Biomea Fusion (BMEA) 10-Q 7 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 31, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	Biomea Fusion, Inc.
Entity Central Index Key	0001840439
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Trading Symbol	BMEA
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		29,396,246
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-40335
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-2520134
Entity Address, Address Line One	900 Middlefield Road, 4th Floor
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94063
City Area Code	650
Local Phone Number	980-9099

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 132,311	$ 145,736
Short-term investments	1,147	27,780
Prepaid expenses and other current assets	5,403	3,045
Total current assets	138,861	176,561
Long-term investments	10	1,876
Property and equipment, net	3,049	2,965
Operating lease right-of-use assets	2,296	2,722
Restricted cash	351	351
Other assets	483	1,230
Total assets	145,050	185,705
Current liabilities:
Accounts payable	1,592	1,329
Accrued expenses and other current liabilities	10,392	2,743
Operating lease liabilities, current	605	565
Total current liabilities	12,589	4,637
Operating lease liabilities, non-current	1,826	2,285
Total liabilities	14,415	6,922
Commitments and contingencies (Note 8)
Stockholders' equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 0 shares issued and outstanding as of September 30, 2022 and December 31, 2021
Common stock, $0.0001 par value; 300,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 29,388,753 and 29,115,421 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	3	3
Additional paid-in capital	236,901	228,532
Accumulated other comprehensive income (loss)	(13)	(10)
Accumulated deficit	(106,256)	(49,742)
Total stockholders' equity	130,635	178,783
Total liabilities and stockholders' equity	$ 145,050	$ 185,705

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	29,388,753	29,115,421
Common stock, shares outstanding	29,388,753	29,115,421

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating expenses:
Research and development	$ 18,242	$ 7,886	$ 42,174	$ 16,908
General and administrative	5,242	4,752	15,184	10,022
Total operating expenses	23,484	12,638	57,358	26,930
Loss from operations	(23,484)	(12,638)	(57,358)	(26,930)
Interest and other income (expense), net	594	32	844	73
Net loss	(22,890)	(12,606)	(56,514)	(26,857)
Other comprehensive loss:
Unrealized gain (loss) on investments, net	4		(3)	2
Comprehensive loss	$ (22,886)	$ (12,606)	$ (56,517)	$ (26,855)
Net loss per common share, basic	$ (0.78)	$ (0.43)	$ (1.93)	$ (1.21)
Net loss per common share, diluted	$ (0.78)	$ (0.43)	$ (1.93)	$ (1.21)
Weighted-average number of common shares used to compute basic net loss per common share	29,319,042	29,001,213	29,214,549	22,105,321
Weighted-average number of common shares used to compute diluted net loss per common share	29,319,042	29,001,213	29,214,549	22,105,321

Condensed Statements of Convert

Condensed Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Series A Convertible Preferred Stock	Common Stock	Common Stock IPO	Additional Paid-In Capital	Additional Paid-In Capital IPO	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Balance at Dec. 31, 2020			$ 55,738
Balance (in shares) at Dec. 31, 2020			7,064,925
Balance at Dec. 31, 2020	$ 5,169			$ 1		$ 13,343			$ (8,175)
Balance (in shares) at Dec. 31, 2020				11,953,107
Series A financing costs			$ (3)
Issuance of restricted stock (in shares)				51,526
Stock-based compensation expense	919					919
Unrealized gain (loss) on investments	(15)							$ (15)
Net loss	(5,852)								(5,852)
Balance at Mar. 31, 2021	221			$ 1		14,262		(15)	(14,027)
Balance (in shares) at Mar. 31, 2021			7,064,925
Balance at Mar. 31, 2021			$ 55,735
Balance (in shares) at Mar. 31, 2021				12,004,633
Balance at Dec. 31, 2020			$ 55,738
Balance (in shares) at Dec. 31, 2020			7,064,925
Balance at Dec. 31, 2020	5,169			$ 1		13,343			(8,175)
Balance (in shares) at Dec. 31, 2020				11,953,107
Issuance of common stock		$ 152,754
Balance at Jun. 30, 2021	202,016			$ 3		224,437		2	(22,426)
Balance (in shares) at Jun. 30, 2021				28,990,180
Balance at Dec. 31, 2020			$ 55,738
Balance (in shares) at Dec. 31, 2020			7,064,925
Balance at Dec. 31, 2020	5,169			$ 1		13,343			(8,175)
Balance (in shares) at Dec. 31, 2020				11,953,107
Unrealized gain (loss) on investments	2
Net loss	(26,857)
Balance at Sep. 30, 2021	191,331			$ 3		226,358		2	(35,032)
Balance (in shares) at Sep. 30, 2021				29,041,708
Balance at Mar. 31, 2021			$ 55,735
Balance (in shares) at Mar. 31, 2021			7,064,925
Balance at Mar. 31, 2021	221			$ 1		14,262		(15)	(14,027)
Balance (in shares) at Mar. 31, 2021				12,004,633
Exercise of stock options	225					225
Exercise of stock options, (in shares)				43,850
Issuance of common stock					$ 1		$ 152,753
Issuance of common stock (in shares)					9,823,532
Issuance of restricted stock (in shares)				53,240
Stock-based compensation expense	1,463					1,463
Conversion of preferred stock to common stock (In Shares)			(7,064,925)
Conversion of preferred stock to common stock			$ (55,735)
Conversion of preferred stock to common stock (In shares)				7,064,925
Conversion of preferred stock to common stock	55,735			$ 1		55,734
Unrealized gain (loss) on investments	17							17
Net loss	(8,399)								(8,399)
Balance at Jun. 30, 2021	202,016			$ 3		224,437		2	(22,426)
Balance (in shares) at Jun. 30, 2021				28,990,180
Issuance of restricted stock (in shares)				51,528
Stock-based compensation expense	1,921					1,921
Net loss	(12,606)								(12,606)
Balance at Sep. 30, 2021	191,331			$ 3		226,358		2	(35,032)
Balance (in shares) at Sep. 30, 2021				29,041,708
Balance at Dec. 31, 2021	178,783			$ 3		228,532		(10)	(49,742)
Balance (in shares) at Dec. 31, 2021				29,115,421
Exercise of stock options	31					31
Exercise of stock options, (in shares)				6,044
Issuance of restricted stock (in shares)				47,216
Stock-based compensation expense	2,330					2,330
Unrealized gain (loss) on investments	(13)							(13)
Net loss	(16,366)								(16,366)
Balance at Mar. 31, 2022	164,765			$ 3		230,893		(23)	(66,108)
Balance (in shares) at Mar. 31, 2022				29,168,681
Balance at Dec. 31, 2021	$ 178,783			$ 3		228,532		(10)	(49,742)
Balance (in shares) at Dec. 31, 2021				29,115,421
Exercise of stock options, (in shares)	76,815
Unrealized gain (loss) on investments	$ (3)
Net loss	(56,514)
Balance at Sep. 30, 2022	130,635			$ 3		236,901		(13)	(106,256)
Balance (in shares) at Sep. 30, 2022				29,388,753
Balance at Mar. 31, 2022	164,765			$ 3		230,893		(23)	(66,108)
Balance (in shares) at Mar. 31, 2022				29,168,681
Exercise of stock options	62					62
Exercise of stock options, (in shares)				9,366
Issuance of restricted stock (in shares)				47,216
Purchases under employee stock purchase plan	256					256
Purchases under employee stock purchase plan (in shares)				54,868
Stock-based compensation expense	2,559					2,559
Unrealized gain (loss) on investments	6							6
Net loss	(17,258)								(17,258)
Balance at Jun. 30, 2022	150,390			$ 3		233,770		(17)	(83,366)
Balance (in shares) at Jun. 30, 2022				29,280,131
Exercise of stock options	400					400
Exercise of stock options, (in shares)				61,405
Issuance of restricted stock (in shares)				47,217
Stock-based compensation expense	2,731					2,731
Unrealized gain (loss) on investments	4							4
Net loss	(22,890)								(22,890)
Balance at Sep. 30, 2022	$ 130,635			$ 3		$ 236,901		$ (13)	$ (106,256)
Balance (in shares) at Sep. 30, 2022				29,388,753

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Activities
Net loss			$ (56,514)	$ (26,857)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation expense	$ 200	$ 100	510	99
Non-cash operating lease expense			426	566
Stock-based compensation expense			7,620	4,303
Net amortization of premiums and accretion of discounts on investments			136	361
Changes in operating assets and liabilities:
Prepaid expenses and other current assets			(2,358)	(1,170)
Other assets			747	(11)
Accounts payable			(13)	419
Accrued expenses and other current liabilities.			7,649	3,205
Operating lease liabilities			(419)	(454)
Net cash used in operating activities			(42,216)	(19,539)
Investing Activities
Purchase of property and equipment			(318)	(2,878)
Purchase of investments				(38,492)
Maturities of investments			28,360	3,465
Net cash provided by (used in) investing activities			28,042	(37,905)
Financing Activities
Proceeds from stock option exercise and purchases under the employee stock purchase plan			749	225
Net proceeds from issuance of common stock from initial public offering				152,753
Series A financing costs incurred				(3)
Payment of Paycheck Protection Program loan				(36)
Net cash provided by financing activities			749	152,939
Net increase (decrease) in cash, cash equivalents, and restricted cash			(13,425)	95,495
Cash, cash equivalents, and restricted cash at the beginning of the period			146,087	61,695
Cash, cash equivalents, and restricted cash at the end of the period	132,662	157,190	132,662	157,190
Non-cash financing and investing activities:
Acquisition of property and equipment in accounts payable and accrued liabilities			276	103
Acquisition of operating lease right-of-use assets				3,216
Conversion of Series A convertible preferred stock into common stock				55,735
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	132,311	156,974	132,311	156,974
Restricted cash	351	216	351	216
Cash, cash equivalents, and restricted cash at the end of the period	$ 132,662	$ 157,190	$ 132,662	$ 157,190

Organization

Organization	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Note 1. Organization Organization Biomea Fusion, Inc. (the Company), was established in the state of Delaware in August 2017 as Biomea Fusion, LLC. In December 2020, all outstanding membership interests in Biomea Fusion, LLC were converted into equity interests in the Company. The capitalization information included in these condensed financial statements is consistently presented as if it is that of Biomea Fusion, Inc., even during the prior period when investors held their equity interests in Biomea Fusion, LLC. The Company is a clinical-stage biopharmaceutical company dedicated to discovering and developing novel covalent small molecules to treat and improve the lives of patients with genetically defined cancers and metabolic disease. Since its inception in 2017, the Company has built its proprietary FUSION TM System platform to design and develop a pipeline of novel covalent product candidates. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2021 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments which are necessary for a fair statement of the Company’s financial information. The interim results of operations for the three months and nine months ended September 30, 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or for any other future year. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K filed with the SEC on February 28, 2022. Forward Stock Split In April 2021, the Company’s board of directors approved an amended and restated certificate of incorporation to effect a split of shares of the Company’s outstanding capital at a ratio of 8.84 -for-1 (the Forward Stock Split) effective as of April 12, 2021. The number of authorized shares and the par values of the common stock and convertible preferred stock were not adjusted as a result of the Forward Stock Split. All references to common stock, options to purchase common stock, convertible preferred stock, share data, per share data and related information contained in the financial statements have been retrospectively adjusted to reflect the effect of the Forward Stock Split for all periods presented. Initial Public Offering On April 16, 2021, the Company’s registration statement on Form S-1 (File No. 333-254793) relating to its initial public offering (IPO) of common stock became effective. The IPO closed on April 20, 2021 at which time the Company issued an aggregate of 9,000,000 shares of its common stock at a price of $ 17.00 per share. Within 30 days following the close, 823,532 shares were issued in connection with the partial exercise by the underwriters of their option to purchase additional shares of common stock. In addition, immediately prior to the closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into 7,064,925 shares of common stock. In connection with the completion of its IPO, the Company’s certificate of incorporation was amended and restated to provide for 300,000,000 authorized shares of common stock with a par value of $ 0.0001 per share and 10,000,000 authorized shares of preferred stock with a par value of $ 0.0001 per share. Proceeds from the IPO, net of underwriting discounts and commissions and offering costs were $ 152.8 million. Liquidity and Capital Resources The Company has incurred net operating losses and negative cash flows from operations since its inception and had an accumulated deficit of $ 106.3 million at September 30, 2022. As of September 30, 2022, the Company had cash, cash equivalents, restricted cash, and investments of $ 133.8 million . Management believes that the existing financial resources are sufficient to continue operating activities for at least one year past the issuance date of these condensed financial statements. The Company has historically financed its operations primarily through the sale of convertible preferred stock and common stock and the issuance of unsecured promissory notes. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any revenue since inception. Management expects operating losses to continue and increase for the foreseeable future, as the Company progresses into clinical development activities for its lead product candidate and advances the preclinical and clinical development of other product candidates. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed below. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to generate sufficient cash flows from operations, raise additional capital or reduce certain discretionary spending would have a material adverse effect on the Company’s ability to achieve its intended business objectives.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including, but not limited to, those related to fair value of assets and liabilities, manufacturing accruals, accrued research and development expenses, fair value of common stock, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities and income taxes. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates . Segments The Company operates and manages its business as one reportable and operating segment, which is the business of developing covalent small molecule drugs to treat patients with genetically defined cancers and metabolic diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States. Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to a concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company invests in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset backed securities. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded in the balance sheet. The Company's investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate debt and commercial paper, and places restrictions on the credit ratings, maturities and concentration by type and issuer. The Company has not experienced any losses on its deposits of cash, cash equivalents and investments. The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of preclinical studies, clinical trials and achievement of milestones, uncertainty of regulatory approval of the Company’s existing and potential product candidates, uncertainty of market acceptance of the Company’s product candidates (if approved), competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships, dependence on key individuals or sole source suppliers and changes in the Company's operating expenses as a result of these uncertainties and other factors, such as inflation. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company is denied approval, approval is delayed or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company. Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist of amounts invested in money market accounts and are stated at fair value. Restricted cash consists of two stand-by letters of credit issued to the Company’s landlord in connection with two of the Company’s leases. Investments The Company’s investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt securities, commercial paper and asset backed securities. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive loss. The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income (expense), net. Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, are also included in other income (expense), net. The Company evaluates securities for other-than-temporary impairment at the balance sheet date. Declines in fair value determined to be other-than-temporary are also included in other income (expense), net. The Company classifies its investments as short or long-term primarily based on the remaining contractual maturity of the securities. Property and Equipment, Net Property and equipment are recorded at cost net of accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. The useful lives of property and equipment are as follows: Computer equipment 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of remaining lease term or estimated useful life Upon retirement or sale of the assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recorded to the statements of operations. Repairs and maintenance are expensed as incurred. Leases The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of September 30, 2022, the Company's lease population consisted of real estate leases and the Company did not have finance leases. Operating leases are included in operating lease right-of-use (ROU) assets, short-term operating lease liabilities and long-term operating lease liabilities on the Company’s condensed balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company. The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and nonlease components are accounted for as a single lease component. The Company has elected to apply the short-term lease exception for all lease agreements with a noncancelable term of less than 12 months. Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There was no impairment of long-lived assets during the three and nine months ended September 30, 2022 and 2021 . Convertible Preferred Stock The Company records shares of convertible preferred stock at fair value on the dates of issuances, net of issuance costs. The Company classifies convertible preferred stock outside of stockholders’ equity because the shares contain liquidation features that are not solely within the Company’s control. The Company analyzed all embedded derivatives and beneficial conversion features for its convertible preferred stock and concluded that none requires bifurcation. The Company has elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because it is uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of convertible preferred stock. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur. Research and Development Expenses The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel-related expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs), for animal studies and other costs related to preclinical and clinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; and (vi) depreciation of equipment and facilities expenses. Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing development, which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with the CROs and CMOs generally include fees such as initiation fees, reservation fees, costs related to animal studies and safety tests, verification run costs, materials and reagents expenses, investigator fees, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion and actual timeline (start- date and end-date) of the services and the agreed-upon fees to be paid for such services. Through September 30, 2022 , there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses. Stock-Based Compensation The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period, and estimates the fair value of share-based awards to employees, non-employees and directors using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. The fair value of restricted stock awards is based on the Company's stock price on the date of grant. The fair value of each purchase under the employee stock purchase plan is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method. Income Taxes The Company began providing for income taxes under the asset and liability method in December 2020 upon conversion from a limited liability company into a corporation. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the financial statement reporting and tax basis of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all the tax benefits will not be realized. The Company accounts for uncertain tax positions in accordance with ASC No. 740 Income Taxes . The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available. The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented. Recent Accounting Pronouncements The Company is an emerging growth company (EGC), as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act), and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards; and as a result of this election, its financial statements may not be comparable to companies that comply with public company effective dates. The JOBS Act also exempts the Company from having to provide an auditor attestation of internal controls over financial reporting under Sarbanes-Oxley Act Section 404(b). The Company will remain an EGC until the earliest of (i) the last day of the fiscal year in which it has total annual gross revenues of $ 1.235 billion or more, (ii) the last day of the fiscal year following the fifth anniversary of the completion of its IPO, (iii) the date on which it has issued more than $ 1.0 billion in nonconvertible debt during the previous three years or (iv) the date on which it is deemed to be a large accelerated filer under the rules of the Securities and Exchange Commission (SEC), which generally is when it has more than $ 700 million in market value of its stock held by non-affiliates, has been a public company for at least 12 months and has filed one annual report on Form 10-K. From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB), or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. Recent Accounting Pronouncements - Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes (ASU 2019-12), which is intended to simplify accounting for income taxes. It removes certain exceptions to the general principles in Topic 740 and amends existing guidance to improve consistent application. The Company adopted ASU 2019-12 as of January 1, 2022 on a prospective basis and there was no impact on the Company’s financial statements and disclosures as a result of this adoption. Recent Accounting Pronouncements - Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. This ASU also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. This ASU is effective for fiscal years beginning after December 15, 2022 and interim periods within those fiscal years. The Company plans to adopt this ASU on January 1, 2023. The Company is currently assessing the impact of this standard on its financial statements and related disclosures.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 3. Fair Value Measurement The Company applies fair value accounting for all financial assets and liabilities. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company classifies money market funds as Level 1 within the fair value hierarchy as the fair value is based on quoted price in active markets. The Company classifies its investments in corporate debt securities, commercial paper and asset backed securities as Level 2 within the fair value hierarchy as the fair value is based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. In addition, the Company assesses the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy. As of September 30, 2022 and December 31, 2021, there were no financial instruments classified as Level 3. The Company evaluates transfers between levels at the end of each reporting period and there were no transfers of financial instruments between the fair value measurement levels during the nine months ended September 30, 2022. As of September 30, 2022, investments measured on a recurring basis and recognized at fair value are as follows (in thousands): September 30, 2022 Fair Value Amortized Unrealized Unrealized Fair Financial assets included in cash and cash Money market funds Level 1 $ 119,713 $ — $ — $ 119,713 Financial assets included in short-term investments: Corporate debt securities Level 2 1,160 — ( 13 ) 1,147 Financial assets included in long-term investments: Asset backed securities Level 2 10 — — 10 Total $ 120,883 $ — $ ( 13 ) $ 120,870 As of December 31, 2021, investments measured on a recurring basis and recognized at fair value are as follows (in thousands): December 31, 2021 Fair Value Amortized Unrealized Unrealized Fair Financial assets included within cash and Money market funds Level 1 $ 112,193 $ — $ — $ 112,193 Financial assets included within short-term Corporate debt securities Level 2 19,258 1 ( 6 ) 19,253 Commercial paper Level 2 4,499 — — 4,499 Asset backed securities Level 2 4,029 — ( 1 ) 4,028 Financial assets included within long-term Corporate debt securities Level 2 1,185 — ( 4 ) 1,181 Asset backed securities Level 2 695 — — 695 Total $ 141,859 $ 1 $ ( 11 ) $ 141,849

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Note 4. Balance Sheet Components Property and Equipment, Net Property and equipment, net consists of the following (in thousands): September 30, December 31, 2022 2021 Laboratory equipment $ 2,069 $ 1,874 Furniture and fixtures 325 315 Computer equipment 130 124 Leasehold improvements 801 828 Construction in progress 457 81 Total property and equipment, gross 3,782 3,222 Less: accumulated depreciation ( 733 ) ( 257 ) Total property and equipment, net $ 3,049 $ 2,965 Depreciation expense for the three and nine months ended September 30, 2022 was $ 0.2 million and $ 0.5 million , respectively. Depreciation expense for the three and nine months ended September 30, 2021 was $ 0.1 million and $ 0.1 million , respectively. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Accrued research and development expenses $ 6,303 $ 1,674 Accrued personnel expenses 3,312 419 Accrued professional services 349 170 Other 428 480 Total accrued expenses and other current liabilities $ 10,392 $ 2,743

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Leases	Note 5. Leases Operating Leases The Company leases its headquarters with its main offices and laboratory facilities in Redwood City and San Carlos, California. In September 2022, the Company entered into a thirty-month sub-lease agreement for office space located at 900 Middlefield Road, Suite 400, Redwood City, California, which is expected to commence in January 2023 and expires in July 2025 . Total future rent payments under the agreement amount to approximately $ 6.8 million. The Company has no t recognized a right-of-use asset or aggregate lease liability as of September 30, 2022 for this lease as the Company did not control the underlying assets at any time as of September 30, 2022. In November 2021, the Company entered into a four-year lease for additional lab space located located at 1585 Industrial Road, San Carlos, California, which is expected to commence in the fourth quarter of 2022. Total future rent payments under the agreement amount to approximately $ 2.2 million. The Company has no t recognized a right-of-use asset or aggregate lease liability as of September 30, 2022 for this lease as the Company did not control the underlying assets at any time as of September 30, 2022. In September 2021, the Company entered into a sub-lease agreement for office space located at 900 Middlefield Road, Suite 400, Redwood City, California, which commenced in January 2022 and expires in December 2022 . In connection with the sub-lease, the Company made a security deposit of $ 1.1 million which is included in prepaid expenses and other current assets on the balance sheet at September 30, 2022. The Company has elected to apply the short-term lease exception in accordance with ASC 842. In March 2021, the Company entered into a five-year lease for new lab space located at 1599 Industrial Road, San Carlos, California, which commenced on May 1, 2021 and expires in April 2026 . The lease was accounted for as an operating lease under ASC 842. Upon initiation, the Company recognized a right-of-use asset and liability of $ 3.2 million, discounted at 5.4 %, the Company’s estimated incremental borrowing rate over the five-year expected remaining term. In February 2021, the Company entered into an eight-month sub-lease agreement for additional office space located at 650 Main Street, Redwood City, California. In September 2021, the Company renewed the lease agreement on a month-to-month basis and the lease ended in January 2022 . The Company has elected to apply the short-term lease exception in accordance with ASC 842. Cash paid for amounts included in the measurement of lease liabilities for the nine months ended September 30, 2022 and 2021 was $ 0.5 million and $ 0.2 million , respectively. Operating lease expense for the three and nine months ended September 30, 2022 was $ 1.0 million and $ 3.1 million , respectively. Operating lease expense for the three and nine months ended September 30, 2021 was $ 0.4 million and $ 0.8 million , respectively. As of September 30, 2022, the weighted-average remaining lease term is 3.6 years and the weighted-average discount rate is 5.4 % . The undiscounted future non-cancellable lease payments under the Company's lease agreements as of September 30, 2022 were as follows (in thousands): Operating Lease Year Ending December 31, Commitments 2022 (remaining three months) $ 178 2023 727 2024 748 2025 771 2026 259 Total undiscounted lease payments 2,683 Less: Present value adjustments ( 252 ) Total operating lease liabilities $ 2,431 Operating lease liabilities, current 605 Operating lease liabilities, non-current 1,826 Total operating lease liabilities $ 2,431

Capital Structure

Capital Structure	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Capital Structure	Note 6. Capital Structure Common Stock In December 2020, all of the outstanding membership interests in Biomea Fusion LLC were exchanged for equity interests in Biomea Fusion, Inc. in a statutory conversion under Delaware law. All of the share information referenced throughout the financial statements and notes to the financial statements have been retroactively adjusted to reflect the change in capital structure. The Company’s amended and restated certificate of incorporation authorizes the Company to issue up to 300,000,000 shares of common stock with a par value of $ 0.0001 per share and 10,000,000 shares of preferred stock with a par value of $ 0.0001 per share. Common stockholders are entitled to dividends when and if declared by the Company’s Board of Directors and after any preferred share dividends are fully paid. The holder of each share of common stock is entitled to one vote per share of common stock. As of September 30, 2022 , no dividends have been declared. The Company had reserved common stock, on an as-converted basis, for future issuance as follows: September 30, December 31, 2022 2021 Stock options, issued and outstanding 5,189,839 4,254,504 Stock options, authorized for future issuance 1,603,260 1,134,944 Employee stock purchase plan, available for future issuance 526,218 284,993 Restricted stock, issued and outstanding 352,265 493,914 Total 7,671,582 6,168,355

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 7. Stock-Based Compensation 2020 Equity Incentive Plan The Company adopted the 2020 Equity Incentive Plan (the 2020 Plan) on December 18, 2020. The 2020 Plan reserved 4,327,799 shares of common stock to grant stock-based compensation awards, including stock options and restricted stock awards, to employees and non-employees. As of April 9, 2021, the Company ceased granting awards under the 2020 Plan. However, 2020 Plan awards will remain subject to the terms of the 2020 Plan. 2021 Equity Incentive Plan In April 2021, the Company adopted the 2021 Equity Incentive Plan (the 2021 Plan). Options granted under the 2021 Plan expire no later than 10 years from the date of grant. The exercise price of options granted under the 2021 Plan must at least be equal to the fair market value of the Company’s common stock on the date of grant. With respect to any participant who owns more than 10 % of the voting power of all classes of the Company’s outstanding stock, the term of an incentive stock option granted to such participant must not exceed five years and the exercise price must equal at least 110 % of the fair market value on the grant date. Employee stock options generally vest 1/16 th quarterly over four years subject to continued service to the Company. Subject to adjustment in the case of certain capitalization events as provided in the 2021 Plan, the Company initially reserved 3,370,000 shares of the Company’s common stock for issuance pursuant to awards under the 2021 Plan. The 2021 Plan is administered by the Compensation Committee of the Company’s Board of Directors. The number of shares of the Company’s common stock available for issuance under the 2021 Plan will also include an annual increase on the first day of each fiscal year beginning in 2022 and ending in 2031, equal to the lesser of (i) 5 % of the Company’s common stock outstanding at December 31 of the immediately preceding year, or (ii) such number of shares as determined by the Company’s Board of Directors. Effective January 1, 2022, the number of shares of common stock available under the 2021 Plan increased by 1,480,466 shares pursuant to the evergreen provision of the 2021 Plan. As of September 30, 2022, 1,603,260 shares of common stock remained available for issuance under the 2021 Plan. 2021 Employee Stock Purchase Plan The Company adopted a 2021 Employee Stock Purchase Plan (ESPP) in April 2021. The ESPP enables eligible employees of the Company and designated affiliates to purchase shares of common stock at a discount of 15 %. Subject to adjustment in the case of certain capitalization events, a total of 306,000 common shares of the Company were available for purchase at adoption of the ESPP. Pursuant to the ESPP, the annual share increase pursuant to the evergreen provision is determined based on the lesser of (i) 1 % of the Company’s common stock outstanding at December 31 of the immediately preceding year, or (ii) such number of shares as determined by the Company’s Board of Directors. Effective January 1, 2022, the number of shares of common stock available under the ESPP increased by 296,093 shares pursuant to the evergreen provision of the ESPP. During the nine months ended September 30, 2022 , the Company issued 54,868 shares of common stock under the ESPP. As of September 30, 2022, 526,218 shares of common stock remained available for issuance under the ESPP. Stock-Based Compensation Expense Total stock-based compensation expense related to the 2020 Plan, 2021 Plan, and ESPP was recorded in the condensed statements of operations and allocated as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Research and development $ 1,186 $ 766 $ 3,451 $ 1,690 General and administrative 1,545 1,155 4,169 2,613 Total stock-based compensation expense $ 2,731 $ 1,921 $ 7,620 $ 4,303 As of September 30, 2022, there was $ 24.9 million of total unrecognized stock-based compensation expense which is expected to be recognized over a weighted-average period of 2.8 years. The Company estimates the fair value of stock options using the Black-Scholes option pricing model and the fair value of these stock options was estimated using the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Expected term in years 6.0 6.0 6.0 6.0 Expected volatility 96 % 91 % 94 % 91 % Risk-free interest rate 3.6 % 0.9 % 3.0 % 0.9 % Dividend yield — — — — Weighted average fair value of share-based awards granted $ 8.81 $ 10.33 $ 4.91 $ 7.26 Stock Options The following table summarizes stock option activity : Outstanding Options Shares Weighted- Weighted- Balance, December 31, 2021 4,254,504 $ 9.89 9.4 Granted 1,379,384 $ 6.39 Exercised ( 76,815 ) $ 6.42 Cancelled ( 367,234 ) $ 13.19 Balance, September 30, 2022 5,189,839 $ 8.78 8.9 Exercisable, September 30, 2022 1,444,905 $ 9.01 8.4 Restricted Stock The Company granted 824,429 restricted stock awards to employees and non-employees during the fourth quarter of 2020 that vest quarterly over four years . Restricted stock awards are share awards that entitle the holder to receive freely tradeable shares of the Company’s common stock. The underlying shares are outstanding as of the issuance date. Any unvested shares are subject to forfeiture in the case that the grantee’s service terminates prior to vesting of the restricted stock. The following table summarizes the restricted stock activity: Number of Weighted-Average Balance, December 31, 2021 493,914 $ 4.02 Granted — — Released ( 141,649 ) 4.02 Forfeited — — Balance, September 30, 2022 352,265 $ 4.02

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 8. Commitments and Contingencies Legal Proceedings The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company records a liability for such matters when it is probable that future losses will be incurred and that such losses can be reasonably estimated. Significant judgment by the Company is required to determine both probability and the estimated amount. Management is currently not aware of any legal matters that could have a material adverse effect on its financial position, results of operations or cash flows. Indemnification The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these arrangements, the Company indemnifies, holds harmless and agrees to reimburse the indemnified parties for losses suffered or incurred by the indemnified party, in connection with any trade secret, copyright, patent or other intellectual property infringement claim by any third party with respect to its technology. The term of these indemnification agreements is generally perpetual any time after the execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these arrangements is not determinable. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, the Company believes the fair value of these agreements is not material. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	Note 9. Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share (in thousands except share and per share data): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 22,890 ) $ ( 12,606 ) $ ( 56,514 ) $ ( 26,857 ) Denominator: Weighted-average common shares outstanding, basic and diluted 29,319,042 29,001,213 29,214,549 22,105,321 Net loss per share, basic and diluted $ ( 0.78 ) $ ( 0.43 ) $ ( 1.93 ) $ ( 1.21 ) Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2022 2021 Stock options, issued and outstanding 5,189,839 2,966,518 Estimated shares issuable under the employee stock purchase plan 97,459 13,461 Restricted stock, issued and outstanding 352,265 593,542 Total 5,639,563 3,573,521

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	Note 10. Subsequent Events None.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including, but not limited to, those related to fair value of assets and liabilities, manufacturing accruals, accrued research and development expenses, fair value of common stock, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities and income taxes. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates .
Segments	Segments The Company operates and manages its business as one reportable and operating segment, which is the business of developing covalent small molecule drugs to treat patients with genetically defined cancers and metabolic diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist of amounts invested in money market accounts and are stated at fair value. Restricted cash consists of two stand-by letters of credit issued to the Company’s landlord in connection with two of the Company’s leases.
Investments	Investments The Company’s investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt securities, commercial paper and asset backed securities. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive loss. The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income (expense), net. Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, are also included in other income (expense), net. The Company evaluates securities for other-than-temporary impairment at the balance sheet date. Declines in fair value determined to be other-than-temporary are also included in other income (expense), net. The Company classifies its investments as short or long-term primarily based on the remaining contractual maturity of the securities.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to a concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company invests in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset backed securities. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded in the balance sheet. The Company's investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate debt and commercial paper, and places restrictions on the credit ratings, maturities and concentration by type and issuer. The Company has not experienced any losses on its deposits of cash, cash equivalents and investments. The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of preclinical studies, clinical trials and achievement of milestones, uncertainty of regulatory approval of the Company’s existing and potential product candidates, uncertainty of market acceptance of the Company’s product candidates (if approved), competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships, dependence on key individuals or sole source suppliers and changes in the Company's operating expenses as a result of these uncertainties and other factors, such as inflation. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company is denied approval, approval is delayed or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost net of accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. The useful lives of property and equipment are as follows: Computer equipment 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of remaining lease term or estimated useful life Upon retirement or sale of the assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recorded to the statements of operations. Repairs and maintenance are expensed as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There was no impairment of long-lived assets during the three and nine months ended September 30, 2022 and 2021 .
Convertible Preferred Stock	Convertible Preferred Stock The Company records shares of convertible preferred stock at fair value on the dates of issuances, net of issuance costs. The Company classifies convertible preferred stock outside of stockholders’ equity because the shares contain liquidation features that are not solely within the Company’s control. The Company analyzed all embedded derivatives and beneficial conversion features for its convertible preferred stock and concluded that none requires bifurcation. The Company has elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because it is uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of convertible preferred stock. Subsequent adjustments to the carrying values to the liquidation preferences will be made only when it becomes probable that such a liquidation event will occur.
Research and Development Expenses	Research and Development Expenses The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel-related expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs), for animal studies and other costs related to preclinical and clinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; and (vi) depreciation of equipment and facilities expenses.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing development, which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with the CROs and CMOs generally include fees such as initiation fees, reservation fees, costs related to animal studies and safety tests, verification run costs, materials and reagents expenses, investigator fees, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion and actual timeline (start- date and end-date) of the services and the agreed-upon fees to be paid for such services. Through September 30, 2022 , there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.
Stock-based compensation	Stock-Based Compensation The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period, and estimates the fair value of share-based awards to employees, non-employees and directors using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. The fair value of restricted stock awards is based on the Company's stock price on the date of grant. The fair value of each purchase under the employee stock purchase plan is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.
Leases	Leases The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of September 30, 2022, the Company's lease population consisted of real estate leases and the Company did not have finance leases. Operating leases are included in operating lease right-of-use (ROU) assets, short-term operating lease liabilities and long-term operating lease liabilities on the Company’s condensed balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company. The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and nonlease components are accounted for as a single lease component. The Company has elected to apply the short-term lease exception for all lease agreements with a noncancelable term of less than 12 months.
Income Taxes	Income Taxes The Company began providing for income taxes under the asset and liability method in December 2020 upon conversion from a limited liability company into a corporation. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the financial statement reporting and tax basis of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all the tax benefits will not be realized. The Company accounts for uncertain tax positions in accordance with ASC No. 740 Income Taxes . The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available. The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.
Recent Accounting Pronouncements	Recent Accounting Pronouncements The Company is an emerging growth company (EGC), as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act), and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards; and as a result of this election, its financial statements may not be comparable to companies that comply with public company effective dates. The JOBS Act also exempts the Company from having to provide an auditor attestation of internal controls over financial reporting under Sarbanes-Oxley Act Section 404(b). The Company will remain an EGC until the earliest of (i) the last day of the fiscal year in which it has total annual gross revenues of $ 1.235 billion or more, (ii) the last day of the fiscal year following the fifth anniversary of the completion of its IPO, (iii) the date on which it has issued more than $ 1.0 billion in nonconvertible debt during the previous three years or (iv) the date on which it is deemed to be a large accelerated filer under the rules of the Securities and Exchange Commission (SEC), which generally is when it has more than $ 700 million in market value of its stock held by non-affiliates, has been a public company for at least 12 months and has filed one annual report on Form 10-K. From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB), or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. Recent Accounting Pronouncements - Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)—Simplifying the Accounting for Income Taxes (ASU 2019-12), which is intended to simplify accounting for income taxes. It removes certain exceptions to the general principles in Topic 740 and amends existing guidance to improve consistent application. The Company adopted ASU 2019-12 as of January 1, 2022 on a prospective basis and there was no impact on the Company’s financial statements and disclosures as a result of this adoption. Recent Accounting Pronouncements - Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. This ASU also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. This ASU is effective for fiscal years beginning after December 15, 2022 and interim periods within those fiscal years. The Company plans to adopt this ASU on January 1, 2023. The Company is currently assessing the impact of this standard on its financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Summary of Useful Lives of Property and Equipment	The useful lives of property and equipment are as follows: Computer equipment 3 years Furniture and fixtures 5 years Laboratory equipment 5 years Leasehold improvements Shorter of remaining lease term or estimated useful life

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Summary of Investments Measured on Recurring Basis and Recognized at Fair Value	As of September 30, 2022, investments measured on a recurring basis and recognized at fair value are as follows (in thousands): September 30, 2022 Fair Value Amortized Unrealized Unrealized Fair Financial assets included in cash and cash Money market funds Level 1 $ 119,713 $ — $ — $ 119,713 Financial assets included in short-term investments: Corporate debt securities Level 2 1,160 — ( 13 ) 1,147 Financial assets included in long-term investments: Asset backed securities Level 2 10 — — 10 Total $ 120,883 $ — $ ( 13 ) $ 120,870 As of December 31, 2021, investments measured on a recurring basis and recognized at fair value are as follows (in thousands): December 31, 2021 Fair Value Amortized Unrealized Unrealized Fair Financial assets included within cash and Money market funds Level 1 $ 112,193 $ — $ — $ 112,193 Financial assets included within short-term Corporate debt securities Level 2 19,258 1 ( 6 ) 19,253 Commercial paper Level 2 4,499 — — 4,499 Asset backed securities Level 2 4,029 — ( 1 ) 4,028 Financial assets included within long-term Corporate debt securities Level 2 1,185 — ( 4 ) 1,181 Asset backed securities Level 2 695 — — 695 Total $ 141,859 $ 1 $ ( 11 ) $ 141,849

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): September 30, December 31, 2022 2021 Laboratory equipment $ 2,069 $ 1,874 Furniture and fixtures 325 315 Computer equipment 130 124 Leasehold improvements 801 828 Construction in progress 457 81 Total property and equipment, gross 3,782 3,222 Less: accumulated depreciation ( 733 ) ( 257 ) Total property and equipment, net $ 3,049 $ 2,965
Summary of Accrued Expense and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Accrued research and development expenses $ 6,303 $ 1,674 Accrued personnel expenses 3,312 419 Accrued professional services 349 170 Other 428 480 Total accrued expenses and other current liabilities $ 10,392 $ 2,743

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Schedule of Undiscounted Future Non-cancellable Lease Payments Under Operating Leases	The undiscounted future non-cancellable lease payments under the Company's lease agreements as of September 30, 2022 were as follows (in thousands): Operating Lease Year Ending December 31, Commitments 2022 (remaining three months) $ 178 2023 727 2024 748 2025 771 2026 259 Total undiscounted lease payments 2,683 Less: Present value adjustments ( 252 ) Total operating lease liabilities $ 2,431 Operating lease liabilities, current 605 Operating lease liabilities, non-current 1,826 Total operating lease liabilities $ 2,431

Capital Structure (Tables)

Capital Structure (Tables)	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Schedule of Reserved Common Stock Converted Basis for Future Issuance	The Company had reserved common stock, on an as-converted basis, for future issuance as follows: September 30, December 31, 2022 2021 Stock options, issued and outstanding 5,189,839 4,254,504 Stock options, authorized for future issuance 1,603,260 1,134,944 Employee stock purchase plan, available for future issuance 526,218 284,993 Restricted stock, issued and outstanding 352,265 493,914 Total 7,671,582 6,168,355

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense Recorded in Statements of Operations and Allocated	Total stock-based compensation expense related to the 2020 Plan, 2021 Plan, and ESPP was recorded in the condensed statements of operations and allocated as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Research and development $ 1,186 $ 766 $ 3,451 $ 1,690 General and administrative 1,545 1,155 4,169 2,613 Total stock-based compensation expense $ 2,731 $ 1,921 $ 7,620 $ 4,303
Summary of Stock Option Activity	The following table summarizes stock option activity : Outstanding Options Shares Weighted- Weighted- Balance, December 31, 2021 4,254,504 $ 9.89 9.4 Granted 1,379,384 $ 6.39 Exercised ( 76,815 ) $ 6.42 Cancelled ( 367,234 ) $ 13.19 Balance, September 30, 2022 5,189,839 $ 8.78 8.9 Exercisable, September 30, 2022 1,444,905 $ 9.01 8.4
Summary of Fair Value of Stock Options Estimated using Weighted-Average Assumptions	The Company estimates the fair value of stock options using the Black-Scholes option pricing model and the fair value of these stock options was estimated using the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Expected term in years 6.0 6.0 6.0 6.0 Expected volatility 96 % 91 % 94 % 91 % Risk-free interest rate 3.6 % 0.9 % 3.0 % 0.9 % Dividend yield — — — — Weighted average fair value of share-based awards granted $ 8.81 $ 10.33 $ 4.91 $ 7.26
Summary of Restricted Stock Activity	The following table summarizes the restricted stock activity: Number of Weighted-Average Balance, December 31, 2021 493,914 $ 4.02 Granted — — Released ( 141,649 ) 4.02 Forfeited — — Balance, September 30, 2022 352,265 $ 4.02

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the basic and diluted net loss per share (in thousands except share and per share data): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 22,890 ) $ ( 12,606 ) $ ( 56,514 ) $ ( 26,857 ) Denominator: Weighted-average common shares outstanding, basic and diluted 29,319,042 29,001,213 29,214,549 22,105,321 Net loss per share, basic and diluted $ ( 0.78 ) $ ( 0.43 ) $ ( 1.93 ) $ ( 1.21 )
Summary of Potential Dilutive Securities Excluded from Calculation of Diluted Per Share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2022 2021 Stock options, issued and outstanding 5,189,839 2,966,518 Estimated shares issuable under the employee stock purchase plan 97,459 13,461 Restricted stock, issued and outstanding 352,265 593,542 Total 5,639,563 3,573,521

Organization - Additional Infor

Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended	9 Months Ended
	Apr. 20, 2021 USD ($) $ / shares shares	Apr. 12, 2021	May 20, 2021 shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 $ / shares shares
Class Of Stock [Line Items]
Forward stock split ratio		8.84
Proceeds from IPO net of underwriting discounts and commissions and offering costs | $				$ 152,753
Common stock, shares authorized					300,000,000	300,000,000	300,000,000
Common stock, par value | $ / shares					$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares authorized					10,000,000	10,000,000	10,000,000
Preferred stock, par value | $ / shares					$ 0.0001	$ 0.0001	$ 0.0001
Accumulated deficit | $					$ (106,256)	$ (49,742)
Cash, cash equivalents, restricted cash, and investments | $					$ 133,800
IPO
Class Of Stock [Line Items]
Issuance of common stock (in shares)	9,000,000
Initial public offering, price per share | $ / shares	$ 17
Shares issued in connection with underwriters exercise of option to purchase additional shares			823,532
Preferred stock converted to common stock	7,064,925
Proceeds from IPO net of underwriting discounts and commissions and offering costs | $	$ 152,800
Common stock, shares authorized	300,000,000
Common stock, par value | $ / shares	$ 0.0001
Preferred stock, shares authorized	10,000,000
Preferred stock, par value | $ / shares	$ 0.0001

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) LetterOfCredit Segment	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment			1
Number of letters of credit issued to landlord constituting restricted cash | LetterOfCredit			2
Number of operating segments | Segment			1
Restricted cash	$ 351,000	$ 216,000	$ 351,000	$ 216,000	$ 351,000
Impairment of long-lived assets	0	$ 0	0	$ 0
Operating lease right-of-use assets	2,296,000		2,296,000		2,722,000
Lease liabilities	$ 605,000		605,000		$ 565,000
Total annual gross revenues			1,235,000,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Issued nonconvertible debt			1,000,000,000
Market value of its stock held by non-affiliates			$ 700,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details)	9 Months Ended
	Sep. 30, 2022
Computer Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	3 years
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years
Laboratory Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	Shorter of remaining lease term or estimated useful life

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments classified as Level 3	$ 120,870,000	$ 141,849,000
Fair value assets transferred from level 1 to level 2	0
Fair value assets transferred from level 2 to level 1	0
Fair value liabilities transferred from level 1 to level 2	0
Fair value liabilities transferred from level 2 to level 1	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments classified as Level 3	$ 0	$ 0

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Investments Measured on Recurring Basis and Recognized at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 120,883	$ 141,859
Unrealized Gains		1
Unrealized Losses	(13)	(11)
Fair Value	120,870	141,849
Asset Backed Securities | Level 2 | Financial Assets Included Within Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		4,029
Unrealized Losses		(1)
Fair Value		4,028
Asset Backed Securities | Level 2 | Financial Assets Included Within Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	10	695
Fair Value	10	695
Money Market Funds | Level 1 | Financial Assets Included Within Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	119,713	112,193
Fair Value	119,713	112,193
Corporate Debt Securities | Level 2 | Financial Assets Included Within Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,160	19,258
Unrealized Gains		1
Unrealized Losses	(13)	(6)
Fair Value	$ 1,147	19,253
Corporate Debt Securities | Level 2 | Financial Assets Included Within Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		1,185
Unrealized Losses		(4)
Fair Value		1,181
Commercial Paper | Level 2 | Financial Assets Included Within Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		4,499
Fair Value		$ 4,499

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 3,782	$ 3,222
Less: accumulated depreciation	(733)	(257)
Total property and equipment, net	3,049	2,965
Laboratory Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	2,069	1,874
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	325	315
Computer Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	130	124
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	801	828
Construction in Progress
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 457	$ 81

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 200	$ 100	$ 510	$ 99

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Accrued Expense and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued Liabilities, Current [Abstract]
Accrued research and development expenses	$ 6,303	$ 1,674
Accrued personnel expenses	3,312	419
Accrued professional services	349	170
Other	428	480
Total accrued expenses and other current liabilities	$ 10,392	$ 2,743

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)	1 Months Ended					3 Months Ended		9 Months Ended
	Sep. 30, 2022	Nov. 30, 2021	Sep. 30, 2021	Mar. 31, 2021	Feb. 28, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	May 01, 2021
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	$ 2,296,000					$ 2,296,000		$ 2,296,000		$ 2,722,000
Operating lease, liability	$ 2,431,000					$ 2,431,000		$ 2,431,000
Operating lease, weighted average discount rate	5.40%					5.40%		5.40%
Operating lease, weighted average remaining lease term	3 years 7 months 6 days					3 years 7 months 6 days		3 years 7 months 6 days
CALIFORNIA
Lessee Lease Description [Line Items]
Operating sublease, term of contract	30 months
Operating lease, lease not yet commenced, term of contract		4 years
Operating lease, lease not yet commenced, monthly lease payments	$ 6,800,000	$ 2,200,000
Operating lease right-of-use assets	0					$ 0		$ 0
Operating lease, liability	$ 0					$ 0		$ 0			$ 3,200,000
Operating sublease, lease not yet commenced, expiration period	2025-07		2022-12
Amount paid as security deposit in connection with sublease included in prepaid expenses and other current assets			$ 1,100,000
Operating lease, lease commenced, term of contract				5 years
Operating lease, lease commenced, expiration period				2026-04
Operating lease, weighted average discount rate	5.40%					5.40%		5.40%
Operating lease, weighted average remaining lease term	5 years					5 years		5 years
Lease expiration date			Jan. 31, 2022
Operating lease expense						$ 1,000,000	$ 400,000	$ 3,100,000	$ 800,000
Cash paid for lease liabilities								$ 500,000	$ 200,000
CALIFORNIA | Level Home, Inc.
Lessee Lease Description [Line Items]
Operating sublease, term of contract					8 months

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, to be Paid [Abstract]
2022 (remaining three months)	$ 178
2023	727
2024	748
2025	771
2026	259
Total undiscounted lease payments	2,683
Less: Present value adjustments	(252)
Total operating lease liabilities	2,431
Operating lease liabilities, current	605	$ 565
Operating lease liabilities, non-current	$ 1,826	$ 2,285

Capital Structure - Additional

Capital Structure - Additional Information (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000	300,000,000
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Dividends declared	$ 0

Capital Structure - Schedule of

Capital Structure - Schedule of Reserved Common Stock Converted Basis for Future Issuance (Details) - shares	Sep. 30, 2022	Dec. 31, 2021
Conversion of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	7,671,582	6,168,355
Stock Options, Issued and Outstanding
Conversion of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	5,189,839	4,254,504
Stock Options, Authorized for Future Issuance
Conversion of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	1,603,260	1,134,944
Employee Stock Purchase Plan, Available for Future Issuance
Conversion of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	526,218	284,993
Restricted Stock, Issued and Outstanding
Conversion of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	352,265	493,914

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2020	Sep. 30, 2022	Dec. 31, 2022	Jan. 01, 2022	Dec. 31, 2021	Dec. 18, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of common stock to grant stock-based compensation awards			7,671,582			6,168,355
Total unrecognized stock-based compensation expense			$ 24.9
Unrecognized stock-based compensation expense, weighted-average period			2 years 9 months 18 days
2020 Equity Incentive Plan | Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of common stock to grant stock-based compensation awards							4,327,799
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of common stock to grant stock-based compensation awards	3,370,000		1,603,260
Options granted expiration period	10 years
Ownership (percent)	10%
Option price as percentage of fair market value of common stock on the date of grant	110%
Vesting description	Employee stock options generally vest 1/16th quarterly over four years subject to continued service to the Company.
Vesting period	4 years
Increase in number of shares of common stock available under evergreen provision					1,480,466
2021 Equity Incentive Plan | Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, percentage of increment based on prior year				5%
2021 Equity Incentive Plan | Grantee Owning More Than 10% of Voting Power
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted expiration period	5 years
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of common stock to grant stock-based compensation awards	306,000		526,218
Increase in number of shares of common stock available under evergreen provision					296,093
Shares issued under ESPP plan			54,868
Discounted percentage for employees and designated affiliates to purchase common stock	15%
2021 Employee Stock Purchase Plan | Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, percentage of increment based on prior year				1%
Restricted Stock | Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards granted		824,429
Vesting period		4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Recorded in Statements of Operations and Allocated (Details) - 2020 Plan, 2021 and ESPP - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,731	$ 1,921	$ 7,620	$ 4,303
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	1,186	766	3,451	1,690
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,545	$ 1,155	$ 4,169	$ 2,613

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Fair Value of Stock Options Estimated using Weighted-Average Assumptions (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected term in years	6 years	6 years	6 years	6 years
Expected volatility	96%	91%	94%	91%
Risk-free interest rate	3.60%	0.90%	3%	0.90%
Dividend yield	0%	0%	0%	0%
Weighted average fair value of share-based awards granted	$ 8.81	$ 10.33	$ 4.91	$ 7.26

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock Option Activity (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2022 $ / shares shares	Dec. 31, 2021 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Shares, Beginning Balance | shares	4,254,504
Shares, Granted | shares	1,379,384
Shares, Exercised | shares	(76,815)
Shares, Cancelled | shares	(367,234)
Shares, Ending Balance | shares	5,189,839	4,254,504
Shares, Exercisable | shares	1,444,905
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 9.89
Weighted Average Exercise Price, Granted | $ / shares	6.39
Weighted Average Exercise Price, Exercised | $ / shares	6.42
Weighted Average Exercise Price, Cancelled | $ / shares	13.19
Weighted Average Exercise Price, Ending Balance | $ / shares	8.78	$ 9.89
Weighted Average Exercise, Exercisable | $ / shares	$ 9.01
Weighted Average Remaining Contract Term	8 years 10 months 24 days	9 years 4 months 24 days
Weighted Average Remaining Contract Term, Exercisable	8 years 4 months 24 days

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) - Restricted Stock	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Restricted Stock Awards | shares	493,914
Number of Restricted Stock Awards, Released | shares	(141,649)
Number of Restricted Stock Awards | shares	352,265
Weighted-Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 4.02
Weighted-Average Grant Date Fair Value, Released | $ / shares	4.02
Weighted-Average Grant Date Fair Value, Ending Balance | $ / shares	$ 4.02

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss	$ (22,890)	$ (17,258)	$ (16,366)	$ (12,606)	$ (8,399)	$ (5,852)	$ (56,514)	$ (26,857)
Denominator:
Weighted-average common shares outstanding, basic	29,319,042			29,001,213			29,214,549	22,105,321
Weighted-average common shares outstanding, diluted	29,319,042			29,001,213			29,214,549	22,105,321
Net loss per share, basic	$ (0.78)			$ (0.43)			$ (1.93)	$ (1.21)
Net loss per share, diluted	$ (0.78)			$ (0.43)			$ (1.93)	$ (1.21)

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Potential Dilutive Securities Excluded from Calculation of Diluted Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	5,639,563	3,573,521
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	5,189,839	2,966,518
Estimated Shares Issuable Under the Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	97,459	13,461
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	352,265	593,542