Omega Therapeutics (OMGA) 10-K 10 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 04, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	Omega Therapeutics, Inc.
Entity Central Index Key	0001850838
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		47,807,651
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	OMGA
Security Exchange Name	NASDAQ
Entity File Number	001-40657
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-3247585
Entity Address, Address Line One	20 Acorn Park Drive
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02140
City Area Code	617
Local Phone Number	949-4360
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
ICFR Auditor Attestation Flag	false
Entity Public Float			$ 0
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference [Text Block]	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s definitive proxy statement relating to its 2022 Annual Meeting of Stockholders, to be filed with the Securities and Exchange Commission within 120 days after the end of the fiscal year ended December 31, 2021, are incorporated herein by reference in Part III.
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	Boston, Massachusetts

Balance sheets

Balance sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 186,482	$ 22,951
Marketable securities	38,845
Accounts receivable, due from related party	257
Prepaid expenses and other current assets	3,702	1,052
Total current assets	229,286	24,003
Property and equipment, net	3,605	3,482
Restricted cash	341	341
Other assets	101	257
Total assets	233,333	28,083
Current liabilities:
Accounts payable	2,109	1,063
Accrued expenses	9,475	3,277
Other current liabilities	399	359
Long-term debt, current portion		3,000
Total current liabilities	11,983	7,699
Long-term debt, net	19,869	8,732
Other liabilities	853	1,055
Total liabilities	32,705	17,486
Commitments and contingencies (Note 9)
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		75,225
Stockholders' equity (deficit):
Preferred stock, $0.001 par value; 10,000,000 shares and no shares authorized as of December 31, 2021 and December 31, 2020, respectively; no shares issued and outstanding as of December 31, 2021 and December 31, 2020
Common stock, $0.001 par value; 200,000,000 and 137,700,000 shares authorized as of December 31, 2021 and December 31, 2020, respectively; 47,793,469 and 4,465,351 issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	48	5
Additional paid-in capital	335,147	1,592
Accumulated other comprehensive loss	(62)	0
Accumulated deficit	(134,505)	(66,225)
Total stockholders' deficit	200,628	(64,628)
Total liabilities, redeemable convertible preferred stock, and stockholders' equity (deficit)	233,333	28,083
Series A Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		26,708
Series B Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock:
Redeemable convertible preferred stock		48,517
Series C Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock:
Redeemable convertible preferred stock

Balance sheets (Parenthetical)

Balance sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Redeemable convertible preferred stock, shares authorized		107,125,232
Redeemable convertible preferred stock, shares issued		89,175,231
Redeemable convertible preferred stock, shares outstanding		89,175,231
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	137,700,000
Common stock, shares issued	47,793,469	4,465,351
Common stock, shares outstanding	47,793,469	4,465,351
Series A Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	57,125,232
Redeemable convertible preferred stock, shares issued	0	56,775,232
Redeemable convertible preferred stock, shares outstanding	0	56,775,232
Series B Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	50,000,000
Redeemable convertible preferred stock, shares issued	0	32,399,999
Redeemable convertible preferred stock, shares outstanding	0	32,399,999
Series C Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	0
Redeemable convertible preferred stock, shares issued	0	0
Redeemable convertible preferred stock, shares outstanding	0	0

Consolidated Statements of oper

Consolidated Statements of operations and comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Collaboration revenue from related party	$ 144
Operating expenses:
Research and development	47,865	$ 21,063
General and administrative	16,603	6,236
Related party expense, net	1,708	1,346
Total operating expenses	66,176	28,645
Loss from operations	(66,032)	(28,645)
Other expense, net:
Interest expense, net	(910)	(777)
Change in fair value of warrant liability	(1,310)	3
Other expense, net	(28)	(28)
Total other expense, net	(2,248)	(802)
Net loss	$ (68,280)	$ (29,447)
Net loss per common stock attributable to common stockholders, basic and diluted	$ (3.05)	$ (7.54)
Weighted-average common stock used in net loss per share attributable to common stockholders, basic and diluted	22,404,058	3,906,168
Comprehensive loss:
Net loss	$ (68,280)	$ (29,447)
Other comprehensive loss:
Unrealized loss on marketable securities	(62)
Comprehensive loss	$ (68,342)	$ (29,447)

Consolidated statements of rede

Consolidated statements of redeemable convertible preferred stock and stockholders' equity (deficit) - USD ($) $ in Thousands	Total	Preferred Stock - Series A	Preferred Stock - Series B	Preferred Stock - Series C	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2019	$ (35,919)				$ 5	$ 854		$ (36,778)
Balance (in shares) at Dec. 31, 2019		56,775,232
Balance at Dec. 31, 2019		$ 26,708
Balance (in shares) at Dec. 31, 2019					3,775,292
Issuance of redeemable convertible preferred stock, shares			32,399,999
Issuance of redeemable convertible preferred stock			$ 48,517
Issuance of common stock for options exercised	102					102
Issuance of common stock for options exercised, shares					196,301
Vesting of restricted stock, shares					496,322
Common stock repurchased	(1)					(1)
Common stock repurchased, shares					(2,564)
Stock-based compensation	637					637
Net loss	(29,447)							(29,447)
Balance at Dec. 31, 2020	$ (64,628)				$ 5	1,592		(66,225)
Balance (in shares) at Dec. 31, 2020	89,175,231	56,775,232	32,399,999	0
Balance at Dec. 31, 2020	$ 75,225	$ 26,708	$ 48,517
Balance (in shares) at Dec. 31, 2020					4,465,351
Issuance of redeemable convertible preferred stock, shares				41,833,328
Issuance of redeemable convertible preferred stock				$ 125,368
Issuance of common stock from initial public offering, net of issuance costs, shares					8,300,976
Issuance of common stock from initial public offering, net of issuance costs	128,112				$ 8	128,104
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering, shares		(56,775,232)	(32,399,999)	(41,833,328)	34,678,733
Conversion of redeemable convertible preferred stock to common stock upon closing of initial public offering	200,594	$ (26,708)	$ (48,517)	$ (125,368)	$ 35	200,559
Conversion of preferred stock warrant to common stock warrant upon closing of initial public offering	1,434					1,434
Cashless exercise of warrants	0
Cashless exercise of warrants, shares					82,193
Issuance of common stock for options exercised	274					274
Issuance of common stock for options exercised, shares					266,216
Other comprehensive loss	(62)						$ (62)
Stock-based compensation	3,184					3,184
Net loss	(68,280)							(68,280)
Balance at Dec. 31, 2021	$ 200,628				$ 48	$ 335,147	$ (62)	$ (134,505)
Balance (in shares) at Dec. 31, 2021		0	0	0
Balance at Dec. 31, 2021
Balance (in shares) at Dec. 31, 2021					47,793,469

Consolidated statements of re_2

Consolidated statements of redeemable convertible preferred stock and stockholders' equity (deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stock issuance costs	$ 3,126
Initial Public Offering
Stock issuance costs	13,005
Preferred Stock - Series B
Stock issuance costs		$ 83
Preferred Stock - Series C
Stock issuance costs	$ 132

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (68,280)	$ (29,447)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,387	1,146
Amortization of debt issuance costs and debt discount	93	48
Accretion of discounts on marketable securities	25
Change in fair value of warrant liability	1,310	(3)
Change in fair value of success fee obligation	6
Non-cash interest expense	164
Stock-based compensation expense	3,184	637
Deferred rent	(157)	(107)
(Gain)/loss on disposal of equipment	(3)	28
Changes in operating assets and liabilities:
Accounts receivable due from related party	(257)
Prepaid expenses and other current assets	(2,646)	(663)
Other assets	(156)	35
Accounts payable	1,040	138
Accrued expenses and other current liabilities	6,379	2,295
Other liabilities	10	(240)
Net cash used in operating activities	(57,609)	(26,133)
Investing activities
Purchases of property and equipment	(1,467)	(1,808)
Purchase of marketable securities	(38,932)
Net cash used in investing activities	(40,399)	(1,808)
Financing activities
Proceeds from issuance of redeemable convertible preferred stock	125,500	48,600
Payments for preferred stock issuance costs	(132)	(83)
Proceeds from initial public offering of common stock, net of commissions and underwriting discounts	131,238
Payments for initial public offering costs	(3,126)
Payment of success fee	(200)
Proceeds from debt financing	8,000
Payments of financing fees	(15)
Proceeds from exercise of stock options	274	101
Net cash provided by financing activities	261,539	48,618
Net increase in cash, cash equivalents and restricted cash	163,531	20,677
Cash, cash equivalents and restricted cash—beginning of period	23,292	2,615
Cash, cash equivalents and restricted cash—end of period	186,823	23,292
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	186,482	22,951
Restricted cash	341	341
Cash, cash equivalents and restricted cash—end of period	186,823	23,292
Supplemental disclosures of cash flow information
Cash paid for interest	754	732
Supplemental disclosure of noncash investing and financing activities
Conversion of preferred stock to common stock	200,594
Reclassification of warrants to additional paid-in capital	1,434
Purchase of property and equipment included accounts payable and accrued expenses	44	23
Fair value attributed to success fee obligation	$ 105	$ 194

Nature of the business and basi

Nature of the business and basis of presentation	12 Months Ended
	Dec. 31, 2021
Nature Of Business And Basis Of Presentation [Abstract]
Nature of the business and basis of presentation	1. Nature of the business and basis of presentation Organization Omega Therapeutics, Inc. (the “Company” or “Omega”) is a development-stage biotechnology company pioneering a systematic approach to use mRNA therapeutics as programmable epigenetic medicines by leveraging its OMEGA Epigenomic Programming platform (“OMEGA platform”). The OMEGA platform harnesses the power of epigenetics, the mechanism that controls gene expression and every aspect of an organism’s life from cell genesis, growth and differentiation to cell death. The OMEGA platform enables control of fundamental epigenetic processes to correct the root cause of disease by restoring aberrant gene expression to a normal range without altering native nucleic acid sequences. The Company was incorporated in July 2016 (“inception”) as a Delaware corporation and its offices are in Cambridge, Massachusetts. Liquidity and going concern Since its inception, the Company has devoted substantially all of the resources to building its platform and advancing development of its portfolio of programs, establishing and protecting its intellectual property, conducting research and development activities, organizing and staffing the Company, business planning, raising capital and providing general and administrative support for 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, developments 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 drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. In August 2021, the Company completed its initial public offering (“IPO”) pursuant to which it issued and sold 8,300,976 shares of its common stock, including 900,976 shares pursuant to the partial exercise of the underwriters’ option to purchase additional shares, at a public offering price of $ 17.00 per share, for aggregate gross proceeds of $ 141.1 million. The Company received approximately $ 128.1 million in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. The Company expects that its cash, cash equivalents, and marketable securities of $ 225.3 million at December 31, 2021 will enable it to fund its operating expenses and capital expenditure requirements for at least twelve months from the filing date of the consolidated financial statements. However, additional funding will be necessary to fund future preclinical and clinical activities and to develop new product candidates. The Company expects to finance its future cash needs through a combination of equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements, or other sources . COVID-19-Related Significant Risks and Uncertainties With the global COVID-19 pandemic continuing throughout 2021, the Company is following, and plans to continue to follow, recommendations from federal, state and local governments regarding workplace policies, practices and procedures. To provide a safe work environment for its employees, the Company has implemented various measures to promote for social distancing, encourage employees to work remotely when possible, increase sanitization of its facilities and provide personal protective equipment for its employees. The Company expects to continue incurring additional costs to ensure it adheres to the guidelines instituted by the federal, state and local governments and to provide a safe working environment to its onsite employees. The extent to which the COVID-19 pandemic and variants of the virus impacts the Company’s business, its corporate development objectives, results of operations and financial condition, and the fair value of and market for its common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements, and the effectiveness of actions taken globally to contain and treat the disease. Disruptions to the global economy, disruption of global healthcare systems, and other significant impacts of the COVID-19 pandemic could have a material adverse effect on the Company’s business, financial condition, results of operations and growth prospects. While the COVID-19 pandemic did not significantly impact the Company’s business or results of operations during the years ended December 31, 2021 and 2020, the length and extent of the pandemic, its consequences, and containment efforts will determine the future impact on the Company’s operations and financial condition. Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”), and Accounting Standards Update (“ASU”), of the Financial Accounting Standards Board (“FASB”). All amounts herein are expressed in U.S. dollars (“USD”) unless otherwise noted.

Summary of significant accounti

Summary of significant accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of significant accounting policies	2. Summary of significant accounting policies Principles of consolidation The accompanying consolidated financial statements include the accounts of Omega Therapeutics, Inc. and its wholly owned subsidiary, Omega Therapeutics Security Corporation, which is a Massachusetts subsidiary. All intercompany transactions and balances have been eliminated in consolidation. Use of estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the selection of useful lives of property and equipment, the fair values of certain financial instruments issued prior to the IPO (common stock, redeemable convertible preferred stock, and warrants), the fair value of the success fee obligation, and stock-based compensation. Actual results could differ from these estimates. Changes in estimates are reflected in reported results in the period in which they become known . Cash and cash equivalents Cash includes cash in readily available checking accounts, and cash equivalents include money market accounts and all highly liquid investments with an original maturity of three months or less from the date of purchase. Cash and cash equivalents are recorded at cost, which approximates fair value. Marketable securities The Company’s marketable securities as of December 31, 2021 consisted of corporate debt securities and are classified as available-for-sale and are reported at fair value. Unrealized gains and losses on available-for-sale debt securities are reported as a component of accumulated other comprehensive loss in stockholders’ equity until realized. Any premium or discount arising at purchase is amortized and/or accreted to interest income and/or expense over the life of the instrument. Realized gains and losses are determined using the specific identification method and are included as a component in other expense, net. The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the consolidated statements of operations and comprehensive loss. Restricted cash Restricted cash represents collateral provided for letters of credit issued as security deposit in connection with the Company’s office lease. Concentrations of credit risk Financial instruments that are potentially subject to significant concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company attempts to minimize the risk related to marketable securities by working with highly rated financial institutions that invest in a broad and diverse range of financial instruments as defined the Company. The Company has established guidelines relative to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. The Company maintains its funds in accordance with its investment policy, which defines allowable investments, specifies credit quality standards and is designed to limit credit exposure to any single issuer. Guarantees and indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, consultants, and employees for certain events or occurrences that happen by reason of the relationship with, or position held at, the Company. Through December 31, 2021 and 2020 , the Company had no t experienced any losses related to these indemnification obligations, and no claims were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related liabilities were established. Property and equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset category as follows: Asset category Estimated useful life Computer equipment and software 3 years Laboratory equipment and office furniture 5 years Leasehold improvements Shorter of useful life or remaining lease term Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred. Accrued research and development expenses The Company estimates accrued research and development expenses based on its estimates of the services received and efforts expended pursuant to quotes and contracts with third-party service providers, including contract research organizations (“CROs”) and contract development and manufacturing organizations (“CDMOs”) that supply, conduct and manage preclinical studies on the Company’s behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to its vendors will exceed the level of services provided and result in a prepayment of the expense, in which it will be evaluated for current or long-term classification based on when it is expected to be realized. 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. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts the accrual or the amount of prepaid expenses accordingly. Debt issuance costs Costs incurred in connection with the issuance of the Company’s long-term debt have been recorded as a direct reduction against the debt and amortized over the life of the associated debt as a component of interest expense using the effective interest method. Warrant liability Warrants for the purchase of Series A redeemable convertible preferred stock (“Series A Preferred Stock”) issued in connection with the loan and security agreement (“Loan Agreement”), as amended, with Pacific Western Bank (“PWB”) were classified as a liability on the consolidated balance sheets at their fair value on the date of issuance. At the end of each reporting period, the change in estimated fair value during the period was recognized as a component of other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of the warrants was remeasured at the end of each reporting period until the closing of the IPO, at which time the liabilities were reclassified to an equity component as the outstanding warrants automatically became warrants to purchase common stock. Success fee obligation The Loan Agreement, as amended, with PWB, requires the Company to pay a success fee (“success fee obligation”) upon the occurrence of a specified liquidity event as described in the Loan Agreement, as amended. The Company determined that this obligation represented a freestanding derivative instrument. Accordingly, the success fee obligation was classified as a liability on the Company’s consolidated balance sheets and initially recorded at fair value, with changes in fair value for each reporting period recognized in other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of such obligation is remeasured at the end of each reporting period until the liability is settled. Deferred rent The Company’s real estate operating leases provide for scheduled annual rent increases throughout the lease terms. The Company recognizes the effects of the scheduled rent increases on a straight-line basis over the full terms of the leases. Tenant improvement allowances, if any, provided by a landlord are recorded as deferred rent and amortized as reductions to rent expense over the lease terms. Equity issuance costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of proceeds generated as a result of the offering. Should a planned equity financing be abandoned, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statement of operations. Upon closing of the IPO, deferred offering costs were derecognized and recorded against the IPO proceeds as a reduction to additional paid-in capital. There were no deferred offering costs as of December 31, 2021 and 2020. Impairment of long-lived assets The Company evaluates its long-lived assets, which consist primarily of property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There were no impairment losses recognized during the years ended December 31, 2021 and 2020 . Fair value measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The fair value of the Company’s cash and cash equivalents and restricted cash are measured through quoted market prices; the fair value of the Company's marketable securities is determined based on the pricing inputs other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date. Other current assets, accounts payable and accrued liabilities approximate their fair values as of December 31, 2021 and 2020, due to their short-term nature. The carrying value of the Company’s debt approximates its fair value due to its variable interest rate, which approximates a market interest rate. The warrant liability and the success fee obligation associated with the Loan Agreement, as amended, contain unobservable inputs that reflect the Company’s own assumptions in which there is little, if any, market activity at the measurement date, thus the Company’s warrant liability and the success fee obligation are measured at their fair values on a recurring basis using unobservable inputs. See further discussion in Note 8, Fair value of financial instruments . Redeemable convertible preferred stock The Company classified redeemable convertible preferred stock as temporary equity on the consolidated balance sheet because it could become redeemable upon occurrence of a deemed liquidation event that is outside of the Company’s control. Upon completion of the Company’s IPO, all of the Company’s then outstanding Preferred Stock was automatically converted into common stock . Revenue recognition Revenue recognized to-date is solely generated from the collaboration agreement with PM (CF) Explorations, Inc., or PMCo. The Company recognizes revenue in accordance with ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and its related amendments, or, collectively, ASC 606. At inception, the Company determines whether contracts are within the scope of ASC 606 or other topics. For contracts that are determined to be within the scope of ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these goods and services. To achieve this core principle, the Company applies the following five steps (i) identify the contract with the customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when performance obligation is satisfied. The Company only applies the five-step model to contracts when it determines that collection of substantially all consideration for goods and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. Performance obligations promised in a contract are identified based on the goods and services that will be transferred to the customer that are both capable of being distinct and are distinct in the context of the contract. To the extent a contract includes multiple promised goods and services, the Company applies judgment to determine whether promised goods and services are both capable of being distinct and distinct in the context of the contract. If these criteria are not met, the promised goods and services are accounted for as a combined performance obligation. The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring goods and services to the customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method, depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in management’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Any estimates, including the effect of the constraint on variable consideration, are evaluated at each reporting period for any changes. Determining the transaction price requires significant judgment. If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative standalone selling price basis unless the transaction price is variable and meets the criteria to be allocated entirely to a performance obligation or to a distinct service that forms part of a single performance obligation. The consideration to be received is allocated among the separate performance obligations based on relative standalone selling prices. The Company satisfies performance obligations either over time or at a point in time. Revenue is recognized over time if either (i) the customer simultaneously receives and consumes the benefits provided by the entity’s performance, (ii) the entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or (iii) the entity’s performance does not create an asset with an alternative use to the entity and the entity has an enforceable right to payment for performance completed to date. If the entity does not satisfy a performance obligation over time, the related performance obligation is satisfied at a point in time by transferring the control of a promised good or service to a customer. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from consideration allocated to the license when the license is transferred to the customer and the customer can use and benefit from the license. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. At the inception of each arrangement that includes milestone payments, the Company evaluates the probability of reaching the milestones and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur in the future, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s are not considered probable of being achieved and therefore revenue recognized is constrained as management is unable to assert that a reversal of revenue would not be possible. The transaction price is then allocated to each performance obligation on a relative standalone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. To date, the Company has not recognized any milestone revenue. Deferred revenue arises from amounts received in advance of the culmination of the earnings process and is recognized as revenue in future periods as performance obligations are satisfied. Deferred revenue expected to be recognized within the next twelve months is classified as a current liability. Research and development expenses Research and development expenses are charged to expense as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation, consulting fees, cost of licensing technology, milestone payment, and external contract research and development and manufacturing expenses. Costs for certain research and development activities are recognized based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses and expensed as the related goods are delivered or the services are performed. Stock-based compensation The Company’s stock-based compensation program allows for grants of incentive stock options, non-qualified stock options, stock appreciation rights, and restricted stock awards, restricted stock units and other stock-based awards to employees, directors and consultants. The Company recognizes all stock-based compensation awards to employees and non-employees as expense in the consolidated statements of operations and comprehensive loss based on their fair values. For stock option awards, the Company estimates the fair value using the Black-Scholes option pricing model. The fair value of the Company’s common stock is used to determine the fair value of restricted stock awards. Stock-based compensation awards are subject to service vesting conditions, and forfeitures are recorded as they occur. Compensation expense related to awards to employees with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. The Company applies ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU No. 2018-07”), in which the measurement date for non-employee awards is determined as the date of grant, and stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (i) the expected stock price volatility, (ii) the expected term of the award, (iii) the risk-free interest rate, and (iv) expected dividends. Due to the lack of a public market for the Company’s common stock prior to the IPO and continued lack of sufficient company-specific historical and implied volatility data, the Company has based its computation of expected volatility on the historical volatility of a representative group of public companies with similar characteristics to the Company, including stage of product development and life science industry focus. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The Company uses the simplified method as prescribed by the Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment , to calculate the expected term for options granted to employees and non-employees, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the options due to its lack of sufficient historical data. The risk-free interest rate is based on U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. Due to the absence of an active market for the Company’s common stock prior to the IPO, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid, Valuation of Privately- Held Company Equity Securities Issued as Compensation , to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the estimated fair value of the common stock as of the measurement date. The estimated fair value of the common stock has been determined at each grant date based upon a variety of factors, including the illiquid nature of the common stock, arm’s-length sales of the Company’s capital stock (including redeemable convertible preferred stock), the effect of the rights and preferences of the preferred shareholders, and the prospects of a liquidity event. Among other factors are the Company’s financial position and historical financial performance, the status of technological developments within the Company’s research, the composition and ability of the current research and management team, an evaluation or benchmark of the Company’s competition, and the current business climate in the marketplace. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date. Subsequent to the IPO, the Company has used the quoted market price of its common stock on the measurement date. Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred as patents have no future alternative use. Income taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and tax returns. Deferred tax assets and liabilities are determined based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards, using enacted tax rates expected to be in effect in the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that these assets may not be realized. As of December 31, 2021 and 2020 , the Company has recorded a full valuation allowance against its deferred tax assets. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for income taxes. Comprehensive loss Comprehensive loss is defined as the change in stockholders’ equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss includes net loss as well as other changes in stockholders’ equity which includes certain changes in equity that are excluded from net loss. The Company’s only element of other comprehensive loss is unrealized gains and losses on its marketable securities. Net loss per share The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of common stock outstanding for the period. Diluted net loss attributable to common stockholders is computed by adjusting net loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the diluted net loss attributable to common stockholders by the weighted average number of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. The Company’s redeemable convertible preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the years ended December 31, 2021 and 2020 . Segment and geographic information Operating segments are defined as components of an entity about which discrete information is available for evaluation by the chief operating decision maker, or CODM, or decision-making group, in deciding how to allocate resources and in assessing performance. The CODM is the Company’s Chief Executive Officer. The CODM views its operations as and manages its business in one operating segment operating exclusively in the United States. Recently issued accounting pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight- line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less may be accounted for similar to existing guidance for operating leases today. As the Company has elected to use the extended transition period for complying with new or revised accounting standards as available under the Jumpstart Our Business Startups Act (“JOBS Act”), the standard is effective for the Company beginning January 1, 2022. The Company adopted ASU 2016-02, and related amendments, on January 1, 2022 using the effective date transition method. The Company has also elected a package of practical expedients, under which an entity need not reassess whether any expired or existing contracts are or contain leases, the lease classification for any expired or existing leases, or initial direct costs for any existing leases. The Company also elected not to separate lease and non-lease components. The Company has completed its initial assessment of the impact of ASU 2016-02 on the Company’s consolidated financial statements and internal controls, including its evaluation of key policy elections. The Company’s assessment included procedures to identify a complete lease population, performing analyses for each lease identified, assessing the differences in accounting that result from adopting this standard and assessing whether the Company meets certain practical expedients. While substantially complete, the Company is still in the process of finalizing its evaluation of the effect on the Company’s financial statements, disclosures, and internal controls. The Company estimates its total assets and total liabilities on the consolidated balance sheet will increase by approximately $ 3.5 million to $ 5.5 million due to the recognition of right-of-use assets

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3. Marketable securities The following table summarizes the Company’s marketable securities (in thousands): December 31, 2021 Amortized cost Gross unrealized losses Fair value Corporate debt securities $ 38,907 $ ( 62 ) $ 38,845 The amortized cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity. At December 31, 2021 , the balance in accumulated other comprehensive loss was comprised solely of activity related to marketable securities. There were no realized gains or losses recognized on the sale or maturity of marketable securities for the year ended December 31, 2021 and, as a result, the Company did no t reclassify any amounts out of accumulated other comprehensive loss during the year. The aggregate fair value of marketable securities that will be matured within 12 months of December 31, 2021 was $ 21.6 million, and the aggregate fair value of marketable securities that will be matured after 12 months of December 31, 2021 was $ 17.3 million. As of December 31, 2021 , the Company did not intend to sell, and was more than likely not required to sell, the debt securities in a loss position before recovery of their amortized cost bases. As a result, the Company determined it did no t hold any investments with any other-than-temporary impairment at December 31, 2021 .

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses and other current assets	4. Prepaid expenses and other current assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2021 2020 Prepaid rent $ 825 $ — Prepaid insurance 1,500 8 Prepaid software 143 78 Prepaid research and development 534 653 Prepaid other 436 120 Other receivables 264 193 Prepaid expenses and other current assets $ 3,702 $ 1,052

Property and equipment, net

Property and equipment, net	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property and equipment, net	. Property and equipment, net Property and equipment, net consists of the following (in thousands): December 31, 2021 2020 Leasehold improvements $ 1,378 $ 1,378 Lab equipment 4,822 3,444 Furniture and fixtures 1,073 985 Computer equipment 129 129 Construction in process 54 16 Total property and equipment 7,456 5,952 Less accumulated depreciation ( 3,851 ) ( 2,470 ) Property and equipment, net $ 3,605 $ 3,482 Depreciation expense for the years ended December 31, 2021 and 2020 was $ 1.4 million and $ 1.1 million, respectively.

Accrued expenses

Accrued expenses	12 Months Ended
	Dec. 31, 2021
Accrued Liabilities Current [Abstract]
Accrued expenses	6. Accrued expenses Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Employee related expenses $ 2,545 $ 1,124 Research costs 5,640 1,724 Professional and consulting fees 759 278 Interest 31 44 Other 500 107 Total $ 9,475 $ 3,277

Term Loan

Term Loan	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Term Loan	7. Term Loan On March 9, 2018 (“Closing Date”), the Company entered into the Loan Agreement with Pacific Western Bank (“PWB”) to initially borrow $ 8.0 million. In conjunction with the Loan Agreement, the Company issued a warrant to PWB to purchase up to 200,000 shares of Series A Preferred Stock at the strike price of $ 0.50 per share. The warrant was exercisable for a 10 -year period. On September 30, 2019, the Company entered into an amendment to the Loan Agreement (the “First Amendment”), in which PWB made an additional term loan to the Company in an aggregate principal amount of $ 12.0 million. In conjunction with the First Amendment, the Company also issued a warrant to purchase 350,000 shares of Series A Preferred Stock, which effectively restated and replaced the original warrant agreement. The strike price of the amended warrant is $ 0.50 per share, and the term remains unchanged, expiring in March 2028 . Refer to Note 8, Fair value of financial instruments , for further discussion on the valuation methodology and inputs for the determination of the fair value of the warrants. As the warrants issued were freestanding financial instruments that were exercisable for contingently redeemable shares, they were initially recorded at fair value on the date of issuance as a liability, with a corresponding discount recorded against the face value of the term loan. The discount was accreted against the face value of the term loan over its remaining term as additional interest expense. The change in estimated fair value of the warrants during the period was remeasured at each reporting date and recognized as a component of other expense, net in the consolidated statements of operations and comprehensive loss. Upon the closing of the IPO, the Company’s outstanding warrants to purchase Series A Preferred Stock automatically became warrants to purchase an aggregate of 92,647 shares of common stock. As a result, the fair value of the warrants was reclassified to additional paid-in capital. Additionally, the remaining unamortized debt discount of $ 0.1 million related to the warrants was written off during the three months ended September 30, 2021. In August 2021, the holders of such warrants completed a cashless exercise of the warrants, resulting in the Company’s issuance of 82,193 shares of its common stock, whereby 10,454 shares of common stock were withheld by the Company to pay for the exercise price of the warrants. On January 22, 2020, the Loan Agreement was further amended (the “Second Amendment”) to extend the principal repayment start date. The Loan Agreement was further amended on December 30, 2020 (the “Third Amendment”) to extend the principal repayment date. The maturity date of the term loan was extended to June 30, 2023 , and it was to be repaid beginning on June 30, 2021 in twenty-four equal installments, including interest at a floating annual rate equal to the greater of (i) 0.75 % above the prime rate then in effect and (ii) 6.00 %, due monthly starting the first month after December 30, 2020. As a result of the closing of Series C redeemable convertible preferred stock (“Series C Preferred Stock”) in March 2021, as further discussed in Note 12, Redeemable convertible preferred stock , the Company satisfied the cash proceeds milestone as defined in the Third Amendment, in which the Company received gross cash proceeds of more than $ 50.0 million from the issuance of new preferred stock prior to June 30, 2021. Accordingly, the principal repayment date of the term loan was further extended to December 31, 2021 and the maturity date was extended to December 31, 2023 . There are no other changes to the terms as a result of the achievement of the cash proceeds milestone. In connection with the Third Amendment, the Company incurred $ 15 thousand of debt issuance costs, which have been recorded as a direct reduction against the term loan and amortized over the life of the associated term loan as a component of interest expense using the effective interest method. In accordance with the Third Amendment, the Company was required to pay a success fee of $ 0.2 million upon the occurrence of a specified liquidity event, including an IPO. The Company determined that this obligation represented a freestanding financial instrument, and accordingly, the success fee obligation was classified as a liability on the Company’s consolidated balance sheet as of December 31, 2020 and initially recorded at fair value, with changes in fair value for each reporting period recognized in other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of such obligation was remeasured at the end of each reporting period until the liability was settled, for which it was settled and paid in August 2021 upon the completion of the IPO . On December 20, 2021, the Company entered into an amendment to the Loan Agreement (the "Fourth Amendment"), in which PWB made an additional term loan in an aggregate principal amount of $ 20.0 million. The proceeds of the term loan pursuant to the Fourth Amendment were first applied to the repayment in full of all outstanding principal and accrued interest on the then outstanding term loan of $ 12.0 million; the remaining cash proceeds of $ 8.0 million was used for general working capital and for capital expenditures purposes. The maturity date of the additional term loan will be on September 30, 2025 , and it will be repaid beginning on September 30, 2023 in twenty-four equal monthly installments, including interest at a floating annual rate equal to the greater of (i) 0.50 % above the prime rate then in effect and (ii) 5.50 %, due monthly starting the first month after December 20, 2021. The Company incurred $ 15 thousand of debt issuance costs, which was recorded as a direct reduction against the additional term loan and amortized over the life of the associated term loan as a component of interest expense using the effective interest method. Pursuant to the Fourth Amendment, the Company is also required to pay a success fee, ranging from $ 0.1 million to $ 0.2 million depending on the timing in achieving a specified liquidity event. T he Company determined that this obligation represented a freestanding financial instrument, and it was classified as a liability on the Company’s consolidated balance sheet as of December 31, 2021 and initially recorded at fair value, with changes in fair value for each reporting period recognized in other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of such obligation is remeasured at the end of each reporting period until the liability is settled. Borrowings under the Loan Agreement, as amended, are collateralized by substantially all of the Company’s personal property, other than its intellectual property. There are no financial covenants associated with the Loan Agreement, as amended; however, the Company is subject to certain affirmative and negative covenants to which the Company will remain subject until maturity. As of December 31, 2021 , the full amount of $ 20.0 million of the term loan was classified long-term based on the repayment start date. As of December 31, 2020 , the long-term debt, current portion was $ 3.0 million and the long-term debt was $ 9.0 million. The Company’s outstanding term loan balance was comprised of the following (in thousands): December 31, 2021 2020 Principal $ 20,000 $ 12,000 Unamortized debt discount ( 131 ) ( 268 ) Net carrying amount $ 19,869 $ 11,732 The Company determined that the expected life of the debt was equal to the term on the term loan. The effective interest rate on the liability component ranged from 5.53 % to 7.51 % for the period from the date of issuance through December 31, 2021 . The following table sets forth total interest expense recognized related to the term loan (in thousands): Year ended December 31, 2021 2020 Contractual interest expense $ 740 $ 732 Amortization of debt issuance costs and debt discount 258 48 Total interest expense $ 998 $ 780 As of December 31, 2021 and 2020 , accrued interest on the term loan was $ 31 thousand and $ 44 thousand, respectively. The Company is required to repay the following principal amounts in connection with its term loan (in thousands): 2022 $ — 2023 2,500 2024 10,000 2025 7,500 $ 20,000

Fair value of financial instrum

Fair value of financial instruments	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair value of financial instruments	. Fair value of financial instruments The fair value of the Company’s financial instruments is summarized in the tables below (in thousands): December 31, 2021 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 110,864 $ — $ — $ 110,864 Marketable securities — 38,845 — 38,845 Total $ 110,864 $ 38,845 $ — $ 149,709 Financial Liabilities Success fee obligation $ — $ — $ 105 $ 105 December 31, 2020 Level 1 Level 2 Level 3 Total Financial Liabilities Warrant liability $ — $ — $ 124 $ 124 Success fee obligation — — 194 194 Total $ — $ — $ 318 $ 318 The Company’s warrant liability and success fee obligation contain unobservable inputs that reflected the Company’s own assumptions in which there is little, if any, market activity at the measurement date. Accordingly, the Company’s warrant liability and success fee obligation are measured at fair value on a recurring basis using unobservable inputs at each reporting period and are classified as Level 3 inputs. As of December 31, 2021, the fair value of the Company's warrant liability was zero as the warrants became warrants to purchase common stock upon the closing of the IPO. As of December 31, 2020, the warrant liability was recorded as other liabilities on the consolidated balance sheet as it was deemed more probable than not by the Company to be settled in longer than one year. The fair value of the warrants was estimated using the Black-Scholes option-pricing model. The expected term represented the remaining contractual term of the warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. The expected dividend was zero as the Company had not paid any dividends on its common stock. The Company was a private company and lacked company-specific historical and implied volatility information of its stock. Therefore, it estimated its expected stock volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrants . The assumptions used in the Black-Scholes option-pricing model for the warrants were as follows: August 3, December 31, 2021 2020 Expected volatility 77.03 - 77.62 % 73.09 - 77.79 % Risk-free interest rate 0.95 - 1.40 % 0.58 - 0.65 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 6.6 - 6.9 7.2 - 7.9 The fair value of the warrants was remeasured at each reporting period, with changes in fair value recognized in the consolidated statements of operations and comprehensive loss, until the warrants were settled in August 2021. The change in the fair value of the warrant liability during the year ended December 31, 2021 was $ 1.3 million; and there was an immaterial change in the fair value of the warrant liability for the year ended December 31, 2020 . The fair value of the success fee obligation was determined using the probability-weighted expected return method. The key estimates and assumptions impacting the fair value included the probability of achieving a specified liquidity event, the expected timing of achieving a liquidity event and discount rate. The fair value of the success fee obligation was remeasured at each reporting period, with changes in fair value recognized in the consolidated statements of operations and comprehensive loss, until such liability was settled. As a result of the completion of the IPO, the Company paid $ 0.2 million of the success fee pursuant to the Third Amendment, and the related liability was zero as of December 31, 2021. In accordance with the Fourth Amendment, the Company will be required to pay a success fee upon the achievement of certain liquidity event; accordingly, the related obligation is recorded as current liabilities on the consolidated balance sheet as it is deemed more probable than not by the Company to be settled in less than one year. The following reflects the significant quantitative inputs used to determine the valuation of the success fee obligations: Year ended December 31, 2021 2020 Discount rate 5.5 % 6.0 % Expected timing of achieving liquidity events (years) 0.6 - 1.8 0.5 - 1 Probability of achieving liquidity events 10 % - 90 % 1 % - 99 % The following table provides a roll-forward of the fair values of the Company’s warrant liability and the success fee obligation for which fair value is determined by Level 3 inputs (in thousands): Warrant liability Success fee obligation from the Third Amendment Success fee obligation from the Fourth Amendment Fair value as of January 1, 2020 $ 127 $ — $ — Initial fair value of success fee obligation — 194 — Change in fair value ( 3 ) — — Fair value as of December 31, 2020 124 194 — Initial fair value of success fee obligation — — 105 Change in fair value 1,310 6 — Reclassification to additional paid-in-capital in connection with IPO ( 1,434 ) — — Settlement of success fee obligation — ( 200 ) — Fair value as of December 31, 2021 $ — $ — $ 105

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	9. Commitments and contingencies Operating leases In 2017, the Company entered a noncancelable operating lease agreement to lease its office space at 325 Vassar Street, Cambridge, Massachusetts, which will expire in September 2024 . The Company is required to pay property taxes, insurance, and normal maintenance costs. The operating lease contains predetermined fixed escalations of minimum rentals during the lease term. During 2018, the Company received $ 1.1 million of landlord-funded leasehold improvements related to the leased office space. The landlord-funded leasehold improvements were recorded as property and equipment, net and deferred rent in the consolidated balance sheets and are being amortized as a reduction to rent expense over the life of the lease. In 2019 and 2020, the Company entered into sublease agreements with two related parties to sublease this office and laboratory space. Refer to Note 17, Related party transactions , for further details. On July 13, 2020, the Company entered into a Shared Space Arrangement (“the Arrangement”) with Senda Biosciences (“Senda”, also formerly known as Kintai Therapeutics, Inc.) to share one-third of Senda’s 69,867 square feet of leased space at 20 Acorn Park Drive, Cambridge, Massachusetts. Senda is a related party as it is an affiliate of Flagship Pioneering (“Flagship”) . The Arrangement commenced on August 1, 2020 and continues through July 31, 2022 with two options to extend the term of the Arrangement for a period of 24 months each. The operating lease contains predetermined fixed escalations of minimum rentals during the lease term, and the Company is required to pay property taxes, insurance, and normal maintenance costs. During the years ended December 31, 2021 and 2020 , the Company incurred rental expenses of $ 2.6 million and $ 1.0 million, respectively. As of December 31, 2021 and 2020 , the Company did no t have any outstanding payments due to Senda. In January 2022, the Company entered into an amendment to the Arrangement with Senda to exercise the option to renew the lease term for another 12 months . The lease term will now expire in July 2023 . The Company also modified certain provisions related to the extension term. In connection with the modifications in the amendment, the Company will pay an upfront payment of $ 2.9 million, which will cover the rent payment for the extended lease term. Additionally, upon the expiration of the lease term, the Company will receive $ 0.7 million from Senda for all furniture, fixtures and equipment owned by the Company that will remain at the lease property. The Company recognizes the rental expense on a straight-line basis over the life of the respective lease from the date the Company takes possession of the office and records the difference between amounts charged to operations and amounts paid as deferred rent. Rent expense under both lease agreements for the years ended December 31, 2021 and 2020 was $ 3.3 million and $ 2.2 million, respectively. As of December 31, 2021, the future minimum lease payments for the Company’s facility operating leases for each of the years ending December 31 were as follows (in thousands): 2022 $ 3,013 2023 10,711 2024 11,766 2025 10,879 2026 11,205 Thereafter 148,290 Total minimum lease payments $ 195,864 On November 4, 2021, the Company entered into a lease with ARE-MA Region No. 94, LLC to lease an aggregate of approximately 89,246 rentable square feet of office and laboratory space located at One Charles Park, Cambridge, Massachusetts, 02142. The term of the lease is estimated to begin on December 15, 2022 and end on January 1, 2037 , subject to certain extension rights. The base rent for the leased space will be $ 115.00 per square foot, subject to an annual upward adjustment of 3 % of the then current rental rate, starting on the first anniversary of the first payment of rent under the lease, and other potential adjustments based on the Company’s utilization of certain tenant improvement allowances. In accordance with the lease agreement, the Company paid $ 0.8 million upon the execution of the lease, which will offset the first month's rent. As of December 31, 2021, the future minimum non-cancelable lease payments amount to approximately $ 190.5 million over the lease term are reflected in the table above.

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2021
License Agreements [Abstract]
License agreements	. License agreements Flagship Pioneering Innovations V, Inc. In March 2019, the Company entered into an exclusive license agreement with Flagship Pioneering Innovations V, Inc., an affiliate of Flagship, under which the Company was granted an exclusive, worldwide, royalty-bearing, sublicensable, transferable license under specified patent rights to develop, manufacture and commercialize licensed products (the “Flagship License”). Under the terms of the Flagship License, the Company is obligated to pay low single digit percentage royalties on net sales of licensed products by the Company. Royalties shall be paid by the Company on a country-by-country basis until expiration or abandonment of the last valid patent claim covering such licensed product in such country. The Company is also obligated to reimburse Flagship for patent prosecution costs. The royalty payment is contingent upon sales of licensed products under the Flagship License. As such, when such expense is considered probable and estimable at the commencement of sales, the Company will account for the royalty expense as cost of sales for the amount it is obligated. Whitehead Institute for Biomedical Research In May 2019, the Company entered into an exclusive license agreement with the Whitehead Institute for Biomedical Research (“WIBR”), an affiliate of one of the Company’s board members, under which the Company was granted an exclusive, worldwide, royalty-bearing, sublicensable license under specified patent rights to research, make, have made, use, sell, offer to sell, lease and import products and to perform and have performed licensed processes (the “WIBR Exclusive License”). Under the terms of the WIBR Exclusive License, the Company paid a nonrefundable upfront fee of less than $ 0.1 million upon the commencement of the exclusive license agreement . The Company is obligated to pay WIBR annual license maintenance fees of less than $ 0.1 million and low single digit percentage royalties on net sales of licensed products by the Company and its affiliates and sublicensees. Additionally, the Company is required to make milestone payments of up to $ 1.7 million in the aggregate for each of the first three licensed products (excluding backup products) upon the achievement of specified clinical and regulatory milestones. In addition, the Company is required to pay to WIBR a percentage of the non-royalty payments that it receives from sublicensees of the WIBR Exclusive License. This percentage ranges from zero to low double-digits and will be based upon the stage of development of the licensed product at the time such sublicense is executed. In May 2019, the Company also entered into a co-exclusive license agreement with WIBR under which the Company was granted a co-exclusive, worldwide, royalty-bearing, sublicensable license under specified patent rights to research, make, have made, use, sell, offer to sell, lease and import products and to perform and have performed licensed processes (the “WIBR Co-Exclusive License”). Under the terms of the WIBR Co-Exclusive License, the Company paid a nonrefundable upfront fee of less than $ 0.1 million upon the commencement of the co-exclusive license agreement . The Company is obligated to pay WIBR annual license maintenance fees of less than $ 0.1 million and sub single digit percentage royalties on net sales of licensed products by the Company and its affiliates and sublicensees as well as low single digit percentage royalties on licensed service income received by the Company and its affiliates. Additionally, the Company is required to make milestone payments of up to $ 1.9 million in the aggregate for each of the first three licensed products (excluding backup products) upon the achievement of specified clinical, regulatory, and sublicensing milestones. In addition, the Company is required to pay to WIBR annual fees of less than $ 0.1 million for each sublicense agreement. During the year ended December 31, 2021 , the Company recognized expense of $ 0.1 million for the license maintenance fees, milestone payment, and the reimbursable patent costs under the agreements. The milestone obligation was incurred upon the achievement of a milestone event pursuant to the exclusive license agreement. During the year ended December 31, 2020 , the Company recognized expense of $ 0.1 million for the license maintenance fees and the reimbursable patent costs under the agreements. There was an immaterial amount of outstanding payment due to WIBR as of December 31, 2021 , and there was no outstanding payment due to WIBR as of December 31, 2020. The annual maintenance fees are recorded as an expense on an annual basis based on the stated amount for the applicable year. Upon determination that a milestone payment is probable to occur, the amount due will be recorded as research and development. As mentioned above, a milestone event was achieved during the year ended December 31, 2021, and the related milestone payment was recorded as research and development expense during the period. As the triggering of these milestone payments was not considered probable during 2020, no expense has been recorded for these milestones during the year ended December 31, 2020. The royalty payments and the sublicense non-royalty payments are contingent upon sales of license products or execution of a sublicence agreement under the WIBR Exclusive and Co-Exclusive Licenses. As such, when such expenses are considered probable and estimable at the commencement of sales or execution of a sublicense agreement, the Company will accrue royalty expense and sublicence non-royalty payments, as applicable, for the amount the Company is obligated. Acuitas Therapeutics, Inc. In October 2020, the Company entered into a development and option agreement (the “Development and Option Agreement”) with Acuitas Therapeutics, Inc. (“Acuitas”). Under the terms of the Development and Option Agreement, the parties agreed to jointly develop certain products combining the Company’s gene modulating therapeutics with Acuitas' lipid nanoparticles . Additionally, in accordance with the Development and Option Agreement, the Company has options to obtain non-exclusive, worldwide, sublicensable licenses under Acuitas’ patents and know-how related to lipid nanoparticle technology (“Acuitas LNP Technology”) with respect to two specified targets (e.g., OEC constructs) (“Reserved Targets”) to develop and commercialize one or more therapeutic products relating to such targets. For each option and Reserved Target, the Company is obligated to pay an annual technology access fee and target reservation and maintenance fees collectively in the low-mid six figures until such Reserved Target is removed from the Reserved Target list or until the Company exercises an option with respect to such Reserved Target. In the event that the Company exercises the options, the Company will pay $ 1.5 million for the first non-exclusive license and $ 1.75 million for the second non-exclusive license. Under the terms of the Development and Option Agreement, the Company is also responsible for the full-time equivalent ("FTE") funding obligations, which is expected to be approximately $ 0.4 million per year, and reimbursements to Acuitas for certain development and material costs incurred by them. In March 2021, the Company exercised the first option under the Development and Option Agreement and entered into a non-exclusive license agreement with Acuitas (the “Acuitas License Agreement”) under which the Company was granted a non-exclusive, worldwide, sublicensable license under the Acuitas LNP Technology to research, develop, manufacture, and commercially exploit products consisting of the Company’s gene modulating therapeutics and Acuitas’ lipid nanoparticles. In connection with the option exercise, the Company incurred an expense for the option exercise fee of $ 1.5 million. Under the Acuitas License Agreement, the Company is required to pay Acuitas an annual license maintenance fee in the high six figures until the Company achieves a certain development milestone. Acuitas is entitled to receive potential clinical and regulatory milestone payments of up to $ 18.0 million in the aggregate. With respect to the sale of each licensed products, the Company is also obligated to pay Acuitas low single digit percentage royalties on net sales of the licensed products by the Company and its affiliates and sublicensees in a given country until the last to occur, in such country, of (i) the expiration or abandonment of all licensed patent rights covering the licensed product, (ii) expiration of any regulatory exclusivity for the licensed product, or (iii) ten years from the first commercial sale of the licensed product. During the year ended December 31, 2021 , the Company recorded an aggregate of $ 3.3 million of research and development expenses, consisting of the expenses incurred for the option exercise fee, technology access fees, target reservation and maintenance fees, the costs of services performed by Acuitas, the material costs and the reimbursable costs. During the year ended December 31, 2020 , the Company recorded an aggregate of $ 0.8 million of research and development expenses, consisting of the expenses incurred for technology access fees, target reservation and maintenance fees, and the costs of services performed by Acuitas, the material costs and the reimbursable costs. The option exercise fee under the Development and Option Agreement was recorded as research and development expense upon the Company’s exercise of the first option. Additionally, the technology access fees, target reservation and maintenance fees, expenses associated with the FTE funding obligations and reimbursements for development and material costs incurred by Acuitas are recorded as research and development expense when incurred. The annual maintenance fee will be recorded as an expense on an annual basis based on the stated amount for the applicable year. Upon determination that a milestone payment is probable to occur, the amount due will be recorded as research and development expense. As the triggering of these milestone payments was not considered probable during the year ended December 31, 2021 , no expense has been recorded for these milestones during the period. The royalty payment is contingent upon sales of licensed products under the Acuitas License Agreement, and when such expenses are considered probable and estimable at the commencement of sales, the Company will accrue royalty expense for the amount the Company is obligated .

Collaboration Agreement

Collaboration Agreement	12 Months Ended
	Dec. 31, 2021
Collaboration Agreement [Abstract]
Collaboration Agreement	11. Collaboration agreement In November 2021, the Company entered into a five-year collaboration agreement with PMCo, an affiliate of Flagship, under which PMCo was granted an exclusive license covering specified patent rights of the Company’s lipid nanoparticle technology to develop one or more therapeutic products to treat diseases related to the cystic fibrosis transmembrane conductance regulator gene, like cystic fibrosis. Under the terms of the agreement, the Company will perform certain research activities in accordance with the research plan, and PMCo will be solely responsible for, at its sole cost and expense, and will have sole discretion with respect to, developing, manufacturing, seeking regulatory approval for and commercializing licensed products. The Company expects to receive approximately $ 3.5 million in cost reimbursement over the course of the next two to three years to fund the related research and development activities. The research plan funding may be adjusted upon mutual written agreement from both parties. Additionally, in the event PMCo is acquired or sold, the Company is entitled to receive a portion of the proceeds of such transaction, subject to various reductions and other amounts payable in accordance with the agreement. The Company assessed this arrangement in accordance with ASC 606 and concluded that the contract counterparty, PMCo, is a customer. The Company determined that the research activities and the exclusive license granted under the collaboration agreement is considered as a single performance obligation, and therefore, the transaction price was allocated entirely to the single performance obligation. The Company recognizes revenue related to the single performance obligation over time as the underlying services are performed and/or external costs are incurred. The transaction price as of the inception of the contract was determined to be $ 3.5 million based on the estimated required efforts to fulfill the performance obligation. As of December 31, 2021 , the remaining transaction price is estimated to be $ 3.4 million, which is expected to be recognized as revenue through 2024. The Company recognized funded research and collaboration revenue of $ 0.1 million in the consolidated statement of operations and comprehensive loss during the year ended December 31, 2021 . Additionally, the Company recognized $ 0.1 million of current deferred revenue as of December 31, 2021 based on the period the services are expected to be performed and/or related costs to be incurred. Costs incurred associated with collaboration agreement was recorded as research and development expenses. Pursuant to the agreement, we are entitled to receive a portion of the sales proceeds in the event PMCo is acquired or sold. At the end of each reporting period, the Company evaluates the probability of occurrence of such transaction. As of December 31, 2021, the Company determined that the proceeds from such transaction was not probable of recognition.

Redeemable convertible preferre

Redeemable convertible preferred stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Redeemable convertible preferred stock	12. Redeemable convertible preferred stock During August 2017 and March 2021, the Company issued Series A, Series B and Series C Preferred Stock (collectively the “Preferred Stock”) to investors in private placements. Upon completion of the Company’s IPO, all of the Company’s then outstanding Preferred Stock was automatically converted into an aggregate of 34,678,733 shares of common stock. Series A Redeemable Convertible Preferred Stock During 2017 and 2019, the Company issued an aggregate of 56,775,232 shares of Series A Preferred Stock at a purchase price of $ 0.50 per share in exchange for cash proceeds of $ 25.5 million and the exchange of approximately $ 2.8 million in outstanding promissory notes, including $ 54 thousand in accrued interest. In connection with the issuance of Series A Preferred Stock during 2017 and 2019, the Company incurred less than $ 0.1 million of issuance costs. No additional shares of Series A Preferred Stock were issued after 2019. Series B Redeemable Convertible Preferred Stock On January 27, 2020, the Company issued 24,066,666 shares of Series B Preferred Stock at a purchase price of $ 1.50 per share for aggregate proceeds of $ 36.1 million. On June 2, 2020, the Company issued an additional 3,333,333 shares of Series B Preferred Stock at the purchase price of $ 1.50 per share for aggregate proceeds of $ 5.0 million. On August 3, 2020, the Company issued 5,000,000 shares of Series B Preferred Stock at the purchase price of $ 1.50 per share for aggregate proceeds of $ 7.5 million. No additional shares of Series B Preferred Stock were issued after August 2020. In connection with the issuance of Series B Preferred Stock in 2020, the Company incurred $ 83 thousand of issuance costs. Series C Redeemable Convertible Preferred Stock In March 2021, the Company issued an aggregate of 41,833,328 shares of Series C Preferred Stock, at a price of $ 3.00 per share, for gross proceeds of $ 125.5 million. The terms of the Series C Preferred Stock are substantially the same as the terms of the Series A and Series B Preferred Stock. No additional shares of Series C Preferred Stock were issued after March 2021. In connection with the issuance of Series C Preferred Stock in March 2021, the Company incurred $ 0.1 million of issuance costs. The Company further amended its Amended and Restated Certificate of Incorporation to increase the authorized preferred stock issuable from 107,125,232 shares to 132,858,564 shares. As of December 31, 2020, the Preferred Stock consisted of the following (in thousands, except for share data : December 31, 2020 Preferred Stock Preferred stock Carrying value Liquidation Common stock Series A Preferred Stock 57,125,232 56,775,232 $ 26,708 $ 25,500 15,028,741 Series B Preferred Stock 50,000,000 32,399,999 48,517 48,600 8,576,470 107,125,232 89,175,231 $ 75,225 $ 74,100 23,605,211

Preferred and Common stock

Preferred and Common stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Preferred and Common Stock	13. Preferred and common stock The Company’s board of directors and stockholders approved an amendment to the Company’s certificate of incorporation, which became effective on July 23, 2021. The amendment, among other things, effected a 1-for-3.777776 reverse stock split of the Company’s issued and outstanding common stock, a proportional adjustment to the conversion price for Series A, B and C Preferred Stock and to the exercise prices and number of shares of common stock underlying the outstanding stock options. All share, per share and additional paid in capital amounts for all periods presented in the accompanying consolidated financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect the reverse stock split. In August 2021, the Company completed its IPO pursuant to which it issued and sold 8,300,976 shares of its common stock, including 900,976 shares pursuant to the partial exercise of the underwriters’ option to purchase additional shares, at a public offering price of $ 17.00 per share, for aggregate gross proceeds of $ 141.1 million. The Company received approximately $ 128.1 million in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. In connection with the completion of the IPO, the Company’s board of directors and stockholders approved the Company’s Amended and Restated Certificate of Incorporation to, among other things, provide for 200,000,000 authorized shares of common stock with a par value of $ 0.001 per share and 10,000,000 authorized shares of preferred stock with a par value of $ 0.001 per share. The holders of common stock are entitled to one vote for each share of common stock. Subject to the payment in full of all preferential dividends to which the holders of the preferred stock are entitled, the holders of common stock shall be entitled to receive dividends out of funds legally available. In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, after the payment or provision for payment of all debts and liabilities of the Company and all preferential amounts to which the holders of preferred stock are entitled with respect to the distribution of assets in liquidation, the holders of common stock shall be entitled to share ratably in the remaining assets of the Company available for distribution. As of December 31, 2021 , the Company has reserved an aggregate of 5,476,484 shares of common stock for the potential exercise of outstanding stock options under its equity incentive plans. Upon the effectiveness of the 2021 Incentive Award Plan (“2021 Plan”), the Company ceased granting awards under the 2017 Equity Incentive Plan (“2017 Plan”), and the 4,844,040 shares of common stock subject to outstanding stock options issued under the 2017 Plan may become available for future issuance under the 2021 Plan to the extent such stock options are forfeited.

Equity incentive plan

Equity incentive plan	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity incentive plan	14. Equity incentive plan 2017 Equity Incentive Plan In June 2017, the Company’s board of directors adopted the 2017 Plan, which provided for the grant of qualified incentive stock options and nonqualified stock options, restricted stock or other awards to the Company’s employees and non-employees for the issuance or purchase of shares of the Company’s common stock. As of December 31, 2021, there were no shares available for future grants under the 2017 Plan and a total of 4,844,040 shares of the Company’s common stock were subject to outstanding stock options issued under the 2017 Plan . The 2017 Plan is administered by the Company’s board of directors or a committee thereof to the extent the Company’s board of directors has delegated its power or authority under the 2017 Plan. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, except that the exercise price per share of stock options may not be less than 100 % of the fair market value of the common stock on the date of grant. Stock options awarded under the 2017 Plan expire 10 years after the grant date unless the board of directors sets a shorter term. Incentive stock options and nonqualified stock options granted to employees and non-employees typically vest over four years . Certain stock options provide for accelerated vesting if there is a change in control, as defined in the 2017 Plan . 2021 Incentive Award Plan The Company's board of directors adopted, and the Company’s stockholders approved the 2021 Plan in July 2021. The 2021 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units, stock appreciation rights and other stock-based awards, and subsequent to the IPO, all equity-based awards are granted under the 2021 Plan. The Company initially reserved 2,960,000 shares of its common stock for future issuance under the 2021 Plan, and such number of shares of common stock is subject to an annual increase on the first day of each calendar year, beginning on January 1, 2022 and ending on and including January 1, 2023, equal to the lesser of (i) 4 % of the aggregate number of shares of common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares of common stock as is determined by the board of directors. As of December 31, 2021 , there were 2,481,751 shares available for future grants under the 2021 Plan, and a total of 632,444 shares of the Company’s common stock were subject to outstanding stock options issued under the 2021 Plan. In December 2021, the Company's compensation committee approved that the number of shares of its common stock for future issuance under the 2021 Plan to be increased by 4 % of the aggregate number of common stock outstanding at December 31, 2021. Such increase was effective on January 1, 2022. For the years ended December 31, 2021 and 2020 , the Company recorded stock-based compensation expense of $ 3.2 million and $ 0.6 million, respectively, allocated to research and development and general and administrative expenses in the consolidated statements of operations and comprehensive loss as follows (in thousands): Year ended December 31, 2021 2020 Research and development $ 1,205 $ 299 General and administrative 1,979 338 Total stock-based compensation expense $ 3,184 $ 637 Stock options The assumptions used in the Black-Scholes option-pricing model for stock options granted were as follows: Year ended December 31, 2021 2020 Expected volatility% 76.73 % - 80.18 % 72.44 - 79.02 % Weighted-average risk-free interest rate% 1.12 % 1.00 % Expected dividend yield% 0.00 % 0.00 % Weighted-average expected term (in years) 6.09 5.91 A summary of option activity under the Company's equity incentive plans during the year ended December 31, 2021 was as follows: Number Weighted Weighted Aggregate Outstanding as of January 1, 2021 3,049,875 $ 1.10 8.86 $ 4,467 Granted 2,967,648 8.39 Exercised ( 266,216 ) 1.03 Forfeitures ( 274,823 ) 4.08 Outstanding as of December 31, 2021 5,476,484 4.90 8.64 39,325 Vested and expected to vest as of December 31, 2021 5,476,484 4.90 8.64 39,325 Exercisable as of December 31, 2021 1,324,664 0.93 7.83 13,780 (1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the common stock for the options that were in the money as of December 31, 2021 . The weighted-average grant date fair value per share of stock options granted during the years ended December 31, 2021 and 2020 was $ 5.71 and $ 1.05 , respectively. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2021 and 2020 was $ 1.8 million and $ 0.4 million, respectively. As of December 31, 2021 , there was $ 14.7 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of approximately 2.8 years. Restricted stock In 2017, the Company issued 1,985,295 shares of restricted common stock to certain scientific founders, having a fair value of $ 0.8 million, and subject to vesting over a period of 4 years . If the holders of restricted common stock cease to have a business relationship with the Company prior to the vesting of such shares, the Company may reacquire any unvested shares of common stock held by these individuals for the original purchase price, and in certain instances for no consideration. The unvested shares of restricted common stock are not considered outstanding shares for accounting purposes until the shares vest. As the restricted stock was fully vested in 2020, there was no remaining unrecognized stock-based compensation expense related to restricted stock as of December 31, 2021.

Net loss per share attributable

Net loss per share attributable to common stockholders	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net loss per share attributable to common stockholders	15. Net loss per share attributable to common stockholders For periods in which the Company reports a net loss attributable to common stockholders, potentially dilutive securities have been excluded from the computation of diluted net loss per share as their effects would be anti-dilutive. Therefore, the weighted average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company (in thousands except share and per share amounts): Year ended December 31, 2021 2020 Numerator: Net loss attributable to common stockholders $ ( 68,280 ) $ ( 29,447 ) Denominator: Weighted average number of common stock, basic and diluted 22,404,058 3,906,168 Net loss per common stock attributable to common stockholders, basic $ ( 3.05 ) $ ( 7.54 ) The Company excluded the following potential common stock, presented based on amounts outstanding at period end, from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect: Year ended December 31, 2021 2020 Redeemable convertible preferred stock — 23,605,211 Outstanding options to purchase common stock 5,476,484 3,049,875 Warrants — 92,647 Total 5,476,484 26,747,733

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income taxes	16. Income taxes A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year ended December 31, 2021 2020 U.S. federal statutory income tax rate 21.0 % 21.0 % State income taxes, net of federal benefit 7.6 7.7 Research and development tax credits 3.0 2.8 Nondeductible/ nontaxable permanent items ( 0.9 ) ( 0.5 ) Change in valuation allowance ( 30.8 ) ( 30.8 ) Other 0.1 ( 0.2 ) Effective income tax rate% 0 % 0 % The components of the Company’s deferred taxes are as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforwards $ 34,194 $ 17,320 Research and development credit carryforwards 5,638 2,424 Accrued expenses 879 539 Stock-based compensation 528 9 Intangibles 152 167 Total deferred tax assets 41,391 20,459 Less: valuation allowance ( 41,203 ) ( 20,217 ) Deferred tax assets, net 188 242 Deferred tax liabilities: Depreciation ( 182 ) ( 242 ) Unrealized gain/loss ( 6 ) — Total deferred tax liabilities ( 188 ) ( 242 ) Net deferred taxes $ — $ — The Company had no income tax expense due to the operating loss incurred for the years ended December 31, 2021 and 2020. Management has evaluated the positive and negative evidence bearing upon the realizability of the Company’s net deferred tax assets and has determined that it is more likely than not that the Company will not recognize the benefits of the net deferred tax assets. As a result, the Company has recorded a full valuation allowance as of December 31, 2021 and 2020. The valuation allowance increased by $ 21.0 million in 2021, due to the increase in deferred tax assets, primarily resulting from the net operating loss carryforwards, research and development tax credits, stock based compensation expense and deductible accrued expenses. Realization of the future tax benefits is dependent on many factors, including the Company’s ability to generate taxable income within the net operating loss carryforward period. Under the provisions of the Internal Revenue Code, certain substantial changes in the Company’s ownership, including a sale of the Company or significant changes in ownership due to sales of equity, may have limited, or may limit in the future, the amount of net operating loss carryforwards, which could be used annually to offset future taxable income. The Company has not completed a study to assess whether a change of control has occurred or whether there have been multiple changes of control since the Company’s formation due to the significant complexity and cost associated with such study and because there could be additional changes in control in the future. As a result, the Company is not able to estimate the effect of the change in control, if any, on the Company’s ability to utilize net operating loss and research and development credit carryforwards in the future. As of December 31, 2021 , the Company had $ 125.8 million of federal and $ 123.0 million of state net operating loss carryforwards. If not utilized, both the federal and state net operating loss carryforwards have components that begin to expire starting in 2036 . Of the $ 125.8 million federal net operating loss carryforwards, $ 120.3 million of net operating loss generated from 2018 to 2021 will not expire. Additionally, as of December 31, 2021 , the Company had $ 3.4 million of federal and $ 2.8 million of Massachusetts tax credits that expire starting in 2036 and 2031, respectively. As of December 31, 2020 , the Company had $ 63.6 million of federal and $ 62.6 million of state net operating loss carryforwards. If not utilized, both the federal and state net operating loss carryforwards have components that begin to expire starting in 2036 . Of the $ 63.6 million federal net operating loss carryforwards, $ 58.1 million of net operating loss generated from 2018 to 2020 will not expire. Additionally, as of December 31, 2020 , the Company had $ 1.4 million of federal and $ 1.3 million of Massachusetts tax credits that expire starting in 2036 and 2031, respectively. As of December 31, 2021 and 2020 , the Company had no uncertain tax positions. The Company will recognize both interest and penalties associated with unrecognized tax benefits as a component of income tax expense. The Company has not recorded any interest or penalties for unrecognized tax benefits since its inception. The Company filed income tax returns in the United States and the Commonwealth of Massachusetts in all tax years since inception. The tax years 2020 and 2019 remain open to examination by these jurisdictions, as carryforward attributes generated in past years may be adjusted in a future period. The Company is not currently under examination by the Internal Revenue Service or any other taxing authority for these years.

Related party transactions

Related party transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related party transactions	17. Related party transactions The majority ownership of the Company is held by Flagship, in which it holds shares representing approximately 54 % of the Company's outstanding voting stock as of December 31, 2021. Flagship historically provided management services (accounting, human resources, information technology, legal and consultation) to the Company. Flagship is also reimbursed for certain expenses, including insurance and benefits, partner and related fees, and software licenses incurred on the Company’s behalf. For the years ended December 31, 2021 and 2020 , the Company incurred $ 1.0 million and $ 0.9 million, respectively, primarily for the management services fees and reimbursable expenses. These expenses are recorded as related party expense in the accompanying consolidated statements of operations and comprehensive loss. As of December 31, 2021, there was an immaterial amount of outstanding payment due to Flagship; as of December 31, 2020 , the Company did no t have any outstanding payments due to Flagship. In September 2020, the Company sublet the entire space of its 325 Vassar Street facility, approximately 19,404 square feet, to LARONDE, Inc. (“LARONDE”, formerly known as VL50, Inc.), which is an affiliate of Flagship. The sublease term will expire at the end of the Company’s lease agreement with the landlord in September 2024. The rental rate for the sublease arrangement is equal to the Company’s rental obligation per the agreement with BMR-325 Vassar Street LLC, reduced by the sublease income received from Cygnal Therapeutics, Inc (“Cygnal”), approximating $ 1.3 million per year. The sublessee 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. Under the sublease agreement, the Company received rental income of $ 2.0 million and 0.6 million, which was recorded as a reduction of rental expenses, during the years ended December 31, 2021 and 2020, respectively. Such rental income was reflected as a reduction of related party expense in the accompanying consolidated statements of operations and comprehensive loss. As of December 31, 2021 and 2020 , there was no outstanding receivable due from LARONDE. In September 2019, the Company sublet approximately 1,445 square feet of its 325 Vassar Street facility to Cygnal, which is an affiliate of Flagship, for two years . The lease term can continue on a month-to-month basis until advanced notice is provided to the Company. Upon the lease term ended in September 2021, Cygnal elected to continue leasing the space until December 2022. The rental rate for the sublease arrangement is equal to the Company’s rental obligation per the agreement with BMR-325 Vassar Street LLC, approximating $ 0.1 million per year. The sublessee 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. Under the sublease agreement, the Company received rental income of $ 0.2 million and $ 0.1 million, which was recorded as reduction of rental expenses, during the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021 and 2020 , there was no outstanding receivable due from Cygnal. Refer to other related party transactions as described in Note 9, Commitments and contingencies , Note 10, License agreements and Note 11, Collaboration agreement .

Employee benefits

Employee benefits	12 Months Ended
	Dec. 31, 2021
Retirement Benefits [Abstract]
Employee benefits	18. Employee benefits In 2018, the Company established a defined-contribution plan under Section 401(k) of the Internal Revenue Code, or 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 pre-tax basis. The Company is not required to make and has not made any matching contributions to the 401(k) Plan to date.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation The accompanying consolidated financial statements include the accounts of Omega Therapeutics, Inc. and its wholly owned subsidiary, Omega Therapeutics Security Corporation, which is a Massachusetts subsidiary. All intercompany transactions and balances have been eliminated in consolidation.
Use of estimates	Use of estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses, and the disclosure of contingent assets and liabilities as of and during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the selection of useful lives of property and equipment, the fair values of certain financial instruments issued prior to the IPO (common stock, redeemable convertible preferred stock, and warrants), the fair value of the success fee obligation, and stock-based compensation. Actual results could differ from these estimates. Changes in estimates are reflected in reported results in the period in which they become known .
Cash and cash equivalents	Cash and cash equivalents Cash includes cash in readily available checking accounts, and cash equivalents include money market accounts and all highly liquid investments with an original maturity of three months or less from the date of purchase. Cash and cash equivalents are recorded at cost, which approximates fair value.
Marketable securities	Marketable securities The Company’s marketable securities as of December 31, 2021 consisted of corporate debt securities and are classified as available-for-sale and are reported at fair value. Unrealized gains and losses on available-for-sale debt securities are reported as a component of accumulated other comprehensive loss in stockholders’ equity until realized. Any premium or discount arising at purchase is amortized and/or accreted to interest income and/or expense over the life of the instrument. Realized gains and losses are determined using the specific identification method and are included as a component in other expense, net. The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the consolidated statements of operations and comprehensive loss.
Restricted cash	Restricted cash Restricted cash represents collateral provided for letters of credit issued as security deposit in connection with the Company’s office lease.
Concentrations of credit risk	Concentrations of credit risk Financial instruments that are potentially subject to significant concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company attempts to minimize the risk related to marketable securities by working with highly rated financial institutions that invest in a broad and diverse range of financial instruments as defined the Company. The Company has established guidelines relative to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. The Company maintains its funds in accordance with its investment policy, which defines allowable investments, specifies credit quality standards and is designed to limit credit exposure to any single issuer.
Guarantees and indemnifications	Guarantees and indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, consultants, and employees for certain events or occurrences that happen by reason of the relationship with, or position held at, the Company. Through December 31, 2021 and 2020 , the Company had no t experienced any losses related to these indemnification obligations, and no claims were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related liabilities were established.
Property and equipment	Property and equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset category as follows: Asset category Estimated useful life Computer equipment and software 3 years Laboratory equipment and office furniture 5 years Leasehold improvements Shorter of useful life or remaining lease term Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred.
Accrued research and development expenses	Accrued research and development expenses The Company estimates accrued research and development expenses based on its estimates of the services received and efforts expended pursuant to quotes and contracts with third-party service providers, including contract research organizations (“CROs”) and contract development and manufacturing organizations (“CDMOs”) that supply, conduct and manage preclinical studies on the Company’s behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to its vendors will exceed the level of services provided and result in a prepayment of the expense, in which it will be evaluated for current or long-term classification based on when it is expected to be realized. 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. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts the accrual or the amount of prepaid expenses accordingly.
Debt issuance costs	Debt issuance costs Costs incurred in connection with the issuance of the Company’s long-term debt have been recorded as a direct reduction against the debt and amortized over the life of the associated debt as a component of interest expense using the effective interest method.
Warrant liability	Warrant liability Warrants for the purchase of Series A redeemable convertible preferred stock (“Series A Preferred Stock”) issued in connection with the loan and security agreement (“Loan Agreement”), as amended, with Pacific Western Bank (“PWB”) were classified as a liability on the consolidated balance sheets at their fair value on the date of issuance. At the end of each reporting period, the change in estimated fair value during the period was recognized as a component of other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of the warrants was remeasured at the end of each reporting period until the closing of the IPO, at which time the liabilities were reclassified to an equity component as the outstanding warrants automatically became warrants to purchase common stock.
Success fee obligation	Success fee obligation The Loan Agreement, as amended, with PWB, requires the Company to pay a success fee (“success fee obligation”) upon the occurrence of a specified liquidity event as described in the Loan Agreement, as amended. The Company determined that this obligation represented a freestanding derivative instrument. Accordingly, the success fee obligation was classified as a liability on the Company’s consolidated balance sheets and initially recorded at fair value, with changes in fair value for each reporting period recognized in other expense, net in the consolidated statements of operations and comprehensive loss. The fair value of such obligation is remeasured at the end of each reporting period until the liability is settled.
Deferred rent	Deferred rent The Company’s real estate operating leases provide for scheduled annual rent increases throughout the lease terms. The Company recognizes the effects of the scheduled rent increases on a straight-line basis over the full terms of the leases. Tenant improvement allowances, if any, provided by a landlord are recorded as deferred rent and amortized as reductions to rent expense over the lease terms.
Equity issuance costs	Equity issuance costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of proceeds generated as a result of the offering. Should a planned equity financing be abandoned, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statement of operations. Upon closing of the IPO, deferred offering costs were derecognized and recorded against the IPO proceeds as a reduction to additional paid-in capital. There were no deferred offering costs as of December 31, 2021 and 2020.
Impairment of long-lived assets	Impairment of long-lived assets The Company evaluates its long-lived assets, which consist primarily of property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There were no impairment losses recognized during the years ended December 31, 2021 and 2020 .
Fair value measurements	Fair value measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The fair value of the Company’s cash and cash equivalents and restricted cash are measured through quoted market prices; the fair value of the Company's marketable securities is determined based on the pricing inputs other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date. Other current assets, accounts payable and accrued liabilities approximate their fair values as of December 31, 2021 and 2020, due to their short-term nature. The carrying value of the Company’s debt approximates its fair value due to its variable interest rate, which approximates a market interest rate. The warrant liability and the success fee obligation associated with the Loan Agreement, as amended, contain unobservable inputs that reflect the Company’s own assumptions in which there is little, if any, market activity at the measurement date, thus the Company’s warrant liability and the success fee obligation are measured at their fair values on a recurring basis using unobservable inputs. See further discussion in Note 8, Fair value of financial instruments .
Redeemable convertible preferred stock	Redeemable convertible preferred stock The Company classified redeemable convertible preferred stock as temporary equity on the consolidated balance sheet because it could become redeemable upon occurrence of a deemed liquidation event that is outside of the Company’s control. Upon completion of the Company’s IPO, all of the Company’s then outstanding Preferred Stock was automatically converted into common stock .
Revenue recognition	Revenue recognition Revenue recognized to-date is solely generated from the collaboration agreement with PM (CF) Explorations, Inc., or PMCo. The Company recognizes revenue in accordance with ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and its related amendments, or, collectively, ASC 606. At inception, the Company determines whether contracts are within the scope of ASC 606 or other topics. For contracts that are determined to be within the scope of ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these goods and services. To achieve this core principle, the Company applies the following five steps (i) identify the contract with the customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when performance obligation is satisfied. The Company only applies the five-step model to contracts when it determines that collection of substantially all consideration for goods and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. Performance obligations promised in a contract are identified based on the goods and services that will be transferred to the customer that are both capable of being distinct and are distinct in the context of the contract. To the extent a contract includes multiple promised goods and services, the Company applies judgment to determine whether promised goods and services are both capable of being distinct and distinct in the context of the contract. If these criteria are not met, the promised goods and services are accounted for as a combined performance obligation. The transaction price is determined based on the consideration to which the Company will be entitled in exchange for transferring goods and services to the customer. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method, depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in management’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Any estimates, including the effect of the constraint on variable consideration, are evaluated at each reporting period for any changes. Determining the transaction price requires significant judgment. If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative standalone selling price basis unless the transaction price is variable and meets the criteria to be allocated entirely to a performance obligation or to a distinct service that forms part of a single performance obligation. The consideration to be received is allocated among the separate performance obligations based on relative standalone selling prices. The Company satisfies performance obligations either over time or at a point in time. Revenue is recognized over time if either (i) the customer simultaneously receives and consumes the benefits provided by the entity’s performance, (ii) the entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or (iii) the entity’s performance does not create an asset with an alternative use to the entity and the entity has an enforceable right to payment for performance completed to date. If the entity does not satisfy a performance obligation over time, the related performance obligation is satisfied at a point in time by transferring the control of a promised good or service to a customer. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from consideration allocated to the license when the license is transferred to the customer and the customer can use and benefit from the license. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. At the inception of each arrangement that includes milestone payments, the Company evaluates the probability of reaching the milestones and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur in the future, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s are not considered probable of being achieved and therefore revenue recognized is constrained as management is unable to assert that a reversal of revenue would not be possible. The transaction price is then allocated to each performance obligation on a relative standalone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. To date, the Company has not recognized any milestone revenue. Deferred revenue arises from amounts received in advance of the culmination of the earnings process and is recognized as revenue in future periods as performance obligations are satisfied. Deferred revenue expected to be recognized within the next twelve months is classified as a current liability.
Research and development expenses	Research and development expenses Research and development expenses are charged to expense as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation, consulting fees, cost of licensing technology, milestone payment, and external contract research and development and manufacturing expenses. Costs for certain research and development activities are recognized based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses and expensed as the related goods are delivered or the services are performed.
Stock-based compensation	Stock-based compensation The Company’s stock-based compensation program allows for grants of incentive stock options, non-qualified stock options, stock appreciation rights, and restricted stock awards, restricted stock units and other stock-based awards to employees, directors and consultants. The Company recognizes all stock-based compensation awards to employees and non-employees as expense in the consolidated statements of operations and comprehensive loss based on their fair values. For stock option awards, the Company estimates the fair value using the Black-Scholes option pricing model. The fair value of the Company’s common stock is used to determine the fair value of restricted stock awards. Stock-based compensation awards are subject to service vesting conditions, and forfeitures are recorded as they occur. Compensation expense related to awards to employees with service-based vesting conditions is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. The Company applies ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU No. 2018-07”), in which the measurement date for non-employee awards is determined as the date of grant, and stock-based compensation costs for non-employees are recognized as expense over the vesting period on a straight-line basis. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (i) the expected stock price volatility, (ii) the expected term of the award, (iii) the risk-free interest rate, and (iv) expected dividends. Due to the lack of a public market for the Company’s common stock prior to the IPO and continued lack of sufficient company-specific historical and implied volatility data, the Company has based its computation of expected volatility on the historical volatility of a representative group of public companies with similar characteristics to the Company, including stage of product development and life science industry focus. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The Company uses the simplified method as prescribed by the Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment , to calculate the expected term for options granted to employees and non-employees, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the options due to its lack of sufficient historical data. The risk-free interest rate is based on U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. Due to the absence of an active market for the Company’s common stock prior to the IPO, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid, Valuation of Privately- Held Company Equity Securities Issued as Compensation , to estimate the fair value of its common stock. In determining the exercise prices for options granted, the Company has considered the estimated fair value of the common stock as of the measurement date. The estimated fair value of the common stock has been determined at each grant date based upon a variety of factors, including the illiquid nature of the common stock, arm’s-length sales of the Company’s capital stock (including redeemable convertible preferred stock), the effect of the rights and preferences of the preferred shareholders, and the prospects of a liquidity event. Among other factors are the Company’s financial position and historical financial performance, the status of technological developments within the Company’s research, the composition and ability of the current research and management team, an evaluation or benchmark of the Company’s competition, and the current business climate in the marketplace. Significant changes to the key assumptions underlying the factors used could result in different fair values of common stock at each valuation date. Subsequent to the IPO, the Company has used the quoted market price of its common stock on the measurement date.
Patent costs	Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred as patents have no future alternative use.
Income taxes	Income taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s consolidated financial statements and tax returns. Deferred tax assets and liabilities are determined based upon the differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities and for loss and credit carryforwards, using enacted tax rates expected to be in effect in the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that these assets may not be realized. As of December 31, 2021 and 2020 , the Company has recorded a full valuation allowance against its deferred tax assets. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. The Company accounts for interest and penalties related to uncertain tax positions as part of its provision for income taxes.
Comprehensive loss	Comprehensive loss Comprehensive loss is defined as the change in stockholders’ equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss includes net loss as well as other changes in stockholders’ equity which includes certain changes in equity that are excluded from net loss. The Company’s only element of other comprehensive loss is unrealized gains and losses on its marketable securities.
Net loss per share	Net loss per share The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of common stock outstanding for the period. Diluted net loss attributable to common stockholders is computed by adjusting net loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the diluted net loss attributable to common stockholders by the weighted average number of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. The Company’s redeemable convertible preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the years ended December 31, 2021 and 2020 .
Segment and geographic information	Segment and geographic information Operating segments are defined as components of an entity about which discrete information is available for evaluation by the chief operating decision maker, or CODM, or decision-making group, in deciding how to allocate resources and in assessing performance. The CODM is the Company’s Chief Executive Officer. The CODM views its operations as and manages its business in one operating segment operating exclusively in the United States.
Recently issued/adopted accounting pronouncements	Recently issued accounting pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight- line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less may be accounted for similar to existing guidance for operating leases today. As the Company has elected to use the extended transition period for complying with new or revised accounting standards as available under the Jumpstart Our Business Startups Act (“JOBS Act”), the standard is effective for the Company beginning January 1, 2022. The Company adopted ASU 2016-02, and related amendments, on January 1, 2022 using the effective date transition method. The Company has also elected a package of practical expedients, under which an entity need not reassess whether any expired or existing contracts are or contain leases, the lease classification for any expired or existing leases, or initial direct costs for any existing leases. The Company also elected not to separate lease and non-lease components. The Company has completed its initial assessment of the impact of ASU 2016-02 on the Company’s consolidated financial statements and internal controls, including its evaluation of key policy elections. The Company’s assessment included procedures to identify a complete lease population, performing analyses for each lease identified, assessing the differences in accounting that result from adopting this standard and assessing whether the Company meets certain practical expedients. While substantially complete, the Company is still in the process of finalizing its evaluation of the effect on the Company’s financial statements, disclosures, and internal controls. The Company estimates its total assets and total liabilities on the consolidated balance sheet will increase by approximately $ 3.5 million to $ 5.5 million due to the recognition of right-of-use assets and lease liabilities upon adoption, net of the impact of eliminating existing deferred rent liabilities and unamortized tenant incentives related to its existing leasing arrangements. This estimated range is based on the Company's current lease portfolio but could be impacted by changes to the lease portfolio, including the total number of leases, lease commencement and end dates and lease termination expectations, as well as changes in anticipated lease incremental borrowing rates. The Company also anticipates changes to its disclosures to comply with the new disclosure requirements under the guidance. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes-Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes, enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. Adoption of the standard requires certain changes to be made prospectively and certain others to be made retrospectively. As the Company has elected to use the extended transition period for complying with new or revised accounting standards as available under the JOBS Act, the standard is effective for the Company beginning January 1, 2022. The Company does not expect ASU 2019-12 to have a material effect on the Company’s consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Estimated Useful Life of Each Asset Category	Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset category as follows: Asset category Estimated useful life Computer equipment and software 3 years Laboratory equipment and office furniture 5 years Leasehold improvements Shorter of useful life or remaining lease term

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities	The following table summarizes the Company’s marketable securities (in thousands): December 31, 2021 Amortized cost Gross unrealized losses Fair value Corporate debt securities $ 38,907 $ ( 62 ) $ 38,845

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Summary of Prepaid Expenses and other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2021 2020 Prepaid rent $ 825 $ — Prepaid insurance 1,500 8 Prepaid software 143 78 Prepaid research and development 534 653 Prepaid other 436 120 Other receivables 264 193 Prepaid expenses and other current assets $ 3,702 $ 1,052

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): December 31, 2021 2020 Leasehold improvements $ 1,378 $ 1,378 Lab equipment 4,822 3,444 Furniture and fixtures 1,073 985 Computer equipment 129 129 Construction in process 54 16 Total property and equipment 7,456 5,952 Less accumulated depreciation ( 3,851 ) ( 2,470 ) Property and equipment, net $ 3,605 $ 3,482

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Accrued Liabilities Current [Abstract]
Summary of Accrued Expenses	Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Employee related expenses $ 2,545 $ 1,124 Research costs 5,640 1,724 Professional and consulting fees 759 278 Interest 31 44 Other 500 107 Total $ 9,475 $ 3,277

Term Loan (Tables)

Term Loan (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Summary of Outstanding Term Loan Balance	As of December 31, 2021 , the full amount of $ 20.0 million of the term loan was classified long-term based on the repayment start date. As of December 31, 2020 , the long-term debt, current portion was $ 3.0 million and the long-term debt was $ 9.0 million. The Company’s outstanding term loan balance was comprised of the following (in thousands): December 31, 2021 2020 Principal $ 20,000 $ 12,000 Unamortized debt discount ( 131 ) ( 268 ) Net carrying amount $ 19,869 $ 11,732
Summary of Interest Expense Recognized Related to Term loan	The following table sets forth total interest expense recognized related to the term loan (in thousands): Year ended December 31, 2021 2020 Contractual interest expense $ 740 $ 732 Amortization of debt issuance costs and debt discount 258 48 Total interest expense $ 998 $ 780
Schedule of Principal Amount in Connection With Term Loan	The Company is required to repay the following principal amounts in connection with its term loan (in thousands): 2022 $ — 2023 2,500 2024 10,000 2025 7,500 $ 20,000

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Fair Value of Financial Instruments	The fair value of the Company’s financial instruments is summarized in the tables below (in thousands): December 31, 2021 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 110,864 $ — $ — $ 110,864 Marketable securities — 38,845 — 38,845 Total $ 110,864 $ 38,845 $ — $ 149,709 Financial Liabilities Success fee obligation $ — $ — $ 105 $ 105 December 31, 2020 Level 1 Level 2 Level 3 Total Financial Liabilities Warrant liability $ — $ — $ 124 $ 124 Success fee obligation — — 194 194 Total $ — $ — $ 318 $ 318
Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Warrants	The assumptions used in the Black-Scholes option-pricing model for the warrants were as follows: August 3, December 31, 2021 2020 Expected volatility 77.03 - 77.62 % 73.09 - 77.79 % Risk-free interest rate 0.95 - 1.40 % 0.58 - 0.65 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 6.6 - 6.9 7.2 - 7.9
Summary of Significant Quantitative Inputs Used to Determine Valuation of Success Fee Obligation	The following reflects the significant quantitative inputs used to determine the valuation of the success fee obligations: Year ended December 31, 2021 2020 Discount rate 5.5 % 6.0 % Expected timing of achieving liquidity events (years) 0.6 - 1.8 0.5 - 1 Probability of achieving liquidity events 10 % - 90 % 1 % - 99 %
Summary of Fair Values of Warrant Liability and Success Fee Obligation	The following table provides a roll-forward of the fair values of the Company’s warrant liability and the success fee obligation for which fair value is determined by Level 3 inputs (in thousands): Warrant liability Success fee obligation from the Third Amendment Success fee obligation from the Fourth Amendment Fair value as of January 1, 2020 $ 127 $ — $ — Initial fair value of success fee obligation — 194 — Change in fair value ( 3 ) — — Fair value as of December 31, 2020 124 194 — Initial fair value of success fee obligation — — 105 Change in fair value 1,310 6 — Reclassification to additional paid-in-capital in connection with IPO ( 1,434 ) — — Settlement of success fee obligation — ( 200 ) — Fair value as of December 31, 2021 $ — $ — $ 105

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments	As of December 31, 2021, the future minimum lease payments for the Company’s facility operating leases for each of the years ending December 31 were as follows (in thousands): 2022 $ 3,013 2023 10,711 2024 11,766 2025 10,879 2026 11,205 Thereafter 148,290 Total minimum lease payments $ 195,864

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Summary of Preferred Stock	As of December 31, 2020, the Preferred Stock consisted of the following (in thousands, except for share data : December 31, 2020 Preferred Stock Preferred stock Carrying value Liquidation Common stock Series A Preferred Stock 57,125,232 56,775,232 $ 26,708 $ 25,500 15,028,741 Series B Preferred Stock 50,000,000 32,399,999 48,517 48,600 8,576,470 107,125,232 89,175,231 $ 75,225 $ 74,100 23,605,211

Equity incentive plan (Tables)

Equity incentive plan (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-based Compensation Expense	For the years ended December 31, 2021 and 2020 , the Company recorded stock-based compensation expense of $ 3.2 million and $ 0.6 million, respectively, allocated to research and development and general and administrative expenses in the consolidated statements of operations and comprehensive loss as follows (in thousands): Year ended December 31, 2021 2020 Research and development $ 1,205 $ 299 General and administrative 1,979 338 Total stock-based compensation expense $ 3,184 $ 637
Summary of Assumptions Used in Black-Scholes Option-pricing Model for Stock Options	The assumptions used in the Black-Scholes option-pricing model for stock options granted were as follows: Year ended December 31, 2021 2020 Expected volatility% 76.73 % - 80.18 % 72.44 - 79.02 % Weighted-average risk-free interest rate% 1.12 % 1.00 % Expected dividend yield% 0.00 % 0.00 % Weighted-average expected term (in years) 6.09 5.91
Summary of Option Activity	A summary of option activity under the Company's equity incentive plans during the year ended December 31, 2021 was as follows: Number Weighted Weighted Aggregate Outstanding as of January 1, 2021 3,049,875 $ 1.10 8.86 $ 4,467 Granted 2,967,648 8.39 Exercised ( 266,216 ) 1.03 Forfeitures ( 274,823 ) 4.08 Outstanding as of December 31, 2021 5,476,484 4.90 8.64 39,325 Vested and expected to vest as of December 31, 2021 5,476,484 4.90 8.64 39,325 Exercisable as of December 31, 2021 1,324,664 0.93 7.83 13,780 (1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the common stock for the options that were in the money as of December 31, 2021 .

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Summary of the Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company (in thousands except share and per share amounts): Year ended December 31, 2021 2020 Numerator: Net loss attributable to common stockholders $ ( 68,280 ) $ ( 29,447 ) Denominator: Weighted average number of common stock, basic and diluted 22,404,058 3,906,168 Net loss per common stock attributable to common stockholders, basic $ ( 3.05 ) $ ( 7.54 )
Schedule of Anti-Dilutive Securities Excluded from Computation of Earnings Per Share	The Company excluded the following potential common stock, presented based on amounts outstanding at period end, from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect: Year ended December 31, 2021 2020 Redeemable convertible preferred stock — 23,605,211 Outstanding options to purchase common stock 5,476,484 3,049,875 Warrants — 92,647 Total 5,476,484 26,747,733

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Summary of Reconciliation of Federal Statutory Income Tax Rate to Effective Income Tax Rate	A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year ended December 31, 2021 2020 U.S. federal statutory income tax rate 21.0 % 21.0 % State income taxes, net of federal benefit 7.6 7.7 Research and development tax credits 3.0 2.8 Nondeductible/ nontaxable permanent items ( 0.9 ) ( 0.5 ) Change in valuation allowance ( 30.8 ) ( 30.8 ) Other 0.1 ( 0.2 ) Effective income tax rate% 0 % 0 %
Summary of Components of Deferred Taxes	The components of the Company’s deferred taxes are as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforwards $ 34,194 $ 17,320 Research and development credit carryforwards 5,638 2,424 Accrued expenses 879 539 Stock-based compensation 528 9 Intangibles 152 167 Total deferred tax assets 41,391 20,459 Less: valuation allowance ( 41,203 ) ( 20,217 ) Deferred tax assets, net 188 242 Deferred tax liabilities: Depreciation ( 182 ) ( 242 ) Unrealized gain/loss ( 6 ) — Total deferred tax liabilities ( 188 ) ( 242 ) Net deferred taxes $ — $ —

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Nature Of Business And Basis Of Presentation [Line Items]
Common stock, shares issued		47,793,469	4,465,351
Gross proceeds from IPO		$ 131,238
Cash, cash equivalents and marketable securities		$ 225,300
IPO
Nature Of Business And Basis Of Presentation [Line Items]
Common stock, shares issued	8,300,976
Offering price per share	$ 17
Gross proceeds from IPO	$ 141,100
Net proceeds	$ 128,100
Underwriters’ Option to Purchase Additional Shares
Nature Of Business And Basis Of Presentation [Line Items]
Common stock, shares issued	900,976

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred offering costs	$ 0	$ 0
Indemnification obligations losses	0	0
Indemnification obligations claims outstanding	0	0
Impairment losses recognized	0	0
Total assets	233,333,000	28,083,000
Total liabilities	32,705,000	$ 17,486,000
Minimum | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total assets	3,500,000
Total liabilities	3,500,000
Maximum | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total assets	5,500,000
Total liabilities	$ 5,500,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Life of Each Asset Category (Details)	12 Months Ended
	Dec. 31, 2021
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Estimated useful life	3 years
Laboratory Equipment and Office Furniture
Property Plant And Equipment [Line Items]
Estimated useful life	5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful life	Shorter of useful life or remaining lease term

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - Corporate Debt Securities $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Debt Securities, Available-for-sale [Line Items]
Marketable Securities, Amortized cost	$ 38,907
Marketable Securities, Gross unrealized losses	(62)
Marketable Securities, Fair value	$ 38,845

Marketable Securities - Additio

Marketable Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)
Investments, Debt and Equity Securities [Abstract]
Realized losses recognized on the sale or maturity of marketable securities	$ 0
Realized gains recognized on the sale or maturity of marketable securities	$ 0
Fair value of marketable securities, description	The aggregate fair value of marketable securities that will be matured within 12 months of December 31, 2021 was $21.6 million, and the aggregate fair value of marketable securities that will be matured after 12 months of December 31, 2021 was $17.3 million.
Aggregate fair value of marketable securities held, current	$ 21,600,000
Aggregate fair value of marketable securities held, noncurrent	17,300,000
Investments with other-than-temporary impairment	0
Debt securities reclassified to accumulated other comprehensive loss	$ 0

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Prepaid rent	$ 825
Prepaid insurance	1,500	$ 8
Prepaid software	143	78
Prepaid research and development	534	653
Prepaid other	436	120
Other receivables	264	193
Prepaid expenses and other current assets	$ 3,702	$ 1,052

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 7,456	$ 5,952
Less accumulated depreciation	(3,851)	(2,470)
Property and equipment, net	3,605	3,482
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	1,378	1,378
Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	4,822	3,444
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	1,073	985
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	129	129
Construction in Process
Property Plant And Equipment [Line Items]
Total property and equipment	$ 54	$ 16

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Depreciation	$ 1,387	$ 1,146

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Employee related expenses	$ 2,545	$ 1,124
Research costs	5,640	1,724
Professional and consulting fees	759	278
Interest	31	44
Other	500	107
Total	$ 9,475	$ 3,277

Term Loan - Additional Informat

Term Loan - Additional Information (Details) - USD ($)	Dec. 20, 2021	Aug. 03, 2021	Dec. 30, 2020	Mar. 09, 2018	Sep. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Debt [Line Items]
Unamortized debt discount						$ 131,000	$ 268,000
Aggregate principal amount						20,000,000	12,000,000
Long-term debt, current portion							3,000,000
Long-term debt							9,000,000
Accrued interest on term loan						$ 31,000	$ 44,000
Maximum
Debt [Line Items]
Effective interest rate on the liability component						7.51%
Minimum
Debt [Line Items]
Effective interest rate on the liability component						5.53%
Pacific Western Bank | Minimum
Debt [Line Items]
Cash proceeds received						$ 50,000,000
Loan Agreement | Pacific Western Bank
Debt [Line Items]
Maximum borrowing capacity				$ 8,000,000
Loan Agreement | Pacific Western Bank | IPO
Debt [Line Items]
Success fee payable			$ 200,000
Loan Agreement | Pacific Western Bank | Series A Redeemable Convertible Preferred Stock
Debt [Line Items]
Shares issued, Price per share				$ 0.50
Warrant exercisable period				10 years
Loan Agreement | Pacific Western Bank | Series A Redeemable Convertible Preferred Stock | Maximum
Debt [Line Items]
Shares, Issued				200,000
First Amendment | Pacific Western Bank
Debt [Line Items]
Warrants exercisable, expiration date					2028-03
Number of shares withheld to pay exercise price of warrants		10,454
Aggregate principal amount					$ 12,000,000
First Amendment | Pacific Western Bank | IPO
Debt [Line Items]
Unamortized debt discount								$ 100,000
First Amendment | Pacific Western Bank | Series A Redeemable Convertible Preferred Stock
Debt [Line Items]
Shares, Issued					350,000
Shares issued, Price per share					$ 0.50
First Amendment | Pacific Western Bank | Common Stock
Debt [Line Items]
Warrant exercisable for number of shares		82,193
First Amendment | Pacific Western Bank | Common Stock | IPO
Debt [Line Items]
Shares, Issued		92,647
Third Amendment | Pacific Western Bank
Debt [Line Items]
Line of credit facility, Floating annual interest rate			0.75%
Line of credit facility, Interest rate during period			6.00%
Maturity date			Jun. 30, 2023			Dec. 31, 2023
Debt issuance costs			$ 15,000
Principal repayment date						Dec. 31, 2021
Fourth Amendment | Pacific Western Bank
Debt [Line Items]
Line of credit facility, Floating annual interest rate	0.50%
Line of credit facility, Interest rate during period	5.50%
Aggregate principal amount	$ 20,000,000
Debt extinguished	12,000,000
Remaining cash proceeds	$ 8,000,000
Maturity date	Sep. 30, 2025
Principal repayment start date	Sep. 30, 2023
Debt issuance costs	$ 15,000
Fourth Amendment | Pacific Western Bank | Maximum
Debt [Line Items]
Success fee payable	200,000
Fourth Amendment | Pacific Western Bank | Minimum
Debt [Line Items]
Success fee payable	$ 100,000

Term Loan - Summary of Outstand

Term Loan - Summary of Outstanding Term Loan Balance (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Principal	$ 20,000	$ 12,000
Unamortized debt discount	(131)	(268)
Net carrying amount	$ 19,869	$ 11,732

Term Loan - Summary of Interest

Term Loan - Summary of Interest Expense Recognized Related to Term loan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Contractual interest expense	$ 740	$ 732
Amortization of debt issuance costs and debt discount	258	48
Total interest expense	$ 998	$ 780

Term Loan - Schedule of Princip

Term Loan - Schedule of Principal Amount in Connection With Term Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2022	$ 0
2023	2,500
2024	10,000
2025	7,500
Long-term Debt	$ 20,000	$ 12,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Financial Assets
Total financial assets	$ 149,709,000
Financial Liabilities
Total financial liabilities		$ 318,000
Warrant Liability
Financial Liabilities
Total financial liabilities	0	124,000
Success Fee Obligation
Financial Liabilities
Total financial liabilities	105,000	194,000
Money Market Funds
Financial Assets
Total financial assets	110,864,000
Marketable Securities
Financial Assets
Total financial assets	38,845,000
Level 1
Financial Assets
Total financial assets	110,864,000
Level 1 | Money Market Funds
Financial Assets
Total financial assets	110,864,000
Level 2
Financial Assets
Total financial assets	38,845,000
Level 2 | Marketable Securities
Financial Assets
Total financial assets	38,845,000
Level 3
Financial Liabilities
Total financial liabilities		318,000
Level 3 | Warrant Liability
Financial Liabilities
Total financial liabilities		124,000
Level 3 | Success Fee Obligation
Financial Liabilities
Total financial liabilities	$ 105,000	$ 194,000

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Additional Information (Details)	1 Months Ended	12 Months Ended
	Aug. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Aug. 03, 2021
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Description of warrant liability		Company's warrant liability was zero as the warrants became warrants to purchase common stock upon the closing of the IPO. As of December 31, 2020, the warrant liability was recorded as other liabilities on the consolidated balance sheet as it was deemed more probable than not by the Company to be settled in longer than one year.
Financial liabilities			$ 318,000
Change in fair value of warrant liability		$ 1,310,000	$ (3,000)
Payment of success fee		$ 200,000
Description of fair value of success fee obligation		As a result of the completion of the IPO, the Company paid $0.2 million of the success fee pursuant to the Third Amendment, and the related liability was zero as of December 31, 2021. In accordance with the Fourth Amendment, the Company will be required to pay a success fee upon the achievement of certain liquidity event; accordingly, the related obligation is recorded as current liabilities on the consolidated balance sheet as it is deemed more probable than not by the Company to be settled in less than one year.
IPO
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Payment of success fee	$ 200,000
Expected Dividend Yield
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		0	0	0
Warrant Liability
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Financial liabilities		$ 0	$ 124,000
Success Fee Obligation
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Financial liabilities		105,000	$ 194,000
Success Fee Obligation | IPO
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Financial liabilities		$ 0

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Warrants (Details)	Dec. 31, 2021	Aug. 03, 2021yr	Dec. 31, 2020yr
Expected Volatility | Minimum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		77.03	73.09
Expected Volatility | Maximum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		77.62	77.79
Risk-free Interest Rate | Minimum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		0.95	0.58
Risk-free Interest Rate | Maximum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		1.40	0.65
Expected Dividend Yield
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input	0	0	0
Expected Term (in years) | Minimum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		6.6	7.2
Expected Term (in years) | Maximum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Warrants, measurement input		6.9	7.9

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Summary of Significant Quantitative Inputs Used to Determine Valuation of Success Fee Obligation (Details)	Dec. 31, 2021	Dec. 31, 2020
Discount Rate
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Success fee, measurement input	5.5	6
Expected Timing of Achieving Liquidity Events (years) | Minimum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Success fee, measurement input	0.6	0.5
Expected Timing of Achieving Liquidity Events (years) | Maximum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Success fee, measurement input	1.8	1
Probability of Achieving Liquidity Events | Minimum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Success fee, measurement input	10	1
Probability of Achieving Liquidity Events | Maximum
Fair Value Liabilities Measured On Recurring Basis [Line Items]
Success fee, measurement input	90	99

Fair Value of Financial Instr_7

Fair Value of Financial Instruments - Summary of Fair Values of Warrant Liability and Success Fee Obligation (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Warrant Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 124	$ 127
Change in fair value	1,310	(3)
Reclassification to additional paid-in-capital in connection with IPO	(1,434)
Ending balance		124
Success Fee Obligation from the Third Amendment
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	194
Initial fair value of success fee obligation		194
Change in fair value	6
Settlement of success fee obligation	(200)
Ending balance		$ 194
Success Fee Obligation from the Fourth Amendment
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Initial fair value of success fee obligation	105
Ending balance	$ 105

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Nov. 04, 2021USD ($)ft²$ / ft²	Jan. 31, 2022USD ($)	Dec. 31, 2021USD ($)ft²Option	Dec. 31, 2020USD ($)Sublease	Dec. 31, 2019Sublease	Dec. 31, 2018USD ($)
Leases [Line Items]
Lease expiration date			Sep. 30, 2024
Landlord-funded leasehold improvements						$ 1,100,000
Rent expenses incurred			$ 2,600,000	$ 1,000,000
Rent expense			3,300,000	2,200,000
Future minimum non-cancelable lease payments			195,864,000
One Charles Park Lease Agreement
Leases [Line Items]
Lessee operating lease, description	The term of the lease is estimated to begin on December 15, 2022 and end on January 1, 2037, subject to certain extension rights.
Rentable square feet of office and laboratory | ft²	89,246
Lease term beginning date	Dec. 15, 2022
Lease term ending date	Jan. 1, 2037
Base rent per square foot | $ / ft²	115
Base rent annual upward adjustment percentage	3.00%
Lease payment	$ 800,000
Future minimum non-cancelable lease payments			$ 190,500,000
Senda Biosciences, Inc
Leases [Line Items]
Lessee operating lease, description			share one-third of Senda’s 69,867 square feet of leased space at 20 Acorn Park Drive, Cambridge, Massachusetts.
Number of options to extend terms | Option			2
Term of lease arrangement period			24 months
Lease arrangement description			The Arrangement commenced on August 1, 2020 and continues through July 31, 2022 with two options to extend the term of the Arrangement for a period of 24 months each.
Area of leased space | ft²			69,867
Accrued rent			$ 0	$ 0
Senda Biosciences, Inc | Subsequent Event
Leases [Line Items]
Term of lease arrangement period		12 months
Upfront payment		$ 2,900,000
Reimbursement for office furniture purchases		$ 700,000
Lease term ending date		Jul. 31, 2023
LARONDE, Inc.
Leases [Line Items]
Number of sublease agreements with related parties | Sublease				2
Cygnal
Leases [Line Items]
Number of sublease agreements with related parties | Sublease					2

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2021USD ($)
Leases [Abstract]
2022	$ 3,013
2023	10,711
2024	11,766
2025	10,879
2026	11,205
Thereafter	148,290
Total minimum lease payments	$ 195,864

License Agreements - Additional

License Agreements - Additional Information (Details)	1 Months Ended			12 Months Ended
	Mar. 31, 2021USD ($)	Oct. 31, 2020USD ($)	May 31, 2019USD ($)Product	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
License Agreements [Line Items]
Milestone payments				$ 0	$ 0
License maintenances fees				100,000	100,000
Outstanding payment due to WIBR					0
Research and development				$ 47,865,000	21,063,000
WIBR Exclusive License Agreement
License Agreements [Line Items]
Number of licensed products | Product			3
Percentage of non-royalty payments description				This percentage ranges from zero to low double-digits and will be based upon the stage of development of the licensed product at the time such sublicense is executed.
WIBR Exclusive License Agreement | Maximum
License Agreements [Line Items]
Nonrefundable upfront fee paid.			$ 100,000
Annual license maintenance fees			100,000
Milestone payments			$ 1,700,000
WIBR Co-Exclusive License Agreement
License Agreements [Line Items]
Number of licensed products | Product			3
WIBR Co-Exclusive License Agreement | Maximum
License Agreements [Line Items]
Nonrefundable upfront fee paid.			$ 100,000
Annual license maintenance fees			100,000
Milestone payments			1,900,000
Annual fees for each sublicense agreement			$ 100,000
Development and Option Agreement
License Agreements [Line Items]
Reimbursements for development and material costs incurred by Acuitas		$ 400,000
Development and Option Agreement | First Non-exclusive License
License Agreements [Line Items]
Annual technology access fee		1,500,000
Development and Option Agreement | Second Non-exclusive License
License Agreements [Line Items]
Annual technology access fee		$ 1,750,000
Acuitas License Agreement
License Agreements [Line Items]
Milestone payments				$ 0
Option exercise fee	$ 1,500,000
Research and development				$ 3,300,000	$ 800,000
Potential clinical and regulatory milestone payments aggregate amount entitled to receive Acuitas	$ 18,000,000

Collaboration Agreement - Addit

Collaboration Agreement - Additional Information (Details) - Collaboration Agreement - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2021	Dec. 31, 2021
Collaboration Agreement [Line Items]
Collaboration agreement period	5 years
Amount of cost reimbursement receivable to fund research and development activities	$ 3.5
Transaction price		$ 3.5
Remaining transaction price		3.4
Research and collaboration revenue		0.1
Current deferred revenue		$ 0.1

Redeemable Convertible Prefer_3

Redeemable Convertible Preferred Stock - Additional Information (Details) - USD ($)	Aug. 03, 2021	Aug. 03, 2020	Jun. 02, 2020	Jan. 27, 2020	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2017	Jun. 30, 2021	Apr. 01, 2021	Dec. 31, 2020	Sep. 01, 2020	Jan. 01, 2020
Class Of Stock [Line Items]
Number of preferred stock converted into common stock	34,678,733
Redeemable convertible preferred stock, shares issued											89,175,231
Conversion of preferred stock to common stock											23,605,211
Redeemable convertible preferred stock, shares authorized					107,125,232				132,858,564		107,125,232
Common stock, shares authorized						200,000,000					137,700,000
Series A Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares issued						0	56,775,232				56,775,232		0
Purchase price per share							$ 0.50	$ 0.50
Cash proceeds from issuance of convertible preferred stock							$ 25,500,000
Proceeds from outstanding promissory notes							2,800,000	$ 2,800,000
Accrued interest on outstanding promissory notes							54,000	$ 54,000
Conversion of preferred stock to common stock											15,028,741
Redeemable convertible preferred stock, shares authorized						0					57,125,232
Series A Redeemable Convertible Preferred Stock | Minimum
Class Of Stock [Line Items]
Stock issuance costs							$ 100,000
Series B Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares issued		5,000,000	3,333,333	24,066,666		0					32,399,999	0
Purchase price per share		$ 1.50	$ 1.50	$ 1.50
Cash proceeds from issuance of convertible preferred stock		$ 7,500,000	$ 5,000,000	$ 36,100,000
Conversion of preferred stock to common stock											8,576,470
Stock issuance costs						$ 83,000
Redeemable convertible preferred stock, shares authorized						0					50,000,000
Series C Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares issued					41,833,328	0				0	0
Purchase price per share					$ 3
Cash proceeds from issuance of convertible preferred stock					$ 125,500,000
Stock issuance costs					$ 100,000
Redeemable convertible preferred stock, shares authorized						0					0

Redeemable Convertible Prefer_4

Redeemable Convertible Preferred Stock - Summary of Redeemable Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 01, 2020	Aug. 03, 2020	Jun. 02, 2020	Jan. 27, 2020	Jan. 01, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Temporary Equity Shares Authorized		132,858,564	107,125,232	107,125,232
Temporary Equity Shares Issued				89,175,231
Temporary Equity Shares Outstanding				89,175,231
Temporary Equity Carrying Amount Attributable To Parent				$ 75,225
Temporary Equity Liquidation Preference				$ 74,100
Convertible Preferred Stock Shares Issued Upon Conversion				23,605,211
Series A Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity Shares Authorized	0			57,125,232
Temporary Equity Shares Issued	0			56,775,232					0	56,775,232
Temporary Equity Shares Outstanding	0			56,775,232						56,775,232
Temporary Equity Carrying Amount Attributable To Parent				$ 26,708						$ 26,708
Temporary Equity Liquidation Preference				$ 25,500
Convertible Preferred Stock Shares Issued Upon Conversion				15,028,741
Series B Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity Shares Authorized	0			50,000,000
Temporary Equity Shares Issued	0			32,399,999	0	5,000,000	3,333,333	24,066,666
Temporary Equity Shares Outstanding	0			32,399,999
Temporary Equity Carrying Amount Attributable To Parent				$ 48,517
Temporary Equity Liquidation Preference				$ 48,600
Convertible Preferred Stock Shares Issued Upon Conversion				8,576,470

Preferred and Common Stock - (A

Preferred and Common Stock - (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock issued and sold		47,793,469	4,465,351
Gross proceeds from IPO		$ 131,238
Shares of common stock authorized		200,000,000	137,700,000
Common stock, par value		$ 0.001	$ 0.001
Shares of preferred stock authorized		10,000,000	0
Preferred stock, par value		$ 0.001	$ 0.001
Amended and Restated Certificate of Incorporation
Class Of Stock [Line Items]
Reverse stock split description		1-for-3.777776
Shares of common stock authorized	200,000,000
Common stock, par value	$ 0.001
Shares of preferred stock authorized	10,000,000
Preferred stock, par value	$ 0.001
2017 Plan
Class Of Stock [Line Items]
Common stock subject to outstanding stock options issued		4,844,040
2017 and 2021 Plans
Class Of Stock [Line Items]
Common stock subject to outstanding stock options issued		5,476,484
IPO
Class Of Stock [Line Items]
Common stock issued and sold	8,300,976
Gross proceeds from IPO	$ 141,100
Offering price per share	$ 17
Net proceeds	$ 128,100
Underwriters’ Option to Purchase Additional Shares
Class Of Stock [Line Items]
Common stock issued and sold	900,976

Equity Incentive Plan - Additio

Equity Incentive Plan - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017	Jul. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense		$ 3,184,000	$ 637,000
2017 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant		0
Common stock subject to outstanding stock options issued		4,844,040
2017 Equity Incentive Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period	10 years
Vesting period	4 years
2017 Equity Incentive Plan | Stock Options | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percentage	100.00%
2017 Equity Incentive Plan | Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period				4 years
Restricted common stock issued				1,985,295
Fair value of restricted common stock				$ 800,000
Unrecognized stock-based compensation expense related to restricted stock		$ 0
2021 Incentive Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant		2,481,751
Common stock subject to outstanding stock options issued		632,444
Common stock reserved for future issuance					2,960,000
Stock-based compensation expense		$ 3,200,000	$ 600,000
Common stock shares reserved for future issuance increased percentage		4.00%
2017 and 2021 Equity Incentive Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value per share of stock options granted		$ 5.71	$ 1.05
Intrinsic value of stock options exercised		$ 1,800,000	$ 400,000
Unrecognized compensation cost related to unvested stock options		$ 14,700,000
Unrecognized compensation cost, weighted-average period of recognition		2 years 9 months 18 days

Equity Incentive Plan - Summary

Equity Incentive Plan - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,184	$ 637
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,205	299
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,979	$ 338

Equity Incentive Plan - Summa_2

Equity Incentive Plan - Summary of Assumptions Used in Black-Scholes Option-pricing Model for Stock Options (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement, Disclosure [Abstract]
Expected volatility%, minimum	76.73%	72.44%
Expected volatility%, maximum	80.18%	79.02%
Weighted-average risk-free interest rate%	1.12%	1.00%
Expected dividend yield%	0.00%	0.00%
Weighted-average expected term (in years)	6 years 1 month 2 days	5 years 10 months 28 days

Equity Incentive Plan - Summa_3

Equity Incentive Plan - Summary of Option Activity (Details) - 2017 and 2021 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options Outstanding, Beginning balance	3,049,875
Number of options, Granted	2,967,648
Number of options, Exercised	(266,216)
Number of options, Forfeitures	(274,823)
Number of options Outstanding, Ending balance	5,476,484	3,049,875
Number of options, Vested and expected to vest	5,476,484
Number of options, Exercisable	1,324,664
Weighted average exercise price Outstanding, Beginning balance	$ 1.10
Weighted average exercise price, Granted	8.39
Weighted average exercise price, Exercised	1.03
Weighted average exercise price, Forfeitures	4.08
Weighted average exercise price Outstanding, Ending balance	4.90	$ 1.10
Weighted average exercise price, Vested and expected to vest	4.90
Weighted average exercise price, Exercisable	$ 0.93
Weighted average remaining contractual life (years), Outstanding	8 years 7 months 20 days	8 years 10 months 9 days
Weighted average remaining contractual life (years), Vested and expected to vest	8 years 7 months 20 days
Weighted average remaining contractual life (years), Exercisable	7 years 9 months 29 days
Aggregate intrinsic value, Outstanding	$ 39,325	$ 4,467
Aggregate intrinsic value, Vested and expected to vest	39,325
Aggregate intrinsic value, Exercisable	$ 13,780

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Summary of the Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss attributable to common stockholders	$ (68,280)	$ (29,447)
Denominator:
Weighted average number of common stock, basic and diluted	22,404,058	3,906,168
Net loss per common stock attributable to common stockholders, basic and diluted	$ (3.05)	$ (7.54)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Schedule of Anti-Dilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,476,484	26,747,733
Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share		23,605,211
Outstanding Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,476,484	3,049,875
Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share		92,647

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Federal Statutory Income Tax Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21.00%	21.00%
State income taxes, net of federal benefit	7.60%	7.70%
Research and development tax credits	3.00%	2.80%
Nondeductible/ nontaxable permanent items	(0.90%)	(0.50%)
Change in valuation allowance	(30.80%)	(30.80%)
Other	0.10%	(0.20%)
Effective income tax rate%	0.00%	0.00%

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Federal net operating loss carryforwards	$ 34,194	$ 17,320
Research and development credit carryforwards	5,638	2,424
Accrued expenses	879	539
Stock-based compensation	528	9
Intangibles	152	167
Total deferred tax assets	41,391	20,459
Less: valuation allowance	(41,203)	(20,217)
Deferred tax assets, net	188	242
Deferred tax liabilities:
Depreciation	(182)	(242)
Unrealized gain/loss	(6)
Total deferred tax liabilities	$ (188)	$ (242)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Income tax expense	$ 0	$ 0
Increase in valuation allowance	21,000,000
Federal net operating loss carryforwards	125,800,000	63,600,000
State net operating loss carryforwards	$ 123,000,000	$ 62,600,000
Federal and state net operating loss carryforwards will begin to expire	Jan. 1, 2036	Jan. 1, 2036
Federal net operating loss carryforwards with no expiration date	$ 120,300,000	$ 58,100,000
Uncertain tax position	0	0
Federal
Operating Loss Carryforwards [Line Items]
Tax credit	3,400,000	1,400,000
Massachusetts
Operating Loss Carryforwards [Line Items]
Tax credit	$ 2,800,000	$ 1,300,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020ft²	Sep. 30, 2019ft²
LARONDE, Inc.
Related Party Transaction [Line Items]
Area of real estate property | ft²			19,404
Sublease income	$ 1,300,000
Outstanding receivable	0	$ 0
Cygnal
Related Party Transaction [Line Items]
Area of real estate property | ft²				1,445
Sublease income	100,000
Outstanding receivable	$ 0	0
Sublease term	2 years
Related Party Expense | LARONDE, Inc.
Related Party Transaction [Line Items]
Sublease rental income received	$ 2,000,000	600,000
Related Party Expense | Cygnal
Related Party Transaction [Line Items]
Sublease rental income received	200,000	100,000
Flagship
Related Party Transaction [Line Items]
Outstanding payments		0
Flagship | Related Party Expense | Management Services Fees and Other Reimbursements
Related Party Transaction [Line Items]
Related party expenses for management service	$ 1,000,000	$ 900,000
Omega Therapeutics, Inc. | Flagship
Related Party Transaction [Line Items]
Ownership percentage	54.00%