0000950170-22-010094 | 10-Q | XBRL Viewer

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Note Payable - Additional Information (Detail) - Revolving Credit Facility [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2022
Debt Instrument [Line Items]
Revolving credit facility with borrowing capacity		$ 50.0
Initial borrowing capacity		$ 5.0
Additional borrowing capacity			$ 45.0
Debt facility payments description	The debt facility provides for at least 48-months of interest-only payments, which may be extended to 60 months
Prepayment of the loan	5.00%
Extended maturity date	7.00%
London Interbank Offered Rate L I B O R [Member]
Debt Instrument [Line Items]
Floating interest rate	8.25%

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	16. RELATED PARTY TRANSACTIONS In October 2020, the Company entered into the Ares Agreement with Ares, pursuant to which the Company obtained an exclusive worldwide license to certain patents and related know-how to research, develop, manufacture, use and commercialize therapeutic products containing atacicept, a recombinant fusion protein used to inhibit B cell growth and differentiation, which could potentially treat some autoimmune diseases. Related party transactions and balances in the current periods presented are described in Note 3 and Note 12.

Non-Marketable Equity Securities - Summary of Carrying Value of the Non-marketable Equity Securities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Investments, Debt and Equity Securities [Abstract]
Balance as of December 31, 2021	$ 867
Change in fair value	(287)
Balance as of March 31, 2022	$ 580

Net Loss Per Common Share - Summary of Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	3,552,867	17,818,492
Redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities		15,774,014
Class A common stock options issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	3,494,577	2,015,523
Unvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	0	28,955
Unvested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	58,290	0

Neubase Asset Sale - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended
	Apr. 26, 2021	Mar. 31, 2022
Gain (loss) on disposition of assets		$ 2,700
Neubase Therapeutics Inc [Member]
Investment owned number of shares placed in escrow account	162,260
Shares eligible for release from escrow		$ 54,070
Neubase Therapeutics Inc [Member] \| Investment In PNAI [Member]
Proceeds received from the disposal of business	$ 800
Disposal group including discontinued operations shares received for disposal	308,635
Investments owned market value	$ 1,800

Leases - Schedule of Future Minimum Lease Payments under Operating Leases (Detail)
$ in Thousands

Dec. 31, 2021

USD ($)

Leases [Abstract]

Operating Leases 2022

$ 2,669

^[1]

Operating Leases 2023

2,755

^[1]

Operating Leases 2024

2,818

^[1]

Operating Leases 2025

1,954

^[1]

Operating Leases, Total minimum lease payments

10,196

^[1]

Sublease Income, 2022

1,901

Sublease Income, 2023

1,964

Sublease Income, 2024

2,029

Sublease Income, 2025

1,569

Sublease Income, Total minimum lease payments

$ 7,463

[1]	Future minimum lease payments include repayment of outstanding restructuring liabilities.

Common Stock	3 Months Ended
Common Stock	Mar. 31, 2022
Stockholders' Equity Note [Abstract]
Common Stock	. COMMON STOCK As of March 31, 2022, the Company’s amended and restated certificate of incorporation authorized the Company to issue 500,000,000 shares of Class A common stock and 14,600,000 shares of Class B common stock, each with a par value of $0.001 per share. Each share of Class A common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Class B common stock is non-voting. The holders of Class A common stock, voting exclusively and as a separate class, have the exclusive right to vote for the election of one director of the Company. Class A common stockholders and holders of Class B common stock are entitled to receive dividends, as may be declared by the board of directors. Through March 31, 2022, no cash dividends have been declared or paid.

- 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.

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+ Details

Licenses and Collaborations

3 Months Ended

Mar. 31, 2022

Licenses And Collaborations [Abstract]

Licenses and Collaborations

12. LICENSES AND COLLABORATIONS

Ares Trading S.A.

In October 2020, the Company entered into a license agreement with Ares (the Ares Agreement), pursuant to which the Company obtained an exclusive worldwide license to certain patents and related know-how to research, develop, manufacture, use and commercialize therapeutic products containing atacicept, a recombinant fusion protein used to inhibit B cell growth and differentiation, which could potentially treat some autoimmune diseases.

As consideration for the Ares Agreement, the Company issued to Ares a non-refundable license issue fee of 22,171,553 shares of Series C redeemable convertible preferred stock resulting in Ares becoming a related party to the Company. The Series C redeemable convertible preferred stock had a deemed issuance price of $0.5918 per share, or $13.1 million in the aggregate.

In December 2020, the Company paid Ares a milestone payment of $25.0 million upon delivery and initiation of the transfer of specified information and materials. The Company is obligated to pay Ares aggregate milestone payments of up to $176.5 million upon the achievement of specified BLA filing or regulatory approval milestones and up to $515.0 million upon the achievement of specified commercial milestones.

The non-refundable license issue fee and milestone payment were recorded to research and development expense in the period incurred.

Ares is performing manufacturing technology and know-how transfer to the Company over a period not to exceed two years from the effective date of the Ares Agreement. The Company recorded related party expense of $1.1 million and $0.3 million to Ares for these services during the three months ended March 31, 2022 and 2021, respectively.

Commencing on the first commercial sale of licensed products, the Company is obligated to pay Ares tiered royalties of low double-digit to mid-teen percentages on annual net sales of the licensed products covered by the license. The Company is obligated to pay royalties on a licensed product-by- licensed product and country-by-country basis from the first commercial sale of a product in a country until the latest of (i) 15 years after the first commercial sale of such licensed product in such country; (ii) the expiration of the last valid claim of a licensed patent that covers such licensed product in, or its use, importation or manufacture with respect to, such country; and (iii) expiration of all applicable regulatory exclusivity periods, including data exclusivity, in such country with respect to such product. If the Company were to sublicense its rights under the Ares Agreement, the Company is obligated to pay Ares a percentage ranging from the mid-single-digit to the low double-digits of specified sublicensing income received.

Amplyx Pharmaceuticals Inc.

In December 2021, the Company entered into an asset purchase agreement (the Amplyx Agreement) with Amplyx Pharmaceuticals Inc. (Amplyx), a wholly owned subsidiary of Pfizer Inc. Pursuant to the terms of the Amplyx Agreement, the Company paid $5.0 million to Amplyx to purchase assets relating to an anti-BKV monoclonal antibody referred to as MAU868 for the treatment of BKV infection pursuant to a License Agreement between Amplyx and Novartis International Pharmaceutical AG (Novartis). In addition, the Company recognized a $2.0 million contingent milestone obligation that is probable of achievement as an assumed liability related to the asset purchase.

The transaction was treated as an asset acquisition, as the assets acquired did not meet the definition of a business. ASC 805-10-55 states that if substantially all the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not considered a business. Since the gross assets acquired are concentrated on a single identifiable asset, MAU868, the transaction was accounted for as an asset acquisition. In accordance with accounting guidance, costs incurred in obtaining technology licenses are charged to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future use. The assets purchased from Amplyx require substantial completion of research and development, regulatory and marketing approval efforts in order to reach technological feasibility. Accordingly, the acquisition cost of $7.0 million was recorded as research and development expense in the statement of operations and comprehensive loss on the acquisition date.

In connection with the Amplyx asset purchase, Amplyx assigned the Exclusive License Agreement between Amplyx and Novartis (the Novartis License) and Manufacturing and Supply Agreements to the Company. Under the Novartis License Agreement, the Company has exclusive worldwide rights from Novartis to develop, manufacture and commercialize MAU868. The Company will be solely responsible for all research, development, regulatory, manufacturing and commercialization activities of MAU868.

Under the Amplyx Agreement, the Company is obligated to make future milestone payments to Amplyx and Novartis totaling up to approximately $76.0 million, contingent upon the achievement of various clinical development and regulatory milestones. Of this total, the Company has recognized $2.0 million of future milestone payments to Novartis as assumed liabilities upon acquisition. In the event that MAU868 is commercialized, the Company is obligated to pay to Amplyx and Novartis royalties based on net sales by country and by product.

Employee Benefit Plans	3 Months Ended
Employee Benefit Plans	Mar. 31, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	11. EMPLOYEE BENEFIT PLANS The Company sponsors a qualified 401(k) defined contribution plan covering eligible employees. Participants may contribute a portion of their annual compensation limited to a maximum annual amount set by the Internal Revenue Service. There were no employer contributions under this plan for the three months ended March 31, 2022.

- Definition

The entire disclosure for retirement benefits.

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+ Details

Other Financial Statement Information - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Other Financial Statement Information [Abstract]
Accrued research and development contract costs	$ 5,200	$ 364
Accrued development milestone	2,000	2,000
Related party payable	1,640	1,022
Accrued payroll	460	1,458
Accrued legal fees	253	457
Accrued expenses and other	598	627
Total accrued expenses and other current liabilities	$ 10,151	$ 5,928

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

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+ Details

Non-Marketable Equity Securities (Tables)

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of Carrying Value of the Non-marketable Equity Securities

The carrying value of the non-marketable equity securities as of March 31, 2022, is summarized below.


Balance as of December 31, 2021	$	867
Change in fair value		(287	)
Balance as of March 31, 2022	$	580

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Jan. 01, 2022	Dec. 31, 2021
Accounting Policies [Line Items]
Income tax provision	$ 0	$ 0
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]			Operating Lease, Right-of-Use Asset
Operating Lease, Right-of-Use Asset	6,275,000		$ 6,800,000	$ 0
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]			us-gaap:OtherLiabilitiesNoncurrent
Operating Lease, Liability	7,847,000		$ 8,500,000
Restructuring lease liability	0		$ 1,600,000	377,000
Money Market Funds [Member]
Accounting Policies [Line Items]
Money market funds	$ 105,300,000			$ 73,800,000

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Condensed Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Preferred stock par or stated value per share	$ 0.001	$ 0.001
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common Class A [Member]
Common stock, Par value	$ 0.001	$ 0.001
Common stock, Shares authorized	500,000,000	500,000,000
Common stock, Shares issued	26,756,235	20,968,376
Common stock, Shares outstanding	26,756,235	20,968,376
Common Class B [Member]
Common stock, Par value	$ 0.001	$ 0.001
Common stock, Shares authorized	14,600,000	14,600,000
Common stock, Shares issued	309,238	309,238
Common stock, Shares outstanding	309,238	309,238

Stock Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail) - 2017 EIP And 2021 EIP [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Beginning	2,924,521
Number of options, Granted	588,002
Number of options, Exercised	(17,946)
Number of options, Cancelled and forfeited	0
Number of options, Ending	3,494,577	2,924,521
Number of options, Options exercisable	672,992
Number of options, Vested and expected to vest	3,494,577
Weighted average exercise price, Opening balance	$ 5.62
Weighted average exercise price, Granted	21.08
Weighted average exercise price, Exercised	3.65
Weighted average exercise price, Cancelled and forfeited	0
Weighted average exercise price, Ending balance	8.23	$ 5.62
Weighted average exercise price, Option exercisable	3.47
Weighted average exercise price, Vested and expected to vest	$ 8.23
Weighted average remaining contractual term	9 years 10 days	9 years 1 month 9 days
Weighted average remaining contractual term, Options exercisable	8 years 8 months 19 days
Weighted average remaining contractual term, Vested and expected to vest	9 years 10 days
Intrinsic Value	$ 53,356	$ 61,712
Intrinsic Value, Options exercisable	13,472
Intrinsic Value, Vested and expected to vest	$ 53,356

Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
Condensed Statements of Cash Flows - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net loss	$ (17,085)	$ (4,714)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and accretion	9	35
Reduction in the carrying amount of operating lease right of use assets	564	0
Stock-based compensation	1,662	404
Restructuring payments	0	(590)
Changes in operating assets and liabilities:
Prepaid expense and other current assets	(3,942)	(127)
Other assets	271	0
Accounts payable	5,943	(198)
Accrued and other current liabilities	4,223	1,069
Operating lease assets and liabilities, net	(626)	0
Net cash used in operating activities	(8,981)	(4,121)
Cash flows from investing activities
Purchase of property and equipment	(18)	0
Purchase of marketable securities	(39,437)	0
Net cash provided by (used in) investing activities	(39,455)	0
Cash flows from financing activities
Proceeds from exercise of stock options and employee stock purchase plan	234	342
Proceeds from issuance of Class A common stock offering, net of underwriting discounts and commissions	86,130	0
Payment of costs related to stock offering	(6,096)	0
Payment of deferred offering costs	0	(369)
Payment on capital lease obligations	0	(1)
Net cash provided by (used in) financing activities	80,268	(28)
Net increase (decrease) in cash and cash equivalents and restricted cash	31,832	(4,149)
Cash, cash equivalents and restricted cash, beginning of period	79,967	53,997
Cash, cash equivalents and restricted cash, end of period	111,799	49,848
Supplemental disclosure of cash flow information
Cash paid for interest expense	104	0
Cash paid for operating leases	656
Deferred offering costs included in accounts payable	0	729
Deferred offering costs included in accrued and other current liabilities	0	195
Cash and cash equivalents [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, end of period	111,506	49,505
Restricted cash [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, end of period	$ 293	$ 343

Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Summarizes the Unrealized Gains and Losses in the Company's Investments in Marketable Securities

The following table summarizes the unrealized gains and losses in the Company's investments in marketable securities (in thousands):


	As of March 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Level 2:
US Government bonds	$	39,444	$	2	$	(14	)	$	39,432
Total marketable securities	$	39,444	$	2	$	(14	)	$	39,432

Leases (Tables)

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

Schedule of Lease Cost

Net lease cost recognized is summarized as follows (in thousands):


	Three Months Ended March 31,
Operating lease cost	$	570
Sublease income		(482	)
Net lease cost	$	88

Schedule of lease liabilities based on minimum lease commitment

As of March 31, 2022, the maturities of the lease liabilities based on minimum lease commitment amount are as follows (in thousands):


Remainder of 2022	$	1,981
2023		2,702
2024		2,742
2025		1,880
2026	-
Total minimum lease payments		9,305
Less: Imputed interest		(1,458	)
Present value of operating lease liabilities		7,847
Less: Current portion of operating lease liabilities		2,490
Non-current operating lease liabilities	$	5,357

Schedule of future minimum lease payments under operating leases

In accordance with ASC 840, Leases, the aggregate minimum non-cancellable annual lease payments for operating leases in effect as of December 31, 2021, were as follows (in thousands):


	Operating Leases (1)		Sublease Income
2022	$	2,669	$	1,901
2023		2,755		1,964
2024		2,818		2,029
2025		1,954		1,569
Total minimum lease payments	$	10,196	$	7,463

(1) Future minimum lease payments include repayment of outstanding restructuring liabilities.

Leases

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

LEASES

7. LEASES

Net lease cost recognized is summarized as follows (in thousands):


	Three Months Ended March 31,
Operating lease cost	$	570
Sublease income		(482	)
Net lease cost	$	88

As of March 31, 2022, the maturities of the lease liabilities based on minimum lease commitment amount are as follows (in thousands):


Remainder of 2022	$	1,981
2023		2,702
2024		2,742
2025		1,880
2026	-
Total minimum lease payments		9,305
Less: Imputed interest		(1,458	)
Present value of operating lease liabilities		7,847
Less: Current portion of operating lease liabilities		2,490
Non-current operating lease liabilities	$	5,357

During the three months ended March 31, 2022, there were no additions of operating or finance lease assets. As of March 31, 2022, the company had not executed any operating or finance leases that were yet to commence. As of March 31, 2022, the weighted-average remaining operating lease term was 3.4 years and the weighted-average discount rate was 9.0% for operating leases recognized in the financial statements.

In accordance with ASC 840, Leases, the aggregate minimum non-cancellable annual lease payments for operating leases in effect as of December 31, 2021, were as follows (in thousands):


	Operating Leases (1)		Sublease Income
2022	$	2,669	$	1,901
2023		2,755		1,964
2024		2,818		2,029
2025		1,954		1,569
Total minimum lease payments	$	10,196	$	7,463

(1) Future minimum lease payments include repayment of outstanding restructuring liabilities.

Note Payable - Schedule of Notes Payable (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Collateralized note , variable	Variable
Collateralized debt instrument maturity date	2026
Collateralized note , Effective interest rate	9.54%
Collateralized note ,Amount	$ 5,000	$ 5,000
Less: Unamortized debt issuance costs	63	77
Total long-term debt	$ 4,937	$ 4,923

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details

Condensed Balance Sheet - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 111,506	$ 79,674
Marketable securities	39,432	0
Prepaid expenses and other current assets	6,805	2,863
Total current assets	157,743	82,537
Restricted cash, noncurrent	293	293
Property and equipment, net	16	0
Operating lease right-of-use assets	6,275	0
Prepaid expenses and other noncurrent assets	67	51
Non-marketable equity securities	580	867
Total assets	164,974	83,748
Current liabilities:
Accounts payable	7,328	1,385
Operating lease liabilities	2,490	0
Restructuring liability	0	377
Accrued expenses and other current liabilities	10,151	5,928
Total current liabilities	19,969	7,690
Long-term debt	4,937	4,923
Operating lease liabilities, noncurrent	5,357	0
Restructuring liability, noncurrent	0	1,257
Accrued and other noncurrent liabilities	286	286
Total liabilities	30,549	14,156
Stockholders' equity
Preferred stock, $0.001 par value; 10,000,000 authorized as of March 31, 2022 and December 31, 2021; no shares issued and outstanding as of March 31, 2022 and December 31, 2021	0	0
Additional paid-in capital	275,551	193,627
Accumulated other comprehensive loss	(12)	0
Accumulated deficit	(141,141)	(124,056)
Total stockholders' equity	134,425	69,592
Total liabilities and stockholders' equity	164,974	83,748
Common Class A [Member]
Stockholders' equity
Common Stock	27	21
Common Class B Non Voting [Member]
Stockholders' equity
Common Stock	$ 0	$ 0

Organization and Description of the Business - Additional Information (Detail) $ / shares in Units, $ in Thousands						1 Months Ended
	Feb. 14, 2022 $ / shares shares	Feb. 09, 2022 USD ($)	May 20, 2021 USD ($) shares	May 13, 2021 $ / shares shares	May 07, 2021	May 31, 2021 shares	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Accumulated deficit							$ (141,141)	$ (124,056)
Cash and cash equivalents							111,506	$ 79,674
Cash And Cash Equivalents And Marketable Securities							$ 150,900
Stock split ratio					11.5869
Underwriting discounts and commissions		$ 5,200	$ 3,900
Offering Costs		800	2,800
Common Class A [Member]
Stock shares issued during the period new issues shares \| shares	748,959
Sale of stock net consideration received on the transaction		$ 80,000
Common Class A [Member] \| IPO [Member]
Stock shares issued during the period new issues shares \| shares				4,350,000
Sale of stock, price per share \| $ / shares				$ 11.00
Sale of stock net consideration received on the transaction			$ 48,400
Common Class A [Member] \| Follow-on Public Offering [Member]
Stock shares issued during the period new issues shares \| shares	5,742,026
Sale of stock, price per share \| $ / shares	$ 15.00
Common Class A [Member] \| Over-Allotment Option [Member]
Stock shares issued during the period new issues shares \| shares			652,500
Common Class A [Member] \| Conversion Of Redeemable Preferred Stock Into Common Stock [Member]
Conversion of redeemable convertible preferred stock to common stock \| shares						15,464,776
Common Class B [Member] \| Conversion Of Redeemable Preferred Stock Into Common Stock [Member]
Conversion of redeemable convertible preferred stock to common stock \| shares						309,238

Employee Benefit Plans - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2022 USD ($)
Retirement Benefits [Abstract]
Employer contributions	$ 0

Restructuring and Related Activities

3 Months Ended

Mar. 31, 2022

Restructuring and Related Activities [Abstract]

Restructuring and Related Activities

14. RESTRUCTURING AND RELATED ACTIVITIES

During the year ended December 31, 2019, the Company completely vacated its leased facilities in Woburn, Massachusetts. In connection with vacating the leased spaces, the Company recorded a discounted lease-related restructuring liability, which was calculated as the present value of the estimated future facility costs for which the Company would obtain no future economic benefit over the term of the lease, reduced for actual or estimated sublease rentals.

In July 2020, the Company initiated a restructuring plan to reduce operating expense as a result of the disposal of PNAi technology. The restructuring plan included reducing the number of employees, vacating leased facilities, and ceasing use of leased equipment.

As a result of this restructuring plan, the Company completely vacated its leased facilities in South San Francisco, California, which was subleased to a third party in November 2020, and returned certain leased equipment to the lessor. The Company recorded a discounted lease-related restructuring liability of $2.2 million and $0.8 million for the abandonment of the leased facilities and equipment, which was calculated as the present value of the estimated future lease costs for which the Company would obtain no future economic benefit over the term of the leases. In addition, the Company recognized restructuring liability of $321 related to severance and other employee termination costs related to the reduction in the number of employees.

The lease related restructuring liability of $1.6 million as of December 31, 2021, was derecognized upon the adoption of ASC 842 on January 1, 2022, and included in operating lease liabilities.

Neubase Asset Sale

3 Months Ended

Mar. 31, 2022

Neubase Asset Sale [Abstract]

Neubase Asset Sale

4. NEUBASE ASSET SALE

On January 27, 2021, the Company entered into an asset purchase agreement with NeuBase Therapeutics, Inc. (“NeuBase”), whereby the Company agreed to sell all assets relating to its investment in PNAi, including all inventory, machinery, intellectual property, goodwill, and licenses, and NeuBase agreed to assume certain related liabilities. The sale of the Company’s investment in PNAi closed on April 26, 2021. The Company received $0.8 million in cash and 308,635 shares of NeuBase common stock, with a fair market value of $1.8 million based on the closing price reported on the Nasdaq Capital Market on the date the sale closed. Of the total NeuBase shares issued to the Company, 162,260 were placed in escrow to secure certain obligations under the asset purchase agreement. In connection with the sale, the Company also assigned certain leases for research and laboratory equipment to NeuBase (see Note 13). The Company recognized a gain of $2.7 million on the sale of assets to NeuBase.

As of March 31, 2022, 54,070 NeuBase shares have been released from escrow.

Leases - Schedule of Lease Cost (Detail) $ in Thousands	3 Months Ended
Leases - Schedule of Lease Cost (Detail) $ in Thousands	Mar. 31, 2022 USD ($)
Leases [Abstract]
Operating lease cost	$ 570
Sublease income	(482)
Net lease cost	$ 88

Non-Marketable Equity Securities

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Non-Marketable Equity Securities

6. NON-MARKETABLE EQUITY SECURITIES

The Company has an investment in NeuBase common stock with restrictions on the sale or transfer of the shares. Fair value is determined using alternative pricing sources and models utilizing market observable inputs. The Company reports the restricted equity securities as non-marketable equity securities on the balance sheet and determines current or non-current classification based on the expected duration of the restriction.

The Company recorded a net unrealized loss of $0.3 million in other expense for the three months ended March 31, 2022. The carrying value is measured as the total initial cost, less the cumulative net unrealized loss. The carrying value of the non-marketable equity securities as of March 31, 2022, is summarized below.


Balance as of December 31, 2021	$	867
Change in fair value		(287	)
Balance as of March 31, 2022	$	580

Common Stock - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Common Class A [Member]
Class of Stock [Line Items]
Common stock shares authorized	500,000,000	500,000,000
Common stock par or stated value per share	$ 0.001	$ 0.001
Common stock conversion basis	one
Cash dividends	$ 0
Common Class B [Member]
Class of Stock [Line Items]
Common stock shares authorized	14,600,000	14,600,000
Common stock par or stated value per share	$ 0.001	$ 0.001
Cash dividends	$ 0

Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and applicable rules and regulations of the SEC regarding interim financial reporting. The U.S. dollar is the Company’s functional and reporting currency.
Unaudited Interim Condensed Financial Statements	Unaudited Interim Condensed Financial Statements The accompanying condensed balance sheet as of March 31, 2022, and condensed statements of operations and comprehensive loss, condensed statements of cash flows, and condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three months ended March 31, 2022 and 2021, are unaudited. The balance sheet as of December 31, 2021, was derived from the audited financial statements as of and for the year ended December 31, 2021. The unaudited condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2021 and in the opinion of management, reflect all adjustments consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of March 31, 2022, and the condensed results of its operations and its cash flows for the three months ended March 31, 2022. The financial data and other information disclosed in these notes related to the three months ended March 31, 2022, are also unaudited. The condensed results of operations for the three months ended March 31, 2022, are not necessarily indicative of the results to be expected for the full year ending December 31, 2022, or any other period. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2021, included in the Company’s final prospectus dated May 13, 2021, for the IPO filed with the SEC on May 17, 2021, pursuant to Rule 424(b)(4) relating to the Company’s Registration Statement on Form S-1, as amended (File No. 333-255492).
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (1) is no longer an emerging growth company or (2) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
Use of Estimates	Use of Estimates The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited condensed financial statements and the reported amounts of expenses during the reporting period. Management estimates that affect the reported amounts of assets and liabilities include the accrual of research and development expenses, restructuring liabilities, fair value of common stock and stock-based compensation expense, determination of incremental borrowing rate for operating leases, the valuation allowance for deferred tax assets, and fair value of marketable and non-marketable securities. The Company evaluates and adjusts its estimates and assumptions on an ongoing basis using historical experience and other factors. Actual results could differ materially from those estimates.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs consisting of legal, accounting and filing fees relating to the IPO are capitalized. The deferred offering costs were offset against the Company’s IPO proceeds upon the closing of the IPO.
Concentrations of Credit Risk and Other Risks and Uncertainties	Concentrations of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains bank deposits in a federally insured financial institution and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current and potential future 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 relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fails to satisfy the Company's requirements on a timely basis, it could suffer delays in its clinical development programs and activities, which could adversely affects is operating results. 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 was denied approval, approval was delayed, or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.
Impact of the COVID-19 Pandemic	Impact of the COVID-19 Pandemic The COVID-19 pandemic continues to evolve. The extent of the impact of the COVID-19 pandemic on the Company’s business, operations, and development timelines and plans remains uncertain, and will depend on certain developments, including the duration and spread of the outbreak and its impact on the Company’s development activities, planned clinical trial enrollment, future trial sites, contract research organizations, third-party manufacturers, and other third parties with whom the Company does business, as well as its impact on regulatory authorities and the Company’s key scientific and management personnel. The ultimate impact of the COVID-19 pandemic or a similar health epidemic is highly uncertain and subject to change. To the extent possible, the Company is conducting business as usual, with necessary or advisable modifications to employee travel and with the Company’s employees working remotely. The Company will continue to actively monitor the evolving situation related to the COVID-19 pandemic and may take further actions that alter the Company’s operations, including those that may be required by federal, state or local authorities, or that the Company determines are in the best interests of its employees and other third parties with whom the Company does business. At this point, the extent to which the COVID-19 pandemic may affect the Company’s business, operations and development timelines and plans, including the resulting impact on expenditures and capital needs, remains uncertain.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds and are stated at fair value.
Marketable Securities	Marketable Securities The Company holds investments in marketable securities, consisting of U.S. government securities. Marketable securities with stated maturities of three months or less from the date of purchase are classified as cash equivalents and those with stated maturities of greater than three months as marketable securities on the balance sheet. The Company designated these securities as available-for-sale to support current operations and are reported at estimated fair value, with unrealized gains and losses recorded in accumulated other comprehensive loss within stockholders’ equity. Interest, amortization and accretion of purchase premiums and discounts on marketable debt securities are included in other income (expense), net, in the condensed statements of operations and comprehensive loss. The cost of available-for-sale marketable securities sold is based on the specific identification method. Realized gains and losses on the sale of available-for-sale marketable securities are recorded in other income (expense), net. The Company regularly reviews all of the marketable securities for decline in fair value to determine whether unrealized losses have resulted from credit loss or other factors. The review includes considerations for the cause of the impairment but is not limited to (i) the consideration of the cause of the decline, (ii) any currently recorded expected credit losses and (iii) the creditworthiness of the respective security issuers. A decline of fair value below cost basis is considered an other-than-temporary impairment if the Company has the intent to sell the security or it is more likely than not that the company will be required to sell the security before recovery of the entire cost basis. Regardless of the Company’s intent or requirement to sell the security, an impairment is considered other-than-temporary if the Company does not expect to recover the entire cost basis. In those instances, an impairment charge equal to the difference between fair value and the cost basis is recorded in other income (expense), on the condensed statements of operations and comprehensive loss. The amortized or accreted cost basis of the marketable securities approximates its fair value.
Restricted Cash	Restricted Cash Restricted cash represents cash held by a financial institution as collateral for a letter of credit securing the Company's operating lease for office and laboratory space, which is classified within non-current assets on the condensed balance sheets.
Comprehensive Loss	Comprehensive Loss Comprehensive loss consists of two components: net loss and other comprehensive loss. Other comprehensive loss refers to gains and losses that are recorded as an element of stockholder's equity and are excluded from net loss. For the three months ended March 31, 2022, other comprehensive loss consists of unrealized gains and losses on marketable securities.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred and consist primarily of employees’ salaries and related benefits, including stock-based compensation and termination expenses for employees engaged in research and development efforts, allocated overhead including rent, depreciation, information technology and utilities, contracted services, license fees, and external expenses to conduct and support the Company’s operations that are directly attributable to the Company’s research and development efforts. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Costs incurred in obtaining technology licenses including upfront and milestone payments incurred under the Company’s licensing agreements are recorded as expense in the period in which they are incurred, provided that the licensed technology, method or process has no alternative future uses other than for the Company’s research and development activities. Where contingent milestone payments are due to third parties under license or other agreements, the milestone payment obligations are recognized as expense when achievement of the contingent milestone is probable, which is generally upon achievement of the milestone.
Research Contract Costs and Accruals	Research Contract Costs and Accruals The Company enters into various research and development and other agreements with commercial firms, researchers, and others for provisions of goods and services from time to time. These agreements are generally cancellable, and the related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to the Company’s employees, nonemployee directors and consultants that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant. For all stock options granted, the Company calculated the expected term using the simplified method (derived from the average midpoint between the weighted average vesting period and the contractual term of the award) for “plain vanilla” stock option awards, as the Company has limited historical information to develop expectations about future exercise patterns and post vesting employment termination behavior. The estimate of expected volatility is based on comparative companies’ volatility. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The Company records forfeitures when they occur. Prior to the IPO, the fair value of the shares of common stock underlying the stock options was determined by the board of directors with the assistance of management and input from an independent third-party valuation firm, as there was no public market for the common stock. The board of directors determined the fair value of the Company’s common stock by considering a number of objective and subjective factors, including the valuation of comparable companies, sales of redeemable convertible preferred stock, the Company’s operating and financial performance, the lack of liquidity of common stock, and general and industry specific economic outlook, amongst other factors. Subsequent to the IPO, the Company determines the fair value using the market closing price of its common stock on the date of grant. The Company records compensation expense for service-based awards on a straight-line basis over the requisite service period, which is generally the vesting period of the award. The amount of stock-based compensation expense recognized during a period is based on the value of the portion of the awards that are ultimately expected to vest.
Income Taxes	Income Taxes The Company did not record an income tax provision for the three months ended March 31, 2022 and 2021, as net operating losses have been incurred since inception. The net deferred tax assets generated from net operating losses are fully offset by a valuation allowance.
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Net loss per share of common stock is computed using the two-class method required for multiple classes of common stock and participating securities based upon their respective rights to receive dividends as if all income for the period has been distributed. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders is therefore the same for Class A and Class B common stock on an individual or combined basis. Prior to the IPO, the Company’s participating securities included the Company’s redeemable convertible preferred stock, as the holders were entitled to receive noncumulative dividends on a pari passu basis in the event that a dividend is paid on common stock. The Company also considers any shares issued on the early exercise of stock options subject to repurchase to be participating securities because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of redeemable convertible preferred stock, as well as the holders of early exercised shares subject to repurchase, did not and do not have a contractual obligation to share in losses of the Company, and therefore during periods of loss there is no allocation required under the two-class method. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, adjusted for outstanding shares that are subject to repurchase. Diluted net loss per share is computed by giving effect to all potentially dilutive securities outstanding for the period using the treasury stock method or the if-converted method based on the nature of such securities. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive shares are not assumed to have been issued if their effect is anti-dilutive.
Leases	Leases The Company leases office and laboratory space under operating leases and determines if the arrangement is a lease at inception. These leases contain lease and non-lease components. Non-lease components include payments for maintenance, utilities, real estate taxes, and management fees. The lease and non-lease components are combined and accounted as a single lease component. Payments made under operating leases (net of any incentive received from the lessors) are recorded on a straight-line basis over the term of the lease. These leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is a hypothetical rate based on the Company's understanding of what the credit rating would be in a similar economic environment. Operating leases are included in operating lease right-of-use assets and operating lease liabilities, current and non-current, on the balance sheets. Leases may include one or more options to renew. The Company does not assume renewals in determination of the lease term unless the renewals are deemed to be reasonably assured. The lease agreements generally do not contain any material residual value guarantees or material restrictive covenants.
Restructuring Costs	Restructuring Costs Restructuring costs primarily consist of contract termination costs related to leases and employee termination costs. The Company recognizes restructuring charges when the liability has been incurred. Key assumptions in determining the restructuring costs include the terms and payments that may be negotiated to terminate certain contractual obligations, cease use date of leased property and equipment, and the timing of employees leaving the Company. Accretion expenses related to restructuring costs are included in general and administrative expenses.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the exchange price to sell an asset or transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should be based on the assumptions market participants would use when pricing the asset or liability. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. Fair value measurements are classified and disclosed in one of the following three categories: Level 1 – Quoted unadjusted prices for identical instruments in active markets. Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all observable inputs and significant value drivers are observable in active markets. Level 3 – Model derived valuations in which one or more significant inputs or significant value drivers are unobservable, including assumptions developed by the Company. Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed in the condensed financial statements on a recurring basis. The Company’s financial instruments consist of cash and cash equivalents, marketable securities, prepaid expenses and other current assets, accounts payable and accrued expenses. Cash and marketable securities are reported at their respective fair values on our condensed balance sheets. The remaining financial instruments are reported on our condensed balance sheets at cost, which approximate their fair value due to their short-term nature. Money market funds are highly liquid investments that are actively traded. The pricing information for the Company’s money market funds are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 1 of the fair value hierarchy. The Company’s non-marketable equity securities (Note 6) are measured at fair value using an option pricing valuation methodology. The option pricing methodology relies on risk-neutral valuation which calculates the value of an asset by discounting the expected value of its future payoffs at the risk-free rate of return. The fair value of the non-marketable equity securities is derived from quoted prices for similar instruments and observable inputs in active markets. This approach results in the classification of these securities as Level 2 of the fair value hierarchy. There were no transfers between Levels 1, 2, or 3 for any of the periods presented. As of March 31, 2022, and December 31, 2021, the Company held $105.3 million and $73.8 million, respectively, in money market funds.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes, related to simplifying the accounting for income taxes. The guidance eliminates certain exceptions from Accounting Standards Codification (ASC) 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The guidance also clarifies and simplifies other aspects of the accounting for income taxes. The guidance became effective for the Company beginning on the first quarter of 2021 on a prospective basis. The Company adopted this standard on January 1, 2021, and it did not have a material impact on the Company's condensed financial statements or related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), subsequently amended by ASU 2018-10, ASU 2018-11, ASU 2018-20, ASU 2019-01 and ASU 2019-10, which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessors and lessees of a contract. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification on the balance sheets. Leases with a term of 12 months or less may be accounted for similar to existing guidance for operating leases today. The Company adopted this standard on January 1, 2022, using the optional transition method, which allows for the prospective application of the standard. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the standard, which allowed the Company to carry forward historical lease classification, to not reassess prior conclusions related to initial direct costs, and to not reassess whether any expired or existing contracts are or contain leases. The Company also elected the practical expedient to not separate lease and non-lease components for all leases. In connection with the adoption of the new guidance, the Company recognized $6.8 million of operating lease right-of-use assets and $8.5 million of operating lease liabilities and derecognized $1.6 million of restructuring lease liability, with immaterial effect to the statements of operations and comprehensive loss and cash flows.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The objective of the standard is to provide information about expected credit losses on financial instruments at each reporting date and to change how other-than temporary impairments on investment securities are recorded. The guidance is effective for the Company beginning on January 1, 2023, with early adoption permitted. The Company is currently evaluating the impact the standard may have on its condensed financial statements and related disclosures. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. In response to concerns about structural risks of the cessation of London Interbank Offered Rate (LIBOR), the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effect of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The expedients and exceptions provided by this amendment do not apply to contract modifications made and hedge relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective for all entities as of March 12, 2020 through December 31, 2022. The Company continues to evaluate contractual arrangements that reference LIBOR and the impact this standard will have on its condensed financial statements and related disclosures. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40). This standard simplifies the accounting for convertible debt instruments and convertible preferred stock by removing the existing guidance in ASC 470-20 that requires entities to account for beneficial conversion features and cash conversion features in equity, separately from the host convertible debt or preferred stock. ASU 2020-06 is effective for the Company for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2023, and early adoption is permitted. The Company is currently evaluating the impact this standard will have on its condensed financial statements and related disclosures.

Organization and Description of the Business

3 Months Ended

Mar. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Description of the Business

1. ORGANIZATION AND DESCRIPTION OF THE BUSINESS

Description of Business

Vera Therapeutics, Inc., (the “Company”) is a clinical late-stage stage biotechnology company focused on developing and commercializing transformative treatments for patients with serious immunological diseases. The Company is headquartered in Brisbane, California and was incorporated in May 2016 in Delaware. In 2017, the Company acquired all of the outstanding shares of PNA Innovations, Inc. (“PNAi”), which was based in Woburn, Massachusetts.

Reverse Stock Split

On May 7, 2021, the Company filed a certificate of amendment to its fourth amended and restated certificate of incorporation to effect a 11.5869-for-one reverse stock split of its issued and outstanding Class A common stock. Adjustments corresponding to the reverse stock split were made to the ratio at which the Company’s redeemable convertible preferred stock converted into Class A common stock. Accordingly, all share and per share amounts related to Class A common stock, stock options and restricted stock awards for all periods presented in the accompanying financial statements and notes thereto have been retroactively adjusted, where applicable to reflect the reverse stock split.

Initial Public Offering

On May 13, 2021, the Company’s registration statement on Form S-1 for its initial public offering (the “IPO”) was declared effective by the Securities and Exchange Commission (the “SEC”), and the shares of its Class A common stock commenced trading on the Nasdaq Global Select Market on May 14, 2021. The IPO closed on May 18, 2021, pursuant to which the Company issued and sold 4,350,000 shares of its Class A common stock at a public offering price of $11.00 per share. On May 20, 2021, the Company issued 652,500 shares of its Class A common stock to the underwriters of the IPO pursuant to the exercise of the underwriters’ option to purchase additional shares. The Company received total net proceeds of $48.4 million from the IPO, after deducting underwriting discounts and commissions of $3.9 million, and offering costs of $2.8 million. Prior to the completion of the IPO, all shares of redeemable convertible preferred stock then outstanding were converted into 15,464,776 shares of Class A common stock and 309,238 shares of Class B common stock.

Follow-on Public Offering

On February 14, 2022, the Company completed a follow-on public offering pursuant to which the Company issued and sold 5,742,026 shares of its Class A common stock at a public offering price of $15.00 per share, including 748,959 shares of Class A common stock pursuant to the full exercise of the underwriters' option to purchase additional shares. The Company received total net proceeds of approximately $80.0 million, after deducting underwriting discounts and commissions of $5.2 million, and offering costs of approximately $0.8 million.

Liquidity

Since inception, the Company devoted substantially all of its resources to its research and development efforts, pre-clinical studies and clinical trials, establishing and maintaining its intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. The Company has incurred recurring net operating losses since its inception and had an accumulated deficit of $141.1 million as of March 31, 2022. The Company had cash, cash equivalents and marketable securities of $150.9 million as of March 31, 2022, and has not generated positive cash flow from operations. The Company has funded its operations primarily through the issuance of common stock, redeemable convertible preferred stock, debt financing and convertible notes. Management expects to continue to incur losses and negative cash flows from operations for at least the next several years.

Management believes that the Company’s cash, cash equivalents and marketable securities as of March 31, 2022 will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months subsequent to the issuance date of these financial statements. The Company intends to raise additional capital through public or private equity offerings or debt financing or other capital sources, which may include strategic collaborations or other arrangements with third parties in order to achieve its long-term business objectives. If the Company fails to obtain necessary capital when needed on acceptable terms, or at all, it could force the Company to delay, limit, reduce or terminate its product development programs, commercialization efforts or other operations.

Note Payable

3 Months Ended

Mar. 31, 2022

Debt Disclosure [Abstract]

Note Payable

8. NOTE PAYABLE

Note payable consists of the following:


	Rate Type	Maturity	Effective Interest Rate	March 31, 2022			December 31, 2021
				(in thousands)			(in thousands)
Collateralized note	Variable	2026	9.54%	$	5,000		$	5,000
Less: Unamortized debt issuance costs					(63	)		(77	)
Net carrying amount of debt				$	4,937		$	4,923

The carrying amount of debt approximates fair value due to its variable interest rate.

In December 2021, the Company entered into a loan and security agreement (the Loan Agreement) for a non-revolving credit facility with borrowing capacity of up to $50.0 million. An initial $5.0 million (the Loan) was funded in December 2021, and an additional $45.0 million will be available in minimum draws of $5.0 million, at the Company’s option through the end of 2022. The Loan matures in December 2026, which may be extended by 12 months subject to certain clinical data milestones. The debt facility provides for at least 48-months of interest-only payments, which may be extended to 60 months if the final maturity date is extended.

Initially, the Loan bears interest at 8.25%, with a floating interest rate tied to LIBOR. The Company is permitted to prepay the Loan, subject to certain conditions. Upon the maturity date or prepayment of the Loan, the Company is required to make a final payment equal to 5.0% (or 7.0% if the maturity date is extended) of the aggregate principal amount of the Loan. The Loan Agreement contains a subjective acceleration clause in the case of an event of default. If such a matter occurs and is continuing, the lender may legally demand the outstanding principal and interest immediately due and payable. There are no financial covenants associated with the credit facility and the Loan is secured by the Company’s assets.

Principal installments due on the note subsequent to March 31, 2022, are as follows (in thousands):


Remainder of 2022	$	—
2023		—
2024		—
2025		—
2026		5,000
Total long-term debt	$	5,000

Stock Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Detail)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected volatility, Minimum	75.80%	76.30%
Expected volatility, Maximum		76.40%
Risk-free rate, Minimum	1.80%	0.60%
Risk-free rate, Maximum	1.90%	0.80%
Minimum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected term (in years)	6 years	6 years
Maximum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days

License and Collaborations - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		12 Months Ended
	Oct. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
License and Collaborations [Line Items]
Research and development		$ 12,549	$ 2,932
Ares Agreement [Member] \| Ares Trading S A [Member]
License and Collaborations [Line Items]
Milestone payments paid					$ 25,000
Payment for royalties on a licensed product, Term		2 years
Related party transaction, expenses from transactions with related party		$ 1,100	$ 300
Ares Agreement [Member] \| Ares Trading S A [Member] \| Achievement Of Specified BLA Filing Or Regulatory Approval Milestones [Member]
License and Collaborations [Line Items]
Milestone payments payable					$ 176,500
Ares Agreement [Member] \| Ares Trading S A [Member] \| Achievement Of Specified Commercial Milestones [Member]
License and Collaborations [Line Items]
Milestone payments payable						$ 515,000
Amplyx Agreement [Member]
License and Collaborations [Line Items]
Milestone payments payable				$ 2,000
Acquisition cost				5,000
Research and development				7,000
Amplyx Agreement [Member] \| Amplyx And Novartis [Member] \| Achievement Of Various Clinical Development And Regulatory Milestones [Member]
License and Collaborations [Line Items]
Milestone payments payable				76,000
Amplyx Agreement [Member] \| Amplyx And Novartis [Member] \| Achievement As Assumed Liabilities Upon Acquisition [Member]
License and Collaborations [Line Items]
Milestone payments payable				$ 2,000
Series C [Member] \| Ares Agreement [Member] \| Ares Trading S A [Member]
License and Collaborations [Line Items]
Temporary equity stock shares issued during the period shares	22,171,553
Temporary equity issue price per share	$ 0.5918
Temporary equity shares issued during the period value	$ 13,100

Stock Compensation

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock Compensation

STOCK COMPENSATION

In April 2021, the Company adopted the 2021 Employee Stock Purchase Plan (“ESPP”) and the 2021 Equity Incentive Plan (“2021 EIP”), each of which became effective in connection with the IPO. The Company has reserved 421,476 and 3,242,762 shares of Class A common stock for future issuance under the ESPP and 2021 EIP, respectively.

The Company may not grant any additional awards under the 2017 Equity Incentive Plan (“2017 EIP”). The 2017 EIP will continue to govern outstanding equity awards granted thereunder. As of March 31, 2022, there were 1,863,512 shares available for issuance under the 2021 EIP.

2017 EIP and 2021 EIP

Stock option activity under the 2017 EIP and 2021 EIP was as follows:


	NUMBER OF OPTIONS			WEIGHTED- AVERAGE EXERCISE PRICE PER SHARE		WEIGHTED- AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)		AGGREGATE INTRINSIC VALUE (000s)
Balance – December 31, 2021		2,924,521		$	5.62		9.11	$	61,712
Granted		588,002			21.08
Exercised		(17,946	)		3.65
Cancelled and forfeited		—			—
Outstanding as of March 31, 2022		3,494,577			8.23		9.03	$	53,356
Options exercisable as of March 31, 2022		672,992			3.47		8.72	$	13,472
Vested and expected to vest as of March 31, 2022		3,494,577		$	8.23		9.03	$	53,356

The aggregate intrinsic value of stock options exercised during the three months ended March 31, 2022, was $0.3 million. The weighted-average grant date fair value of options granted during the three months ended March 31, 2022, was $14.08 per share.

ESPP

The ESPP enables eligible employees to purchase shares of the Company's Class A common stock at the end of each offering period at a price equal to 85% of the fair market value of the shares on the first trading day or the last trading day of the offering period, whichever is lower. Eligible employees generally include all employees. Share purchases are funded through payroll deductions of at least 1% and up to 15% of an employee's eligible compensation for each payroll period. The number of shares reserved for issuance under the ESPP increase automatically on the first day of each fiscal year, beginning on January 1, 2022, by a number equal to the lesser of 440,502 shares, 1% of the total number of shares of the Company's capital stock (including all classes of the Company's common stock) outstanding on the last day of the calendar month prior to the date of the increase, or such lower number of shares. (including no shares) approved by the Company's board of directors. As of March 31, 2022, 8,458 shares have been issued pursuant to the ESPP. The ESPP generally provides for six-month consecutive offering periods beginning on September 14, 2021. The ESPP is a compensatory plan as defined by the authoritative guidance for stock compensation. As such, stock-based compensation expense has been recorded for the three months ended March 31, 2022.

Stock-Based Compensation Expense

The following tables summarize the stock-based compensation expense for stock options and restricted stock awards granted to employees and nonemployees that was recorded in the Company’s statements of operations and comprehensive loss for the three months ended March 31, 2022 and 2021.


	Three Months Ended March 31,
	2022		2021
Research and development	$	902	$	60
General and administrative		760		344
Total stock-based compensation expense	$	1,662	$	404


	Three Months Ended March 31,
	2022		2021
Employees	$	1,014	$	399
Nonemployees		648		5
Total stock-based compensation expense	$	1,662	$	404

As of March 31, 2022, the Company had $17.1 million of unrecognized stock-based compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of approximately 2.93 years.

The fair value of stock options granted during the three months ended March 31, 2022 and 2021 was estimated using the Black-Scholes option pricing model based on the following weighted-average assumptions.


	Three Months Ended March 31,
	2022	2021
Expected term (in years)	6.0 – 6.1	6.0 – 6.1
Expected volatility	75.8%	76.3% – 76.4%
Risk-free rate	1.8% –1.9%	0.6% – 0.8%
Dividend yield	—	—

Restricted Stock Awards

In October 2020, in conjunction with the Series C redeemable convertible preferred stock issuance, the Company restricted 49,636 shares of fully issued and outstanding Class A common stock held by the Company’s Chief Executive Officer and founder. The restriction allowed the Company to repurchase shares that have not vested. The vesting term of restricted stock was one year. Restricted stock awards fully vested in October 2021. The grant date fair value of the restricted shares was $6.37.

For the three months ended March 2022 and 2021, the Company recognized zero and $0.1 million, respectively, of stock-based compensation expense related to restricted stock awards that vested during the period.

Restricted Stock Units

The Company grants restricted stock units ("RSU") pursuant to the 2021 EIP and satisfies such grants through the issuance of the Company's common stock. The following table shows RSU activity for the period ending March 31, 2022.


	NUMBER OF OPTIONS			WEIGHTED- AVERAGE GRANT DATE FAIR VALUE PER SHARE
Unvested balance at December 31, 2021		77,719		$	23.99
Granted		—			—
Vested		(19,429	)		23.99
Cancelled and forfeited		—			—
Unvested balance at March 31, 2022		58,290			8.23

As of March 31, 2022, the Company recognized $0.5 million of stock-based compensation for restricted stock units and the Company had $1.3 million of unrecognized stock-based compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted-average period of approximately 0.72 years.

Marketable Securities

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

5. MARKETABLE SECURITIES

Marketable securities are debt securities measured at fair value on a recurring basis and accounted for as available-for-sale. These securities are classified within Level 2 in the fair value hierarchy because the Company uses quoted market prices to the extent available or alternative pricing sources to determine fair value. Marketable securities have maturities less than one year as of the condensed balance sheet date.

Unrealized gains and losses are reported as a component of other comprehensive loss. Fair value of the debt securities totaled $39.4 million as of March 31, 2022. The Company did not hold marketable debt securities as of December 31, 2021.

The following table summarizes the unrealized gains and losses in the Company's investments in marketable securities (in thousands):


	As of March 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Level 2:
US Government bonds	$	39,444	$	2	$	(14	)	$	39,432
Total marketable securities	$	39,444	$	2	$	(14	)	$	39,432

Stock compensation - Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	$ 1,662	$ 404
Employees [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	1,014	399
Nonemployees [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	648	5
Research and development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	902	60
General and administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	$ 760	$ 344

Note Payable - Schedule Principal Installments Due (Detail) $ in Thousands	Mar. 31, 2022 USD ($)
Debt Disclosure [Abstract]
2026	$ 5,000
Total long-term debt	$ 5,000

Other Financial Statement Information (Tables)

3 Months Ended

Mar. 31, 2022

Other Financial Statement Information [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following:


	March 31, 2022		December 31, 2021
Prepaid contract costs	$	5,117	$	320
Prepaid insurance		452		1,193
Prepaid recruiting fees		258		253
Prepaid rent		219		219
Prepaid follow-on financing costs		—		275
Prepaid audit fees		—		123
Other		759		480
Total prepaid expenses and other current assets	$	6,805	$	2,863

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	March 31, 2022		December 31, 2021
Accrued research and development contract costs	$	5,200	$	364
Accrued development milestone		2,000		2,000
Related party payable		1,640		1,022
Accrued payroll		460		1,458
Accrued legal fees		253		457
Accrued expenses and other		598		627
Total accrued expenses and other current liabilities	$	10,151	$	5,928

Restructuring and Related Activities - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Nov. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring liability	$ 1,600
Employee Severance And Other Employee Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability		$ 321
Leased Facilities Abandoned [Member] \| Discounted Lease Related Restructuring Liability [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability		2,200
Equipment Abandoned [Member] \| Discounted Lease Related Restructuring Liability [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring liability		$ 800

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

13. COMMITMENTS AND CONTINGENCIES

Facilities Leases

In November 2020, the Company entered into a non-cancellable sublease agreement for the facilities in South San Francisco, California, under the terms of which the Company is entitled to receive $7,925 in sublease payments over the term of the sublease, which ends concurrently with the original lease in September 2025. As tenant, the Company remains responsible for the minimum lease commitment on the facilities.

In November 2021, the Company entered a lease for approximately 4,900 square feet of office space for a term of 36 months in Brisbane, California. The base rent is approximately $0.3 million for the first year with scheduled annual 3% increases. The lease includes renewal options for the Company.

Net Loss Per Share Attributable To Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Summary of Dilutive Shares Excluded From Computation of Diluted Net Loss Per Share

The following outstanding potentially dilutive shares were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented, because including them would have been anti-dilutive (on an as-converted basis).


	Three Months Ended March 31,
	2022		2021
Redeemable convertible preferred stock		—		15,774,014
Class A common stock options issued and outstanding		3,494,577		2,015,523
Unvested restricted stock awards		—		28,955
Unvested restricted stock units		58,290		—
Total		3,552,867		17,818,492

Leases - Schedule of lease liabilities based on minimum lease commitment (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Jan. 01, 2022	Dec. 31, 2021
Leases [Abstract]
Remainder of 2022	$ 1,981
2023	2,702
2024	2,742
2025	1,880
2026	0
Total minimum lease payments	9,305
Less: Imputed interest	(1,458)
Present value of operating lease liabilities	7,847	$ 8,500
Less: Current portion of operating lease liabilities	2,490		$ 0
Non-current operating lease liabilities	$ 5,357		$ 0

Stock Compensation - Summary of Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Detail) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested as of December 31, 2021 \| shares	77,719
Granted \| shares	0
Vested \| shares	(19,429)
Cancelled and forfeited \| shares	0
Unvested as of March 31, 2022 \| shares	58,290
Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 23.99
Weighted Average Grant Date Fair Value, Granted \| $ / shares	0
Weighted Average Grant Date Fair Value, Vested \| $ / shares	23.99
Weighted Average Grant Date Fair Value, Cancelled and Forfeited \| $ / shares	0
Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 8.23

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	Nov. 30, 2021 USD ($) ft²	Dec. 31, 2021 USD ($)	Nov. 30, 2020 USD ($)
Other Commitments [Line Items]
Operating lease minimum future commitments		$ 7,463
PNAI [Member] \| Office and Laboratory Space at Woborn Massauchets [Member]
Other Commitments [Line Items]
Area of real estate availed on lease \| ft²	4,900
Operating lease term	36 months
Base rent	$ 300
Operating lease minimum future commitments			$ 7,925
Percentage of increase in rent annually	3.00%

Other Financial Statement Information

3 Months Ended

Mar. 31, 2022

Other Financial Statement Information [Abstract]

Other Financial Statement Information

3. OTHER FINANCIAL STATEMENT INFORMATION

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following:


	March 31, 2022		December 31, 2021
Prepaid contract costs	$	5,117	$	320
Prepaid insurance		452		1,193
Prepaid recruiting fees		258		253
Prepaid rent		219		219
Prepaid follow-on financing costs		—		275
Prepaid audit fees		—		123
Other		759		480
Total prepaid expenses and other current assets	$	6,805	$	2,863

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	March 31, 2022		December 31, 2021
Accrued research and development contract costs	$	5,200	$	364
Accrued development milestone		2,000		2,000
Related party payable		1,640		1,022
Accrued payroll		460		1,458
Accrued legal fees		253		457
Accrued expenses and other		598		627
Total accrued expenses and other current liabilities	$	10,151	$	5,928

Related party payable represents amounts due to Ares Trading S.A. (“Ares”), an affiliate of Merck KGaA, Darmstadt, Germany, related to manufacturing technology and know-how transfer services performed for atacicept pursuant to the license agreement between the Company and Ares (see Note 12).

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 12,549	$ 2,932
General and administrative	4,472	1,784
Total operating expenses	17,021	4,716
Loss from operations	(17,021)	(4,716)
Other income (expense):
Interest income	26	2
Interest expense	(118)	0
Other Income	315	0
Change in fair value of non-marketable equity securities	(287)	0
Total other (expense) income	(64)	2
Net loss	(17,085)	(4,714)
Change in unrealized loss on marketable securities	(12)
Total loss and other comprehensive loss	$ (17,097)	$ 4,714
Net loss per share attributable to common stockholders, basic and diluted	$ (0.71)	$ (12.23)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	24,227,282	385,401

Net Loss Per Share Attributable To Common Stockholders

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Net Loss per Share Attributable to Common Stockholders

15. NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS


	Three Months Ended March 31,
	2022		2021
Redeemable convertible preferred stock		—		15,774,014
Class A common stock options issued and outstanding		3,494,577		2,015,523
Unvested restricted stock awards		—		28,955
Unvested restricted stock units		58,290		—
Total		3,552,867		17,818,492

Other Financial Statement Information - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Other Financial Statement Information [Abstract]
Prepaid contract costs	$ 5,117	$ 320
Prepaid insurance	452	1,193
Prepaid recruiting fees	258	253
Prepaid rent	219	219
Prepaid follow-on financing costs		275
Prepaid audit fees		123
Other	759	480
Total prepaid expenses and other current assets	$ 6,805	$ 2,863

Marketable Equity Securities - Summarizes the Unrealized Gains and Losses in the Company's Investments in Marketable Securities (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Marketable Securities [Line Items]
Amortized Cost	$ 39,444
Unrealized Gains	2
Unrealized Losses	(14)
Estimated Fair Value	39,432
Government Bonds [Member]
Marketable Securities [Line Items]
Amortized Cost	39,444
Unrealized Gains	2
Unrealized Losses	(14)
Estimated Fair Value	$ 39,432

Leases - Additional Information (Detail) - USD ($)	Mar. 31, 2022	Jan. 01, 2022	Dec. 31, 2021
Leases [Abstract]
Finance lease asset	$ 0
Operating lease right-of-use assets	6,275,000	$ 6,800,000	$ 0
Additions to operating lease assets	$ 0
Operating Lease, Weighted Average Remaining Lease Term	3 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent	9.00%

Stock Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Oct. 31, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Apr. 30, 2021
Share Based Payment Arrangement [Line Items]
Share based compensation arrangement by share based payment award, Options exercised in period, Total intrinsic value		$ 300
Stock-based compensation expense		1,662	$ 404
Unvested Stock Options [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized Stock options and equity instruments other than options		$ 17,100
Employee Stock Purchase Plan ESPP [Member]
Share Based Payment Arrangement [Line Items]
Common stock capital, Shares reserved for future issuance					421,476
2021 Equity Incentive Plan [Member]
Share Based Payment Arrangement [Line Items]
Common stock capital, Shares reserved for future issuance					3,242,762
Share-based compensation arrangement by share-based payment award, Number of shares available for issuance		1,863,512
2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation arrangement by share based payment award, Options granted in period, Weighted average grant date fair value		$ 14.08
2017 and 2021 Amended Equity Incentive Plan [Member] \| Unvested Stock Options [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized period of recognition stock options and equity instruments other than options		2 years 11 months 4 days
2017 and 2021 Amended Equity Incentive Plan [Member] \| Unvested Stock Options And Restricted Stock Unit [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized Stock options and equity instruments other than options		$ 1,300
Restricted Stock [Member]
Share Based Payment Arrangement [Line Items]
Weighted average Grant date fair value		$ 8.23		$ 23.99
Restricted Stock [Member] \| Unvested Stock Options And Restricted Stock Unit [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized period of recognition stock options and equity instruments other than options		8 months 19 days
Restricted Stock [Member] \| 2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation arrangement by share based payment award, Vesting period	1 year
Weighted average Grant date fair value	$ 6.37
Stock-based compensation expense		$ 0	$ 100
ESPP [Member]
Share Based Payment Arrangement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock Percent of Fair Market Value		85.00%
Share purchases funded through payroll deductions for employee's eligible minimum annual compensation, percentage		1.00%
Share purchases funded through payroll deductions for employee's eligible maximum annual compensation, percentage		15.00%
Potential increase in shares reserved for future issuance (in shares)		440,502
Potential increase in shares reserved for future issuance as percentage of outstanding share		1.00%
Number of shares issued under share-based payment arrangement		8,458
Restricted Stock Units (RSUs) [Member] \| 2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Payment Arrangement [Line Items]
Stock-based compensation expense		$ 500
Common Class A [Member] \| Restricted Stock [Member]
Share Based Payment Arrangement [Line Items]
Share based compensation arrangement by share based payment award, Restricted shares of fully issued and outstanding common stock	49,636

Non-Marketable Equity Securities (Additional Information) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ (287)
Other Expense [Member]
Debt and Equity Securities, FV-NI [Line Items]
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 300

Basis of Presentation and Significant Accounting Policies

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Basis of Presentation and Significant Accounting Policies

2. BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying unaudited condensed financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and applicable rules and regulations of the SEC regarding interim financial reporting. The U.S. dollar is the Company’s functional and reporting currency.

Unaudited Interim Condensed Financial Statements

The accompanying condensed balance sheet as of March 31, 2022, and condensed statements of operations and comprehensive loss, condensed statements of cash flows, and condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three months ended March 31, 2022 and 2021, are unaudited. The balance sheet as of December 31, 2021, was derived from the audited financial statements as of and for the year ended December 31, 2021. The unaudited condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2021 and in the opinion of management, reflect all adjustments consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of March 31, 2022, and the condensed results of its operations and its cash flows for the three months ended March 31, 2022. The financial data and other information disclosed in these notes related to the three months ended March 31, 2022, are also unaudited. The condensed results of operations for the three months ended March 31, 2022, are not necessarily indicative of the results to be expected for the full year ending December 31, 2022, or any other period. These unaudited condensed financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2021, included in the Company’s final prospectus dated May 13, 2021, for the IPO filed with the SEC on May 17, 2021, pursuant to Rule 424(b)(4) relating to the Company’s Registration Statement on Form S-1, as amended (File No. 333-255492).

Emerging Growth Company Status

The Company is an emerging growth company as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (1) is no longer an emerging growth company or (2) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Use of Estimates

The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited condensed financial statements and the reported amounts of expenses during the reporting period. Management estimates that affect the reported amounts of assets and liabilities include the accrual of research and development expenses, restructuring liabilities, fair value of common stock and stock-based compensation expense, determination of incremental borrowing rate for operating leases, the valuation allowance for deferred tax assets, and fair value of marketable and non-marketable securities. The Company evaluates and adjusts its estimates and assumptions on an ongoing basis using historical experience and other factors. Actual results could differ materially from those estimates.

Deferred Offering Costs

Deferred offering costs consisting of legal, accounting and filing fees relating to the IPO are capitalized. The deferred offering costs were offset against the Company’s IPO proceeds upon the closing of the IPO.

Concentrations of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains bank deposits in a federally insured financial institution and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash and cash equivalents.

The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current and potential future 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 relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fails to satisfy the Company's requirements on a timely basis, it could suffer delays in its clinical development programs and activities, which could adversely affects is operating results.

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 was denied approval, approval was delayed, or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Impact of the COVID-19 Pandemic

The COVID-19 pandemic continues to evolve. The extent of the impact of the COVID-19 pandemic on the Company’s business, operations, and development timelines and plans remains uncertain, and will depend on certain developments, including the duration and spread of the outbreak and its impact on the Company’s development activities, planned clinical trial enrollment, future trial sites, contract research organizations, third-party manufacturers, and other third parties with whom the Company does business, as well as its impact on regulatory authorities and the Company’s key scientific and management personnel. The ultimate impact of the COVID-19 pandemic or a similar health epidemic is highly uncertain and subject to change. To the extent possible, the Company is conducting business as usual, with necessary or advisable modifications to employee travel and with the Company’s employees working remotely. The Company will continue to actively monitor the evolving situation related to the COVID-19 pandemic and may take further actions that alter the Company’s operations, including those that may be required by federal, state or local authorities, or that the Company determines are in the best interests of its employees and other third parties with whom the Company does business. At this point, the extent to which the COVID-19 pandemic may affect the Company’s business, operations and development timelines and plans, including the resulting impact on expenditures and capital needs, remains uncertain.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds and are stated at fair value.

Marketable Securities

The Company holds investments in marketable securities, consisting of U.S. government securities. Marketable securities with stated maturities of three months or less from the date of purchase are classified as cash equivalents and those with stated maturities of greater than three months as marketable securities on the balance sheet. The Company designated these securities as available-for-sale to support current operations and are reported at estimated fair value, with unrealized gains and losses recorded in accumulated other comprehensive loss within stockholders’ equity. Interest, amortization and accretion of purchase premiums and discounts on marketable debt securities are included in other income (expense), net, in the condensed statements of operations and comprehensive loss.

The cost of available-for-sale marketable securities sold is based on the specific identification method. Realized gains and losses on the sale of available-for-sale marketable securities are recorded in other income (expense), net.

The Company regularly reviews all of the marketable securities for decline in fair value to determine whether unrealized losses have resulted from credit loss or other factors. The review includes considerations for the cause of the impairment but is not limited to (i) the consideration of the cause of the decline, (ii) any currently recorded expected credit losses and (iii) the creditworthiness of the respective security issuers. A decline of fair value below cost basis is considered an other-than-temporary impairment if the Company has the intent to sell the security or it is more likely than not that the company will be required to sell the security before recovery of the entire cost basis. Regardless of the Company’s intent or requirement to sell the security, an impairment is considered other-than-temporary if the Company does not expect to recover the entire cost basis. In those instances, an impairment charge equal to the difference between fair value and the cost basis is recorded in other income (expense), on the condensed statements of operations and comprehensive loss.

The amortized or accreted cost basis of the marketable securities approximates its fair value.

Restricted Cash

Restricted cash represents cash held by a financial institution as collateral for a letter of credit securing the Company's operating lease for office and laboratory space, which is classified within non-current assets on the condensed balance sheets.

Comprehensive Loss

Comprehensive loss consists of two components: net loss and other comprehensive loss. Other comprehensive loss refers to gains and losses that are recorded as an element of stockholder's equity and are excluded from net loss. For the three months ended March 31, 2022, other comprehensive loss consists of unrealized gains and losses on marketable securities.

Research and Development Costs

Research and development costs are expensed as incurred and consist primarily of employees’ salaries and related benefits, including stock-based compensation and termination expenses for employees engaged in research and development efforts, allocated overhead including rent, depreciation, information technology and utilities, contracted services, license fees, and external expenses to conduct and support the Company’s operations that are directly attributable to the Company’s research and development efforts. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered.

Costs incurred in obtaining technology licenses including upfront and milestone payments incurred under the Company’s licensing agreements are recorded as expense in the period in which they are incurred, provided that the licensed technology, method or process has no alternative future uses other than for the Company’s research and development activities. Where contingent milestone payments are due to third parties under license or other agreements, the milestone payment obligations are recognized as expense when achievement of the contingent milestone is probable, which is generally upon achievement of the milestone.

Research Contract Costs and Accruals

The Company enters into various research and development and other agreements with commercial firms, researchers, and others for provisions of goods and services from time to time. These agreements are generally cancellable, and the related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates.

Stock-Based Compensation

The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to the Company’s employees, nonemployee directors and consultants that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant.

For all stock options granted, the Company calculated the expected term using the simplified method (derived from the average midpoint between the weighted average vesting period and the contractual term of the award) for “plain vanilla” stock option awards, as the Company has limited historical information to develop expectations about future exercise patterns and post vesting employment termination behavior. The estimate of expected volatility is based on comparative companies’ volatility. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The Company records forfeitures when they occur.

Prior to the IPO, the fair value of the shares of common stock underlying the stock options was determined by the board of directors with the assistance of management and input from an independent third-party valuation firm, as there was no public market for the common stock. The board of directors determined the fair value of the Company’s common stock by considering a number of objective and subjective factors, including the valuation of comparable companies, sales of redeemable convertible preferred stock, the Company’s operating and financial performance, the lack of liquidity of common stock, and general and industry specific economic outlook, amongst other factors. Subsequent to the IPO, the Company determines the fair value using the market closing price of its common stock on the date of grant.

The Company records compensation expense for service-based awards on a straight-line basis over the requisite service period, which is generally the vesting period of the award. The amount of stock-based compensation expense recognized during a period is based on the value of the portion of the awards that are ultimately expected to vest.

Income Taxes

The Company did not record an income tax provision for the three months ended March 31, 2022 and 2021, as net operating losses have been incurred since inception. The net deferred tax assets generated from net operating losses are fully offset by a valuation allowance.

Net Loss Per Share Attributable to Common Stockholders

Net loss per share of common stock is computed using the two-class method required for multiple classes of common stock and participating securities based upon their respective rights to receive dividends as if all income for the period has been distributed. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders is therefore the same for Class A and Class B common stock on an individual or combined basis.

Prior to the IPO, the Company’s participating securities included the Company’s redeemable convertible preferred stock, as the holders were entitled to receive noncumulative dividends on a pari passu basis in the event that a dividend is paid on common stock. The Company also considers any shares issued on the early exercise of stock options subject to repurchase to be participating securities because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of redeemable convertible preferred stock, as well as the holders of early exercised shares subject to repurchase, did not and do not have a contractual obligation to share in losses of the Company, and therefore during periods of loss there is no allocation required under the two-class method.

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, adjusted for outstanding shares that are subject to repurchase.

Diluted net loss per share is computed by giving effect to all potentially dilutive securities outstanding for the period using the treasury stock method or the if-converted method based on the nature of such securities. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive shares are not assumed to have been issued if their effect is anti-dilutive.

Leases

The Company leases office and laboratory space under operating leases and determines if the arrangement is a lease at inception. These leases contain lease and non-lease components. Non-lease components include payments for maintenance, utilities, real estate taxes, and management fees. The lease and non-lease components are combined and accounted as a single lease component. Payments made under operating leases (net of any incentive received from the lessors) are recorded on a straight-line basis over the term of the lease.

These leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is a hypothetical rate based on the Company's understanding of what the credit rating would be in a similar economic environment. Operating leases are included in operating lease right-of-use assets and operating lease liabilities, current and non-current, on the balance sheets.

Leases may include one or more options to renew. The Company does not assume renewals in determination of the lease term unless the renewals are deemed to be reasonably assured. The lease agreements generally do not contain any material residual value guarantees or material restrictive covenants.

Restructuring Costs

Restructuring costs primarily consist of contract termination costs related to leases and employee termination costs. The Company recognizes restructuring charges when the liability has been incurred. Key assumptions in determining the restructuring costs include the terms and payments that may be negotiated to terminate certain contractual obligations, cease use date of leased property and equipment, and the timing of employees leaving the Company.

Accretion expenses related to restructuring costs are included in general and administrative expenses.

Fair Value Measurements

Fair value is defined as the exchange price to sell an asset or transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should be based on the assumptions market participants would use when pricing the asset or liability. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date.

Fair value measurements are classified and disclosed in one of the following three categories:

Level 1 – Quoted unadjusted prices for identical instruments in active markets.

Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all observable inputs and significant value drivers are observable in active markets.

Level 3 – Model derived valuations in which one or more significant inputs or significant value drivers are unobservable, including assumptions developed by the Company.

Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed in the condensed financial statements on a recurring basis. The Company’s financial instruments consist of cash and cash equivalents, marketable securities, prepaid expenses and other current assets, accounts payable and accrued expenses. Cash and marketable securities are reported at their respective fair values on our condensed balance sheets. The remaining financial instruments are reported on our condensed balance sheets at cost, which approximate their fair value due to their short-term nature.

Money market funds are highly liquid investments that are actively traded. The pricing information for the Company’s money market funds are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 1 of the fair value hierarchy.

The Company’s non-marketable equity securities (Note 6) are measured at fair value using an option pricing valuation methodology. The option pricing methodology relies on risk-neutral valuation which calculates the value of an asset by discounting the expected value of its future payoffs at the risk-free rate of return. The fair value of the non-marketable equity securities is derived from quoted prices for similar instruments and observable inputs in active markets. This approach results in the classification of these securities as Level 2 of the fair value hierarchy.

There were no transfers between Levels 1, 2, or 3 for any of the periods presented. As of March 31, 2022, and December 31, 2021, the Company held $105.3 million and $73.8 million, respectively, in money market funds.

Recently Adopted Accounting Pronouncements

In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes, related to simplifying the accounting for income taxes. The guidance eliminates certain exceptions from Accounting Standards Codification (ASC) 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The guidance also clarifies and simplifies other aspects of the accounting for income taxes. The guidance became effective for the Company beginning on the first quarter of 2021 on a prospective basis. The Company adopted this

standard on January 1, 2021, and it did not have a material impact on the Company's condensed financial statements or related disclosures.

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), subsequently amended by ASU 2018-10, ASU 2018-11, ASU 2018-20, ASU 2019-01 and ASU 2019-10, which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessors and lessees of a contract. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification on the balance sheets. Leases with a term of 12 months or less may be accounted for similar to existing guidance for operating leases today. The Company adopted this standard on January 1, 2022, using the optional transition method, which allows for the prospective application of the standard. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the standard, which allowed the Company to carry forward historical lease classification, to not reassess prior conclusions related to initial direct costs, and to not reassess whether any expired or existing contracts are or contain leases. The Company also elected the practical expedient to not separate lease and non-lease

components for all leases. In connection with the adoption of the new guidance, the Company recognized $6.8 million of operating lease right-of-use assets and $8.5 million of operating lease liabilities and derecognized $1.6 million of restructuring lease liability, with immaterial effect to the statements of operations and comprehensive loss and cash flows.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The objective of the standard is to provide information about expected credit losses on financial instruments at each reporting date and to change how other-than temporary impairments on investment securities are recorded. The guidance is effective for the Company beginning on January 1, 2023, with early adoption permitted. The Company is currently evaluating the impact the standard may have on its condensed financial statements and related disclosures.

In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. In response to concerns about structural risks of the cessation of London Interbank Offered Rate (LIBOR), the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effect of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The expedients and exceptions provided by this amendment do not apply to contract modifications made and hedge relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective for all entities as of March 12, 2020 through December 31, 2022. The Company continues to evaluate contractual arrangements that reference LIBOR and the impact this standard will have on its condensed financial statements and related disclosures.

In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40). This standard simplifies the accounting for convertible debt instruments and convertible preferred stock by removing the existing guidance in ASC 470-20 that requires entities to account for beneficial conversion features and cash conversion features in equity, separately from the host convertible debt or preferred stock. ASU 2020-06 is effective for the Company for annual reporting periods, and interim reporting periods within those annual periods, beginning after December 15, 2023, and early adoption is permitted. The Company is currently evaluating the impact this standard will have on its condensed financial statements and related disclosures.

Condensed Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Accumulated Deficit [Member]	Redeemable Convertible Preferred Stock [Member]	Common Class A [Member] Common Stock [Member]	Common Class B [Member] Common Stock [Member]
Beginning Balance, Temporary Equity, shares at Dec. 31, 2020					182,772,372
Beginning Balance, Temporary Equity Value at Dec. 31, 2020					$ 139,576
Beginning balance, shares at Dec. 31, 2020						355,296
Beginning Balance, Value at Dec. 31, 2020	$ (89,348)	$ 2,099		$ (91,447)
Issuance of Class A common stock upon exercise of options	342	342
Issuance of Class A common stock upon exercise of options, shares						113,683
Stock-based compensation	404	404
Net loss	(4,714)			(4,714)
Ending Balance, shares at Mar. 31, 2021						468,979
Ending Balance, Value at Mar. 31, 2021	(93,316)	2,845		(96,161)
Ending Balance, Temporary Equity , shares at Mar. 31, 2021					182,772,372
Ending Balance, Temporary Equity Value at Mar. 31, 2021					$ 139,576
Beginning balance, shares at Dec. 31, 2021						20,968,376	309,238
Beginning Balance, Value at Dec. 31, 2021	69,592	193,627		(124,056)		$ 21
Issuance of common stock from underwritten follow-on offering, net of offering costs, shares						5,742,026
Issuance of common stock from underwritten follow-on offering, net of offering costs	80,034	80,028				$ 6
Issuance of Class A common stock upon exercise of options	65	65
Issuance of Class A common stock upon exercise of options, shares						17,946
Issuance of common stock pursuant to employee stock purchase plan value	169	169
Issuance of common stock pursuant to employee stock purchase plan, shares						8,458
Issuance of common stock upon vesting of restricted stock, shares						19,429
Stock-based compensation	1,662	1,662
Unrealized loss on marketable securities	(12)		$ (12)
Net loss	(17,085)			(17,085)
Ending Balance, shares at Mar. 31, 2022						26,756,235
Ending Balance, Value at Mar. 31, 2022	$ 134,425	$ 275,551	$ (12)	$ (141,141)		$ 27	$ 309,238

Marketable Equity Securities - Additional Information (Detail) $ in Thousands	Mar. 31, 2022 USD ($)
Fair value of the debt securities	$ 39,432

Stock Compensation (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount


	Three Months Ended March 31,
	2022		2021
Research and development	$	902	$	60
General and administrative		760		344
Total stock-based compensation expense	$	1,662	$	404


	Three Months Ended March 31,
	2022		2021
Employees	$	1,014	$	399
Nonemployees		648		5
Total stock-based compensation expense	$	1,662	$	404

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions


	Three Months Ended March 31,
	2022	2021
Expected term (in years)	6.0 – 6.1	6.0 – 6.1
Expected volatility	75.8%	76.3% – 76.4%
Risk-free rate	1.8% –1.9%	0.6% – 0.8%
Dividend yield	—	—

Summary of Share-based Compensation Arrangements by Share-based Payment Award

Stock option activity under the 2017 EIP and 2021 EIP was as follows:


	NUMBER OF OPTIONS			WEIGHTED- AVERAGE EXERCISE PRICE PER SHARE		WEIGHTED- AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)		AGGREGATE INTRINSIC VALUE (000s)
Balance – December 31, 2021		2,924,521		$	5.62		9.11	$	61,712
Granted		588,002			21.08
Exercised		(17,946	)		3.65
Cancelled and forfeited		—			—
Outstanding as of March 31, 2022		3,494,577			8.23		9.03	$	53,356
Options exercisable as of March 31, 2022		672,992			3.47		8.72	$	13,472
Vested and expected to vest as of March 31, 2022		3,494,577		$	8.23		9.03	$	53,356

Summary of Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity

The following table shows RSU activity for the period ending March 31, 2022.


	NUMBER OF OPTIONS			WEIGHTED- AVERAGE GRANT DATE FAIR VALUE PER SHARE
Unvested balance at December 31, 2021		77,719		$	23.99
Granted		—			—
Vested		(19,429	)		23.99
Cancelled and forfeited		—			—
Unvested balance at March 31, 2022		58,290			8.23

Note Payable (Tables)

3 Months Ended

Mar. 31, 2022

Debt Disclosure [Abstract]

Schedule of Notes Payable

Note payable consists of the following:


	Rate Type	Maturity	Effective Interest Rate	March 31, 2022			December 31, 2021
				(in thousands)			(in thousands)
Collateralized note	Variable	2026	9.54%	$	5,000		$	5,000
Less: Unamortized debt issuance costs					(63	)		(77	)
Net carrying amount of debt				$	4,937		$	4,923

Schedule Principal Installments Due

Principal installments due on the note subsequent to March 31, 2022, are as follows (in thousands):


Remainder of 2022	$	—
2023		—
2024		—
2025		—
2026		5,000
Total long-term debt	$	5,000