anti-dilutive (in thousands):


	December 31,
	2022	2021
Outstanding stock options	5,244	3,266
Unvested RSAs	81	295
Unvested RSUs	323	—
Warrants to purchase common stock	59	59
Total	5,707	3,620

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On March 15, 2023, the Company borrowed an aggregate principal amount of $40.0 million as a term loan under the Loan Agreement with PWB. The draw was made in accordance with the initial terms and conditions of the Loan Agreement. The Company will begin to repay the principal in twenty-four equal monthly payments beginning on September 1, 2024. Refer to Note 8, Term Loan, for additional details on the Term Loan. During the period beginning January 1, 2023 and ending March 23, 2023, the Company issued and sold approximately 3.8 million shares of its common stock in connection with the ATM Offering, resulting in gross proceeds of approximately $8.8 million before deducting sales commissions and offering expenses. Refer to Note 9, Common and Preferred Stock, for additional details on the ATM Offering.

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation and ConsolidationThe accompanying consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and generally accepted accounting principles in the United States of America (“GAAP”) as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Consolidation	The accompanying consolidated financial statements include the accounts of Werewolf Therapeutics, Inc. and its wholly-owned subsidiary, Werewolf Therapeutics Mass Securities, Inc. All intercompany transactions and balances have been eliminated in consolidation.
Segment Information	Segment Information Operating segments are identified as components of an enterprise for which separate discrete financial information is available for evaluation by the Company’s Chief Operating Decision Maker (“CODM”) to make decisions with respect to resource allocation and assessment of performance. The CODM is the Company’s Chief Executive Officer. The CODM manages the Company’s operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular concentration is focused on the discovery and development of cancer therapeutics by advancing a novel class of conditionally activated proinflammatory immune modulators.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, estimates related to the application of Revenue from Contracts with Customers (Topic 606) (“ASC 606”) to the Company’s collaboration agreement with Jazz Pharmaceuticals Ireland Limited, the accrual of research and development expenses, the expected future lives of property and equipment, the valuation of stock-based awards, and the success based fee associated with the Company’s debt agreement. Actual results could differ from those estimates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure for Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes between the following: •Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. •Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. •Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company’s cash and cash equivalents consist of cash maintained within a standard checking account. The Company also maintains a cash sweep account in which cash from its main operating cash account is invested overnight in highly liquid, short-term investments. The Company considers all highly liquid investments with a maturity date of 90 days or less at the date of purchase to be cash equivalents.
Property and Equipment	Property and Equipment Property and equipment is recorded at cost and consists of laboratory equipment, furniture and office equipment, computer equipment, and leasehold improvements. The Company capitalizes property and equipment that is acquired for research and development activities and that has alternate future use. Expenditures for maintenance and repairs are recorded to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. Leasehold improvements are depreciated over the lesser of their useful life or the term of the lease. Depreciation is calculated over the estimated useful lives of the assets using the straight-line method.
Impairment of Long-lived Assets	Impairment of Long-lived Assets Long-lived assets consist of property and equipment. The Company reviews its property and equipment whenever events or changes in circumstances indicate that the carrying value of certain assets might not be recoverable. If such events or changes in circumstances arise, the Company compares the carrying amount of the long-lived assets to the estimated future undiscounted cash flows expected to be generated by the long-lived assets. If the estimated aggregate undiscounted cash flows are less than the carrying amount of the long-lived assets, an impairment charge, calculated as the amount by which the carrying amount of the assets exceeds the fair value of the assets, is recorded. The fair value of the long-lived assets is determined based on the estimated discounted cash flows expected to be generated from the long-lived assets. The Company has not recorded any material impairment charges during the years presented.
Leases	Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and short-term and long-term lease liabilities, as applicable. The Company does not recognize leases with terms of one year or less on the balance sheet. Options to renew a lease are not included in the Company’s initial lease term assessment unless there is reasonable certainty that the Company will renew. The Company monitors its plans to renew its material leases on a quarterly basis. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate (“IBR”), which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, and in a similar economic environment. The Company subsequently measures its lease liability at the present value of remaining lease payments, discounted using the IBR for the lease. The right-of-use asset is subsequently measured at the amount of the lease liability, adjusted for prepaid or accrued lease payments and the remaining balance of lease incentives received. The Company recognizes operating lease expense on a straight-line basis over the lease term.
Revenue Recognition	Revenue Recognition The Company analyzes its collaborations to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”). For elements of collaboration arrangements that are accounted for pursuant to Topic 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election. For those elements of the arrangement that are accounted for pursuant to ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. In applying ASC 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the promises and performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligations. The Company only applies the five-step model to contracts when it is probable that it will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. As part of the assessment, the Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include reimbursement rates for personnel costs, development timelines and probabilities of regulatory success. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of promised goods or services to the customer will be one year or less. Arrangements that include upfront payments may require deferral of revenue recognition to a future period until obligations under these arrangements are fulfilled. The event-based milestone payments represent variable consideration, and the Company uses the “most likely amount” method to estimate this variable consideration. Given the high degree of uncertainty around the occurrence of these events, the Company determined the milestone and other contingent amounts to be fully constrained until the uncertainty associated with these payments is resolved. Revenue will be recognized from sales-based royalty payments when or as the sales occur. The Company will re-evaluate the transaction price in each reporting period as uncertain events are resolved and other changes in circumstances occur.
Research and Development Expenses	Research and Development Expenses Expenditures relating to research and development are expensed as incurred. Research and development expenses include external expenses incurred under arrangements with third parties, academic and non-profit institutions and consultants; salaries and personnel-related costs, including non-cash stock-based compensation expense; license fees to acquire in-process technology and other expenses, which include direct and allocated expenses for laboratory, facilities and other costs. Non‑refundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. As part of the process of preparing the consolidated financial statements, the Company is required to estimate its accrued research and development expenses as of each balance sheet date. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. This process involves reviewing open contracts and purchase orders, communicating with internal personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The Company periodically confirms the accuracy of its estimates with its service providers and makes adjustments if necessary. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The financial terms of agreements with these service providers are subject to negotiation, vary from contract to contract and may result in uneven payment flows. In circumstances where amounts have been paid in excess of costs incurred, the Company records a prepaid expense.
Intellectual Property Expenses	Intellectual Property Expenses The Company expenses costs associated with intellectual property-related matters as incurred and classifies such costs as general and administrative expenses within the consolidated statements of operations.
Stock-based Compensation	Stock-based Compensation The Company accounts for stock-based payments in accordance with ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASC 718”). This guidance requires all stock-based payments to employees, including grants of employee stock options and restricted stock awards (“RSAs”), to be recognized as expense in the consolidated statements of operations and comprehensive (loss) income based on their grant date fair values. For stock options granted to employees and to members of the Company’s board of directors for their services on the board of directors, the Company estimates the grant date fair value of each stock option using the Black-Scholes option-pricing model. For restricted stock units (“RSUs”) and RSAs granted to employees, the Company estimates the grant date fair value of each award using intrinsic value, which is based on the value of the underlying common stock less any purchase price. For stock-based payments subject to service-based vesting conditions, the Company recognizes stock-based compensation expense equal to the grant date fair value of stock-based payment on a straight-line basis over the requisite service period. The Black‑Scholes option pricing model requires the input of certain subjective assumptions, including (i) the calculation of expected term of the stock-based payment, (ii) the risk‑free interest rate, (iii) the expected stock price volatility and (iv) the expected dividend yield. The Company uses the simplified method as proscribed by SEC Staff Accounting Bulletin No. 107 to calculate the expected term for stock options granted to employees as the Company does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. The Company determines the risk‑free interest rate based on a treasury instrument whose term is consistent with the expected term of the stock options. Because there had been no public market for the Company’s common stock prior to the Company’s IPO, there is a lack of Company‑specific historical and implied volatility data. Accordingly, the Company bases its estimates of expected volatility on the historical volatility of a group of publicly-traded companies with similar characteristics to itself, including stage of product development and therapeutic focus within the life sciences industry. Historical volatility is calculated over a period of time commensurate with the expected term of the stock-based payment. The Company uses an assumed dividend yield of zero as the Company has never paid dividends on its common stock, nor does it expect to pay dividends on its common stock in the foreseeable future. The Company accounts for forfeitures of all stock-based payments when such forfeitures occur.
Income Taxes	Income Taxes Income taxes are recorded in accordance with ASU No. 2019-12, Income Taxes (Topic 740) (“ASC 740”) which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a more-likely-than-not threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors, including, but not limited to, changes in the law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position.
Comprehensive Loss	Comprehensive Loss The Company does not have items of other comprehensive loss for the years ended December 31, 2022 and 2021, and therefore does not present a consolidated statement of comprehensive loss. The Company’s comprehensive loss equals its net loss.
Net Loss per Common Share	Net Loss per Common Share Basic net loss per share is calculated based upon the weighted-average number of common shares outstanding during the period, excluding outstanding stock options and RSUs that have been issued but are not yet vested. Diluted net loss per share is calculated based upon the weighted-average number of common shares outstanding during the period plus the dilutive impact of weighted-average common equivalent shares outstanding during the period. The potentially dilutive shares of common stock resulting from the assumed exercise of outstanding stock options and the assumed vesting of RSUs are determined under the treasury stock method.
Concentration of Credit Risk	Concentration of Credit Risk and Off-Balance Sheet RiskFinancial instruments that potentially subject the Company to significant concentrations of credit risk consist of cash and cash equivalents. Cash is held in a checking account at two financial institutions. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents.
Off-Balance Sheet Risk	The Company has no significant off-balance sheet concentrations of credit risk, such as foreign currency exchange contracts, option contracts or other hedging arrangements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s consolidated financial statements upon adoption.
Subsequent Events	Subsequent EventsThe Company has evaluated subsequent events and transactions that occurred after the balance sheet date up to the date that the financial statements were issued. Other than as described in these financial statements, the Company did not identify any subsequent events that would have required adjustment to or disclosure in the financial statements

Jazz Collaboration Agreement (Tables)

12 Months Ended

Dec. 31, 2022

Business Combination and Asset Acquisition [Abstract]

Contract with Customer, Contract Asset, Contract Liability, and Receivable

The following table presents changes in the Company’s contract liabilities during the year ended December 31, 2022 (in thousands):


	Balance as of						Balance as of
	December 31, 2021		Additions		Reductions		December 31, 2022
Contract liabilities:
Deferred revenue	$	—	$	15,000	$	(7,340)	$	7,660
Totals	$	—	$	15,000	$	(7,340)	$	7,660

Financial Instruments and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Assets Measured at Fair Value on a Recurring Basis

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2022 were as follows (in thousands):


	Quoted Price in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market funds	$	128,812	$	—	$	—	$	128,812
Total assets	$	128,812	$	—	$	—	$	128,812
Liabilities
Success payment liability	$	—	$	—	$	570	$	570
Total liabilities	$	—	$	—	$	570	$	570

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2021 were as follows (in thousands):


	Quoted Price in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market funds	$	157,531	$	—	$	—	$	157,531
Total assets	$	157,531	$	—	$	—	$	157,531

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation

The following table reconciles the change in fair value of the success payment liability during the year ended December 31, 2022 based on Level 3 inputs (in thousands):


	Year Ended December 31, 2022
Balance at December 31, 2021	$	—
Additions	1,125
Change in fair value	(555)
Balance at December 31, 2022	$	570

Fair Value, Liabilities Measured on Recurring Basis

Management determined the fair value of the success payment liability as of December 31, 2022 using the following significant unobservable inputs:


	As of December 31, 2022
Probability of Success Fee Event	75	%
Expected term (in years)	0.33 - 0.75
Discount rate	7.1	%

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Cash and Cash Equivalents (Tables)

12 Months Ended

Dec. 31, 2022

Cash and Cash Equivalents [Abstract]

Restrictions on Cash and Cash Equivalents

These amounts are comprised solely of letters of credit required pursuant to the Company’s leased office spaces.


	Year Ended December 31, 2022				Year Ended December 31, 2021
	Beginning of Period		End of Period		Beginning of Period		End of Period
Cash and cash equivalents	$	157,531	$	129,315	$	92,570	$	157,531
Restricted cash	1,299		1,214		207		1,299
Cash, cash equivalents and restricted cash	$	158,830	$	130,529	$	92,777	$	158,830

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment

Property and equipment, net as of December 31, 2022 and 2021 was comprised as follows (in thousands):


		December 31,
	Estimated Useful Life (in years)	2022		2021
Laboratory equipment	5	$	1,635	$	839
Furniture and office equipment	5	264		9
Computer equipment	3	418		221
Leasehold improvements	Shorter of 7 years or remaining lease term	7,971		274
Construction in progress		106		1,961
Total property and equipment, gross		10,394		3,304
Less: accumulated depreciation		(1,406)		(391)
Total property and equipment, net		$	8,988	$	2,913

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2022

Payables and Accruals [Abstract]

Accrued Expenses

Accrued expenses and other current liabilities as of December 31, 2022 and 2021 were comprised as follows (in thousands):


	December 31,
	2022		2021
Manufacturing	$	6,674	$	3,427
Employee compensation and benefits	3,135		2,200
Professional fees	613		433
Contract research	2,990		2,542
Success payment liability	570		—
Other	170		163
Total accrued expenses and other current liabilities	$	14,152	$	8,765

Common and Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Schedule of Common Stock Reserved for Issuance

The Company had reserved shares of common stock for issuance as follows (in thousands):


	As of December 31,
	2022	2021
Shares reserved for exercises of outstanding stock options	5,244	3,266
Shares reserved for vesting of restricted stock units	323	—
Shares reserved for exercises of warrants	59	59
Shares reserved for future issuance under the 2021 Stock Incentive Plan	939	1,939
Total shares reserved for future issuance	6,565	5,264

Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-based Compensation Expense Recognized

Total stock-based compensation expense recognized in the consolidated statements of operations for the years ended December 31, 2022 and 2021 was as follows (in thousands):


	Year Ended December 31,
	2022		2021
Research and development	$	3,410	$	1,524
General and administrative	3,990		2,571
Total stock-based compensation	$	7,400	$	4,095

Restricted Stock Awards Activity

The following table summarizes restricted stock award activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2021	295	$	1.35
Granted	—	$	—
Vested	(214)	$	1.34
Forfeited	—	$	—
Unvested at December 31, 2022	81	$	1.38

The Company has also granted RSUs to its employees under the 2021 Plan. The following table summarizes RSU activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Shares/Units	Weighted-Average Grant Date Fair Value Per Share
Unvested at December 31, 2021	—	$	—
Granted	364	$	4.39
Vested	—	$	—
Forfeited	(41)	$	4.97
Unvested at December 31, 2022	323	$	4.32

Weighted -average Valuation Assumptions

The fair value of stock options granted during the years ended December 31, 2022 and 2021 was calculated on the date of grant using the following weighted-average assumptions:


	Year Ended December 31,
	2022		2021
Risk-free interest rate	2.3	%	1.0	%
Expected term (in years)	6.0		6.0
Dividend yield	—	%	—	%
Expected volatility	77.0	%	78.7	%

Summary of Stock Option Activity

The following table summarizes stock option activity during the year ended December 31, 2022 (in thousands, except per share amounts):


	Options Outstanding
	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (in years)
Outstanding at December 31, 2021	3,266	$	8.24	9.02
Granted	2,183	$	7.14
Exercised	(80)	$	2.82
Cancelled	(125)	$	8.55
Outstanding, December 31, 2022	5,244	$	7.86	8.34
Exercisable at December 31, 2022	1,683	$	8.00	8.09

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Summary of Operating Lease Costs

The following table summarizes operating lease costs (in thousands):


	Year Ended December 31,
	2022		2021
Operating lease costs	$	2,537	$	1,312
Variable lease costs	837		398
Short-term lease costs	228		411
Sublease income	(834)		—
Total	$	2,768	$	2,121

The following table summarizes the lease term and discount rate for operating leases:


	As of December 31,
	2022		2021
Weighted-average remaining lease term (years)	7.0		7.6
Weighted-average discount rate	8.1	%	8.1	%

Future Minimum Lease Payments

As of December 31, 2022, the future minimum lease payments due under the Company’s leases are as follows (in thousands):


	Amount
2023	$	3,133
2024	2,505
2025	2,337
2026	2,403
2027	2,472
Thereafter	6,258
Total remaining minimum rental payments	19,108
Less: effect of discounting	(4,424)
Total lease liability	$	14,684

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the expected income tax (benefit) computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows:


	Year Ended December 31,
	2022		2021
Income tax computed at federal statutory rate	21.0	%	21.0	%
State taxes	8.3		5.7
Change in valuation allowance	(30.4)		(27.2)
R&D credit carryovers	2.4		1.8

Stock-based compensation	(1.5)		(0.9)

Permanent differences	0.2		(0.4)
Effective income tax rate	0.0	%	0.0	%

Schedule of Deferred Tax Assets and Liabilities

The Company’s deferred tax assets consist of the following (in thousands):


	As of December 31,
	2022		2021
Deferred tax assets:
Net operating losses	$	26,234	$	22,831
Tax credit carryforwards	3,819		1,918
Lease liability	4,180		4,393
Other capitalized costs—net of amortization	103		111
Reserves and accruals	950		658
Stock-based compensation	1,448		500
Capitalized research and experimental expenditures—net of amortization	9,474		—
Deferred tax assets	46,208		30,411
Valuation allowance	(42,417)		(26,110)
Deferred tax assets recognized	3,791		4,301
Deferred tax liabilities:
Right of use asset	(2,358)		(3,762)
Fixed assets and depreciation	(1,433)		(6)
Construction in progress	—		(533)

Deferred tax liabilities	(3,791)		(4,301)
Net deferred tax assets	$	—	$	—

Net Loss Attributable to Common Stockholders per Share (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of (Loss) Income per Share


	December 31,
	2022	2021
Outstanding stock options	5,244	3,266
Unvested RSAs	81	295
Unvested RSUs	323	—
Warrants to purchase common stock	59	59
Total	5,707	3,620

Nature of Business (Details) - USD ($) $ in Thousands	12 Months Ended
Nature of Business (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Proceeds from initial public offering of common stock	$ 0	$ 111,600
Cash and cash equivalents	$ 129,315	$ 157,531	$ 92,570

Basis of Presentation and Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2022 institution
Accounting Policies [Abstract]
Expected dividend yield	0.00%
Number of financial institutions	2

Jazz Collaboration Agreement - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Collaboration revenue		$ 16,401	$ 0
Research and development		53,761	35,269
Deferred revenue, current		6,532	0
Deferred revenue, net of current portion		1,128	$ 0
Jazz Collaboration Agreement
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Non-Refundable Upfront Cash Payment Received	$ 15,000
Development and regulatory milestones (up to)	520,000
Sales-Based Milestones (up to)	740,000
Transaction price	33,500
Estimated future reimbursable costs	$ 18,500
Collaboration agreement, term	3 years 8 months 12 days
Upfront payment		7,300
Research and development		$ 9,100

Jazz Collaboration Agreement - Contract with Customer, Contract Asset, Contract Liability, and Receivable (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Contract liabilities:
Beginning balance	$ 0
Additions	15,000
Reductions	(7,340)
Ending balance	$ 7,660

Financial Instruments and Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Success payment liability	$ 570	$ 0
Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	128,812	157,531
Success payment liability	570
Total liabilities	570
Money market funds \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	128,812	157,531
Fair Value, Inputs, Level 1 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	128,812	157,531
Success payment liability	0
Total liabilities	0
Fair Value, Inputs, Level 1 \| Money market funds \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	128,812	157,531
Fair Value, Inputs, Level 2 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Success payment liability	0
Total liabilities	0
Fair Value, Inputs, Level 2 \| Money market funds \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	0	0
Fair Value, Inputs, Level 3 \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	0	0
Success payment liability	570
Total liabilities	570	0
Fair Value, Inputs, Level 3 \| Money market funds \| Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Money market funds	$ 0	$ 0

Financial Instruments and Fair Value Measurements - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Success payment liability	$ 570,000	$ 0
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Success payment liability	1,600,000
Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value on recurring basis		$ 0
Success payment liability	570,000
Recurring \| Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Success payment liability	570,000
Change in fair value	$ (555,000)

Financial Instruments and Fair Value Measurements - Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - Recurring $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ending balance	$ 570
Fair Value, Inputs, Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0
Additions	1,125
Change in fair value	(555)
Ending balance	$ 570

Financial Instruments and Fair Value Measurements - Unobservable Inputs (Details) - Recurring	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Probability of Success Fee Event	0.75
Discount rate	0.071
Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected term (in years)	3 months 29 days
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected term (in years)	9 months

Restricted Cash - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Non-current restricted cash	$ 1.2	$ 1.3
Restricted cash included in "Prepaid expenses and other current assets"		$ 0.1

Restricted Cash - Summary of Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 129,315	$ 157,531	$ 92,570
Restricted cash	1,214	1,299	207
Cash, cash equivalents and restricted cash	$ 130,529	$ 158,830	$ 92,777

Property and Equipment, Net - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 10,394	$ 3,304
Less: accumulated depreciation	(1,406)	(391)
Total property and equipment, net	$ 8,988	2,913
Laboratory equipment
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	5 years
Total property, plant and equipment, gross	$ 1,635	839
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	5 years
Total property, plant and equipment, gross	$ 264	9
Computer equipment
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Total property, plant and equipment, gross	$ 418	221
Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	7 years
Total property, plant and equipment, gross	$ 7,971	274
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 106	$ 1,961

Property and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,104	$ 216

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Manufacturing	$ 6,674	$ 3,427
Employee compensation and benefits	3,135	2,200
Professional fees	613	433
Contract research	2,990	2,542
Success payment liability	570	0
Other	170	163
Total accrued expenses and other current liabilities	$ 14,152	$ 8,765

Term Loan (Details) - USD ($)	1 Months Ended	12 Months Ended
Term Loan (Details) - USD ($)	Apr. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Floating rate spread in effect (greater than) (percent)	4.50%
Proceeds from at the market offering of common stock		$ 16,191,000	$ 0
Debt Instrument, Conditional Fee, Liability		1,100,000
Prime Rate
Debt Instrument [Line Items]
Floating rate spread in effect (greater than) (percent)	0.50%
Term loan \| In FY 2021
Debt Instrument [Line Items]
Delayed draw fee	$ 200,000
Success Fee (percent)	2.00%
Term loan \| After FY 2021
Debt Instrument [Line Items]
Delayed draw fee	$ 400,000
Success Fee (percent)	4.00%
Term loan \| Tranche I Loan
Debt Instrument [Line Items]
Term loan available	$ 20,000,000
Term loan \| Tranche II Loan
Debt Instrument [Line Items]
Term loan available	$ 20,000,000
Term loan \| Term Loans
Debt Instrument [Line Items]
Drawings on Term Loans		0
Outstanding borrowings		0
Default payment fee (percent)	5.00%
Maximum annual capital expenditures	1.25
Proceeds from at the market offering of common stock		50,000,000
Cash		20,000,000
Capacity available to draw on the Term Loans		$ 40,000,000

Common and Preferred Stock - Narrative (Details)	12 Months Ended
Common and Preferred Stock - Narrative (Details)	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares	May 10, 2022 USD ($)
Class of Stock [Line Items]
Common stock authorized (shares)	200,000,000
Dividends Payable \| $	$ 0
Proceeds from at the market offering of common stock \| $	$ 16,191,000	$ 0
Preferred stock authorized (shares)	5,000,000
Preferred stock issued (shares)	0	0
Preferred stock outstanding (shares)	0	0
ATM Offering
Class of Stock [Line Items]
Sales Commissions, Percentage			0.030
Issuance of common stock from initial public offering, net of issuance costs (shares)	3,827,567
Price per share (in usd per share) \| $ / shares	$ 4.36
Proceeds from at the market offering of common stock \| $	$ 15,700,000
Maximum \| ATM Offering
Class of Stock [Line Items]
Common Stock, Amount Authorized \| $			$ 50,000,000

Common and Preferred Stock - Schedule of Common Stock Reserved for Issuance (Details) - shares shares in Thousands	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Common stock available for issuance (shares)	6,565	5,264
Shares reserved for exercises of outstanding stock options
Class of Stock [Line Items]
Common stock available for issuance (shares)	5,244	3,266
Shares reserved for vesting of restricted stock units
Class of Stock [Line Items]
Common stock available for issuance (shares)	323	0
Shares reserved for exercises of warrants
Class of Stock [Line Items]
Common stock available for issuance (shares)	59	59
Shares reserved for future issuance under the 2021 Stock Incentive Plan
Class of Stock [Line Items]
Common stock available for issuance (shares)	939	1,939

Stock-based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Apr. 30, 2021 shares	Apr. 30, 2021 shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Jan. 01, 2022 shares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock available for issuance (shares)			6,565,000	5,264,000
Share-based compensation expense not yet recognized \| $			$ 18,300
Dividend yield			0.00%
Total stock-based compensation \| $			$ 7,400	$ 4,095
2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Maximum number of shares to be added annually, as a percentage of outstanding shares (percent)	0.05
2017 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock available for issuance (shares)			938,587
2021 Stock Employee Stock Purchase Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense not yet recognized \| $			$ 100
Maximum annual contributions per employee, percent		15.00%
Offering period		6 months
ESPP purchase price, percent	0.85	0.85
Risk-free interest rate		4.70%
Expected term (in years)		6 months
Expected volatility		77.00%
Dividend yield		0.00%
Total stock-based compensation \| $			100
Common Stock
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (shares)	3,352,725	3,352,725			1,380,397
Common Stock \| 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (shares)	2,843,116	2,843,116
Common Stock \| 2017 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (shares)	31,884	31,884
Unvested RSAs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense not yet recognized \| $			$ 100
Share-based compensation not yet recognized, recognition period			4 months 24 days
Aggregate fair value of awards that vested \| $			$ 1,200	$ 3,600
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			214,000
Granted (shares)			0
Weighted Average Grant Date Fair Value - Granted (in usd per share) \| $ / shares			$ 0
Unvested RSAs \| 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (shares)	477,725	477,725
Employee stock \| 2021 Stock Employee Stock Purchase Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Common stock authorized to be issued (shares)	244,000	244,000
Maximum number of shares to be added annually, as a percentage of outstanding shares (percent)	0.01
Employee stock \| 2021 Stock Employee Stock Purchase Plan \| Minimum
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Maximum number of shares to be added annually, as a percentage of outstanding shares (shares)	488,000
Stock options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation not yet recognized, recognition period			2 years 2 months 12 days
Weighted-average grant date fair value of awards (in usd per share) \| $ / shares			$ 5.98	$ 9.72
Aggregate intrinsic fair value of options exercised \| $			$ 400	$ 800
Risk-free interest rate			2.30%	1.00%
Expected term (in years)			6 years	6 years
Expected volatility			77.00%	78.70%
Dividend yield			0.00%	0.00%
Shares reserved for vesting of restricted stock units \| 2021 Stock Incentive Plan
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense not yet recognized \| $			$ 1,000
Share-based compensation not yet recognized, recognition period			1 year 2 months 26 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			0
Granted (shares)			364,000
Weighted Average Grant Date Fair Value - Granted (in usd per share) \| $ / shares			$ 4.39
Performance Shares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			0
Granted (shares)			883,352
Weighted Average Grant Date Fair Value - Granted (in usd per share) \| $ / shares			$ 3.36

Stock-based Compensation - Expense Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 7,400	$ 4,095
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	3,410	1,524
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 3,990	$ 2,571

Stock-based Compensation - Restricted Stock Award Activity (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Unvested RSAs
Shares/Units
Unvested at beginning of period (shares) \| shares	295,000
Granted (shares) \| shares	0
Vested (shares) \| shares	(214,000)
Forfeited (shares) \| shares	0
Unvested at end of period (shares) \| shares	81,000
Weighted-Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value - Unvested at beginning of period (in usd per share) \| $ / shares	$ 1.35
Weighted Average Grant Date Fair Value - Granted (in usd per share) \| $ / shares	0
Weighted Average Grant Date Fair Value - Vested (in usd per share) \| $ / shares	1.34
Weighted Average Grant Date Fair Value - Forfeited (in usd per share) \| $ / shares	0
Weighted Average Grant Date Fair Value - Unvested at end of period (in usd per share) \| $ / shares	$ 1.38
Shares reserved for vesting of restricted stock units \| 2021 Stock Incentive Plan
Shares/Units
Unvested at beginning of period (shares) \| shares	0
Granted (shares) \| shares	364,000
Vested (shares) \| shares	0
Forfeited (shares) \| shares	(41,000)
Unvested at end of period (shares) \| shares	323,000
Weighted-Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value - Unvested at beginning of period (in usd per share) \| $ / shares	$ 0
Weighted Average Grant Date Fair Value - Granted (in usd per share) \| $ / shares	4.39
Weighted Average Grant Date Fair Value - Vested (in usd per share) \| $ / shares	0
Weighted Average Grant Date Fair Value - Forfeited (in usd per share) \| $ / shares	4.97
Weighted Average Grant Date Fair Value - Unvested at end of period (in usd per share) \| $ / shares	$ 4.32

Stock-based Compensation - Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Dividend yield	0.00%
Stock options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Risk-free interest rate	2.30%	1.00%
Expected term (in years)	6 years	6 years
Dividend yield	0.00%	0.00%
Expected volatility	77.00%	78.70%

Stock-based Compensation - Stock Option Activity (Details) - Stock options - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of Options
Outstanding at beginning of period (shares)	3,266
Granted (shares)	2,183
Exercised (shares)	(80)
Cancelled (shares)	(125)
Outstanding at end of period (shares)	5,244	3,266
Exercisable at end of period (shares)	1,683
Weighted-Average Exercise Price
Weighted-Average Exercise Price - Outstanding at beginning of period (in usd per share)	$ 8.24
Weighted-Average Exercise Price - Granted (in usd per share)	7.14
Weighted-Average Exercise Price - Exercised (in usd per share)	2.82
Weighted-Average Exercise Price - Cancelled (in usd per share)	8.55
Weighted-Average Exercise Price - Outstanding at end of period (in usd per share)	7.86	$ 8.24
Weighted-Average Exercise Price - Exercisable at end of period (in usd per share)	$ 8.00
Weighted-Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life - Outstanding	8 years 4 months 2 days	9 years 7 days
Weighted Average Remaining Contractual Life - Exercisable	8 years 1 month 2 days

Commitments and Contingencies - Narrative (Details) $ in Thousands		1 Months Ended		12 Months Ended			46 Months Ended
	Dec. 20, 2019 USD ($)	May 31, 2022 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2021 targetOption	Nov. 30, 2022 USD ($)	Mar. 31, 2022 ft²	Jun. 30, 2021 USD ($) ft²	Apr. 30, 2019 ft²
Loss Contingencies [Line Items]
Sublease income				$ 834	$ 0
Research and development				$ 53,761	$ 35,269
Lease commenced in April 2019
Loss Contingencies [Line Items]
Laboratory and office space to be rented (in sqft) \| ft²											9,949
Sublease Agreement, Year One
Loss Contingencies [Line Items]
Sublease income		$ 1,100
Sublease Agreement, Year Two
Loss Contingencies [Line Items]
Sublease income		$ 1,000
Lease commenced in April 2021
Loss Contingencies [Line Items]
Laboratory and office space to be rented (in sqft) \| ft²									7,500
Lease commencing April 2022
Loss Contingencies [Line Items]
Laboratory and office space to be rented (in sqft) \| ft²										25,778
Tenant improvements										$ 5,700
Security deposit provided										$ 1,000
Harpoon \| Assignment and License Agreement
Loss Contingencies [Line Items]
Reimbursable legal costs	$ 75
Minimum annual royalties	$ 250
Research and development						$ 500
Upfront fee paid						$ 500
License agreement termination, prior written notice required	30 days
Adimab \| Development and Option Agreement
Loss Contingencies [Line Items]
Research and development			$ 100
Upfront fee paid			100
Upfront and final fee			200
Exercised option fee			500					$ 500
Adimab \| Development and Option Agreement \| Minimum
Loss Contingencies [Line Items]
Research program milestone fees			150					500
Exercised option milestone fee			1,000					1,000
Target options exercised \| targetOption							0
Adimab \| Development and Option Agreement \| Maximum
Loss Contingencies [Line Items]
Research program milestone fees			200					1,500
Exercised option milestone fee			$ 4,000					$ 2,000

Commitments and Contingencies - Summarizes Operating Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Operating lease costs	$ 2,537	$ 1,312
Variable lease costs	837	398
Short-term lease costs	228	411
Sublease Income	(834)	0
Total	$ 2,768	$ 2,121

Commitments and Contingencies - Summarizes The Lease Term and Discount Rate For Operating Leases (Details)	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Weighted-average remaining lease term (years)	7 years	7 years 7 months 6 days
Weighted-average discount rate	8.10%	8.10%

Commitments and Contingencies - Future Minimum Lease Payment (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2023	$ 3,133
2024	2,505
2025	2,337
2026	2,403
2027	2,472
Thereafter	6,258
Total remaining minimum rental payments	19,108
Less: effect of discounting	(4,424)
Total lease liability	$ 14,684

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Capitalized research and experimentation expenses	$ 36,100
Current income tax expenses	0	$ 0
Deferred income tax expenses	0	0
Valuation allowance, deferred tax asset, increase amount	16,300	14,300
Deferred tax assets, operating loss carryforwards not subject to expiration	$ 92,000
UNITED STATES \| Research And Experimentation
Operating Loss Carryforwards [Line Items]
Amortization of R&E expenses, period	5 years
Non-US \| Research And Experimentation
Operating Loss Carryforwards [Line Items]
Amortization of R&E expenses, period	15 years
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards subject to expiration	$ 92,100	80,300
Domestic Tax Authority \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	2,600	1,300
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	86,100	74,500
Tax credit carryforwards	$ 1,200	$ 600

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Total income tax expense (benefit) differs from the U.S. federal income tax rate to pre-tax income (loss)
Income tax computed at federal statutory rate	21.00%	21.00%
State taxes	8.30%	5.70%
Change in valuation allowance	(30.40%)	(27.20%)
R&D credit carryovers	2.40%	1.80%
Stock-based compensation	(1.50%)	(0.90%)
Permanent differences	0.20%	(0.40%)
Effective income tax rate	(0.00%)	(0.00%)

Income Taxes -Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating losses	$ 26,234	$ 22,831
Tax credit carryforwards	3,819	1,918
Lease liability	4,180	4,393
Other capitalized costs—net of amortization	103	111
Reserves and accruals	950	658
Stock-based compensation	1,448	500
Capitalized research and experimental expenditures—net of amortization	9,474	0
Deferred tax assets	46,208	30,411
Valuation allowance	(42,417)	(26,110)
Deferred tax assets recognized	3,791	4,301
Deferred tax liabilities:
Right of use asset	(2,358)	(3,762)
Fixed assets and depreciation	(1,433)	(6)
Construction in progress	0	(533)
Deferred tax liabilities	(3,791)	(4,301)
Net deferred tax assets	$ 0	$ 0

Related Parties (Details) - USD ($) $ in Thousands	12 Months Ended
Related Parties (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Related Party Transactions [Abstract]
Sublease Income	$ (834)	$ 0
Security deposit liability	$ 200

401(k) Savings Plan (Details) $ in Thousands	12 Months Ended
401(k) Savings Plan (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Retirement Benefits [Abstract]
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percent of employees' gross pay	6.00%
Defined contribution plan expense	$ 200

Net Loss Attributable to Common Stockholders per Share - Antidilutive Shares (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,707	3,620
Shares reserved for future issuance under the 2021 Stock Incentive Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,244	3,266
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	81	295
Shares reserved for vesting of restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	323	0

Subsequent Events (Details) - USD ($)	3 Months Ended	12 Months Ended
Subsequent Events (Details) - USD ($)	Mar. 17, 2023	Dec. 31, 2022	Dec. 31, 2021	Mar. 15, 2023
Subsequent Event [Line Items]
Proceeds from at the market offering of common stock		$ 16,191,000	$ 0
ATM Offering
Subsequent Event [Line Items]
Issuance of common stock from initial public offering, net of issuance costs (shares)		3,827,567
Price per share (in usd per share)		$ 4.36
Proceeds from at the market offering of common stock		$ 15,700,000
Term Loans \| Term loan
Subsequent Event [Line Items]
Outstanding borrowings		0
Proceeds from at the market offering of common stock		$ 50,000,000
Subsequent Event \| ATM Offering
Subsequent Event [Line Items]
Issuance of common stock from initial public offering, net of issuance costs (shares)	3,800,000
Proceeds from at the market offering of common stock	$ 8,800,000
Subsequent Event \| Term Loans \| Term loan
Subsequent Event [Line Items]
Outstanding borrowings				$ 40,000,000

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details