0001564590-21-043461 | 10-Q | XBRL Viewer

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2021	Aug. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
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		28,998,352
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity Current Reporting Status	No
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	726 Main Street
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 - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 166,037,000	$ 61,695,000
Short-term investments	32,535,000
Prepaid expenses and other current assets	1,949,000	528,000
Total current assets	200,521,000	62,223,000
Property and equipment, net	1,495,000	81,000
Restricted cash	216,000	0
Prepaid and other long term assets		12,000
Long-term investments	4,256,000
Right-of-use asset	3,045,000	210,000
Total assets	209,533,000	62,526,000
Current liabilities:
Accounts payable	1,350,000	727,000
Accrued expenses and other current liabilities	3,116,000	633,000
Loan payable		36,000
Short-term operating lease liability	476,000	223,000
Total current liabilities	4,942,000	1,619,000
Long-term operating lease liability	2,575,000
Total liabilities	7,517,000	1,619,000
Commitments and contingencies (Note 9)
Stockholders' equity
Preferred stock, $0.0001 par value; 10,000,000 and 0 shares authorized as of June 30, 2021 and December 31, 2020; 0 and 0 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively
Common stock, $0.0001 par value; 300,000,000 and 25,300,080 shares authorized as of June 30, 2021 and December 31, 2020, respectively; 28,990,180 and 11,953,107 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	2,000	1,000
Additional paid-in capital	224,438,000	13,343,000
Accumulated other comprehensive income	2,000
Accumulated deficit	(22,426,000)	(8,175,000)
Total stockholders' equity	202,016,000	5,169,000
Total liabilities and stockholders' equity	$ 209,533,000	62,526,000
Series A Convertible Preferred Stock
Current liabilities:
Series A convertible preferred stock, $0.0001 par value; 0 and 7,064,925 shares authorized as of June 30, 2021 and December 31, 2020; 0 and 7,064,925 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively		$ 55,738,000

Condensed Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Preferred stock, shares outstanding	0
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	25,300,080
Common stock, shares issued	28,990,180	11,953,107
Common stock, shares outstanding	28,990,180	11,953,107
Series A Convertible Preferred Stock
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	7,064,925
Preferred stock, shares issued	0	7,064,925
Preferred stock, shares outstanding	0	7,064,925

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
Research and development	$ 5,224	$ 216	$ 9,022	$ 550
General and administrative	3,211	79	5,270	143
Total operating expenses	8,435	295	14,292	693
Loss from operations	(8,435)	(295)	(14,292)	(693)
Interest and other income, net	36	2	41	2
Net loss	(8,399)	(293)	(14,251)	(691)
Other comprehensive loss:
Changes in unrealized gain on short term investments, net	17		2
Comprehensive loss	$ (8,382)	$ (293)	$ (14,249)	$ (691)
Net loss per common share, basic and diluted	$ (0.33)	$ (0.03)	$ (0.77)	$ (0.07)
Weighted-average number of common shares used to compute basic and diluted net loss per common share	25,161,038	9,746,868	18,598,521	9,252,931

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, 2019	$ (21)			$ 1		$ 2,829			$ (2,851)
Balance (in shares) at Dec. 31, 2019				8,703,234
Issuance of common stock, net of offering costs	50					50
Issuance of common stock, net of offering costs (in shares)				230,650
Net loss and comprehensive loss	(398)								(398)
Balance at Mar. 31, 2020	(369)			$ 1		2,879			(3,249)
Balance (in shares) at Mar. 31, 2020				8,933,884
Balance at Dec. 31, 2019	(21)			$ 1		2,829			(2,851)
Balance (in shares) at Dec. 31, 2019				8,703,234
Net loss and comprehensive loss	(691)
Balance at Jun. 30, 2020	8,830			$ 1		12,371			(3,542)
Balance (in shares) at Jun. 30, 2020				11,724,100
Balance at Mar. 31, 2020	(369)			$ 1		2,879			(3,249)
Balance (in shares) at Mar. 31, 2020				8,933,884
Issuance of common stock, net of offering costs	9,492					9,492
Issuance of common stock, net of offering costs (in shares)				2,790,216
Net loss and comprehensive loss	(293)								(293)
Balance at Jun. 30, 2020	8,830			$ 1		12,371			(3,542)
Balance (in shares) at Jun. 30, 2020				11,724,100
Balance at Dec. 31, 2020	5,169			$ 1		13,343			(8,175)
Balance (in shares) at Dec. 31, 2020			7,064,925
Balance at Dec. 31, 2020			$ 55,738
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 and comprehensive 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	5,169			$ 1		13,343			(8,175)
Balance (in shares) at Dec. 31, 2020			7,064,925
Balance at Dec. 31, 2020			$ 55,738
Balance (in shares) at Dec. 31, 2020				11,953,107
Unrealized gain (loss) on investments	2
Net loss and comprehensive loss	(14,251)
Balance at Jun. 30, 2021	$ 202,016			$ 2		224,438		2	(22,426)
Balance (in shares) at Jun. 30, 2021	0		0
Balance (in shares) at Jun. 30, 2021				28,990,180
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
Issuance of common stock, net of offering costs		$ 152,754			$ 1		$ 152,753
Issuance of common stock, net of offering costs (in shares)					9,823,532
Issuance of restricted stock (in shares)				53,240
Stock-based compensation expense	1,463					1,463
Exercise of stock options	$ 225					225
Exercise of stock options, (in shares)	43,850			43,850
Conversion of preferred stock to common stock	$ 55,735					55,735
Conversion of preferred stock to common stock (in shares)			(7,064,925)
Conversion of convertible preferred stock into common stock			$ (55,735)
Conversion of preferred stock to common stock (in shares)				7,064,925
Unrealized gain (loss) on investments	17							17
Net loss and comprehensive loss	(8,399)								(8,399)
Balance at Jun. 30, 2021	$ 202,016			$ 2		$ 224,438		$ 2	$ (22,426)
Balance (in shares) at Jun. 30, 2021	0		0
Balance (in shares) at Jun. 30, 2021				28,990,180

Condensed Statements of Cash Flows - USD ($)	3 Months Ended		6 Months Ended
Condensed Statements of Cash Flows - USD ($)	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating Activities
Net loss			$ (14,251,000)	$ (691,000)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	$ 22,000	$ 0	34,000	0
Non-cash operating lease expense			381,000
Stock-based compensation expense			2,382,000
Net amortization of premiums and accretion of discounts on investments			204,000
Changes in operating assets and liabilities:
Prepaid expenses and other current assets			(1,421,000)	6,000
Other assets			12,000
Accounts payable			237,000	72,000
Accrued expenses and other current liabilities			2,259,000	(8,000)
Lease liabilities			(388,000)
Net cash used in operating activities			(10,551,000)	(621,000)
Investing Activities
Purchase of property and equipment			(838,000)
Purchase of short-term and long-term investments			(38,492,000)
Maturities of short-term and long-term investments			1,500,000
Net cash used in investing activities			(37,830,000)
Financing Activities
Proceeds from issuance of common stock from series seed				9,610,000
Series A financing costs incurred			(3,000)	(68,000)
Net proceeds from issuance of common stock from initial public offering			152,753,000
Proceeds from stock option exercise			225,000
Proceeds (payments) from Paycheck Protection Program loan			(36,000)	36,000
Net cash provided by financing activities			152,939,000	9,578,000
Net increase in cash, cash equivalents, and restricted cash			104,558,000	8,957,000
Cash, cash equivalents, and restricted cash at the beginning of the period			61,695,000	239,000
Cash, cash equivalents, and restricted cash at the end of the period	166,253,000	9,196,000	166,253,000	9,196,000
Non-cash financing and investing activities:
Acquisition of fixed assets in accounts payable and accrued liabilities			610,000
Acquisition of right of use asset			3,216,000
Change in unrealized gain on investments			2,000
Conversion of convertible preferred stock into common stock			55,735,000
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	166,037,000	9,196,000	166,037,000	9,196,000
Restricted cash	216,000		216,000
Cash, cash equivalents, and restricted cash at the end of the period	$ 166,253,000	$ 9,196,000	$ 166,253,000	$ 9,196,000

Organization

6 Months Ended

Jun. 30, 2021

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 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 biopharmaceutical company focused on the discovery and development of irreversible small molecules to treat patients with genetically defined cancers. Since its inception in 2017, the Company has built its proprietary FUSION System platform to design and develop a pipeline of novel irreversible therapies.

Basis of presentation

The accompanying interim condensed financial statements as of June 30, 20201 and for the three and six months ended June 30, 2021, and the related interim information contained within the notes to the financial statements, are unaudited. The unaudited interim condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) for interim financial information and on the same basis as the audited financial statements included on the Company’s annual financial statements filed with the Securities and Exchange Commission (“SEC”) within the Company’s Prospectus dated April 15, 2021 (the “Prospectus”). In the opinion of management, the accompanying unaudited interim condensed financial statements contain all adjustments (consisting of normal recurring adjustments) necessary to state fairly the Company’s financial position as of June 30, 2021, and the results of its operations and cash flows for the three and six months ended June 30, 2021. All such adjustments are of a normal and recurring nature. The interim financial data as of June 30, 2021 is not necessarily indicative of the results to be expected for the year ending December 31, 2021, or for any future period.

The accompanying condensed financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2020.

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. Subsequent to the close, an additional 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, on April 20, 2021, 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 approximately $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 $22.4 million at June 30, 2021. As of June 30, 2021, the Company had cash, cash equivalents, restricted cash, and investments of $203.0 million. 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. 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 Accounting Policies

6 Months Ended

Jun. 30, 2021

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 U.S. 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 accrued research and development expenses, the fair value of common stock, stock-based compensation expense, income taxes and uncertain tax positions. 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 clinical product candidates for the treatment of cancer patients. 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

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 as of June 30, 2021 included a $216,000 stand-by letter of credit issued in favor of the landlord in connection with a new lease of lab space located in San Carlos, California, which is classified in noncurrent assets. There was no restricted cash as of December 31, 2020.

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, and commercial paper. 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. Long term investments consist of asset backed securities and corporate debt.

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 and cash equivalents. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash and cash equivalents.

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 clinical trials and reaching milestones, uncertainty of regulatory approval of the

Company’s potential product candidates, uncertainty of market acceptance of the Company’s product candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals or sole source suppliers. 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 are recorded at cost net of accumulated depreciation and amortization. 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:


Laboratory equipment		3-5 years
Furniture and fixtures		5 years
Leasehold improvements		Shorter of remaining lease term or estimated useful life
Computer equipment		3 years

Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization 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

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 have been no such impairments of long-lived assets for any of the periods presented.

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 (deficit) 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’s research and development expenses consist primarily of external and internal costs incurred in connection with the research and development of its research programs and product candidates.

External costs include:

•	expenses incurred under agreements with third-party contract manufacturing organizations (“CMOs”), contract research organizations (“CROs”), research and development service providers, academic research institutions and consulting costs; and

•	laboratory expenses, including supplies and services.

Internal costs include:

•	personnel-related expenses, including salaries, benefits and stock-based compensation for personnel in research and product development roles; and

•	facilities and other allocated expenses, including expenses for rent and facilities maintenance, and amortization.

The Company expenses research and development costs in the periods in which they are incurred. Nonrefundable advance payments for goods or services to be received in future periods for use in research and development activities are deferred and capitalized. The capitalized amounts are then expensed as the related goods are delivered and as services are performed. The Company tracks direct costs by stage of program, clinical or preclinical. However, it does not track indirect costs on a stage of program basis because these costs are deployed across multiple programs and, as such, are not separately classified.

Accrued research and development expenses

The Company records accruals for estimated costs of research, preclinical, 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, 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 June 30, 2021, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.

Patent costs

All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the accompanying statements of operations.

Stock-based compensation

The Company’s measures stock options and other stock-based awards granted to directors, employees and non-employees based on their fair value on the date of the grant and recognizes the corresponding compensation expense of those awards over the requisite service period, which is generally the vesting period of the respective award, and estimates the fair value of share-based awards to employees and directors using the Black-Scholes option-pricing valuation model. The Company has only issued stock options and restricted share awards with service-based vesting conditions and records the expense for these awards using the straight-line method. The Company accounts for the forfeitures as they occur.

Leases

On January 1, 2020, the Company early adopted ASC 842, Leases (“ASC 842”) and its associated amendments using the modified retrospective transition approach. The Company elected to take the practical expedient to not separate the lease and non-lease components as part of the adoption. There was no cumulative-effect adjustment recorded to accumulated deficit upon adoption. The Company recorded right-of-use assets and lease liabilities of $0.3 million upon adoption.

Under ASC 842, the Company determines if an arrangement is a lease at inception. Lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected 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. The Company’s operating leases have one single component. The lease component results in a right-of-use asset being recorded on the balance sheet and expensed as lease expense on a straight-line basis in the Company’s statements of operations.

Building improvements are paid for by the tenant and are capitalized as leasehold improvements and included in property and equipment, net in the balance sheet.

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.

Comprehensive loss

Other comprehensive loss represents the changes in stockholders’ equity except those resulting from distributions to stockholders. The Company’s unrealized losses on short term available-for-sale investment securities represent components of other comprehensive loss that are excluded from the reported net loss and are presented in the consolidated statements of operations and comprehensive loss.

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 periods, 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 the periods 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 $1.07 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.

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. Early adoption is permitted. The Company is currently assessing the impact of this standard on its financial statements and related disclosures.

In December 2019, the Financial Accounting Standards Board issued ASU No 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”). ASU 2019-12 removes certain exceptions to the general principles in Topic 740 in Generally Accepted Accounting Principles. ASU 2019-12 is effective for public entities for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company does not expect ASU 2019-12 to have a material effect on the Company’s current financial position, results of operations or financial statement disclosures.

Fair Value Measurement

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurement

Note 3. Fair Value Measurement

The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. 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.

The Company’s cash equivalents includes investments in money market funds that are classified as Level 1 of the fair value hierarchy. The Company values the funds at $1 stable net asset value, which is the quoted price in active markets for identical assets that the Company has the ability to access. The Company’s cash equivalents and short-term investments also include commercial paper, asset backed securities, and corporate notes, which have been classified within Level 2 of the fair value of the hierarchy because of the sufficient observable inputs for revaluation.

Financial instruments classified within Level 2 of the fair value hierarchy are valued 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 June 30, 2021 and December 31, 2020, there were no financial instruments classified as Level 3.

The fair value of the Company’s cash equivalents and short-term investments approximates their respective carrying amounts due to their short-term maturity. The following tables set forth the fair value of the Company’s financial assets, which consist of investments measured and recognized at fair value (in thousands):

		June 30, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses				Fair Value
Money market funds⁽¹⁾	Level 1	$	18,036	$	—	$	—		$		18,036
Investments
Corporate notes	Level 2		20,724		—		—				20,724
Commercial paper	Level 2		10,491		4		—				10,495
Asset backed securities	Level 2		5,574		—		(2	)			5,572
Total		$	54,825	$	4	$	(2	)	$		54,827

⁽¹⁾

^{Included in cash and cash equivalents on the balance sheets}^.

The Company did not have any investments as of December 31, 2020.

Realized gains or losses from the sale of investments and other-than-temporary impairments, if any, on available-for-sale securities are reported in other income (expense), net as incurred. The cost of securities sold was determined based on the specific identification method. The amount of realized gains and realized losses on investments for the periods presented have not been material.

- Definition

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

+ References + Details

Property and Equipment

6 Months Ended

Jun. 30, 2021

Property Plant And Equipment [Abstract]

Property and Equipment

Note 4. Property and Equipment

Property and equipment, net consisted of the following:

(in thousands)	June 30, 2021			December 31, 2020
Computers	$	73		$	—
Furniture and fixtures		272			7
Lab equipment		115			—
Leasehold improvements		63			24
Construction in progress		1,014			58
Total property and equipment, gross		1,537			89
Less: accumulated depreciation		(42	)		(8	)
Total property and equipment, net	$	1,495		$	81

Depreciation expense was $22,000 and $34,000, respectively, for the three and six months June 30, 2021 and was $0 for each of the three and six months ended June 30, 2020.

Leases

6 Months Ended

Jun. 30, 2021

Leases [Abstract]

Leases

Note 5. Leases

The Company early adopted Accounting Standards Update ASU 842 on January 1, 2020. There was no cumulative-effect adjustment recorded to accumulated deficit upon adoption.

Under ASC 842, 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. As of December 31, 2020, the Company’s lease population consisted of real estate. As of the date of adoption of ASC 842 and December 31, 2020, the Company did not have finance leases.

Operating leases are included in operating lease right-of-use (“ROU”) assets, lease liabilities, current, and lease liabilities, non-current in the Company’s 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 base 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. Lease agreements entered into after the adoption of ASC 842 that include lease and non-lease components are accounted for as a single lease component. Lease agreements with a noncancelable term of less than 12 months are not recorded on the Company’s balance sheet.

Operating leases

The Company leases its office and lab space in Redwood City, California and San Carlos, California respectively. Both of the 12.5 month leases were entered into in August 2020. Future lease payments under the two leases are $50,391 for the remaining six months in 2021.

In February 2021, the Company entered into an 8-month sublease agreement with Level Home, Inc. for additional office space located in Redwood City, California. Rent is $38,766 per month with an abatement of base rent for the first month. This lease will be treated as a short-term lease in accordance with ASC 842 and therefore, is excluded from the right-of -use asset and liability.

In March 2021, the Company signed a 5-year lease for new lab space located in San Carlos, California. The lease commenced on May 1, 2021 with monthly lease payments of $57,638 with annual increases of 3%. This lease is accounted for 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 5 year expected remaining term.

Lease expense was $319,000 and $460,000, respectively, for the three and six months ended June 30, 2021 and $6,000 and $28,000, respectively, for the three and six months ended June 30, 2020.

The undiscounted future non-cancellable lease payments under the Company’s operating leases as of June 30, 2021 is as follows:

(In thousands)
Years ending December 31,
2021 (remaining six months)	$	281
2022		705
2023		727
2024		748
2025		771
Thereafter		259
Total undiscounted lease payments		3,491
Less: Present value adjustments		(440	)
Present value of lease payments	$	3,051

Balance Sheet Components

6 Months Ended

Jun. 30, 2021

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

Note 6. Balance Sheet Components

Prepaid expenses and other current assets

Prepaid expenses and other current assets consisted of the following:

	June 30,		December 31,
	2021		2020
	(in thousands)
Prepaid expenses and receivables	$	1,675	$	463
Other current asset		—		29
Interest receivable		200		—
Security deposits		74		36
Total prepaid expenses and other current assets	$	1,949	$	528

Accrued expenses and other current liabilities

Accrued expense and other current liabilities consisted of the following:

	June 30,		December 31,
	2021		2020
	(in thousands)
Accrued research and development materials and services	$	1,717	$	519
Accrued professional services		530		67
Accrued personnel expenses		853		47
Other liabilities		16		—
Total accrued liabilities	$	3,116	$	633

Capital Structure

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Capital Structure

Note 7. Capital Structure

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.

In connection with the completion of its IPO, on April 20, 2021, 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.

Common stock

The Company is authorized to issue 300,000,000 shares of common stock, par value $0.0001 per share. As of December 31, 2020, there were 12,702,942 shares of common stock outstanding, including 749,835 unvested restricted shares of common stock subject to repurchase. There were no options to purchase common stock outstanding as of December 31, 2020. As of June 30, 2021, there were 29,635,249 shares of common stock outstanding, including 645,069 unvested restricted shares of common stock subject to repurchase. There were zero and 2,670,999 options to purchase common stock outstanding as of December 31, 2020 and June 30, 2021, respectively.

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.

Series A convertible preferred stock

In December 2020, the Company issued 7,064,925 shares of its convertible preferred stock, par value $0.0001, raising $55.7 million in net proceeds. Prior to the December 2020 convertible preferred stock financing, there were no shares of convertible preferred stock outstanding.

Preferred stock consisted of the following as of December 31, 2020 (in thousands, except share numbers):

authorized

issued and

outstanding

Original

issue

price

Carrying

value

Liquidation

preference

Series A convertible preferred stock

7,064,925

7.93

55,738

56,000

Immediately prior to the closing of the IPO, all outstanding shares of the Company’s convertible preferred stock converted into 7,064,925 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of convertible preferred stock outstanding as of June 30, 2021.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

Note 8. Stock-Based Compensation

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.

In April 2021, the Company adopted the 2021 Equity Incentive Plan (the “2021 Plan”). 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. Under the 2021 Plan, no more than 25,000,000 shares may be issued pursuant to the exercise of Incentive Stock Options.

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%. No more than 4,500,000 shares may be issued under the ESPP Plan. As of June 30, 20201, no shares have been issued under the ESPP plan.

Stock options

The Company’s measures stock options and other stock-based awards granted to directors, employees and non-employees based on their fair value on the date of the grant and recognizes the corresponding compensation expense of those awards over the requisite service period, which is generally the vesting period of the respective award. The Company has only issued stock options and restricted share awards with service-based vesting conditions and records the expense for these awards using the straight-line method. Forfeitures are accounted for as they occur.

The Company granted its first restricted stock awards in the fourth quarter of 2020. The Company has determined the fair value of restricted stock awards granted based on the fair value of its common stock.

There were no stock options outstanding as of December 31, 2020. The Company issued its first stock options in the first quarter of 2021. The Company estimates the fair value of each stock option grant using the Black-Scholes option pricing model, which uses as inputs the following assumptions:

Expected term—The expected term represents the period that the stock-based awards are expected to be outstanding. The Company uses the simplified method to determine the expected term, which is based on the average of the time-to-vesting and the contractual life of the options.

Expected volatility—Because the Company has been privately held and does not have any trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded biotechnology companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on the similar size, stage in life cycle or area of specialty. The Company will continue to take this approach until a sufficient amount of historical information regarding the volatility of its own stock price becomes available.

Risk-free interest rate—The risk-free interest rate is based on the yield of the U.S. Treasury notes as of the grant date with terms commensurate with the expected term of the awards.

Dividend yield—The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero.

Total stock-based compensation expense recorded in the condensed statements of operations and allocated as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
Research and development	$	611	$	—	$	924	$	—
General and administrative		852		—		1,458		—
Total stock-based compensation expense	$	1,463	$	—	$	2,382	$	—

Stock Options

The following table summarizes stock option activity:

				Outstanding Options
	Shares Available for Grant			Shares			Weighted- Average Exercise		Weighted- Average Remaining Contractual Term (Years)
Balance—December 31, 2020		4,327,799			—		$	—
Granted		(2,068,111	)		2,068,111		$	6.47
Balance—March 31, 2021		2,259,688			2,068,111		$	6.47		9.8
Authorized for Issuance under the 2021 Plan		25,000,000
Granted		(646,738	)		646,738		$	17.89
Exercised					(43,850	)	$	5.14
Balance—June 30, 2021		24,353,262			2,670,999		$	9.25		9.8

The fair value of employee stock options was estimated using the following weighted-average assumptions:

	Three Months Ended			Six Months Ended
	June 30, 2021			June 30, 2021
Expected term in years		6.0			6.0
Expected volatility		91	%		91	%
Risk-free interest rate		1.0	%		0.9	%
Dividend yield		—			—
Weighted average fair value of share-based awards granted	$	13.27		$	6.93

Restricted stock

The Company has 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. As of December 31, 2020, a total of 74,594 restricted shares had vested, and 749,835 restricted common stock shares remained unvested subject to repurchase. As of June 30, 2021, a total of 179,360 restricted shares had vested, and 645,069 restricted common shares remained unvested subject to repurchase. There were no restricted shares issued during the six months ended June 30, 2021.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 9. Commitments and Contingencies

Legal proceedings

From time to time, the Company may become involved in legal proceedings arising from 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

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. 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.

Debt

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Debt

Note 10. Debt

On May 5, 2020, the Company entered into a promissory note with City National Bank, which provided a loan in the amount of $35,637 (“PPP Loan”) pursuant to the Paycheck Protection Program (“PPP”), administered by the Small Business Administration under the CARES Act. The PPP Loan has a two-year term and bears interest at a rate of 1% per annum. Monthly principal and interest payments are deferred for seven months after the date of disbursement. The PPP Loan may be prepaid at any time prior to maturity with no prepayment penalties. The PPP loan may be partially or wholly forgiven if the funds are used for certain qualifying expenses as described in the CARES Act. The Company has used the entire PPP loan amount for qualifying expenses and repaid the loan in full during the three months ended June 30, 2021.

Related Party Transactions

6 Months Ended

Jun. 30, 2021

Related Party Transactions

Note 11. Related Party Transactions

During the year ended December 31, 2019, A2A Pharmaceuticals and Biomea Health, LLC invested a combined $1.4 million in the Company in exchange for 4,428,500 shares of the Company’s common stock. Biomea Health, LLC’s initial investment of $0.2 million was in the form of expenses paid by Biomea Health, LLC on behalf of the Company. During the six months ended June 30, 2021, A2A Pharmaceuticals and Biomea Health, LLC invested a combined $0.3 million in the Company in exchange for 799,569 shares of the Company’s common stock. As of June 30, 2021 and December 31, 2020, the Company had an outstanding receivable balance from Biomea Health LLC of approximately $0 and $8,000, respectively. This receivable balance as of December 31, 2020 is related to operating expenses paid for by the Company on behalf of Biomea Health LLC.

Net Loss and Net Loss Per Share

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Net Loss and Net Loss Per Share

Note 12. Net Loss and Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share:

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Numerator:
Net loss attributable to common stockholders, basic and diluted	$	(8,399	)	$	(293	)	$	(14,251	)	$	(691	)
Denominator:
Weighted-average common shares outstanding		25,161,038			9,746,868			18,598,521			9,252,931
Net loss per share attributable to common stockholders:
Basic and diluted	$	(0.33	)	$	(0.03	)	$	(0.77	)	$	(0.07	)

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:

	Outstanding June 30,
	2021		2020

Common stock options outstanding		2,670,999		-
Restricted common stock subject to repurchase		645,069		-
Total		3,316,068		-

Subsequent Events

6 Months Ended

Jun. 30, 2021

Subsequent Events [Abstract]

Subsequent Events

Note 13. Subsequent Events

The Company did not have any subsequent events as of the filing date of this Quarterly Report on Form 10Q.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2021

Accounting Policies [Abstract]

Use of Estimates

Use of estimates

Segments

Cash, Cash Equivalents, and Restricted Cash

Cash, cash equivalents, and restricted cash

Investments

Concentration of Credit Risk and Other Risks and Uncertainties

Concentration of credit risk and other risks and uncertainties

Property and Equipment, Net

Property and equipment, net


Laboratory equipment		3-5 years
Furniture and fixtures		5 years
Leasehold improvements		Shorter of remaining lease term or estimated useful life
Computer equipment		3 years

Impairment of Long-Lived Assets

Impairment of long-lived assets

Convertible Preferred Stock

Convertible preferred stock

Research and Development Expenses

Research and development expenses

External costs include:

•	expenses incurred under agreements with third-party contract manufacturing organizations (“CMOs”), contract research organizations (“CROs”), research and development service providers, academic research institutions and consulting costs; and

•	laboratory expenses, including supplies and services.

Internal costs include:

•	personnel-related expenses, including salaries, benefits and stock-based compensation for personnel in research and product development roles; and

•	facilities and other allocated expenses, including expenses for rent and facilities maintenance, and amortization.

Accrued Research and Development Expenses

Accrued research and development expenses

Patent Costs

Patent costs

Stock-based compensation

Leases

Building improvements are paid for by the tenant and are capitalized as leasehold improvements and included in property and equipment, net in the balance sheet.

Income Taxes

Income taxes

The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary.

Comprehensive Loss

Comprehensive loss

Net Loss Per Share

Net loss per share

Recent Accounting Pronouncements

Recent accounting pronouncements

Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2021

Property Plant And Equipment [Abstract]

Summary of Useful Lives of Property and Equipment

The useful lives of property and equipment are as follows:


Laboratory equipment		3-5 years
Furniture and fixtures		5 years
Leasehold improvements		Shorter of remaining lease term or estimated useful life
Computer equipment		3 years

Fair Value Measurement (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Summary of Fair Value of Financial Assets Consist of Investments Measured and Recognized at Fair Value

The following tables set forth the fair value of the Company’s financial assets, which consist of investments measured and recognized at fair value (in thousands):

		June 30, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses				Fair Value
Money market funds⁽¹⁾	Level 1	$	18,036	$	—	$	—		$		18,036
Investments
Corporate notes	Level 2		20,724		—		—				20,724
Commercial paper	Level 2		10,491		4		—				10,495
Asset backed securities	Level 2		5,574		—		(2	)			5,572
Total		$	54,825	$	4	$	(2	)	$		54,827

⁽¹⁾

^{Included in cash and cash equivalents on the balance sheets}^.

Property and Equipment (Tables)

6 Months Ended

Jun. 30, 2021

Property Plant And Equipment [Abstract]

Summary of Property and Equipment, Net

Property and equipment, net consisted of the following:

(in thousands)	June 30, 2021			December 31, 2020
Computers	$	73		$	—
Furniture and fixtures		272			7
Lab equipment		115			—
Leasehold improvements		63			24
Construction in progress		1,014			58
Total property and equipment, gross		1,537			89
Less: accumulated depreciation		(42	)		(8	)
Total property and equipment, net	$	1,495		$	81

Leases (Tables)

6 Months Ended

Jun. 30, 2021

Leases [Abstract]

Schedule of Undiscounted Future Non-cancellable Lease Payments Under Operating Leases

The undiscounted future non-cancellable lease payments under the Company’s operating leases as of June 30, 2021 is as follows:

(In thousands)
Years ending December 31,
2021 (remaining six months)	$	281
2022		705
2023		727
2024		748
2025		771
Thereafter		259
Total undiscounted lease payments		3,491
Less: Present value adjustments		(440	)
Present value of lease payments	$	3,051

Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2021

Balance Sheet Related Disclosures [Abstract]

Summary of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:

	June 30,		December 31,
	2021		2020
	(in thousands)
Prepaid expenses and receivables	$	1,675	$	463
Other current asset		—		29
Interest receivable		200		—
Security deposits		74		36
Total prepaid expenses and other current assets	$	1,949	$	528

Summary of Accrued Expense and Other Current Liabilities

Accrued expense and other current liabilities consisted of the following:

	June 30,		December 31,
	2021		2020
	(in thousands)
Accrued research and development materials and services	$	1,717	$	519
Accrued professional services		530		67
Accrued personnel expenses		853		47
Other liabilities		16		—
Total accrued liabilities	$	3,116	$	633

Capital Structure (Tables)

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Schedule of Series A Convertible Preferred Stock

Preferred stock consisted of the following as of December 31, 2020 (in thousands, except share numbers):

authorized

issued and

outstanding

Original

issue

price

Carrying

value

Liquidation

preference

Series A convertible preferred stock

7,064,925

7.93

55,738

56,000

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65888546&loc=d3e21300-112643

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 10
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=65877616&loc=d3e177068-122764

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21488-112644

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock-Based Compensation Expense Recorded in Condensed Statements of Operations and Allocated

Total stock-based compensation expense recorded in the condensed statements of operations and allocated as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
Research and development	$	611	$	—	$	924	$	—
General and administrative		852		—		1,458		—
Total stock-based compensation expense	$	1,463	$	—	$	2,382	$	—

Summary of Stock Option Activity

The following table summarizes stock option activity:

				Outstanding Options
	Shares Available for Grant			Shares			Weighted- Average Exercise		Weighted- Average Remaining Contractual Term (Years)
Balance—December 31, 2020		4,327,799			—		$	—
Granted		(2,068,111	)		2,068,111		$	6.47
Balance—March 31, 2021		2,259,688			2,068,111		$	6.47		9.8
Authorized for Issuance under the 2021 Plan		25,000,000
Granted		(646,738	)		646,738		$	17.89
Exercised					(43,850	)	$	5.14
Balance—June 30, 2021		24,353,262			2,670,999		$	9.25		9.8

Summary of Fair Value of Employee Stock Options Estimated using Weighted-Average Assumptions

The fair value of employee stock options was estimated using the following weighted-average assumptions:

	Three Months Ended			Six Months Ended
	June 30, 2021			June 30, 2021
Expected term in years		6.0			6.0
Expected volatility		91	%		91	%
Risk-free interest rate		1.0	%		0.9	%
Dividend yield		—			—
Weighted average fair value of share-based awards granted	$	13.27		$	6.93

Net Loss and Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2021

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:

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Numerator:
Net loss attributable to common stockholders, basic and diluted	$	(8,399	)	$	(293	)	$	(14,251	)	$	(691	)
Denominator:
Weighted-average common shares outstanding		25,161,038			9,746,868			18,598,521			9,252,931
Net loss per share attributable to common stockholders:
Basic and diluted	$	(0.33	)	$	(0.03	)	$	(0.77	)	$	(0.07	)

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:

	Outstanding June 30,
	2021		2020

Common stock options outstanding		2,670,999		-
Restricted common stock subject to repurchase		645,069		-
Total		3,316,068		-

Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands					6 Months Ended
	Apr. 21, 2021 shares	Apr. 20, 2021 USD ($) $ / shares shares	Apr. 19, 2021 shares	Apr. 12, 2021	Jun. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Class Of Stock [Line Items]
Forward stock split ratio				8.84
Preferred stock converted to common stock			7,064,925
Net proceeds from issuance of common stock from initial public offering \| $					$ 152,753
Common stock, shares authorized					300,000,000	25,300,080
Common stock, par value \| $ / shares					$ 0.0001	$ 0.0001
Preferred stock, shares authorized					10,000,000	0
Preferred stock, par value \| $ / shares					$ 0.0001	$ 0.0001
Accumulated deficit \| $					$ (22,426)	$ (8,175)
Cash, cash equivalents, restricted cash, and investments \| $					$ 203,000
IPO
Class Of Stock [Line Items]
Issuance of common stock, net of offering costs (in shares)		9,000,000
Initial public offering, price per share \| $ / shares		$ 17.00
Shares issued in connection with underwriters exercise of option to purchase additional shares	823,532
Preferred stock converted to common stock		7,064,925
Net proceeds from issuance of common stock from initial public offering \| $		$ 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 Accounting Policies - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) Segment	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jan. 01, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments \| Segment			1
Number of operating segments \| Segment			1
Restricted cash	$ 216,000		$ 216,000		$ 0
Impairment of long-lived assets	0	$ 0	0	$ 0
Right-of-use asset	3,045,000		3,045,000		210,000	$ 300,000
Lease liabilities	476,000		476,000		$ 223,000	$ 300,000
Total annual gross revenues			1,070,000,000.00
Minimum
Summary Of Significant Accounting Policies [Line Items]
Issued nonconvertible debt			1,000,000,000.0
Market value of its stock held by non-affiliates			700,000,000
Stand-by Letter of Credit
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	$ 216,000		$ 216,000

Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details)	6 Months Ended
	Jun. 30, 2021
Laboratory Equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	3 years
Laboratory Equipment \| Maximum
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years
Furniture and Fixtures
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
Computer Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	3 years

Fair Value Measurement - Additional Information (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Stable net asset value	$ 1
Financial instruments classified as Level 3	54,827,000
Investments		$ 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 - Summary of Fair Value of Financial Assets Consist of Investments Measured and Recognized at Fair Value (Details)
$ in Thousands

Jun. 30, 2021

USD ($)

Schedule Of Available For Sale Securities [Line Items]

Amortized Cost

$ 54,825

Gross Unrealized Gains

Gross Unrealized Losses

(2)

Fair Value

54,827

Money Market Funds | Level 1

Schedule Of Available For Sale Securities [Line Items]

Amortized Cost

18,036

^[1]

Fair Value

18,036

^[1]

Corporate Notes | Level 2

Schedule Of Available For Sale Securities [Line Items]

Amortized Cost

20,724

Fair Value

20,724

Commercial Paper | Level 2

Schedule Of Available For Sale Securities [Line Items]

Amortized Cost

10,491

Gross Unrealized Gains

Fair Value

10,495

Asset Backed Securities | Level 2

Schedule Of Available For Sale Securities [Line Items]

Amortized Cost

5,574

Gross Unrealized Losses

(2)

Fair Value

$ 5,572

[1]	^{Included in cash and cash equivalents on the balance sheets}

Property and Equipment - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 1,537	$ 89
Less: accumulated depreciation	(42)	(8)
Total property and equipment, net	1,495	81
Computers
Property Plant And Equipment [Line Items]
Total property and equipment, gross	73
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, gross	272	7
Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	115
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	63	24
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 1,014	$ 58

Property and Equipment - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Property Plant And Equipment [Abstract]
Depreciation expense	$ 22,000	$ 0	$ 34,000	$ 0

Leases - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
Leases - Additional Information (Details) - USD ($)	Feb. 28, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Lessee Lease Description [Line Items]
Operating lease liability to be paid in remainder of fiscal year		$ 281,000		$ 281,000
Right-of-use asset		3,045,000		3,045,000			$ 210,000	$ 300,000
Operating lease, liability		3,051,000		3,051,000
Operating lease expense		319,000	$ 6,000	460,000	$ 28,000
California
Lessee Lease Description [Line Items]
Operating lease liability to be paid in remainder of fiscal year		$ 50,391		$ 50,391
Operating lease, term of contract		12 months 15 days		12 months 15 days
Operating lease, lease not yet commenced, term of contract						5 years
Operating lease, lease not yet commenced, monthly lease payments				$ 57,638
Operating lease, lease not yet commenced, rate of annual increases to rent		3.00%		3.00%
Right-of-use asset		$ 3,200,000		$ 3,200,000
Operating lease, liability		$ 3,200,000		$ 3,200,000
Operating lease, weighted average discount rate		5.40%		5.40%
Operating lease, weighted average remaining lease term		5 years		5 years
California \| Level Home, Inc.
Lessee Lease Description [Line Items]
Operating sublease, term of contract	8 months
Monthly rental payment	$ 38,766

Leases - Schedule of Undiscounted Future Non-cancellable Lease Payments Under Operating Leases (Details) $ in Thousands	Jun. 30, 2021 USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2021 (remaining six months)	$ 281
2022	705
2023	727
2024	748
2025	771
Thereafter	259
Total undiscounted lease payments	3,491
Less: Present value adjustments	(440)
Present value of lease payments	$ 3,051

Balance Sheet Components - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses and receivables	$ 1,675	$ 463
Other current asset		29
Interest receivable	200
Security deposits	74	36
Total prepaid expenses and other current assets	$ 1,949	$ 528

Balance Sheet Components - Summary of Accrued Expense and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued research and development materials and services	$ 1,717	$ 519
Accrued professional services	530	67
Accrued personnel expenses	853	47
Other liabilities	16
Total accrued liabilities	$ 3,116	$ 633

Capital Structure - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended
	Apr. 20, 2021	Apr. 19, 2021	Dec. 31, 2020	Jun. 30, 2021	Mar. 31, 2021	Nov. 30, 2020
Class Of Stock [Line Items]
Preferred stock, shares authorized			0	10,000,000
Preferred stock, par value			$ 0.0001	$ 0.0001
Common stock, par value			$ 0.0001	$ 0.0001
Common stock, shares authorized			25,300,080	300,000,000
Common stock, shares outstanding			12,702,942	29,635,249
Options to purchase common stock outstanding			0	2,670,999	2,068,111
Convertible preferred stock, shares outstanding				0
Preferred stock converted to common stock		7,064,925
Restricted Stock
Class Of Stock [Line Items]
Unvested restricted shares of common stock			749,835	645,069
IPO
Class Of Stock [Line Items]
Preferred stock, shares authorized	10,000,000
Preferred stock, par value	$ 0.0001
Common stock, par value	$ 0.0001
Common stock, shares authorized	300,000,000
Preferred stock converted to common stock	7,064,925
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares authorized			7,064,925	0
Convertible preferred stock, shares issued			7,064,925	0
Convertible preferred stock par value			$ 0.0001	$ 0.0001
Proceeds from issuance of convertible preferred stock			$ 55.7
Convertible preferred stock, shares outstanding			7,064,925	0	7,064,925	0

Capital Structure - Schedule of Series A Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Nov. 30, 2020
Class Of Stock [Line Items]
Preferred stock, shares outstanding	0
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares authorized	0		7,064,925
Preferred stock, shares issued	0		7,064,925
Preferred stock, shares outstanding	0	7,064,925	7,064,925	0
Original issue price			$ 7.93
Carrying value		$ 55,735	$ 55,738
Liquidation preference			$ 56,000

Stock-Based Compensation - Additional Information (Details) - shares	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2020	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2021	Dec. 18, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant		4,327,799	24,353,262	4,327,799	2,259,688
Stock options outstanding		0	2,670,999	0	2,068,111
Expected dividend yield			0.00%
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 \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future issuance	25,000,000
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Discounted percentage for employees and designated affiliates to purchase common stock	15.00%
Shares issued under ESPP plan			0
2021 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future issuance	4,500,000
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards granted			0
Vested restricted stock awards			179,360	74,594
Unvested restricted awards		749,835	645,069	749,835
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 - Summary of Stock-Based Compensation Expense Recorded in Condensed Statements of Operations and Allocated (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,463	$ 2,382
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	611	924
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 852	$ 1,458

Stock-Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	3 Months Ended
	Jun. 30, 2021	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Available for Grant, Beginning Balance	2,259,688	4,327,799
Shares Available for Grant, Authorized for issuance under the 2021 Plan	25,000,000
Share Available for Grant, Granted	(646,738)	(2,068,111)
Shares Available for Grant, Ending Balance	24,353,262	2,259,688
Shares, Beginning Balance	2,068,111	0
Shares, Granted	646,738	2,068,111
Shares, Exercised	(43,850)
Shares, Ending Balance	2,670,999	2,068,111
Weighted Average Exercise Price, Beginning Balance	$ 6.47
Weighted Average Exercise Price, Granted	17.89	$ 6.47
Weighted Average Exercise Price, Exercised	5.14
Weighted Average Exercise Price, Ending Balance	$ 9.25	$ 6.47
Weighted Average Remaining Contract Term	9 years 9 months 18 days	9 years 9 months 18 days

Stock-Based Compensation - Summary of Fair Value of Employee Stock Options Estimated using Weighted-Average Assumptions (Details) - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 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
Expected volatility	91.00%	91.00%
Risk-free interest rate	1.00%	0.90%
Expected dividend yield		0.00%
Weighted average fair value of share-based awards granted	$ 13.27	$ 6.93

Debt - Additional Information (Details) - Promissory Note - City National Bank - PPP Loan - CARES Act	May 05, 2021 USD ($)
Debt Instrument [Line Items]
Loan amount	$ 35,637
Loan term	2 years
Interest rate	1.00%
Monthly principal and interest payments deferral period	7 months
Prepayment penalties	$ 0

Related Party Transactions - Additional Information (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2019	Dec. 31, 2020
A2A Pharmaceuticals and Biomea Health, LLC
Related Party Transaction [Line Items]
Amount invested in exchange of common stock shares	$ 300,000	$ 1,400,000
Number of common stock shares exchanged	799,569	4,428,500
Biomea Health, LLC
Related Party Transaction [Line Items]
Expenses paid		$ 200,000
Outstanding receivable balance	$ 0		$ 8,000

Net Loss and 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				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net loss attributable to common stockholders, basic and diluted	$ (8,399)	$ (5,852)	$ (293)	$ (398)	$ (14,251)	$ (691)
Denominator:
Weighted-average common shares outstanding	25,161,038		9,746,868		18,598,521	9,252,931
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.33)		$ (0.03)		$ (0.77)	$ (0.07)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Net Loss and Net Loss Per Share - Summary of Potential Dilutive Securities Excluded from Calculation of Diluted Per Share (Details)	6 Months Ended
	Jun. 30, 2021 shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	3,316,068
Common Stock Options Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	2,670,999
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	645,069