0001564590-22-007624 | 10-K | XBRL Viewer

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Statements of Cash Flows - USD ($)	12 Months Ended
Statements of Cash Flows - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (41,567,000)	$ (5,324,000)	$ (1,198,000)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation expense	249,000	8,000	0
Non-cash operating lease expense	704,000	124,000
Stock-based compensation expense	6,234,000	322,000
Net amortization of premiums and accretion of discounts on investments	516,000
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,517,000)	(472,000)	7,000
Other assets	(1,218,000)	(12,000)
Accounts payable	640,000	418,000	(98,000)
Accrued expenses and other current liabilities	2,110,000	588,000	10,000
Operating lease liabilities	(589,000)	(111,000)
Net cash used in operating activities	(35,438,000)	(4,459,000)	(1,279,000)
Cash flows from investing activities
Purchase of property and equipment	(3,171,000)	(51,000)
Purchase of investments	(38,492,000)
Maturities of investments	8,308,000
Net cash used in investing activities	(33,355,000)	(51,000)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs		10,192,000	1,440,000
Proceeds from issuance of Series A convertible preferred stock, net of issuance costs		55,738,000
Proceeds from issuance of common stock from initial public offering, net of issuance costs	152,753,000
Proceeds from exercise of stock options and purchases under the employee stock purchase plan	468,000
Proceeds (payment) from Paycheck Protection Program loan	(36,000)	36,000
Net cash provided by financing activities	153,185,000	65,966,000	1,440,000
Net increase in cash, cash equivalents, and restricted cash	84,392,000	61,456,000	161,000
Cash, cash equivalents, and restricted cash at the beginning of the period	61,695,000	239,000	78,000
Cash, cash equivalents, and restricted cash at the end of the period	146,087,000	61,695,000	239,000
Non-cash financing and investing activities:
Conversion of Series A convertible preferred stock into common stock	55,735,000
Acquisition of operating lease right-of-use assets	3,216,000	334,000
Acquisition of property and equipment included in accounts payable and accrued liabilities		38,000
Unpaid deferred offering costs		29,000
Reconciliation of cash, cash equivalents, and restricted cash:
Cash and cash equivalents	145,736,000	61,695,000	239,000
Restricted cash	351,000
Cash, cash equivalents, and restricted cash at the end of the period	$ 146,087,000	$ 61,695,000	$ 239,000

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Common Stock
Issuance of common stock issuance costs		$ 68
Series A Convertible Preferred Stock
Issuance of Series A convertible preferred stock, issuance costs		$ 261
IPO \| Common Stock
Issuance of common stock issuance costs	$ 2,557

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Schedule of Maturities of Lease Liabilities

Maturities of lease liabilities as of December 31, 2021 were as follows (in thousands):

	Operating Lease
Year Ending December 31,	Commitments
2022	$	705
2023		727
2024		748
2025		771
2026		259
Thereafter		—
Total undiscounted lease payments		3,210
Less: Present value adjustments		(360	)
Total operating lease liabilities	$	2,850
Short-term operating lease liabilities		565
Long-term operating lease liabilities		2,285
Total operating lease liabilities	$	2,850

Commitments and Contingencies - Schedule of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Operating Lease Liabilities Payments Due [Abstract]
2022	$ 705
2023	727
2024	748
2025	771
2026	259
Total undiscounted lease payments	3,210
Less: Present value adjustments	(360)
Total operating lease liabilities	2,850
Short-term operating lease liabilities	565	$ 223
Long-term operating lease liabilities	$ 2,285

Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands			12 Months Ended
	Apr. 20, 2021 USD ($) $ / shares shares	Apr. 12, 2021	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / 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	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 \| $			$ (49,742)	$ (8,175)
Cash, cash equivalents, restricted cash, and investments \| $			$ 175,700
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
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

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2022	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		5,077,634		6,168,355	5,077,634
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			1,134,944
Options granted expiration period	10 years
Ownership (percent)	10.00%
Option price as percentage of fair market value of common stock on the date of grant	110.00%
Vesting description	Employee stock options generally vest 1/16th quarterly over four years subject to continued service to the Company.
Vesting period	4 years
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			5.00%
2021 Equity Incentive Plan \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock available under evergreen provision						1,480,466
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			284,993
Discounted percentage for employees and designated affiliates to purchase common stock	15.00%
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			1.00%
2021 Employee Stock Purchase Plan \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock available under evergreen provision						296,093
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost related to stock options under the plans				$ 26.4
Unrecognized stock-based compensation cost, weighted-average period				3 years 3 months 18 days
Aggregate intrinsic value of options exercised				$ 0.5	$ 0.0
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards granted				0
Unvested restricted awards		749,835		493,914	749,835
Restricted Stock \| Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Restricted stock awards granted		824,429

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [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 statements of operations and allocated as follows (in thousands):

	Year Ended December 31,
	2021		2020		2019
Research and development	$	2,637	$	89	$	—
General and administrative		3,597		233		—
Total stock-based compensation expense	$	6,234	$	322	$	—

Summary of Stock Option Activity

The following table summarizes stock option activity:

	Number of Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of December 31, 2020		—		$	—		—	$	—
Granted		4,457,606			9.80
Exercised		(48,663	)		5.22
Cancelled		(154,439	)		8.76
Balance as of December 31, 2021		4,254,504		$	9.89		9.4	$	1,868
Options exercisable as of December 31, 2021		636,356		$	8.98		8.8	$	573

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

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

	Year Ended December 31,
	2021			2020		2019
Expected term in years		6.0			—		—
Expected volatility		91.0	%		—		—
Risk-free interest rate		1.1	%		—		—
Dividend yield		—			—		—
Weighted average fair value of options granted	$	7.28		$	—	$	—

Summary of Restricted Stock Activity

The following table summarizes the restricted stock activity:

	Number of Restricted Stock Awards			Weighted-Average Grant Date Fair Value
Balance, December 31, 2020		749,835		$	4.02
Granted		—			—
Released		(204,187	)		4.02
Forfeited		(51,734	)		4.02
Balance, December 31, 2021		493,914		$	4.02

Capital Structure - Schedule of Reserved Common Stock Converted Basis for Future Issuance (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Conversion Of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	6,168,355	5,077,634
Stock Options Issued and Outstanding
Conversion Of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	4,254,504
Stock Options, Authorized for Future Issuance
Conversion Of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	1,134,944	4,327,799
Employee Stock Purchase Plan, Available for Future Issuance
Conversion Of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	284,993
Restricted Stock Issued and Outstanding
Conversion Of Stock [Line Items]
Common Stock, Capital shares reserved for future issuance	493,914	749,835

Balance Sheet Components - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 249,000	$ 8,000	$ 0

Fair Value Measurement

12 Months Ended

Dec. 31, 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.

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 December 31, 2021, there were no financial instruments classified as Level 3.

As of December 31, 2021, investments measured and recognized at fair value are as follows (in thousands):

		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Financial assets included within cash and cash equivalents:
Money market funds	Level 1	$	112,193	$	—	$	—		$	112,193
Financial assets included within short-term investments:
Corporate notes	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 investments:
Corporate notes	Level 2		1,185		—		(4	)		1,181
Asset backed securities	Level 2		695		—					695
Total		$	141,859	$	1	$	(11	)	$	141,849

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

- 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

Taxes - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 7,689	$ 286
Accrued liabilities and reserves	65	11
Stock-based compensation	675
Intangible assets	1,044	1
Operating lease liabilities	599	62
Research and development credits	278
Property and equipment		2
Gross deferred tax assets	10,350	362
Valuation allowance	(9,730)	(303)
Total deferred tax assets	620	59
Deferred tax liabilities:
Property and equipment	(48)
Operating lease right-of-use assets	(572)	(59)
Total deferred tax liabilities	$ (620)	$ (59)

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, 2018	$ (263)					$ 1,390			$ (1,653)
Balance (in shares) at Dec. 31, 2018				4,274,734
Issuance of common stock	1,440			$ 1		1,439
Issuance of common stock (in shares)				4,428,500
Net loss	(1,198)								(1,198)
Balance at Dec. 31, 2019	(21)			$ 1		2,829			(2,851)
Balance (in shares) at Dec. 31, 2019				8,703,234
Issuance of Series A convertible preferred stock, net of issuance costs of $261			$ 55,738
Issuance of Series A convertible preferred stock, net of issuance costs of $261 (in shares)			7,064,925
Issuance of common stock	10,192					10,192
Issuance of common stock (in shares)				3,175,279
Issuance of restricted stock (in shares)				74,594
Stock-based compensation expense	322					322
Net loss	(5,324)								(5,324)
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 convertible preferred stock issuance costs			$ (3)
Issuance of common stock		$ 152,754			$ 1		$ 152,753
Issuance of common stock (in shares)					9,823,532
Issuance of restricted stock (in shares)				204,187
Conversion of Series A convertible preferred stock into common stock	55,735			$ 1		55,734
Conversion of Series A convertible preferred stock into common stock (in shares)			(7,064,925)
Conversion of Series A convertible preferred stock into common stock			$ (55,735)
Conversion of Series A convertible preferred stock into common stock (in shares)				7,064,925
Exercise of stock options	$ 254					254
Exercise of stock options, (in shares)	48,663			48,663
Purchases under employee stock purchase plan	$ 214					214
Purchases under employee stock purchase plan (in shares)				21,007
Stock-based compensation expense	6,234					6,234
Unrealized gain (loss) on investments, net	(10)							$ (10)
Net loss	(41,567)								(41,567)
Balance at Dec. 31, 2021	$ 178,783			$ 3		$ 228,532		$ (10)	$ (49,742)
Balance (in shares) at Dec. 31, 2021			0
Balance (in shares) at Dec. 31, 2021				29,115,421

Balance Sheet Components - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 3,222	$ 89
Less: accumulated depreciation	(257)	(8)
Total property and equipment, net	2,965	81
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	124
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, gross	315	7
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	1,874
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	828	24
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 81	$ 58

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 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 (in thousands except share and per share data):

	Year Ended December 31,
	2021			2020			2019
Numerator:
Net loss	$	(41,567	)	$	(5,324	)	$	(1,198	)
Denominator:
Weighted-average number of shares outstanding, basic and diluted		23,858,552			10,532,942			6,051,712
Net loss per share, basic and diluted	$	(1.74	)	$	(0.51	)	$	(0.20	)

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:

	December 31,
	2021		2020		2019
Series A convertible preferred stock		—		7,064,925		—
Stock options, issued and outstanding		4,254,504		—		—
Estimated shares issuable under the employee stock purchase plan		6,542		—		—
Restricted stock, issued and outstanding		493,914		749,835		—
Total		4,754,960		7,814,760		—

Capital Structure (Tables)

12 Months Ended

Dec. 31, 2021

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:

	December 31,
	2021		2020
Stock options, issued and outstanding		4,254,504		—
Stock options, authorized for future issuance		1,134,944		4,327,799
Employee stock purchase plan, available for future issuance		284,993		—
Restricted stock, issued and outstanding		493,914		749,835
Total		6,168,355		5,077,634

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.

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-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21484-112644

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644

+ Details

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) - Restricted Stock	12 Months Ended
	Dec. 31, 2021 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Stock Awards	749,835
Restricted stock awards granted	0
Number of Restricted Stock Awards, Released	(204,187)
Number of Restricted Stock Awards, Forfeited	(51,734)
Number of Restricted Stock Awards	493,914
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, Forfeited \| $ / shares	4.02
Weighted-Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 4.02

Capital Structure - Additional Information (Details)	1 Months Ended	12 Months Ended
Capital Structure - Additional Information (Details)	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) Director $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Apr. 20, 2021 $ / shares shares	Nov. 30, 2020 shares
Class Of Stock [Line Items]
Preferred stock, shares authorized \| shares	0	10,000,000	0
Preferred stock, par value \| $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, par value \| $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized \| shares	25,300,080	300,000,000	25,300,080
Dividends declared \| $	$ 0	$ 0	$ 0
Proceeds from issuance of Series A convertible preferred stock, net of issuance costs \| $			55,738,000
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Dividends declared \| $	$ 0		$ 0
Convertible preferred stock, shares issued \| shares	7,064,925	0	7,064,925
Convertible preferred stock par value \| $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Proceeds from issuance of Series A convertible preferred stock, net of issuance costs \| $	$ 55,700,000
Convertible preferred stock, shares outstanding \| shares	7,064,925	0	7,064,925		0
Conversion of stock, description		Each share of Series A convertible preferred stock is convertible at an option of the holder into one share of common stock
Preferred stock, liquidation preference per share \| $ / shares		$ 7.93
Number of directors elected \| Director		2
Series A Convertible Preferred Stock \| Minimum
Class Of Stock [Line Items]
Proceeds from issuance of Series A convertible preferred stock, net of issuance costs \| $		$ 75,000,000.0
Common Stock
Class Of Stock [Line Items]
Number of directors elected \| Director		3
IPO
Class Of Stock [Line Items]
Preferred stock, shares authorized \| shares				10,000,000
Preferred stock, par value \| $ / shares				$ 0.0001
Common stock, par value \| $ / shares				$ 0.0001
Common stock, shares authorized \| shares				300,000,000

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

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 clinical and preclinical accruals, accrued research and development expenses, fair value of common stock, stock-based compensation and operating lease right-of-use (ROU) assets and liabilities. 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 and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States of America.

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 invests in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate notes, commercial paper, and asset backed securities. 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 a default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded on the balance sheets. 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, 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 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.

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 primarily of amounts invested in money market accounts and are stated at fair value. Restricted cash consisted of two stand-by letters of credit issued to the Company’s landlord in connection with one 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, 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 balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income. The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in interest and other income (loss), net.

Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, are also included in interest and other income (loss), 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 interest and other income (loss), 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 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	5 years
Computers	3 years
Furniture and fixtures	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 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 was no impairment of long-lived assets during the years ended December 31, 2021 and 2020.

Convertible Preferred Stock

The Company records shares of convertible preferred stock at their respective fair values on the dates of issuance, net of issuance costs. The convertible preferred stock is recorded outside of stockholders’ deficit on the balance sheets because the shares contain liquidation features that are not solely within the Company’s control. The Company has elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because of the uncertainty of whether or when such an event would occur. Subsequent adjustments to increase 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 developments 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, 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 December 31, 2021, 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 grant-date fair value. The fair value of each purchase under the employee stock purchase plan (ESPP) 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.

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.

Leases

On January 1, 2020, the Company elected to early adopt Accounting Standard Update (ASU) No. 2016-02, Leases (ASC 842) and its associated amendments using the modified retrospective transition approach. 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. 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 December 31, 2021, the Company's lease population consisted of real estate. As of the date of adoption of ASC 842, 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. For more information about the impact of adoption and disclosures on the Company’s leases, refer to “Note 8 – Commitments and Contingencies.”

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.

Deferred Offering Costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity as a reduction of additional paid-in capital generated as a result of the equity financing. There were zero and $29,000 of deferred offering costs recorded on the balance sheet as of December 31, 2021 and December 31, 2020, respectively.

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 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. ASU 2019-12 is effective for annual periods beginning after December 15, 2021, and interim periods within those fiscal years. Early adoption is permitted. The Company is in the process of evaluating the impact of this new guidance on its financial statements and does not expect the adoption to have a material impact on its financial statements.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Note 2. Summary of Significant Accounting Policies

Use of Estimates

Segments

Concentration of Credit Risk and Other Risks and Uncertainties

Cash, Cash Equivalents and Restricted Cash

Investments

Property and Equipment, Net


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

Impairment of Long-Lived Assets

Convertible Preferred Stock

Research and Development Expenses

Accrued Research and Development Expenses

Stock-Based Compensation

Net Loss Per Share

Leases

Income Taxes

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

Deferred Offering Costs

Recent Accounting Pronouncements

Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Summary of Reconciliation of Statutory Federal Income Tax Rate to Company's Effective Tax Rate

The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate:

	Year ended December 31,
	2021			2020
Federal statutory income tax rate		21.0	%		21.0	%
State income tax rate		0.5	%		1.1	%
Tax credits		0.2	%		—
Stock-based compensation		(1.5	)%		—
Amortization		2.6	%		—
LLC loss prior to C-Corp conversion		—			(17.7	)%
Change in valuation allowance		(22.7	)%		(4.3	)%
Other		(0.1	)%		(0.1	)%
Effective income tax rate		0.0	%		0.0	%

Summary of Deferred Tax Assets and Liabilities

Deferred tax assets and liabilities consist of the following (in thousands):

	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	7,689		$	286
Accrued liabilities and reserves		65			11
Stock-based compensation		675			—
Intangible assets		1,044			1
Operating lease liabilities		599			62
Research and development credits		278			—
Property and equipment		—			2
Gross deferred tax assets		10,350			362
Valuation allowance		(9,730	)		(303	)
Total deferred tax assets		620			59
Deferred tax liabilities:
Property and equipment		(48	)		—
Operating lease right-of-use assets		(572	)		(59	)
Total deferred tax liabilities		(620	)		(59	)
Net deferred tax assets	$	—		$	—

Schedule of Unrecognized Tax Benefits

The following table summarizes the activity related to the Company’s gross unrecognized tax benefits (in thousands):

	Year ended December 31,
	2021		2020
Beginning balance	$	—	$	—
Increases for tax provisions related to prior year		1		—
Increases for tax provisions related to current year		111		—
Ending balance	$	112	$	—

Selected Quarterly Financial Data (Unaudited) - Summary of Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 11,088	$ 7,886	$ 5,224	$ 3,798	$ 2,332	$ 789	$ 216	$ 334	$ 27,996	$ 3,671	$ 1,092
General and administrative	3,649	4,752	3,211	2,059	1,167	346	79	64	13,671	1,656	103
Total operating expenses	14,737	12,638	8,435	5,857	3,499	1,135	295	398	41,667	5,327	1,195
Loss from operations	(14,737)	(12,638)	(8,435)	(5,857)	(3,499)	(1,135)	(295)	(398)	(41,667)	(5,327)	(1,195)
Interest and other income (loss), net	27	32	36	5	1		2		100	3	(3)
Net loss	$ (14,710)	$ (12,606)	$ (8,399)	$ (5,852)	$ (3,498)	$ (1,135)	$ (293)	$ (398)	$ (41,567)	$ (5,324)	$ (1,198)
Net loss per share, basic and diluted	$ (0.51)	$ (0.43)	$ (0.33)	$ (0.49)	$ (0.29)	$ (0.10)	$ (0.03)	$ (0.05)	$ (1.74)	$ (0.51)	$ (0.20)
Weighted-average number of shares outstanding, basic and diluted	29,061,076	29,001,213	25,161,038	11,964,205	11,871,494	11,724,100	9,746,868	8,758,995	23,858,552	10,532,942	6,051,712

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 32
-Subparagraph (f)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 250
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-Paragraph 4
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 45
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
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-Subparagraph (SX 210.13-02(a)(4)(i))
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Laboratory Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	5 years
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
Leasehold Improvements
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	Shorter of remaining lease term or estimated useful life

Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended				12 Months Ended
	Nov. 30, 2021	Sep. 30, 2021	Mar. 31, 2021	Feb. 28, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	May 01, 2021
Commitments And Contingencies [Line Items]
Operating lease right-of-use assets					$ 2,722,000	$ 210,000
Operating lease, liability					2,850,000
Cash paid for lease liabilities					300,000	0
CALIFORNIA
Commitments And Contingencies [Line Items]
Operating lease, lease not yet commenced, term of contract	4 years
Operating lease, lease not yet commenced, monthly lease payments	$ 2,200,000
Operating lease right-of-use assets					0			$ 3,200,000
Operating lease, liability					$ 0			$ 3,200,000
Operating sublease, lease not yet commenced, expiration period		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%
Operating lease, weighted average remaining lease term					5 years
Lease expiration date		Jan. 31, 2022
Operating lease expense					$ 1,300,000	$ 200,000	$ 100,000
CALIFORNIA \| Level Home, Inc.
Commitments And Contingencies [Line Items]
Operating sublease, term of contract				8 months

Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Taxes

Note 7. Taxes

Biomea Fusion is subject to U.S. federal and state income taxes as a corporation. Prior to the tax-free reorganization in December 2020, Biomea Fusion, LLC was treated as a pass-through entity for U.S. federal income tax purposes, and as such, was generally not subject to U.S. federal income tax at the entity level. Rather, the tax liability with respect to its taxable income, was passed through to its unitholders.

There was zero income tax expense for the years ended December 31, 2021 and 2020. The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate:

	Year ended December 31,
	2021			2020
Federal statutory income tax rate		21.0	%		21.0	%
State income tax rate		0.5	%		1.1	%
Tax credits		0.2	%		—
Stock-based compensation		(1.5	)%		—
Amortization		2.6	%		—
LLC loss prior to C-Corp conversion		—			(17.7	)%
Change in valuation allowance		(22.7	)%		(4.3	)%
Other		(0.1	)%		(0.1	)%
Effective income tax rate		0.0	%		0.0	%

Deferred tax assets and liabilities consist of the following (in thousands):

	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	7,689		$	286
Accrued liabilities and reserves		65			11
Stock-based compensation		675			—
Intangible assets		1,044			1
Operating lease liabilities		599			62
Research and development credits		278			—
Property and equipment		—			2
Gross deferred tax assets		10,350			362
Valuation allowance		(9,730	)		(303	)
Total deferred tax assets		620			59
Deferred tax liabilities:
Property and equipment		(48	)		—
Operating lease right-of-use assets		(572	)		(59	)
Total deferred tax liabilities		(620	)		(59	)
Net deferred tax assets	$	—		$	—

The provisions of ASC Topic 740, Accounting for Income Taxes (ASC 740), require an assessment of both positive and negative evidence when determining whether it is more likely than not that deferred tax assets are recoverable. For the years ended December 31, 2021 and 2020, based on all available objective evidence, including the existence of cumulative losses, the Company determined that it was not more likely than not that the net deferred tax assets were fully realizable. Accordingly, the Company established a full valuation allowance against its deferred tax assets. The Company intends to maintain a full valuation allowance on net deferred tax assets until sufficient positive evidence exists to support reversal of the valuation allowance. The Company’s valuation allowance increased by $9.4 million during the year ended December 31, 2021, primarily because of an increase to the Company's net operating losses, credits and intangible deferred tax assets. The Company’s valuation allowance increased by $0.3 million during the year ended December 31, 2020, primarily because of an increase to the Company's net operating loss deferred tax assets.

At December 31, 2021, the Company had net operating loss carryforwards available to reduce future taxable income, if any, for federal and California income tax purposes of approximately $36.3 million and $1.0 million, respectively. The federal net operating loss carryforwards at December 31, 2021 can be carried forward indefinitely, subject to an annual limitation of 80% of taxable income. The California net operating loss carryforward begins expiring in 2040.

At December 31, 2021, the Company also had federal and California research and development tax credit carryforwards of $0.1 million and $0.3 million, respectively, available to offset future income tax, if any. The federal credit carryforwards begins expiring in 2040, and the California credits can be carried forward indefinitely.

Under Section 382 and 383 of the Internal Revenue Code of 1986, as amended, if a corporation undergoes an “ownership change,” the corporation's ability to use its pre-change net operating loss carryforwards and other pre-change attributes, such as research tax credits, to offset its post-change income may be limited. In general, an “ownership change” will occur if there is a cumulative change in the Company's ownership by “5-percent shareholders” that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws. Therefore, certain of the Company's carryforward tax attributes may be subject to an annual limitation regarding their utilization against taxable income in future periods. The Company has performed a Section 382 study and has concluded that ownership changes through December 31, 2021 will not result in federal and California NOL carryforwards and tax credit carryforwards expiring before being applied to reduce future income tax liabilities.

Uncertain Tax Positions

The Company adopted the provisions of ASC 740, which requires companies to determine whether it is “more likely than not” that a tax position will be sustained upon examination by the appropriate taxing authorities before

any tax benefit can be recorded in the financial statements. It also provides guidance on the recognition, measurement, classification and interest and penalties related to uncertain tax positions.

The following table summarizes the activity related to the Company’s gross unrecognized tax benefits (in thousands):

	Year ended December 31,
	2021		2020
Beginning balance	$	—	$	—
Increases for tax provisions related to prior year		1		—
Increases for tax provisions related to current year		111		—
Ending balance	$	112	$	—

The unrecognized tax benefits, if recognized, would not affect the effective income tax rate due to the valuation allowance that currently offsets deferred tax assets. Interest and penalties were zero. The Company does not expect the unrecognized tax benefits to change significantly over the next twelve months.

The Company files federal and state income tax returns. All periods since inception are subject to examination by federal and state authorities, where applicable. There are currently no pending income tax examinations.

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details

Selected Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2021

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Data (Unaudited)

Note 10. Selected Quarterly Financial Data (Unaudited)

The following tables provide the selected quarterly financial data for the years ended December 31, 2021 and 2020 (in thousands, except share and per share data):

	2021
	First			Second			Third			Fourth
	Quarter			Quarter			Quarter			Quarter
Statements of Operations Data:
Operating expenses:
Research and development	$	3,798		$	5,224		$	7,886		$	11,088
General and administrative		2,059			3,211			4,752			3,649
Total operating expenses		5,857			8,435			12,638			14,737
Loss from operations		(5,857	)		(8,435	)		(12,638	)		(14,737	)
Interest and other income (loss), net		5			36			32			27
Net loss	$	(5,852	)	$	(8,399	)	$	(12,606	)	$	(14,710	)
Net loss per share, basic and diluted	$	(0.49	)	$	(0.33	)	$	(0.43	)	$	(0.51	)
Weighted-average number of shares outstanding, basic and diluted		11,964,205			25,161,038			29,001,213			29,061,076

	2020
	First			Second			Third			Fourth
	Quarter			Quarter			Quarter			Quarter
Statements of Operations Data:
Operating expenses:
Research and development	$	334		$	216		$	789		$	2,332
General and administrative		64			79			346			1,167
Total operating expenses		398			295			1,135			3,499
Loss from operations		(398	)		(295	)		(1,135	)		(3,499	)
Interest and other income (loss), net		—			2			—			1
Net loss	$	(398	)	$	(293	)	$	(1,135	)	$	(3,498	)
Net loss per share, basic and diluted	$	(0.05	)	$	(0.03	)	$	(0.10	)	$	(0.29	)
Weighted-average number of shares outstanding, basic and diluted		8,758,995			9,746,868			11,724,100			11,871,494

Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2021

Quarterly Financial Information Disclosure [Abstract]

Summary of Selected Quarterly Financial Data

The following tables provide the selected quarterly financial data for the years ended December 31, 2021 and 2020 (in thousands, except share and per share data):

	2021
	First			Second			Third			Fourth
	Quarter			Quarter			Quarter			Quarter
Statements of Operations Data:
Operating expenses:
Research and development	$	3,798		$	5,224		$	7,886		$	11,088
General and administrative		2,059			3,211			4,752			3,649
Total operating expenses		5,857			8,435			12,638			14,737
Loss from operations		(5,857	)		(8,435	)		(12,638	)		(14,737	)
Interest and other income (loss), net		5			36			32			27
Net loss	$	(5,852	)	$	(8,399	)	$	(12,606	)	$	(14,710	)
Net loss per share, basic and diluted	$	(0.49	)	$	(0.33	)	$	(0.43	)	$	(0.51	)
Weighted-average number of shares outstanding, basic and diluted		11,964,205			25,161,038			29,001,213			29,061,076

	2020
	First			Second			Third			Fourth
	Quarter			Quarter			Quarter			Quarter
Statements of Operations Data:
Operating expenses:
Research and development	$	334		$	216		$	789		$	2,332
General and administrative		64			79			346			1,167
Total operating expenses		398			295			1,135			3,499
Loss from operations		(398	)		(295	)		(1,135	)		(3,499	)
Interest and other income (loss), net		—			2			—			1
Net loss	$	(398	)	$	(293	)	$	(1,135	)	$	(3,498	)
Net loss per share, basic and diluted	$	(0.05	)	$	(0.03	)	$	(0.10	)	$	(0.29	)
Weighted-average number of shares outstanding, basic and diluted		8,758,995			9,746,868			11,724,100			11,871,494

Capital Structure

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Capital Structure

Note 5. 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.

In connection with the completion of its IPO, on April 20, 2021, the Company’s certificate of incorporation was amended and restated to authorize 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. As of December 31, 2021 and December 31, 2020, no dividends have been declared.

The Company had reserved common stock, on an as-converted basis, for future issuance as follows:

	December 31,
	2021		2020
Stock options, issued and outstanding		4,254,504		—
Stock options, authorized for future issuance		1,134,944		4,327,799
Employee stock purchase plan, available for future issuance		284,993		—
Restricted stock, issued and outstanding		493,914		749,835
Total		6,168,355		5,077,634

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

As of December 31, 2020, the holders of the convertible preferred stock had the following rights and preferences:

Conversion Rights

Each share of Series A convertible preferred stock is convertible at an option of the holder into one share of common stock (subject to adjustment for certain events, including dilutive issuances, stock splits, and reclassifications). The Series A convertible preferred stock will also be converted automatically into shares of common stock (1) immediately prior to an initial public offering with aggregate proceeds of at least $75.0 million at a per share price equal to or greater than the original issuance price or (2) upon the date specified by written consent of holders of a majority of the outstanding preferred shares on an as-converted basis.

Dividends

Each holder is entitled to dividends per share, if and when declared by the board of directors. Dividends are to be paid in advance of any distributions to common stockholders. No dividends have been declared as of December 31, 2020.

Liquidation Preference

In the event of any liquidation, dissolution, or winding-up of the Company, including a merger, acquisition, or sale of assets, as defined, each Series A convertible preferred stock holder is entitled to receive the greater of i) an

amount of $7.93 per share for each share of Series A convertible preferred stock held (as adjusted for recapitalizations, stock combinations, stock dividends, stock splits, and reclassifications), plus any declared but unpaid dividends prior to and in preference to any distribution to the holders of common stock or ii) an amount of cash, securities or other property per share on an as-converted to common stock basis. If the assets of the Company are insufficient to make payment in full to all Series A convertible preferred stockholders then the assets or consideration will be distributed ratably among such holders. Any remaining assets would then be distributed among the holders of the common stock on a pro rata basis based on the number of shares of common stock held by them.

Voting

Each holder of shares of Series A convertible preferred stock is entitled to the number of votes equal to the number of shares of common stock into which such shares could be converted and has voting rights and powers equal to the voting rights and powers of the common stock, and except as provided by law or by other provisions of the Company’s Certificate of Incorporation shall vote together with the common stock as a single class on an as-converted basis on all matters as to which holders of common stock have the right to vote.

The holders of Series A convertible preferred stock, voting separately as a single class, are entitled to elect two members of the Company’s board of directors. The holders of shares of common stock, voting separately as a single class, are entitled to elect three members of the Company’s board of directors. All remaining members of the Company’s board of directors are elected by the holders of the common stock and preferred stock voting together as a single class.

Redemption

The convertible preferred stock is not redeemable.

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 December 31, 2021.

- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Stock-Based Compensation

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

Note 6. 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. As of December 31, 2021, 1,134,944 shares of common stock remained available for issuance under the 2021 Plan. 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.

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. As of December 31, 2021, 284,993 shares of common stock remained available for issuance under the ESPP. 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.

Stock-Based Compensation Expense

Total stock-based compensation expense related to the 2020 Plan, 2021 Plan, and ESPP was recorded in the statements of operations and allocated as follows (in thousands):

	Year Ended December 31,
	2021		2020		2019
Research and development	$	2,637	$	89	$	—
General and administrative		3,597		233		—
Total stock-based compensation expense	$	6,234	$	322	$	—

Stock Options

The following table summarizes stock option activity:

	Number of Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of December 31, 2020		—		$	—		—	$	—
Granted		4,457,606			9.80
Exercised		(48,663	)		5.22
Cancelled		(154,439	)		8.76
Balance as of December 31, 2021		4,254,504		$	9.89		9.4	$	1,868
Options exercisable as of December 31, 2021		636,356		$	8.98		8.8	$	573

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

	Year Ended December 31,
	2021			2020		2019
Expected term in years		6.0			—		—
Expected volatility		91.0	%		—		—
Risk-free interest rate		1.1	%		—		—
Dividend yield		—			—		—
Weighted average fair value of options granted	$	7.28		$	—	$	—

As of December 31, 2021, there was $26.4 million of total unrecognized compensation cost related to stock options under the Plans. The unrecognized stock-based compensation cost is expected to be recognized over a weighted-average period of 3.3 years. The aggregate intrinsic value of options exercised for the years ended December 31, 2021 and December 31, 2020 was $0.5 million and zero, respectively. Intrinsic values are

calculated as the difference between the exercise price of the underlying options and the fair value of the common stock on the date of exercise.

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. As of December 31, 2020, a total of 749,835 restricted common stock shares remained unvested subject to repurchase. As of December 31, 2021, a total of 493,914 restricted common shares remained unvested subject to repurchase. There were no restricted shares issued during the year ended December 31, 2021.

The following table summarizes the restricted stock activity:

	Number of Restricted Stock Awards			Weighted-Average Grant Date Fair Value
Balance, December 31, 2020		749,835		$	4.02
Granted		—			—
Released		(204,187	)		4.02
Forfeited		(51,734	)		4.02
Balance, December 31, 2021		493,914		$	4.02

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 145,736	$ 61,695
Short-term investments	27,780
Prepaid expenses and other current assets	3,045	528
Total current assets	176,561	62,223
Property and equipment, net	2,965	81
Restricted cash	351
Other assets	1,230	12
Long-term investments	1,876
Operating lease right-of-use assets	2,722	210
Total assets	185,705	62,526
Current liabilities:
Accounts payable	1,329	727
Accrued expenses and other current liabilities	2,743	633
Loan payable		36
Short-term operating lease liabilities	565	223
Total current liabilities	4,637	1,619
Long-term operating lease liabilities	2,285
Total liabilities	6,922	1,619
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 and 0 shares authorized as of December 31, 2021 and December 31, 2020; 0 shares issued and outstanding as of December 31, 2021 and December 31, 2020
Common stock, $0.0001 par value; 300,000,000 and 25,300,080 shares authorized as of December 31, 2021 and December 31, 2020, respectively; 29,115,421 and 11,953,107 shares issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	3	1
Additional paid-in capital	228,532	13,343
Accumulated other comprehensive loss	(10)
Accumulated deficit	(49,742)	(8,175)
Total stockholders' equity	178,783	5,169
Total liabilities, convertible preferred stock, and stockholders' equity	$ 185,705	62,526
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 December 31, 2021 and December 31, 2020, respectively; 0 and 7,064,925 shares issued and outstanding as of December 31, 2021 and December 31, 2020, respectively; aggregate liquidation preference of $0 and $56,000 as of December 31, 2021 and December 31, 2020, respectively		$ 55,738

Net Loss Per Share - Summary of Potential Dilutive Securities Excluded from Calculation of Diluted Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	4,754,960	7,814,760
Series A Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares		7,064,925
Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	4,254,504
Estimated Shares Issuable Under the Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	6,542
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti Dilutive Shares	493,914	749,835

Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
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	29,115,421	11,953,107
Common stock, shares outstanding	29,115,421	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
Preferred stock, aggregate liquidation preference	$ 0	$ 56,000

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 27,996	$ 3,671	$ 1,092
General and administrative	13,671	1,656	103
Total operating expenses	41,667	5,327	1,195
Loss from operations	(41,667)	(5,327)	(1,195)
Interest and other income (loss), net	100	3	(3)
Net loss	(41,567)	(5,324)	(1,198)
Other comprehensive loss:
Unrealized gain (loss) on investments, net	(10)
Comprehensive loss	$ (41,577)	$ (5,324)	$ (1,198)
Net loss per share, basic and diluted	$ (1.74)	$ (0.51)	$ (0.20)
Weighted-average number of shares outstanding, basic and diluted	23,858,552	10,532,942	6,051,712

Subsequent Events

12 Months Ended

Dec. 31, 2021

Subsequent Events [Abstract]

Subsequent Events

Note 11. Subsequent Events

None.

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options Outstanding	0
Number of Options Outstanding, Granted	4,457,606
Number of Options Outstanding, Exercised	(48,663)
Number of Options Outstanding, Cancelled	(154,439)
Number of Options Outstanding	4,254,504
Number of Options Outstanding, Options exercisable	636,356
Weighted Average Exercise Price, Granted \| $ / shares	$ 9.80
Weighted Average Exercise Price, Exercised \| $ / shares	5.22
Weighted Average Exercise Price, Cancelled \| $ / shares	8.76
Weighted Average Exercise Price, Ending Balance \| $ / shares	9.89
Weighted Average Exercise Price,Options Exercisable \| $ / shares	$ 8.98
Weighted Average Remaining Contract Term	9 years 4 months 24 days
Weighted Average Remaining Contract Term,Options Exercisable	8 years 9 months 18 days
Aggregate Intrinsic Value \| $	$ 1,868
Aggregate Intrinsic Value,Options Exercisable \| $	$ 573

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 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	5 years
Computers	3 years
Furniture and fixtures	5 years
Leasehold improvements	Shorter of remaining lease term or estimated useful life

Fair Value Measurement - Summary of Investments Measured and Recognized at Fair Value (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 141,859
Gross Unrealized Gains	1
Gross Unrealized Losses	(11)
Fair Value	141,849
Money Market Funds \| Level 1 \| Financial Assets Included Within Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	112,193
Fair Value	112,193
Corporate Notes \| Level 2 \| Financial Assets Included Within Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	19,258
Gross Unrealized Gains	1
Gross Unrealized Losses	(6)
Fair Value	19,253
Corporate Notes \| Level 2 \| Financial Assets Included Within Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,185
Gross 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
Asset Backed Securities \| Level 2 \| Financial Assets Included Within Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	4,029
Gross 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	695
Fair Value	$ 695

Capital Structure - Schedule of Series A Convertible Preferred Stock (Details) - Series A Convertible Preferred Stock - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2020
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	0
Original issue price		$ 7.93
Carrying value		$ 55,738
Liquidation preference	$ 0	$ 56,000

- Definition

Carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.

+ References + Details

Stock-Based Compensation - Summary of Fair Value of Stock Options Estimated using Weighted-Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2021 $ / shares
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Expected term in years	6 years
Expected volatility	91.00%
Risk-free interest rate	1.10%
Dividend yield	0.00%
Weighted average fair value of options granted	$ 7.28

Taxes - Schedule of Unrecognized Tax Benefits (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Increases for tax provisions related to prior year	$ 1
Increases for tax provisions related to current year	111
Ending balance	$ 112

Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Summary of Investments Measured and Recognized at Fair Value

As of December 31, 2021, investments measured and recognized at fair value are as follows (in thousands):

		December 31, 2021
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Financial assets included within cash and cash equivalents:
Money market funds	Level 1	$	112,193	$	—	$	—		$	112,193
Financial assets included within short-term investments:
Corporate notes	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 investments:
Corporate notes	Level 2		1,185		—		(4	)		1,181
Asset backed securities	Level 2		695		—					695
Total		$	141,859	$	1	$	(11	)	$	141,849

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2021

Balance Sheet Related Disclosures [Abstract]

Property, Plant and Equipment [Table Text Block]

Property and equipment, net consists of the following (in thousands):

	December 31,
	2021			2020
Computer equipment	$	124		$	—
Furniture and fixtures		315			7
Laboratory equipment		1,874			—
Leasehold improvements		828			24
Construction in progress		81			58
Total property and equipment, gross		3,222			89
Less: accumulated depreciation		(257	)		(8	)
Total property and equipment, net	$	2,965		$	81

Schedule of Accrued Liabilities [Table Text Block]

Accrued expenses and other current liabilities consisted of the following (in thousands):

	December 31,
	2021		2020
Accrued research and development materials and services	$	1,674	$	519
Accrued professional services		170		67
Accrued personnel expenses		419		47
Other		480		—
Total accrued expenses and other current liabilities	$	2,743	$	633

Taxes - Additional Information (Details) - USD ($)	12 Months Ended
Taxes - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Income tax expense	$ 0	$ 0
Valuation allowance, deferred tax asset, increase (decrease), amount	9,400,000	300,000
Net operating loss carryforwards available to reduce future taxable income	7,689,000	286,000
Research and development tax credit carryforwards	$ 278,000
Tax credit carryforward, description	In general, an “ownership change” will occur if there is a cumulative change in the Company's ownership by “5-percent shareholders” that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws. Therefore, certain of the Company's carryforward tax attributes may be subject to an annual limitation regarding their utilization against taxable income in future periods. The Company has performed a Section 382 study and has concluded that ownership changes through December 31, 2021 will not result in
Interest and penalties	$ 0
Significant change in unrecognized tax benefits, nature of event	The Company does not expect the unrecognized tax benefits to change significantly over the next twelve months.
Income tax examination, description	There are currently no pending income tax examinations.
Tax Year 2021
Income Tax [Line Items]
Operating loss carryforwards, limitations on use	subject to an annual limitation of 80% of taxable income
Federal \| Tax Year 2021
Income Tax [Line Items]
Net operating loss carryforwards available to reduce future taxable income	$ 36,300,000
Federal \| Tax Year 2021 \| Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Tax credit carryforward, expiration year	2040
Research and development tax credit carryforwards	$ 100,000
California \| Tax Year 2021
Income Tax [Line Items]
Net operating loss carryforwards available to reduce future taxable income	$ 1,000,000.0
Tax credit carryforward, expiration year	2040
California \| Tax Year 2021 \| Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Research and development tax credit carryforwards		$ 300,000

Commitments and Contingencies

12 Months Ended

Dec. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 8. Commitments and Contingencies

Operating Leases

The Company leases its headquarters with its main offices and laboratory facilities in Redwood City and San Carlos, California.

In November 2021, the Company entered into a four-year lease for additional lab space located in San Carlos, California which is expected to commence in September 2022. Total future rent payments under the agreement amount to approximately $2.2 million. The Company has not recognized a right-of-use asset or aggregate lease liability as of December 31, 2021 for this lease as the Company did not control the underlying assets at any time during the year ended December 31, 2021.

In September 2021, the Company entered into a sub-lease agreement for additional office space in 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 December 31, 2021. This lease is 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 entered into a five-year lease for new lab space located in San Carlos, California, which commenced on May 1, 2021 and expires in April 2026. The lease was 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 five-year expected remaining term.

In February 2021, the Company entered into an eight-month sublease agreement for additional office space located in 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. This lease was treated as a short-term lease in accordance with ASC 842 and therefore, is excluded from the right-of -use asset and liability.

Cash paid for amounts included in the measurement of lease liabilities for the years ended December 31, 2021 and 2020 was $0.3 million and zero, respectively.

Lease expense was $1.3 million, $0.2 million and $0.1 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Maturities of lease liabilities as of December 31, 2021 were as follows (in thousands):

	Operating Lease
Year Ending December 31,	Commitments
2022	$	705
2023		727
2024		748
2025		771
2026		259
Thereafter		—
Total undiscounted lease payments		3,210
Less: Present value adjustments		(360	)
Total operating lease liabilities	$	2,850
Short-term operating lease liabilities		565
Long-term operating lease liabilities		2,285
Total operating lease liabilities	$	2,850

Legal Proceedings

The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the years ended December 31, 2021 and 2020, and, to the best of its knowledge, no material legal proceedings are currently pending or threatened.

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.

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	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 6,234	$ 322
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,637	89
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,597	$ 233

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) Segment LetterOfCredit	Dec. 31, 2020 USD ($)	Jan. 01, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments \| Segment	1
Number of operating segments \| Segment	1
Number of letters of credit issued to landlord constituting restricted cash \| LetterOfCredit	2
Impairment of long-lived assets	$ 0	$ 0
Right-of-use asset	2,722,000	210,000
Lease liabilities	565,000	223,000
Deferred offering costs	$ 0	$ 29,000
Accounting Standards Update 2016-02
Summary Of Significant Accounting Policies [Line Items]
Right-of-use asset			$ 300,000
Lease liabilities			$ 300,000

Balance Sheet Components - Summary of Accrued Expense and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued research and development materials and services	$ 1,674	$ 519
Accrued professional services	170	67
Accrued personnel expenses	419	47
Other	480
Total accrued expenses and other current liabilities	$ 2,743	$ 633

Balance Sheet Components

12 Months Ended

Dec. 31, 2021

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):

	December 31,
	2021			2020
Computer equipment	$	124		$	—
Furniture and fixtures		315			7
Laboratory equipment		1,874			—
Leasehold improvements		828			24
Construction in progress		81			58
Total property and equipment, gross		3,222			89
Less: accumulated depreciation		(257	)		(8	)
Total property and equipment, net	$	2,965		$	81

Depreciation expense was approximately $0.2 million, $8,000 and zero for the years ended December 31, 2021, 2020 and 2019, respectively.

Accrued Expenses and Other Current Labilities

Accrued expenses and other current liabilities consisted of the following (in thousands):

	December 31,
	2021		2020
Accrued research and development materials and services	$	1,674	$	519
Accrued professional services		170		67
Accrued personnel expenses		419		47
Other		480		—
Total accrued expenses and other current liabilities	$	2,743	$	633

Fair Value Measurement - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments classified as Level 3	$ 141,849,000
Investments		$ 0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments classified as Level 3	$ 0

Taxes - Summary of Reconciliation of Statutory Federal Income Tax Rate to Company's Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%
State income tax rate	0.50%	1.10%
Tax credits	0.20%
Stock-based compensation	(1.50%)
Amortization	2.60%
LLC loss prior to C-Corp conversion		(17.70%)
Change in valuation allowance	(22.70%)	(4.30%)
Other	(0.10%)	(0.10%)
Effective income tax rate	0.00%	0.00%

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								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (14,710)	$ (12,606)	$ (8,399)	$ (5,852)	$ (3,498)	$ (1,135)	$ (293)	$ (398)	$ (41,567)	$ (5,324)	$ (1,198)
Denominator:
Weighted-average number of shares outstanding, basic and diluted	29,061,076	29,001,213	25,161,038	11,964,205	11,871,494	11,724,100	9,746,868	8,758,995	23,858,552	10,532,942	6,051,712
Net loss per share, basic and diluted	$ (0.51)	$ (0.43)	$ (0.33)	$ (0.49)	$ (0.29)	$ (0.10)	$ (0.03)	$ (0.05)	$ (1.74)	$ (0.51)	$ (0.20)

- Definition

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

+ References

+ Details

Organization

12 Months Ended

Dec. 31, 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 covalent small molecule therapeutics to treat patients with genetically defined cancers and metabolic diseases. Since its inception in 2017, the Company has built its proprietary FUSION System to design and develop a pipeline of novel irreversible therapies.

Basis of Presentation

These financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP).

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 $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 $49.7 million at December 31, 2021. As of December 31, 2021, the Company had cash, cash equivalents, restricted cash, and investments of $175.7 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. 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.

Net Loss Per Share

12 Months Ended

Dec. 31, 2021

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):

	Year Ended December 31,
	2021			2020			2019
Numerator:
Net loss	$	(41,567	)	$	(5,324	)	$	(1,198	)
Denominator:
Weighted-average number of shares outstanding, basic and diluted		23,858,552			10,532,942			6,051,712
Net loss per share, basic and diluted	$	(1.74	)	$	(0.51	)	$	(0.20	)

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:

	December 31,
	2021		2020		2019
Series A convertible preferred stock		—		7,064,925		—
Stock options, issued and outstanding		4,254,504		—		—
Estimated shares issuable under the employee stock purchase plan		6,542		—		—
Restricted stock, issued and outstanding		493,914		749,835		—
Total		4,754,960		7,814,760		—