Verve Therapeutics (VERV) 10-Q 10 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 05, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Entity Registrant Name	VERVE THERAPEUTICS, INC.
Entity Central Index Key	0001840574
Trading Symbol	VERV
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		48,661,446
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common stock, par value $0.001 per share
Entity File Number	001-40489
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4800132
Entity Address, Address Line One	500 Technology Square, Suite 901
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	603-0070
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 91,420	$ 64,330
Marketable securities	231,879	296,112
Prepaid expenses and other current assets	5,531	6,686
Total current assets	328,830	367,128
Property and equipment, net	11,132	7,224
Restricted cash	5,237	5,237
Operating lease right-of-use assets	1,340	1,839
Other long term assets	2,702	2,696
Total assets	349,241	384,124
Current liabilities:
Accounts payable	2,438	7,077
Accrued expenses	10,933	12,992
Operating lease obligations, current portion	1,432	1,955
Total current liabilities	14,803	22,024
Success Payment Liability	2,694	4,371
Other long term liabilities	354	377
Total liabilities	17,851	26,772
Commitments and contingencies (See Note 7 and Note 8)
Stockholders' equity (deficit):
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	0	0
Common stock, $0.001 par value; 200,000,000 and 255,000,000 shares authorized, 48,655,241 and 48,511,735 shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	49	49
Additional paid-in capital	549,089	544,381
Accumulated other comprehensive income	(732)	(228)
Accumulated deficit	(217,016)	(186,850)
Total stockholders equity	331,390	357,352
Total liabilities, convertible preferred stock, and stockholders' equity (deficit)	$ 349,241	$ 384,124

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock fair value	$ 0.001	$ 0.001
Common Stock, Shares Authorized	200,000,000	200,000,000
Common stock shares issued	48,655,241	48,511,735
Common Stock, Shares, Outstanding	48,655,241	48,511,735

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 24,490	$ 11,345
General and administrative	7,435	2,716
Total operating expenses	31,925	14,061
Loss from operations	(31,925)	(14,061)
Other income
Change in fair value of antidilution rights liability	0	396
Change in fair value of success payment liability	1,677	382
Interest and other income, net	82	20
Total other income, net	1,759	798
Net loss	$ (30,166)	$ (13,263)
Net loss per common share attributable to common stockholders, basic and diluted	$ (0.62)	$ (4.99)
Weighted-average common shares used in net loss per share attributable to common stockholders, basic and diluted	48,571,214	2,656,278
Comprehensive Loss:
Net loss	$ (30,166)	$ (13,263)
Other comprehensive loss:
Unrealized loss on marketable securities	(504)	(1)
Comprehensive loss	$ (30,670)	$ (13,264)

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ (63,909)	$ 125,160	$ 3	$ 2,616	$ 8	$ (66,536)
Beginning Balance (in shares) at Dec. 31, 2020		179,519,032	2,585,789
Issuance of Series B convertible preferred stock, net of issuance costs of $241		$ 93,759
Issuance of Series B convertible preferred stock, net of issuance costs (in shares)		77,163,022
Vesting of restricted common stock (in shares)			134,409
Exercise of stock options	72			72
Exercise of stock options (in shares)			48,745
Unrealized loss on available-for-sale securities	(1)				(1)
Stock-based compensation	670			670
Net loss	(13,263)					(13,263)
Ending Balance at Mar. 31, 2021	(76,431)	$ 218,919	$ 3	3,358	7	(79,799)
Ending balance (in shares) at Mar. 31, 2021		256,682,054	2,768,943
Beginning Balance at Dec. 31, 2021	$ 357,352	$ 0	$ 49	544,381	(228)	(186,850)
Beginning Balance (in shares) at Dec. 31, 2021	48,511,735	0	48,511,735
Exercise of stock options	$ 505			505
Exercise of stock options (in shares)	143,506		143,506
Unrealized loss on available-for-sale securities	$ (504)				(504)
Stock-based compensation	4,203			4,203
Net loss	(30,166)					(30,166)
Ending Balance at Mar. 31, 2022	$ 331,390	$ 0	$ 49	$ 549,089	$ (732)	$ (217,016)
Ending balance (in shares) at Mar. 31, 2022	48,655,241	0	48,655,241

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance Costs Of Series B Convertible Preferred Stock	$ 241

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (30,166)	$ (13,263)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	514	294
Non-cash lease expense	499	418
Amortization of premium on marketable securities	730	208
Stock-based compensation	4,203	670
Change in fair value of antidilution rights	0	(396)
Change in fair value of success payments liabilities	(1,677)	(382)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,149	(1,128)
Accounts payable	(5,105)	1,928
Accrued expenses and other liabilities	(3,131)	(3,047)
Operating lease liabilities	(523)	(443)
Net cash used in operating activities	(33,507)	(15,141)
Cash flows from investing activities:
Purchases of property and equipment	(2,908)	(1,070)
Purchases of marketable securities	0	(11,176)
Maturities of marketable securities	63,000	23,960
Net cash provided by investing activities	60,092	11,714
Cash flows from financing activities:
Proceeds from issuance of Series B convertible preferred stock, net	0	93,759
Proceeds from exercise of stock options	505	72
Net cash provided by financing activities	505	93,831
Increase in cash, cash equivalents and restricted cash	27,090	90,404
Cash, cash equivalents and restricted cash—beginning of period	69,567	9,456
Cash, cash equivalents and restricted cash—end of period	96,657	99,860
Supplemental disclosure of noncash investing and financing activities:
Property and equipment additions included in accounts payable and accrued expenses	2,017	528
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 0	$ 462

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the business and basis of presentation Organization Verve Therapeutics, Inc. (the “Company” or “Verve”) is a genetic medicines company pioneering a new approach to the care of cardiovascular disease, transforming treatment from chronic management to single-course gene editing medicines. The Company was incorporated on March 9, 2018 as Endcadia, Inc., a Delaware corporation, and began operations shortly thereafter. In January 2019, the Company amended its certificate of incorporation to change its name to Verve Therapeutics, Inc. The Company’s principal offices are located in Cambridge, Massachusetts. Liquidity and capital resources Since its inception, the Company has devoted its efforts principally to research and development and raising capital. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. On June 21, 2021, the Company completed its initial public offering, or IPO, in which the Company issued and sold 16,141,157 shares of its common stock, including 2,105,368 shares pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $ 19.00 per share, for aggregate gross proceeds of $ 306.7 million . The Company received approximately $ 281.6 million in net proceeds after deducting underwriting discounts and offering expenses payable by the Company. In connection with the IPO, all outstanding shares of convertible preferred stock converted into 27,720,923 shares of the Company’s common stock. In connection with the Company's IPO, the Company effected a one-for-9.2595 reverse stock split of the Company’s issued and outstanding common stock. Accordingly, all shares of common stock and per share amounts, as well as the conversion ratio of the Company’s outstanding convertible preferred stock, for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been retroactively adjusted, where applicable, to reflect the reverse stock split, including reclassification of par and additional paid-in capital amounts as a result of the reverse stock split. The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. The Company expects that its cash, cash equivalents and marketable securities of $ 323.3 million as of March 31, 2022 will be sufficient to fund its operations and capital expenditure requirements beyond the next 12 months from the date of issuance of these financial statements. The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to raise capital as and when needed could have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so. Basis of presentation The accompanying condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). 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”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of March 31, 2022, the results of its operations and other comprehensive loss for the three months ended March 31, 2022 and 2021, convertible preferred stock and stockholders’ equity for the three months ended March 31, 2022 and 2021 and cash flows for the three months ended March 31, 2022 and 2021. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2022 are not necessarily indicative of the results for the year ending December 31, 2022 , or for any future period. These interim financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2021, and the notes thereto, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 14, 2022.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. S ummary of significant accounting policies The Company's significant accounting policies are disclosed in Note 2, "Summary of significant accounting policies," in the audited consolidated financial statements for the year ended December 31, 2021, and notes thereto, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 14, 2022. Since the date of those financial statements, there have been no changes to its significant accounting policies. Cash, cash equivalents and restricted cash Restricted cash represents collateral provided for letters of credit issued as security deposits in connection with the Company’s leases of its corporate facilities. A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows: March 31, March 31, (in thousands) 2022 2021 Cash and cash equivalents $ 91,420 $ 99,397 Restricted cash 5,237 463 Total cash, cash equivalents and restricted cash $ 96,657 $ 99,860 Recently adopted accounting pronouncements During the quarter ended September 30, 2021, the Company early adopted ASC Topic 842, “Leases” (“ASC 842”) using the revised modified retrospective approach as of January 1, 2021. The unaudited interim condensed consolidated financial statements for the three months ended March 31, 2021 have been retroactively adjusted to reflect the adoption of ASC 842, including retroactive adjustments to the unaudited interim condensed consolidated statement of cash flows and certain additional footnote disclosures as included herein. The adoption of ASC 842 had no material impact to the Company’s unaudited condensed consolidated statement of operations and comprehensive loss for the three months ended March 31, 2021. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on specific facts and circumstances, the existence of an identified asset(s), if any, and the Company’s control over the use of the identified asset(s), if applicable. The lease liability is measured at the present value of future lease payments, discounted using the discount rate as of the lease commencement date. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes the incremental borrowing rate, which is the rate incurred to borrow, on a collateralized basis over a similar term, an amount equal to the lease payments in a similar economic environment. The Company recognizes a corresponding lease right of use (“ROU”) asset, initially measured as the amount of lease liability, adjusted for any initial lease costs or lease payments made before or at the commencement of the lease, and reduced by any lease incentives. The Company’s leases consist of only operating leases. Operating leases are recognized on the balance sheet as ROU lease assets, lease liabilities current and lease liabilities non-current. Fixed rents are included in the calculation of the lease balances while certain variable costs paid for certain operating and pass-through costs are excluded. Lease expense is recognized over the expected term on a straight-line basis.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3. Marketable securities Marketable securities by security type consisted of the following: March 31, 2022 (in thousands) Amortized Gross Gross Fair U.S. treasury bills and notes $ 218,875 $ — $ ( 711 ) $ 218,164 U.S. agency securities 13,736 — ( 21 ) 13,715 Total $ 232,611 $ — $ ( 732 ) $ 231,879 December 31, 2021 (in thousands) Amortized Gross Gross Fair U.S. treasury bills and notes $ 277,559 $ — $ ( 218 ) $ 277,341 U.S. agency securities 18,781 — ( 10 ) 18,771 Total $ 296,340 $ — $ ( 228 ) $ 296,112 The remaining contractual maturities of all marketable securities were less than one year as of March 31, 2022 and December 31, 2021 .

Property and equipment, net

Property and equipment, net	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property and equipment, net	4. P roperty and equipment, net Property and equipment, net, consist of the following: (in thousands) March 31, 2022 December 31, 2021 Lab equipment $ 11,814 $ 8,567 Leasehold improvements 266 266 Furniture and fixtures 1,451 566 Computer equipment 448 158 Total property and equipment 13,979 9,557 Less accumulated depreciation ( 2,847 ) ( 2,333 ) Property and equipment, net $ 11,132 $ 7,224 Depreciation expense for the three months ended March 31, 2022 and 2021 was $ 0.5 million and $ 0.3 million, respectively.

Fair value of financial instrum

Fair value of financial instruments	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair value of financial instruments	5. f air value of financial instruments The Company’s financial instruments that are measured at fair value on a recurring basis consist of money market funds, marketable securities, and a derivative liability (success payment liability) pursuant to our license agreements with the President and Fellows of Harvard College, or Harvard, and The Broad Institute, Inc., or Broad, which license agreements are referred to herein as the Harvard/Broad License Agreement and Broad License Agreement. The following tables set forth the fair value of the Company’s financial instruments by level within the fair value hierarchy: As of March 31, 2022 (in thousands) Fair Level 1 Level 2 Level 3 Assets Money market funds $ 65,035 $ 65,035 $ — $ — Marketable securities: U.S. treasury bills and notes 218,164 — 218,164 — U.S. agency securities 13,715 — 13,715 — Total assets $ 296,914 $ 65,035 $ 231,879 $ — Liabilities Success payment liability 2,694 — — 2,694 Total liabilities $ 2,694 $ — $ — $ 2,694 As of December 31, 2021 (in thousands) Fair Level 1 Level 2 Level 3 Assets Money market funds $ 58,127 $ 58,127 $ — $ — Marketable securities: U.S. treasury bills and notes 277,341 — 277,341 — U.S. agency securities 18,771 — 18,771 — Total assets $ 354,239 $ 58,127 $ 296,112 $ — Liabilities Success payment liability 4,371 — — 4,371 Total liabilities $ 4,371 $ — $ — $ 4,371 Cash Equivalents —Cash equivalents of $ 65.0 million and $ 58.1 million as of March 31, 2022 and December 31, 2021, respectively, consisted of money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. Marketable Securities— The Company measures its marketable securities at fair value on a recurring basis and classifies those instruments within Level 2 of the fair value hierarchy. Marketable securities are classified within Level 2 of the fair value hierarchy because pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reporting date, and fair value is determined through the use of models or other valuation methodologies. Antidilution Rights Liability —The antidilution rights liability represented the obligation to issue additional shares of common stock to Harvard and Broad following the completion of (1) a defined aggregate level of preferred stock financing and (2) either a sale of the Company’s preferred stock, an initial public offering, or a company sale meeting a certain value threshold. The antidilution rights liability is stated at fair value and is considered Level 3 in the fair value hierarchy because its fair value measurement is based, in part, on significant inputs not observed in the market. The antidilution rights liability related to meeting a defined aggregate level of preferred stock financing was valued using a probability-weighted present value model that considered the probability of meeting the defined aggregate level of preferred stock financing, as well as the fair value of the Company’s common stock. The antidilution rights liability related to the achievement of a specified valuation through either a sale of the Company’s preferred stock, an initial public offering, or a company sale was valued using a Monte Carlo simulation model, which models the value of the liability based on several key variables, including probability of event occurrence, timing of event occurrence, as well as the fair value of the Company’s common stock. In June 2021, upon completion of its IPO, the Company settled the antidilution rights liability in full through the issuance of 878,098 shares of the Company's common stock for a settlement amount of $ 32.5 million. Prior to settlement, the Company remeasured the liability at fair value with a decrease of $ 0.4 million to other income for the three months ended March 31, 2021. As the antidilution rights liability was settled in full in June 2021, there were no amounts for such liability included in the condensed consolidated balance sheet as of March 31, 2022 or December 31, 2021. Success Payment Liability —The Company is obligated to pay to Harvard and Broad tiered success payments in the event its average market capitalization exceeds specified thresholds for a specified period of time ascending from a high nine-digit dollar amount to $ 10.0 billion, or sale of the Company for consideration in excess of those thresholds. In the event of a change of control or a sale of the Company, the Company is required to pay success payments in cash within a specified period following such event. Otherwise, the success payments may be settled at the Company’s option in either cash or shares of its common stock, or a combination of cash and shares of its common stock. The maximum aggregate success payments that could be payable by the Company is $ 31.3 million (after termination of the Broad License Agreement). The success payments liability is stated at fair value and is considered Level 3 because its fair value measurement is based, in part, on significant inputs not observed in the market. The Company used a Monte Carlo simulation model, which models the value of the liability based on several key variables, including probability of event occurrence, timing of event occurrence, as well as the value of the Company’s common stock. The Company also estimated the likelihood that it would maintain the Harvard/Broad License Agreement based on its ongoing research efforts. The Company remeasured the liability at fair value with corresponding increases of $ 1.7 million and $ 0.4 million recorded to other income for the three months ended March 31, 2022 and 2021, respectively. In September 2021, multiple success payments were triggered and amounts due to Harvard and Broad totaled $ 6.3 million. These amounts were settled in cash in November 2021. The Company will continue to adjust the remaining success payment liability for changes in fair value until the earlier of the achievement or expiration of the obligation. The primary inputs used in valuing the success payments liability associated with the Company’s realization of a certain valuation threshold, were as follows: At At Fair value of common stock (per share) $ 22.82 $ 36.87 Equity volatility 76 % 77 % In February 2021, the Company provided written notice to Broad of its election to terminate the Broad License Agreement, which termination became effective in June 2021. The reconciliation of changes in the fair value of financial instruments based on Level 3 inputs for the three months ended March 31, 2022 is as follows: (in thousands) Success Balance at December 31, 2021 $ 4,371 Changes in fair value ( 1,677 ) Balance at March 31, 2022 $ 2,694 The reconciliation of changes in the fair value of financial instruments based on Level 3 inputs for the three months ended March 31, 2021 is as follows: (in thousands) Antidilution rights liability Success Total Balance at December 31, 2020 $ 6,916 $ 2,806 $ 9,722 Changes in fair value ( 396 ) ( 382 ) ( 778 ) Balance at March 31, 2021 $ 6,520 $ 2,424 $ 8,944

Accrued expenses

Accrued expenses	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Accrued expenses	6. Accrued expenses Accrued expenses consist of the following: (in thousands) March 31, December 31, Employee compensation and related benefits $ 2,280 $ 6,050 Accrued external research and development expenses 5,361 5,041 Professional fees 1,237 1,109 Other 2,055 792 Total $ 10,933 $ 12,992

Leases

Leases	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Leases	7. Leases The Company’s operating lease activity is comprised of non-cancelable facility leases for office and laboratory space in Cambridge, Massachusetts. The Company has also entered into multiple contract research and contract manufacturing service agreements with third parties which contain embedded leases within the scope of ASC 842. The embedded leases are considered short term leases, as the contractual terms are 12 months or less. Accordingly, no lease liability or ROU asset has been recorded, and the Company has recognize d $ 0.3 million and $ 0.6 million of sh ort term lease costs associated with the embedded leases during the three months ended March 31, 2022 and 2021, respectively. The components of operating lease cost were as follows: Three months ended March 31, (in thousands) 2022 2021 Operating lease costs $ 505 $ 449 Variable lease costs 211 189 Total $ 716 $ 638 Supplemental cash flow information related to operating leases was as follows: Three months ended March 31, (in thousands) 2022 2021 Cash paid for amounts included in the measurements of lease liabilities: Operating cash flows related to operating leases $ 529 $ 474 As of March 31, 2022 , the Company’s operating leases were measured using a weighted-average incremental borrowing rate of 1.57 % over a weighted-average remaining lease term of 0.7 years. As of March 31, 2021, the Company’s operating leases were measured using a weighted-average incremental borrowing rate of 4.69 % over a weighted-average remaining lease term of 1.3 years. On August 19, 2021, the Company entered into a lease agreement with ARE-MA Region No. 87 Tenant, LLC, a Delaware limited liability company (the “Landlord”), pursuant to which the Company will lease approximately 104,933 square feet of office and laboratory space located at 201 Brookline Avenue, Boston, Massachusetts (the “Boston Lease”), further amended in January 2022 to include an additional 211 square feet, for a total of 105,144 square feet (the “Premises”). The Boston Lease premises have not been made available to the Company as of March 31, 2022 and therefore the Boston Lease has not commenced. The term of the Boston Lease will commence on the earlier of (1) the date the Landlord delivers the Premises to the Company, which the parties expect to be on or prior to September 1, 2022, or (2) the date the Landlord could have delivered the Premises but for any delays attributable to the Company (the “Commencement Date”). The Company’s obligation for the payment of base rent for the Premises begins 90 days after the Commencement Date (the “Rent Commencement Date”) and will initially be $0.8 million per month, which will increase by approximately 3% per annum . The Boston Lease has a term of 10 years, measured from the Rent Commencement Date. The Company has the option to extend the term of the Boston Lease for a period of an additional five years . Under the terms of the Boston Lease, the Landlord has agreed to make up to $ 21.0 million in certain tenant improvements to the Premises to suit the Company’s use (the “Tenant Improvement Allowance”), which amount is included in the base rent set forth in the Boston Lease. In addition to the Tenant Improvement Allowance, the Company may receive up to $ 5.2 million for additional improvements to the Premises, which amount is subject to an 8 % annual interest charge and may be paid in equal monthly installments. In connection with its entry into the Boston Lease and as a security deposit, the Company has provided the Landlord a letter of credit in the amount of approximately $ 4.8 million, which may be reduced to approximately $ 3.5 million on the expiration of the 36-month anniversary of the Rent Commencement Date so long as there are, and have been, no defaults by the Company under the terms of the Boston Lease. The Company also paid a deposit in the amount of $ 0.8 million, which is equal to the first month of base rent. The Landlord has the right to terminate the Boston Lease upon customary events of default. The Company may also terminate the Boston Lease if the Premises are not ready for occupancy within a specified time period after September 1, 2022. The Boston Lease requires the Landlord to perform a scope of work to build-out the base building prior to the construction of the Premises. The Company concluded the accounting commencement date will occur when the Landlord completes the build-out of the base building and control passes to the Company. The Company will assess the classification of the Boston Lease at the accounting commencement date, and measure the right-of-use asset and lease liability. Payments made by the Company prior to commencement will be treated as prepaid rent which will increase the right-of-use asset. As of March 31, 2022 the Company has incurred an aggregate of $ 1.9 million related to the build out of the Premises prior to the commencement date. In October 2021, the Company entered into a sublease for 11,931 square feet of office and laboratory space in Cambridge, Massachusetts. The sublease commenced in December 2021 and has an initial noncancelable term of 12 months . The Company has the option to extend the sublease for one extension term of three months by written notice not less than six months prior to the expiration of the sublease term, which the Company is not reasonably certain of exercising . Therefore, this sublease is treated as a sh ort term lease. The total fixed lease payments over the sublease term are approximately $ 1.4 million and the Company is also required to pay its proportional share of operating expenses. Future minimum commitments under non-cancellable leases as of March 31, 2022 were as follows: Years ending December 31, Amount (in thousands) Remainder of 2022 $ 3,208 2023 9,688 2024 9,978 2025 10,278 2026 10,586 Thereafter 65,172 Total lease payments $ 108,910 Less: interest ( 7 ) Present value of operating lease liabilities $ 108,903 Rent expense was $ 0.8 million and $ 0.4 million for the three months ended March 31, 2022 and 2021 , respectively.

License Agreements

License Agreements	3 Months Ended
	Mar. 31, 2022
License Agreement [Abstract]
License Agreement	8. License agreements The Company's significant license agreements are disclosed in Note 8, "License agreements," in the audited consolidated financial statements for the year ended December 31, 2021, and notes thereto, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 14, 2022. Since the date of those financial statements, there have been no changes to its license agreements, except as noted below. Harvard/Broad license agreement and Broad license agreement In March 2019, the Company simultaneously entered into the Harvard/Broad License Agreement and Broad License Agreement (the “license agreements”) for certain base editing technologies pursuant to which the Company received exclusive, worldwide, sublicensable, royalty-bearing licenses under specified patent rights to develop and commercialize licensed products and nonexclusive, worldwide, sublicensable, royalty-bearing licenses under certain patent rights to research and develop licensed products. The Company agreed to use commercially reasonable efforts to develop licensed products in accordance with the development plans, to introduce any licensed products that gain regulatory approval into the commercial market, to market licensed products that have gained regulatory approval following such introduction into the market, and to make licensed products that have gained regulatory approval reasonably available to the public. The term of the agreements will continue until the expiration of the last to expire valid claim. The Company may terminate either of the license agreements without cause upon four months’ prior written notice to Harvard and Broad, unless terminated earlier. In February 2021, the Company provided written notice to Broad of its intent to terminate the Broad License Agreement, which termination was effective in June 2021. As partial consideration for the rights granted under the Harvard/ Broad License Agreement and Broad License Agreement, the Company paid $ 0.3 million in non-refundable upfront license fees and also issued 276,075 shares of its common stock with a fair value of $ 0.3 million. Additional consideration under the license agreements is as follows: Antidilution Rights —The initial shares of common stock issued to Harvard and Broad were subject to antidilution provisions as further described in Note 5, "Fair value of financial instruments." The antidilution rights associated with the Company achieving a defined aggregate level of preferred stock financing were partially satisfied in 2019 and fully satisfied in 2020, which settlement amounts totaled $ 0.1 million and $ 0.5 million, respectively, and which amounts were settled through issuances of 121,411 and 187,867 shares of common stock, respectively. The remaining antidilution rights obligation was fully satisfied in the three months ended June 30, 2021 with the Company’s IPO. The settlement amount totaled $ 32.5 million, and was settled through issuance of 878,098 shares of common stock. Success Payments —The Company is required to make success payments under the license agreements as further described in Note 5, "Fair value of financial instruments." In September 2021, certain success payments were triggered and amounts due to Harvard and Broad totaled $ 6.3 million. These amounts were settled in cash in November 2021. Other Payments —The Company agreed to pay an annual license maintenance fee ranging from low-to-mid five figures to low six figures, depending on the particular calendar year, for each of the license agreements. The Company is responsible for the payment of certain patent prosecution and maintenance costs incurred by Harvard and Broad related to licensed patents. To the extent achieved, the Company is obligated to pay up to an aggregate of $ 46.2 million and $ 108 million in development and sales-based milestones, respectively. During the three months ended March 31, 2022, the first milestone was triggered and amounts due to Harvard and Broad totaled $ 0.3 million. These amounts remain payable as of March 31, 2022 and will be settled in cash. If the Company undergoes a change of control during the term of the license agreements, then certain of the milestone payments would be increased by a mid-double-digit percentage. To the extent there are sales of a licensed product, the Company is required to pay low single digit royalties on net sales, for each of the license agreements. The Company is entitled to certain reductions and offsets on these royalties with respect to a licensed product in a given country. Beam license agreement In April 2019, the Company and Beam Therapeutics, Inc. ("Beam") entered into a collaboration and license agreement. Pursuant to the agreement, the Company received an exclusive, worldwide, sublicensable license under certain of Beam’s base editing technology, gene editing, and delivery technologies to develop, make, use, offer for sale, sell and import base editing products and nuclease products using Beam’s CRISPR associated protein 12b, or Cas12b technology, in each case, directed to any of four gene targets, including the PCSK9 and ANGPTL3 genes, that are associated with an increased risk of coronary diseases. In addition, the Company granted Beam an exclusive, worldwide, sublicensable license under certain of its delivery technology to develop, manufacture, sell and import product candidates and products, except for base editor products licensed to Verve. Both parties may conduct certain activities in accordance with an agreed-upon research and/or development plan. Following the final dosing of a patient in a Phase 1 clinical trial of a given licensed product, Beam has the right to opt in to share 33% of worldwide expenses of the development of such licensed product, as well as jointly commercialize and share profits and expenses of commercializing such licensed product in the United States on a 50/50 basis. If Beam exercises its opt-in right for a given licensed product, which we refer to following such opt-in as a collaboration product, it will be obligated to pay for a specified percentage of the development and commercialization costs of such collaboration product and will have the right to receive a specified percentage of the profits from any sales of such collaboration product. The term of the agreement continues until the last to expire of any royalty term for any product. The Company has the right to terminate the agreement as to any licensed product, but not for any collaboration product, by delivering a 90-day termination notice to Beam, provided that Beam has elected not to exercise its opt-in right or the period to exercise such opt-in right has expired. The Company is responsible for all costs and expenses incurred in the conduct of activities under the research plan, any development plan and any costs and expenses for the development of a licensed product for which Beam has not elected to opt-in. As partial consideration for the license rights granted by Beam under this agreement, the Company paid a one-time, nonrefundable fee through issuing 276,075 shares of its common stock with a fair value of $ 0.3 million. To the extent achieved, for each licensed product, the Company is also obligated to pay up to $ 11.3 million in development and regulatory-based milestones and $ 15.0 million in sales-based milestones. To the extent there are sales of a licensed product, the Company is required to pay low-to-mid single digit royalties on net sales. To the extent achieved, for each collaboration product outside of the United States, the Company is obligated to pay up to $ 5.6 million in development and regulatory-based milestones and $ 7.5 million in sales-based milestones. To the extent there are ex-U.S. sales of a collaboration product, the Company is required to pay low-to-mid single digit royalties on net sales. The Company has not triggered any milestone payments pursuant to its arrangement with Beam, and no expense has been recorded for milestones as of March 31, 2022. To the extent there are sales of a delivery technology product, each party will pay the other party low-to-mid single digit royalties based on the annual aggregate worldwide net sales resulting from the sale of each delivery technology product of such paying party; provided, however, that such royalty payments will not apply to net sales of the collaboration products or licensed products. The Company concluded the receipt of any milestone or royalty payments under the agreement was not probable as of March 31, 2022. Beam materials exchange letter agreement In October 2020, the Company and Beam entered into a materials exchange agreement wherein the parties agreed that Beam would provide certain mRNA, gRNA, and protein to the Company and that the Company would provide certain gRNAs to Beam at an agreed upon price per each material provided. For the three months ended March 31, 2022 and 2021, the Company did no t purchase any materials from Beam. For the three months ended March 31, 2022 , the Company did not sell any materials to Beam. For the three months ended March 31, 2021, the Company recognized $ 0.2 million as a reduction to research and development expense related to reimbursements received for materials sold to Beam. Acuitas agreements Development and option agreement In December 2019, the Company and Acuitas Therapeutics, Inc. ("Acuitas") entered into a development and collaboration agreement, which agreement was amended and restated in October 2020. The Company agreed to reimburse Acuitas on a quarterly basis for its services performed related to the program activities based on an agreed upon number of fulltime employees committed to work on the program at an annual rate per employee, including reimbursement of reasonable external costs. The Company recognized research and development expense during the three months ended March 31, 2022 and 2021 of $ 0.1 million and $ 0.3 million, respectively, related to the reimbursement of research and development services provided by Acuitas. License agreement In October 2020, the Company paid Acuitas a non-refundable, upfront license fee of $ 2.0 million (less a previously paid target reservation fee) to exercise an option with respect to a licensed product and a licensed genome target and entered into a non-exclusive, worldwide license with Acuitas, with a right to sub-license through multiple tiers, under the licensed LNP technology to research, develop and commercialize the licensed products using the LNP technology in connection with the PCSK9 gene target for all human therapeutic or prophylactic uses. To the extent achieved, the Company is also obligated to pay up to an aggregate of $ 9.8 million in clinical and regulatory milestones and $ 9.5 million in sales-based milestones. The milestones have not been achieved and no expense has been recorded for these milestones as of March 31, 2022. Third-party license agreements In October 2021, the Company entered into a license agreement with a third party to obtain a non-exclusive license to certain technology the Company is using for research and development. As consideration for the license and rights granted under the agreement, the Company made a one-time, non-refundable, upfront payment of $ 0.8 million during the three months ended December 31, 2021. The license agreement provides for specified development milestones relating to the licensed technology and requires the Company to make payments upon achievement of each milestone up to an aggregate amount of $ 10.0 million.

Preferred and Common Stock

Preferred and Common Stock	3 Months Ended
	Mar. 31, 2022
Preferred Stock [Abstract]
Preferred and Common Stock	. Preferred and common stock In January 2021, the Company issued 77,163,022 shares of Series B Preferred Stock at a price of $ 1.2182 per share for gross proceeds of $ 94.0 million. The Company incurred issuance costs in connection with this transaction of $ 0.2 million. In June 2021, the Company amended and restated its certificate of incorporation to authorize 5,000,000 shares of preferred stock, which shares of preferred stock are currently undesignated, and 200,000,000 shares of common stock, $ 0.001 par value per share. In June 2021, the Company completed its IPO, pursuant to which the Company issued and sold 16,141,157 shares of its common stock, including 2,105,368 shares pursuant to the full exercise of the underwriters' option to purchase additional shares, at a public offering price of $ 19.00 per share, for aggregate gross proceeds of $ 306.7 million . The Company received approximately $ 281.6 million in net proceeds, after deducting underwriting discounts and offering expenses payable by the Company. Upon the closing of the IPO, all outstanding shares of the Company's preferred stock automatically converted into 27,720,923 shares of the Company's common stock. In June 2021, the Company issued 878,098 shares of its common stock to Harvard and Broad as final settlement of its antidilution rights obligation. The holders of common stock are entitled to one vote for each share of common stock.

Stock-based compensation

Stock-based compensation	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-based compensation	10. Stock-based compensation The 2018 Equity Incentive Plan, or the 2018 Plan, adopted by the board of directors in August 2018 provided for the grant of qualified incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s employees, officers, directors, advisors, and outside consultants for the issuance or purchase of shares of the Company’s common stock. The maximum number of shares of common stock that were authorized for issuance under the 2018 Plan was 6,885,653 . In June 2021, the Company's board of directors adopted, and the Company's stockholders approved, the 2021 Stock Incentive Plan, or the 2021 Plan, which became effective on June 16, 2021. The 2021 Plan provides for grant of qualified and nonqualified stock options, stock appreciation rights, restricted and unrestricted stock and stock units, performance awards, and other share-based awards to the Company's employees, directors, advisors and outside consultants. Under the 2021 Plan, the number of shares of common stock initially reserved for issuance was the sum of: (1) 3,466,530 ; plus (2) the number of shares as was equal to the sum of (x) the number of shares of common stock reserved for issuance under the 2018 Plan that remained available for grant under the 2018 Plan on June 16, 2021 and (y) the number of shares of common stock subject to outstanding awards granted under the 2018 Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase, to be added on the first day of each fiscal year, commencing on January 1, 2022 and continuing until, and including, January 1, 2031, equal to the lesser of (i) 5 % of the number of shares of common stock outstanding on such date and (ii) the number of shares of common stock determined by the Company’s board of directors. On January 1, 2022, 2,425,587 shares of the Company's common stock were added to the amount reserved for issuance under the 2021 Plan in accordance with the 2021 Plan described above. As of March 31, 2022 , the Company had reserved 7,057,629 shares of the Company's common stock for issuance of equity awards, of which 4,149,943 shares remained outstanding for future grant under the 2021 Plan. Upon effectiveness of the 2021 Plan, the Company ceased granting additional awards under the 2018 Plan. Stock-based compensation expense recorded in the condensed consolidated statements of operations and comprehensive loss is as follows: Three months ended March 31, (in thousands) 2022 2021 Research and development $ 2,465 $ 313 General and administrative 1,738 357 Total stock-based compensation expense $ 4,203 $ 670 Stock options The following table provides a summary of stock option activity during the three months ended March 31, 2022: Number of Weighted Weighted Aggregate (2) Outstanding at December 31, 2021 6,119,295 $ 9.44 Granted 1,633,600 31.08 Exercised ( 143,506 ) 3.52 Forfeited ( 73,017 ) 27.96 Outstanding at March 31, 2022 7,536,372 $ 14.15 8.8 $ 91,068 Exercisable at March 31, 2022 1,856,666 $ 3.36 7.9 $ 36,140 Expected to vest after March 31, 2022 (1) 5,679,706 $ 17.68 9.0 $ 54,928 (1) This represents the number of unvested options outstanding as of March 31, 2022 that are expected to vest in the future. (2) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money as of March 31, 2022 . As of March 31, 2022 , there was $ 68.7 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of approximately 3.0 years. Restricted stock units During the three months ended March 31, 2022 , the Company granted 195,550 restricted stock units under the 2021 Plan. These restricted stock units vest annually over a four-year period. A summary of the status of and change in unvested restricted stock units as of March 31, 2022 was as follows: Shares Weighted- Unvested restricted stock units as of December 31, 2021 32,000 $ 36.58 Restricted stock units granted 195,550 $ 31.12 Restricted stock units forfeited ( 1,850 ) $ 30.94 Unvested restricted stock units as of March 31, 2022 225,700 $ 31.86 As of March 31, 2022 , there was $ 7.0 million of unrecognized stock-based compensation expense related to restricted stock units that are expected to vest. These costs are expected to be recognized over a weighted-average remaining vesting period of 4.0 years. 2021 Amended and Restated Employee Stock Purchase Plan In June 2021, the board of directors adopted, and the Company's stockholders approved, the 2021 Employee Stock Purchase Plan, or the ESPP, as amended and restated, which became effective on June 16, 2021. The Company initially reserved 433,316 shares of common stock for sale under the ESPP. The aggregate number of shares reserved for sale under the ESPP increases automatically on the first day of each fiscal year commencing on January 1, 2022 through January 1, 2031, by the number of shares equal to the least of (a) 1,083,290 shares, (b) 1 % of the total outstanding shares of common stock on such date, and (c) a number of shares as may be determined by the board of directors in any particular year. The first offering period under the ESPP commenced on June 16, 2021 and ended on December 13, 2021. On January 1, 2022, 485,117 shares of common stock were added to the amount reserved for sale under the ESPP. As of March 31, 2022 , 870,136 shares remained available for issuance under the ESPP. The second offering period commenced on December 14, 2021 and will end on May 31, 2022.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	11. Net loss per share attributable to common stockholders The Company’s potential dilutive securities, which include convertible preferred stock, unvested restricted stock, unvested restricted stock units and common stock options, have been excluded from the computation of diluted net loss per share as the effects would be anti-dilutive. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share attributable to common stockholders for the period indicated because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Convertible preferred stock — 27,720,923 Unvested restricted stock — 403,224 Unvested restricted stock units 225,700 — Outstanding options to purchase common stock 7,536,372 5,188,558 Total 7,762,072 33,312,705 As part of the license agreement with Harvard and Broad, the Company is required to make success payments. The Company may elect to make these payments by issuing shares of the Company's common stock. As of December 31, 2021, an aggregate of $ 6.3 million was earned relating to these success payments, which the Company settled in cash.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	12. Income taxes Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using statutory rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. Due to the uncertainty surrounding the realization of the favorable tax attributes in future tax returns, the Company has recorded a full valuation allowance against the Company’s otherwise recognizable net deferred tax assets.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	13. Related party transactions An executive officer of Beam is a board member of the Company. In October 2020, the Company and Beam entered into a materials exchange agreement wherein the parties agreed that Beam would provide certain mRNA, gRNA, and protein to the Company and that the Company would provide certain gRNAs to Beam at an agreed upon price per each material provided. For the three months ended March 31, 2021, the Company recognized $ 0.2 million as a reduction to research and development expense related to reimbursements received for materials sold to Beam. For the three months ended March 31, 2022, the Company did not sell any materials to Beam. In October 2021, the Company entered into a sublease agreement with Beam for laboratory and office space in Cambridge, Massachusetts. The sublease commenced in December 2021. Total expenses incurred under this sublease were $ 0.5 million for the three months ended March 31, 2022, which amounts remained payable at March 31, 2022 and will be settled in cash in the three months ended June 30, 2022. An executive of Broad was a board member of the Company. The board member resigned, effective May 2021. In March 2019, the Company simultaneously entered into the Harvard/Broad License Agreement and Broad License Agreement for certain base editing technologies pursuant to which the Company received exclusive, worldwide, sublicensable, royalty-bearing licenses under specified patent rights to develop and commercialize licensed products and nonexclusive, worldwide, sublicensable, royalty-bearing licenses under certain patent rights to research and develop licensed products. Additional consideration under the license agreements include success payments. See Note 8, "License agreements."

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	14. S ubsequent events The Company evaluated all subsequent events and determined there are no material recognized or unrecognized subsequent events requiring disclosure.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents and restricted cash Restricted cash represents collateral provided for letters of credit issued as security deposits in connection with the Company’s leases of its corporate facilities. A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows: March 31, March 31, (in thousands) 2022 2021 Cash and cash equivalents $ 91,420 $ 99,397 Restricted cash 5,237 463 Total cash, cash equivalents and restricted cash $ 96,657 $ 99,860
Recently Adopted Accounting Pronouncements	Recently adopted accounting pronouncements During the quarter ended September 30, 2021, the Company early adopted ASC Topic 842, “Leases” (“ASC 842”) using the revised modified retrospective approach as of January 1, 2021. The unaudited interim condensed consolidated financial statements for the three months ended March 31, 2021 have been retroactively adjusted to reflect the adoption of ASC 842, including retroactive adjustments to the unaudited interim condensed consolidated statement of cash flows and certain additional footnote disclosures as included herein. The adoption of ASC 842 had no material impact to the Company’s unaudited condensed consolidated statement of operations and comprehensive loss for the three months ended March 31, 2021. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on specific facts and circumstances, the existence of an identified asset(s), if any, and the Company’s control over the use of the identified asset(s), if applicable. The lease liability is measured at the present value of future lease payments, discounted using the discount rate as of the lease commencement date. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes the incremental borrowing rate, which is the rate incurred to borrow, on a collateralized basis over a similar term, an amount equal to the lease payments in a similar economic environment. The Company recognizes a corresponding lease right of use (“ROU”) asset, initially measured as the amount of lease liability, adjusted for any initial lease costs or lease payments made before or at the commencement of the lease, and reduced by any lease incentives. The Company’s leases consist of only operating leases. Operating leases are recognized on the balance sheet as ROU lease assets, lease liabilities current and lease liabilities non-current. Fixed rents are included in the calculation of the lease balances while certain variable costs paid for certain operating and pass-through costs are excluded. Lease expense is recognized over the expected term on a straight-line basis.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Reconciliation of Cash, Cash Equivalents and Restricted Cash	A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows: March 31, March 31, (in thousands) 2022 2021 Cash and cash equivalents $ 91,420 $ 99,397 Restricted cash 5,237 463 Total cash, cash equivalents and restricted cash $ 96,657 $ 99,860

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities by Security	Marketable securities by security type consisted of the following: March 31, 2022 (in thousands) Amortized Gross Gross Fair U.S. treasury bills and notes $ 218,875 $ — $ ( 711 ) $ 218,164 U.S. agency securities 13,736 — ( 21 ) 13,715 Total $ 232,611 $ — $ ( 732 ) $ 231,879 December 31, 2021 (in thousands) Amortized Gross Gross Fair U.S. treasury bills and notes $ 277,559 $ — $ ( 218 ) $ 277,341 U.S. agency securities 18,781 — ( 10 ) 18,771 Total $ 296,340 $ — $ ( 228 ) $ 296,112

Property and equipment, net (Ta

Property and equipment, net (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, net	Property and equipment, net, consist of the following: (in thousands) March 31, 2022 December 31, 2021 Lab equipment $ 11,814 $ 8,567 Leasehold improvements 266 266 Furniture and fixtures 1,451 566 Computer equipment 448 158 Total property and equipment 13,979 9,557 Less accumulated depreciation ( 2,847 ) ( 2,333 ) Property and equipment, net $ 11,132 $ 7,224

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Instruments, Assets and Liabilities	The following tables set forth the fair value of the Company’s financial instruments by level within the fair value hierarchy: As of March 31, 2022 (in thousands) Fair Level 1 Level 2 Level 3 Assets Money market funds $ 65,035 $ 65,035 $ — $ — Marketable securities: U.S. treasury bills and notes 218,164 — 218,164 — U.S. agency securities 13,715 — 13,715 — Total assets $ 296,914 $ 65,035 $ 231,879 $ — Liabilities Success payment liability 2,694 — — 2,694 Total liabilities $ 2,694 $ — $ — $ 2,694 As of December 31, 2021 (in thousands) Fair Level 1 Level 2 Level 3 Assets Money market funds $ 58,127 $ 58,127 $ — $ — Marketable securities: U.S. treasury bills and notes 277,341 — 277,341 — U.S. agency securities 18,771 — 18,771 — Total assets $ 354,239 $ 58,127 $ 296,112 $ — Liabilities Success payment liability 4,371 — — 4,371 Total liabilities $ 4,371 $ — $ — $ 4,371
Schedule of Fair Value Liabilities Measured on Recurring Basis	The primary inputs used in valuing the success payments liability associated with the Company’s realization of a certain valuation threshold, were as follows: At At Fair value of common stock (per share) $ 22.82 $ 36.87 Equity volatility 76 % 77 %
Schedule of Reconciliation of Changes in Fair Value of Financial Instruments	The reconciliation of changes in the fair value of financial instruments based on Level 3 inputs for the three months ended March 31, 2022 is as follows: (in thousands) Success Balance at December 31, 2021 $ 4,371 Changes in fair value ( 1,677 ) Balance at March 31, 2022 $ 2,694 The reconciliation of changes in the fair value of financial instruments based on Level 3 inputs for the three months ended March 31, 2021 is as follows: (in thousands) Antidilution rights liability Success Total Balance at December 31, 2020 $ 6,916 $ 2,806 $ 9,722 Changes in fair value ( 396 ) ( 382 ) ( 778 ) Balance at March 31, 2021 $ 6,520 $ 2,424 $ 8,944

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following: (in thousands) March 31, December 31, Employee compensation and related benefits $ 2,280 $ 6,050 Accrued external research and development expenses 5,361 5,041 Professional fees 1,237 1,109 Other 2,055 792 Total $ 10,933 $ 12,992

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Components of Operating Lease Cost	The components of operating lease cost were as follows: Three months ended March 31, (in thousands) 2022 2021 Operating lease costs $ 505 $ 449 Variable lease costs 211 189 Total $ 716 $ 638
Supplemental Cash Flow Information Related to Operating Leases	Supplemental cash flow information related to operating leases was as follows: Three months ended March 31, (in thousands) 2022 2021 Cash paid for amounts included in the measurements of lease liabilities: Operating cash flows related to operating leases $ 529 $ 474
Schedule of Future Minimum Lease Commitments under Non-Cancellable Leases	Future minimum commitments under non-cancellable leases as of March 31, 2022 were as follows: Years ending December 31, Amount (in thousands) Remainder of 2022 $ 3,208 2023 9,688 2024 9,978 2025 10,278 2026 10,586 Thereafter 65,172 Total lease payments $ 108,910 Less: interest ( 7 ) Present value of operating lease liabilities $ 108,903

Stock-based compensation (Table

Stock-based compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Summary of Stock Based Compensation Expense	Stock-based compensation expense recorded in the condensed consolidated statements of operations and comprehensive loss is as follows: Three months ended March 31, (in thousands) 2022 2021 Research and development $ 2,465 $ 313 General and administrative 1,738 357 Total stock-based compensation expense $ 4,203 $ 670
Schedule of Stock Option Activity	The following table provides a summary of stock option activity during the three months ended March 31, 2022: Number of Weighted Weighted Aggregate (2) Outstanding at December 31, 2021 6,119,295 $ 9.44 Granted 1,633,600 31.08 Exercised ( 143,506 ) 3.52 Forfeited ( 73,017 ) 27.96 Outstanding at March 31, 2022 7,536,372 $ 14.15 8.8 $ 91,068 Exercisable at March 31, 2022 1,856,666 $ 3.36 7.9 $ 36,140 Expected to vest after March 31, 2022 (1) 5,679,706 $ 17.68 9.0 $ 54,928 (1) This represents the number of unvested options outstanding as of March 31, 2022 that are expected to vest in the future. (2) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money as of March 31, 2022 .
Schedule of Status and Change in Unvested Restricted Stock	A summary of the status of and change in unvested restricted stock units as of March 31, 2022 was as follows: Shares Weighted- Unvested restricted stock units as of December 31, 2021 32,000 $ 36.58 Restricted stock units granted 195,550 $ 31.12 Restricted stock units forfeited ( 1,850 ) $ 30.94 Unvested restricted stock units as of March 31, 2022 225,700 $ 31.86

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Potential Common Shares, Based on Amounts Outstanding at Period End were Excluded From the Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share attributable to common stockholders for the period indicated because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Convertible preferred stock — 27,720,923 Unvested restricted stock — 403,224 Unvested restricted stock units 225,700 — Outstanding options to purchase common stock 7,536,372 5,188,558 Total 7,762,072 33,312,705

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 21, 2021	Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cash, cash equivalents, and marketable securities		$ 323.3
IPO
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Reverse stock split		one-for-9.2595
Shares issued and sold	16,141,157
Public offering price per share	$ 19
Proceeds from initial public offering, net of underwriting discount	$ 306.7
Net proceeds from sale of common stock	$ 281.6
Shares issued upon conversion of preferred stock	27,720,923
Underwriters Option
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Shares issued and sold	2,105,368

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 91,420	$ 64,330	$ 99,397
Restricted cash	5,237		463
Total cash, cash equivalents and restricted cash	$ 96,657	$ 69,567	$ 99,860	$ 9,456

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Operating lease liability	$ 108,903
Operating lease right-of-use assets	$ 1,340	$ 1,839

Marketable securities - Schedul

Marketable securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	$ 232,611	$ 296,340
Gross unrealized gains	0	0
Gross unrealized losses	(732)	(228)
Fair value	231,879	296,112
U.S. Treasury Bills and Notes [Member]
Marketable Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	218,875	277,559
Gross unrealized gains	0	0
Gross unrealized losses	(711)	(218)
Fair value	218,164	277,341
U.S. Agency Securities [Member]
Marketable Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	13,736	18,781
Gross unrealized gains	0	0
Gross unrealized losses	(21)	(10)
Fair value	$ 13,715	$ 18,771

Marketable securities - Additio

Marketable securities - Additional Information (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Remaining contractual maturities of marketable securities term	1 year	1 year

Property and Equipment, net - S

Property and Equipment, net - Schedule of Property and Equipment, net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 13,979	$ 9,557
Less accumulated depreciation	(2,847)	(2,333)
Property and equipment, net	11,132	7,224
Lab equipment
Property Plant And Equipment [Line Items]
Total property and equipment	11,814	8,567
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	266	266
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	1,451	566
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 448	$ 158

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation	$ 0.5	$ 0.3

Fair value of financial instr_3

Fair value of financial instruments - Summary of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets
Total assets	$ 296,914	$ 354,239
Liabilities
Total liabilities	2,694	4,371
Success Payment Liability
Liabilities
Total liabilities	2,694	4,371
U.S. Treasury Bills and Notes
Assets
Total assets	218,164	277,341
U.S. Agency Securities
Assets
Total assets	13,715	18,771
Level 1
Assets
Total assets	65,035	58,127
Liabilities
Total liabilities	0	0
Level 1 | Success Payment Liability
Liabilities
Total liabilities	0	0
Level 1 | U.S. Treasury Bills and Notes
Assets
Total assets	0	0
Level 1 | U.S. Agency Securities
Assets
Total assets	0	0
Level 2
Assets
Total assets	231,879	296,112
Liabilities
Total liabilities	0	0
Level 2 | Success Payment Liability
Liabilities
Total liabilities	0	0
Level 2 | U.S. Treasury Bills and Notes
Assets
Total assets	218,164	277,341
Level 2 | U.S. Agency Securities
Assets
Total assets	13,715	18,771
Level 3
Assets
Total assets	0	0
Liabilities
Total liabilities	2,694	4,371
Level 3 | Success Payment Liability
Liabilities
Total liabilities	2,694	4,371
Level 3 | U.S. Treasury Bills and Notes
Assets
Total assets	0	0
Level 3 | U.S. Agency Securities
Assets
Total assets	0	0
Money Market Funds
Assets
Total assets	65,035	58,127
Money Market Funds | Level 1
Assets
Total assets	65,035	58,127
Money Market Funds | Level 2
Assets
Total assets	0	0
Money Market Funds | Level 3
Assets
Total assets	$ 0	$ 0

Fair value of financial instr_4

Fair value of financial instruments - Summary of Assets and Liabilities Measured at Fair Value (Parenthetical) (Details) $ in Millions	Sep. 30, 2021USD ($)
Harvard and Board
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Success payment liability, current portion	$ 6.3

Fair value of financial instr_5

Fair value of financial instruments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		$ 65,000	$ 58,100
Common stock shares issued		48,655,241	48,511,735
Issuance of common stock, value		$ 49	$ 49
Other Income
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, payable	$ 400	1,700
Harvard and Board
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, payable		10,000,000
Success payment liability		300		$ 6,300
Success payment liability, current portion				$ 6,300
Harvard | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, payable		$ 31,300
Broad License Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock shares issued		276,075
Antidilution Rights Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock shares issued					878,098
Issuance of common stock, value					$ 32,500
Antidilution Rights Liability | Other Expense
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Increase in liabilities	$ 400

Fair value of financial instr_6

Fair value of financial instruments - Schedule of Fair Value Liabilities Measured on Recurring Basis (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of common stock (per share)	$ 22.82	$ 36.87
Equity Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity volatility	76.00%	77.00%

Fair value of financial instr_7

Fair value of financial instruments - Schedule of Reconciliation of Changes in Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance		$ 9,722
Changes in fair value		(778)
Ending balance		8,944
Antidilution Rights Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance		6,916
Changes in fair value		(396)
Ending balance		6,520
Success Payment Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 4,371	2,806
Changes in fair value	(1,677)	(382)
Ending balance	$ 2,694	$ 2,424

Accrued expenses - Schedule of

Accrued expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Employee compensation and related benefits	$ 2,280	$ 6,050
Accrued external research and development expenses	5,361	5,041
Professional fees	1,237	1,109
Other	2,055	792
Total	$ 10,933	$ 12,992

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	Aug. 19, 2021USD ($)ft²	Oct. 31, 2021USD ($)ft²	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	Jan. 31, 2022ft²
Lessee, Lease, Description [Line Items]
Operating lease, rent expense			$ 800	$ 400
Increase in operating lease liability			$ (523)	$ (443)
Lease Noncancelable Term		12 months
Lessee, Operating Lease, Option to Extend		The Company has the option to extend the sublease for one extension term of three months by written notice not less than six months prior to the expiration of the sublease term, which the Company is not reasonably certain of exercising
Lease Commencement Date		2021-12
Operating lease incremental borrowing rate			1.57%	4.69%
Weighted average remaining lease term			21 days	1 year 3 months 18 days
Lease space build out cost prior to commencement			$ 1,900
Operating Lease, Payments			$ 529	$ 474
New Amendment [Member]
Lessee, Lease, Description [Line Items]
Lease area | ft²					105,144
Additional Lease Area | ft²					211
Premises
Lessee, Lease, Description [Line Items]
Lease area | ft²	104,933	11,931
Lease not yet commenced , lease term	10 years
Option to extend, lease not yet commenced	five years
Operating lease payment term, lease not yet commenced, terms and conditions			The Company’s obligation for the payment of base rent for the Premises begins 90 days after the Commencement Date (the “Rent Commencement Date”) and will initially be $0.8 million per month, which will increase by approximately 3% per annum
Option to terminate, lease not yet commenced	true
Tenant improvements allowance	$ 21,000
Additional tenant improvements allowance	$ 5,200
Improvement allowance interest rate	8.00%
Prepaid rent			$ 800
Operating Lease, Payments		$ 1,400
Premises | Letter of Credit
Lessee, Lease, Description [Line Items]
Letter of credit issued	$ 4,800
Letter of credit reduced value	$ 3,500
ASC 842
Lessee, Lease, Description [Line Items]
Short-term Lease, Cost			$ 300	$ 600

Leases - Summary of Components

Leases - Summary of Components of Operating Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lease, Cost [Abstract]
Operating lease costs	$ 505	$ 449
Variable lease costs	211	189
Total	$ 716	$ 638

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information Related to Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash paid for amounts included in the measurements of lease liabilities [Abstract]
Operating cash flows related to operating leases	$ 529	$ 474

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Commitments under Non-Cancellable Operating Leases (Details) $ in Thousands	Mar. 31, 2022USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2022	$ 3,208
2023	9,688
2024	9,978
2025	10,278
2026	10,586
Thereafter	65,172
Total lease payments	108,910
Less: interest	(7)
Present value of operating lease liabilities	$ 108,903

License Agreements - Additional

License Agreements - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended		10 Months Ended	12 Months Ended
	Oct. 31, 2021	Apr. 30, 2019	Mar. 31, 2022	Mar. 31, 2021	Oct. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021	Sep. 30, 2021
Research And Development Arrangement Contract To Perform For Others [Line Items]
Research and development expenses			$ 24,490,000	$ 11,345,000
Common stock shares issued			48,655,241					48,511,735
Issuance of common stock, value			$ 49,000					$ 49,000
Broad License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common stock shares issued			276,075
Issuance of common stock			$ 300,000
Preferred stock financing partially satisfied							$ 100,000
Preferred stock financing were fully satisfied						$ 500,000
Common stock issued for partly satisfying preferred stock financing							$ 121,411
Common stock issued for fully satisfying preferred stock financing						187,867
Payment of milestone development			46,200,000
Payment of sales based milestone			108,000,000
Harvard and Board
Research And Development Arrangement Contract To Perform For Others [Line Items]
Success payment liability			300,000						$ 6,300,000
Beam License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Research and development expenses			0	0
Common stock shares issued		276,075
Issuance of common stock		$ 300,000
Payment of milestone development		11,300,000
Payment of sales based milestone		15,000,000
Reimbursement received related to reduction to research and development expense				200,000
Milestone related expenses			0
Beam License Agreement | Non-US
Research And Development Arrangement Contract To Perform For Others [Line Items]
Payment of milestone development		5,600,000
Payment of sales based milestone		$ 7,500,000
Acuitas Agreements
Research And Development Arrangement Contract To Perform For Others [Line Items]
Research and development expenses			100,000	$ 300,000
License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Non Refundable Upfront License Fee					$ 2,000,000
Clinical And Regulatory Milestone			9,800,000
Sales Based Milestone			9,500,000
Milestone related expenses	$ 10,000,000		0
License Agreement | Broad License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Non-Refundable Upfront License Fees Paid			$ 300,000
Antidilution Rights | Broad License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common stock shares issued			878,098
Issuance of common stock, value			$ 32,500,000

Preferred Stock Tranche Liabili

Preferred Stock Tranche Liability - Additional Information (Details) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, value per share	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0

Preferred and Common Stock - Ad

Preferred and Common Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2021	Jun. 21, 2021
Subsidiary Sale Of Stock [Line Items]
Preferred stock, shares issued		0			0
Preferred stock, value per share		$ 0.001			$ 0.001
Proceeds from issuance of Preferred Stock, net		$ 0	$ 93,759
Preferred stock, shares authorized		5,000,000			5,000,000
Common stock, shares authorized		200,000,000			200,000,000
Common stock shares issued		48,655,241			48,511,735
Common Stock, Par Value		$ 0.001			$ 0.001
Harvard and Board [Member]
Subsidiary Sale Of Stock [Line Items]
Common stock shares issued				878,098
IPO
Subsidiary Sale Of Stock [Line Items]
Proceeds from issuance of Preferred Stock, net		$ 281,600
Additional shares of common stock				2,105,368
Public price				$ 19
Proceeds from common stock, gross				$ 306,700
Shares issued upon conversion of preferred stock						27,720,923
Preferred Stock
Subsidiary Sale Of Stock [Line Items]
Preferred stock, shares authorized				5,000,000
Preferred Stock | Series B Preferred Stock
Subsidiary Sale Of Stock [Line Items]
Preferred stock, shares issued	77,163,022
Preferred stock, value per share	$ 1.2182
Proceeds from issuance of Preferred Stock, net	$ 94,000
Transaction costs on issuance	$ 200
Common Stock
Subsidiary Sale Of Stock [Line Items]
Common stock, shares authorized				200,000,000
Common Stock, Par Value				$ 0.001
Common Stock | IPO
Subsidiary Sale Of Stock [Line Items]
Common stock shares issued				16,141,157

Stock-based compensation - Addi

Stock-based compensation - Additional Information (Details) - USD ($) $ in Millions	Jan. 01, 2022	Mar. 31, 2022	Jun. 16, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance		7,057,629
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation cost		$ 68.7
Weighted average period over which unrecognized compensation is expected to be recognized		3 years
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation cost		$ 7
Weighted average period over which unrecognized compensation is expected to be recognized		4 years
Twent Eighteen | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance		6,885,653
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance		433,316
Stock available for issuance under ESPP		870,136
Increase in common stock capital shares, reserved for future issuance	485,117
ESPP | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of outstanding stock, reserved for issuance		1.00%
Increase in common stock capital shares, reserved for future issuance		1,083,290
2021 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance	2,425,587		3,466,530
Share-based Compensation Arrangement by Share-based Payment Award, Description		an annual increase, to be added on the first day of each fiscal year, commencing on January 1, 2022 and continuing until, and including, January 1, 2031, equal to the lesser of (i) 5% of the number of shares of common stock outstanding on such date
Shares available for future grant		4,149,943
2021 Stock Incentive Plan | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of outstanding stock, reserved for issuance	5.00%
2021 Stock Incentive Plan | Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant		195,550

Stock-based compensation - Summ

Stock-based compensation - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 4,203	$ 670
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,465	313
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,738	$ 357

Stock-based compensation - Sche

Stock-based compensation - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Number of options, Outstanding, Beginning balance | shares	6,119,295
Number of options, Granted | shares	1,633,600
Number of options, Exercised | shares	(143,506)
Number of options, Forfeited | shares	(73,017)
Number of options, Outstanding, Ending balance | shares	7,536,372
Number of options, Exercisable | shares	1,856,666
Number of options, Expected to vest | shares	5,679,706	[1]
Weighted average exercise price, Beginning balance | $ / shares	$ 9.44
Weighted average exercise price, Granted | $ / shares	31.08
Weighted average exercise price, Exercised | $ / shares	3.52
Weighted average exercise price, Forfeited | $ / shares	27.96
Weighted average exercise price, Ending balance | $ / shares	14.15
Weighted average exercise price, Exercisable | $ / shares	3.36
Weighted average exercise price, Expected to vest | $ / shares	$ 17.68	[1]
Weighted average remaining contractual life (in years), Outstanding	8 years 9 months 18 days
Weighted average remaining contractual life (in years), Exercisable	7 years 10 months 24 days
Weighted average remaining contractual life (in years), Expected to vest	9 years	[1]
Aggregate intrinsic value, Outstanding | $	$ 91,068	[2]
Aggregate intrinsic value, Exercisable | $	36,140	[2]
Aggregate intrinsic value, Expected to vest | $	$ 54,928	[1],[2]
[1]	This represents the number of unvested options outstanding as of March 31, 2022 that are expected to vest in the future.
[2]	The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money as of March 31, 2022 .

Stock-based compensation - Su_2

Stock-based compensation - Summary of the Restricted Stock Units (Details) - RSU	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested RSUs, beginning balance, Unvested | shares	32,000
Restricted stock units granted | shares	195,550
Restricted stock units forfeited | shares	(1,850)
Unvested RSUs, ending balance, unvested | shares	225,700
Weighted-Average Grant Date Fair Value Per Share, beginning balance, Unvested | $ / shares	$ 36.58
Weighted-Average Grant-Date Fair Value, Granted | $ / shares	31.12
Weighted-Average Grant-Date Fair Value, forfeited | $ / shares	30.94
Weighted-Average Grant Date Fair Value Per Share, ending balance, Unvested | $ / shares	$ 31.86

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Potential Common Shares, Based on Amounts Outstanding at Period End were Excluded From the Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	7,762,072	33,312,705
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	0	27,720,923
Unvested Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	0	403,224
Unvested restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	225,700	0
Outstanding Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	7,536,372	5,188,558

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Success payment liability	$ 2,694	$ 4,371
License Agreement [Member] | Harvard and Board [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Success payment liability		$ 6,300

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Related Party Transaction [Line Items]
Research and development expenses	$ 24,490	$ 11,345
Lease Rent Payment	500
Beam License Agreement
Related Party Transaction [Line Items]
Research and development expenses	$ 0	0
Beam | Materials Exchange Agreement | Research and Development
Related Party Transaction [Line Items]
Research and development expenses		$ 200

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Oct. 31, 2021	Mar. 31, 2022
Subsequent Event [Line Items]
Lease Commitment Amount		$ 0.5
License Agreement
Subsequent Event [Line Items]
Non-refundable upfront payment	$ 0.8
Milestone related expenses	$ 10	$ 0