Vera Therapeutics (VERA) 10-Q 9 Nov 23 2023 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2023	Nov. 07, 2023
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Trading Symbol	VERA
Entity Registrant Name	Vera Therapeutics, Inc.
Entity Central Index Key	0001831828
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Class A common stock, $0.001 par value per share
Security Exchange Name	NASDAQ
Securities Act File Number	001-40407
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2744449
Document Quarterly Report	true
Document Transition Report	false
Entity Address, Address Line One	8000 Marina Boulevard
Entity Address, Address Line Two	Suite 120
Entity Address, City or Town	Brisbane
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94005
City Area Code	650
Local Phone Number	770-0077
Entity Common Stock, Shares Outstanding		44,432,945

Condensed Balance Sheet

Condensed Balance Sheet - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 27,441	$ 43,459
Marketable securities	132,498	71,194
Prepaid expenses and other current assets	11,681	11,045
Total current assets	171,620	125,698
Restricted cash, noncurrent	0	293
Property and equipment, net	34	51
Operating lease right-of-use assets	3,481	5,173
Prepaid expenses and other noncurrent assets	470	162
Non-marketable equity securities	13	58
Total assets	175,618	131,435
Current liabilities:
Accounts payable	12,300	11,991
Operating lease liabilities	2,518	2,645
Accrued expenses and other current liabilities	9,803	10,964
Total current liabilities	24,621	25,600
Long-term debt	25,042	24,810
Operating lease liabilities, noncurrent	1,962	3,831
Accrued and other noncurrent liabilities	286	286
Total liabilities	51,911	54,527
Stockholders' equity
Preferred stock, $0.001 par value; 10,000,000 authorized as of September 30, 2023 and December 31, 2022; no shares issued and outstanding as of September 30, 2023 and December 31, 2022	0	0
Additional paid-in capital	407,185	290,216
Accumulated other comprehensive loss	(75)	(224)
Accumulated deficit	(283,447)	(213,112)
Total stockholders' equity	123,707	76,908
Total liabilities and stockholders' equity	175,618	131,435
Common Class A [Member]
Stockholders' equity
Class A common stock, $0.001 par value; 500,000,000 shares authorized as of September 30, 2023 and December 31, 2022; 44,432,945 and 27,800,861 shares issued and outstanding as of September 30, 2023 and December 31, 2022, respectively	$ 44	$ 28

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
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	44,432,945	27,800,861
Common stock, Shares outstanding	44,432,945	27,800,861

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 16,100	$ 19,656	$ 57,440	$ 42,317
General and administrative	5,656	5,588	17,544	15,005
Total operating expenses	21,756	25,244	74,984	57,322
Loss from operations	(21,756)	(25,244)	(74,984)	(57,322)
Other income (expense):
Interest income	2,158	567	6,019	856
Interest expense	(943)	(147)	(2,730)	(393)
Other income	452	347	1,405	987
Change in fair value of non-marketable equity securities	(15)	(202)	(45)	(745)
Total other income	1,652	565	4,649	705
Net loss	(20,104)	(24,679)	(70,335)	(56,617)
Other comprehensive loss:
Change in unrealized loss on marketable securities	67	(127)	149	(279)
Comprehensive loss	$ (20,037)	$ (24,806)	$ (70,186)	$ (56,896)
Net loss per share attributable to common stockholders, basic	$ (0.45)	$ (0.91)	$ (1.67)	$ (2.16)
Net loss per share attributable to common stockholders, diluted	$ (0.45)	$ (0.91)	$ (1.67)	$ (2.16)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic	44,363,419	27,215,874	42,124,779	26,184,816
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted	44,363,419	27,215,874	42,124,779	26,184,816

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Common Class A [Member]	Common Class A [Member] Common Stock [Member]	Common Class B [Member]
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 Class A common stock from underwritten follow-on offering, net of offering costs					5,742,026
Issuance of Class A common stock from underwritten follow-on offering, net of offering costs, value	80,034	80,028			$ 6
Issuance of Class A common stock pursuant to exercise of options, value	65	65
Issuance of Class A common stock pursuant to exercise of options					17,946
Issuance of Class A common stock pursuant to employee stock purchase plan					8,458
Issuance of Class A common stock pursuant to employee stock purchase plan, value	169	169
Issuance of Class A common stock upon vesting of restricted stock units, shares					19,429
Stock-based compensation	1,662	1,662
Unrealized gain (loss) on marketable securities	(12)		$ (12)
Net loss	(17,085)			(17,085)
Ending Balance, shares at Mar. 31, 2022					26,756,235		309,238
Ending Balance, Value at Mar. 31, 2022	134,425	275,551	(12)	(141,141)		27
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 for payment of licensing fees, net of offering costs, shares					283,034
Net loss	(56,617)
Ending Balance, shares at Sep. 30, 2022					27,607,449
Ending Balance, Value at Sep. 30, 2022	105,718	286,642	(279)	(180,673)		28
Beginning balance, shares at Mar. 31, 2022					26,756,235		309,238
Beginning Balance, Value at Mar. 31, 2022	134,425	275,551	(12)	(141,141)		27
Issuance of Class A common stock pursuant to exercise of options, value	47	47
Issuance of Class A common stock pursuant to exercise of options					12,641
Issuance of Class A common stock upon vesting of restricted stock units, shares					19,430
Conversion of Class B common stock into Class A common stock, Shares					210,000		(210,000)
Stock-based compensation	2,025	2,025
Unrealized gain (loss) on marketable securities	(140)		(140)
Net loss	(14,853)			(14,853)
Ending Balance, shares at Jun. 30, 2022					26,998,306		99,238
Ending Balance, Value at Jun. 30, 2022	121,504	277,623	(152)	(155,994)		27
Issuance of Class A common stock pursuant to exercise of options, value	853	853
Issuance of Class A common stock pursuant to exercise of options					200,571
Issuance of Class A common stock pursuant to employee stock purchase plan					6,870
Issuance of Class A common stock pursuant to employee stock purchase plan, value	122	122
Issuance of Class A common stock upon vesting of restricted stock units, shares					19,430
Issuance of common stock for payment of licensing fees, net of offering costs, shares					283,034
Issuance of common stock for payment of licensing fees in equity, net of offering cost	5,593	5,592			$ 1
Conversion of Class B common stock into Class A common stock, Shares					99,238		(99,238)
Stock-based compensation	2,452	2,452
Unrealized gain (loss) on marketable securities	(127)		(127)
Net loss	(24,679)			(24,679)
Ending Balance, shares at Sep. 30, 2022					27,607,449
Ending Balance, Value at Sep. 30, 2022	105,718	286,642	(279)	(180,673)		28
Beginning balance, shares at Dec. 31, 2022					27,800,861
Beginning Balance, Value at Dec. 31, 2022	76,908	290,216	(224)	(213,112)		28
Issuance of Class A common stock from underwritten follow-on offering, net of offering costs					16,428,572
Issuance of Class A common stock from underwritten follow-on offering, net of offering costs, value	107,743	107,727			$ 16
Issuance of Class A common stock pursuant to exercise of options, value	65	65
Issuance of Class A common stock pursuant to exercise of options					3,750
Issuance of Class A common stock pursuant to employee stock purchase plan					27,926
Issuance of Class A common stock pursuant to employee stock purchase plan, value	175	175
Stock-based compensation	2,667	2,667
Unrealized gain (loss) on marketable securities	220		220
Net loss	(30,069)			(30,069)
Ending Balance, shares at Mar. 31, 2023					44,261,109
Ending Balance, Value at Mar. 31, 2023	157,709	400,850	(4)	(243,181)		44
Beginning balance, shares at Dec. 31, 2022					27,800,861
Beginning Balance, Value at Dec. 31, 2022	76,908	290,216	(224)	(213,112)		28
Issuance of common stock for payment of licensing fees, net of offering costs, shares					283,034
Net loss	(70,335)
Ending Balance, shares at Sep. 30, 2023					44,432,945
Ending Balance, Value at Sep. 30, 2023	123,707	407,185	(75)	(283,447)		44
Beginning balance, shares at Mar. 31, 2023					44,261,109
Beginning Balance, Value at Mar. 31, 2023	157,709	400,850	(4)	(243,181)		44
Issuance of Class A common stock pursuant to exercise of options, value	432	432
Issuance of Class A common stock pursuant to exercise of options					44,820
Issuance of Class A common stock upon vesting of restricted stock units, shares					2,500
Stock-based compensation	2,682	2,682
Unrealized gain (loss) on marketable securities	(138)		(138)
Net loss	(20,162)		0	(20,162)
Ending Balance, shares at Jun. 30, 2023					44,308,429
Ending Balance, Value at Jun. 30, 2023	140,523	403,964	(142)	(263,343)		44
Issuance of Class A common stock pursuant to exercise of options, value	197	197
Issuance of Class A common stock pursuant to exercise of options					45,078
Issuance of Class A common stock pursuant to employee stock purchase plan					16,554
Issuance of Class A common stock pursuant to employee stock purchase plan, value	101	101
Issuance of Class A common stock upon vesting of restricted stock units, shares					62,884
Stock-based compensation	2,923	2,923
Unrealized gain (loss) on marketable securities	67		67
Net loss	(20,104)			(20,104)
Ending Balance, shares at Sep. 30, 2023					44,432,945
Ending Balance, Value at Sep. 30, 2023	$ 123,707	$ 407,185	$ (75)	$ (283,447)		$ 44

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (70,335)	$ (56,617)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and accretion	(2,919)	(249)
Reduction in the carrying amount of operating lease right of use assets	1,692	1,676
Stock-based compensation	8,272	6,139
Issuance of Class A common stock for licensing payment	0	3,661
Change in fair value of non-marketable equity securities	45	745
Changes in operating assets and liabilities:
Prepaid expense and other current assets	(636)	(7,700)
Other assets	(308)	(98)
Accounts payable	309	5,627
Accrued and other current liabilities	(1,161)	2,291
Operating lease liabilities	(1,996)	(1,909)
Net cash used in operating activities	(67,037)	(46,434)
Cash flows from investing activities
Purchase of property and equipment	0	(62)
Purchase of marketable securities	(171,730)	(137,927)
Proceeds from maturities of marketable securities	104,200	54,000
Proceeds from sale of marketable securities	9,543	0
Net cash used in investing activities	(57,987)	(83,989)
Cash flows from financing activities
Proceeds from exercise of stock options and employee stock purchase plan	969	1,256
Proceeds from issuance of Class A common stock in follow-on offering	115,000	86,132
Payment of costs and underwriting discounts and commissions related to follow-on offering	(7,256)	(6,164)
Net cash provided by financing activities	108,713	81,224
Net decrease in cash and cash equivalents and restricted cash	(16,311)	(49,199)
Cash, cash equivalents and restricted cash, beginning of period	43,752	79,967
Cash, cash equivalents and restricted cash, end of period	27,441	30,768
Supplemental disclosure of cash flow information
Cash paid for interest	2,499	336
Cash paid for operating leases	2,238	1,991
Issuance of Class A common stock in payment of accrued development milestone	0	2,000
Cash and cash equivalents [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, end of period	27,441	30,475
Restricted cash [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash, end of period	$ 0	$ 293

Organization and Description of

Organization and Description of the Business	9 Months Ended
	Sep. 30, 2023
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 stage biotechnology company focused on developing and commercializing treatments for patients with serious immunological diseases. The Company was incorporated in May 2016 in Delaware. The Company’s headquarters and operations are located in Brisbane, California. The Company operates in one segment. 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 Offerings 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 $ 0.9 million . On February 6, 2023, the Company completed a follow-on public offering pursuant to which the Company issued and sold 16,428,572 shares of its Class A common stock at an offering price of $ 7.00 per share, including the exercise in full by the underwriters of their option to purchase an additional 2,142,857 shares of Class A common stock. The Company received total net proceeds of approximately $ 107.7 million, after deducting underwriting discounts and commissions of $ 6.9 million, and offering costs of approximately $ 0.4 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 and has not generated positive cash flow from operations since its inception, and had an accumulated deficit of $ 283.4 million as of September 30, 2023. The Company had cash, cash equivalents and marketable securities of $ 159.9 million as of September 30, 2023 and has access to additional debt financing under a credit facility (see Note 7). 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 September 30, 2023 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 .

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
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 unaudited interim condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States (GAAP), and in the opinion of management, include all adjustments of a normal recurring nature necessary for fair financial statement presentation. Interim results are not necessarily indicative of the results to be expected for the full year ending December 31, 2023, or any other period. The condensed balance sheet as of December 31, 2022 included herein was derived from the audited financial statements as of that date, but may not include all disclosures notes required by GAAP. These unaudited condensed financial statements and other information presented in this Form 10-Q should be read in conjunction with the Company’s audited financial statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 28, 2023. Emerging Growth Company Status T he 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 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. 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, cash equivalents and marketable securities. 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, cash equivalents, and marketable securities to the extent recorded in the balance sheet. The Company has not experienced any losses to date related to these concentrations. 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 affect 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. Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies from the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. Recently Adopted 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. Further, the FASB issued ASU No. 2018-19, ASU No. 2019-04, ASU No. 2019-05, ASU 2019-10, ASU 2019-11, ASU 2020-02 and ASU 2020-03 to provide additional guidance on the credit losses standard. The guidance is effective for the annual period beginning after December 15, 2022, with early adoption permitted. The Company adopted the ASUs on January 1, 2023. The ASUs did not have a material impact on the Company’s financial statements. Recently Issued Accounting Pronouncement Not Yet Adopted In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions . This standard clarifies the guidance in Topic 210, when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security and introduces new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The guidance is effective for the annual period beginning after December 15, 2023, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on its financial statements and related disclosures.

Other Financial Statement Infor

Other Financial Statement Information	9 Months Ended
	Sep. 30, 2023
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 (in thousands): September 30, December 31, Prepaid clinical trial and drug manufacturing expenses $ 8,189 $ 8,487 Prepaid insurance 905 998 Prepaid equity financing costs 409 490 Prepaid rent 256 247 Other 1,922 823 Total prepaid expenses and other current assets $ 11,681 $ 11,045 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, Accrued clinical trial and drug manufacturing expenses $ 4,195 $ 4,334 Accrued payroll 2,645 3,217 Related party payable 2,389 2,780 Accrued legal fees 63 338 Accrued expenses and other 511 295 Total accrued expenses and other current liabilities $ 9,803 $ 10,964 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 11).

Cash Equivalents And Marketable

Cash Equivalents And Marketable Securities	9 Months Ended
	Sep. 30, 2023
Cash Equivalents And Marketable Securities [Abstract]
Cash Equivalents and Marketable Securities	4 . CASH EQUIVALENTS AND MARKETABLE SECURITIES Cash equivalents and marketable debt 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. The Company’s debt securities are accounted for as available-for-sale securities. Unrealized gains and losses are reported as a component of other comprehensive loss. Fair value of the debt securities were $ 132.5 million and $ 71.2 million as of September 30, 2023 and December 31, 2022, respectively. The following table summarizes the unrealized gains and losses in fair value of the Company’s investments in debt securities (in thousands): As of September 30, 2023 Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Level 2: Money market funds $ 26,140 $ - $ - $ 26,140 U.S. Government bonds 132,572 2 ( 76 ) 132,498 Total cash equivalents and marketable securities $ 158,712 $ 2 $ ( 76 ) $ 158,638 As of December 31, 2022 Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Level 2: Money market funds $ 42,495 $ - $ - $ 42,495 U.S. Government bonds 71,418 1 ( 225 ) 71,194 Total cash equivalents and marketable securities $ 113,913 $ 1 $ ( 225 ) $ 113,689 Marketable debt securities that had been in unrealized loss positions as of September 30, 2023 and December 31, 2022 were in an unrealized loss position for less than 12 months. Unrealized losses from marketable debt securities are primarily attributable to changes in interest rates. Management does not believe any remaining unrealized losses represent impairments based on evaluation of available evidence. The following table classifies the estimated fair value of investments in available-for-sale marketable debt securities by effective contractual maturity dates (in thousands): September 30, 2023 Due within one year $ 132,498 Due after one year to two years — Total marketable securities $ 132,498

Non-Marketable Equity Securitie

Non-Marketable Equity Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Non-Marketable Equity Securities	5 . NON-MARKETABLE EQUITY SECURITIES In 2021, the Company disposed of its previous research program through the sale of assets and certain related liabilities to NeuBase Therapeutics, Inc. (NeuBase) in exchange for cash and shares of NeuBase common stock. The shares have certain restrictions on sale or transfer. Fair value of this asset 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 condensed balance sheet and determines current or non-current classification based on the expected duration of the restriction. The carrying value is measured as the total initial cost, less the cumulative net unrealized loss. The following table summarizes the value of non-marketable equity securities using the measurement alternative (in thousands): September 30, December 31, Initial cost $ 1,759 $ 1,759 Cumulative net fair value adjustments ( 1,746 ) ( 1,701 ) Total non-marketable equity securities $ 13 $ 58

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
LEASES	6. LEASES Net lease costs recognized were as follows (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Operating lease cost $ 644 $ 594 $ 1,933 $ 1,734 Sublease income ( 482 ) ( 482 ) ( 1,446 ) ( 1,446 ) Net lease cost $ 162 $ 112 $ 487 $ 288 As of September 30, 2023, the maturities of the lease liabilities based on minimum lease commitment amount are as follows (in thousands): 2023 (remaining three months) $ 762 2024 3,022 2025 1,880 2026 - 2027 - Total minimum lease payments 5,664 Less: Imputed interest ( 1,184 ) Present value of operating lease liabilities 4,480 Less: Current portion of operating lease liabilities ( 2,518 ) Non-current operating lease liabilities $ 1,962 In November 2020, the Company entered into a non-cancellable sublease agreement for the leased facilities in South San Francisco, California, which ends concurrently with the original lease in September 2025. As of September 30, 2023, under the terms of the sublease agreement, the Company is entitled to receive future annual sublease payments as follows (in thousands): 2023 (remaining three months) $ 480 2024 1,954 2025 1,496 Total sublease payments $ 3,930 As tenant, the Company remains responsible for minimum lease commitments of $ 5.0 million as of September 30, 2023, on the South San Francisco facilities. In July 2022, the Company amended an existing lease agreement to increase the amount of leased office space in its Brisbane, California, headquarters, from approximately 4,900 square feet to approximately 9,900 square feet. The leases have scheduled annual 3 % increases and include renewal options for the Company. As of September 30, 2023, the Company had not executed any finance leases that were yet to commence. As of September 30, 2023, the weighted-average remaining operating lease term was 1.8 years and the weighted-average discount rate was 9.1 % for operating leases recognized in the condensed financial statements.

Note Payable

Note Payable	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Note Payable	7. NOTE PAYABLE Note payable consists of the following ($ in thousands): September 30, 2023 December 31, 2022 Maturity Effective Amount Effective Amount Collateralized note 2021-12 2027 14.72 % $ 5,000 13.57 $ 5,000 Collateralized note 2022-11 2027 14.86 % 20,000 13.74 20,000 Total borrowings 25,000 25,000 Less: Unamortized debt issuance costs 42 ( 190 ) Net carrying amount of debt $ 25,042 $ 24,810 The carrying amount of debt approximates fair value due to its variable interest rate. In December 2021, the Company entered into a non-revolving loan and security agreement (the “Loan Facility”) with borrowing capacity of up to $ 50.0 million, which was scheduled to expire in December 2022. In November 2022, the Company entered into an amendment of the Loan Facility. Among other changes, the amendment extended the scheduled expiration of the Loan Facility to December 2023 and modified the reference rate from the London Interbank Offered Rate (“LIBOR”) to the Secured Overnight Financial Rate (“SOFR”). In conjunction with the amendment, the Company borrowed an additional $ 20.0 million from the Loan Facility. As of September 30, 2023, the Company’s outstanding borrowing under the Loan Facility was $ 25.0 million, and an additional $ 25.0 million remains available if drawn by December 29, 2023. In March 2023, upon achievement of a clinical data milestone, the Company elected to exercise a borrower option to extend the maturity of the outstanding loan by 12 months, from December 2026 to December 2027. The interest-only payment period was also extended by 12 months to December 2026. The Company is permitted to prepay the loan, subject to certain conditions. The final payment upon the maturity date or prepayment of the loan increased from 5% to 7% of the aggregate principal balance of the loan. The variable interest rate on the drawn amount is adjusted SOFR plus 825 basis points, subject to a per annum floor rate of 8.25 %. The Loan Facility 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 Loan Facility and the loan is secured by the Company’s assets. The Loan Facility is available for working capital, capital expenditures, and other general corporate purposes. Principal installments due on the notes are as follows (in thousands): Remainder of 2023 $ — 2024 — 2025 — 2026 — 2027 25,000 Total long-term debt $ 25,000

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Common Stock	8. COMMON STOCK As of September 30, 2023, 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. 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 September 30, 2023 , no cash dividends have been declared or paid. In February 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. In May 2022, 210,000 shares of Class B common stock were converted into 210,000 shares of Class A common stock. In September 2022, the remaining 99,238 shares of Class B common stock were converted into 99,238 shares of Class A common stock. The shares of Class B common stock that were converted into shares of Class A common stock have been retired and cancelled, and therefore will not be available for reissuance. In June 2022, the Company filed a shelf registration statement on Form S-3 (File No. 333-265408) with the Securities and Exchange Commission, which permits the offering, issuance, and sale of up to a maximum aggregate offering price of $ 400.0 million of the Company’s common stock, preferred stock, debt securities and warrants. Up to a maximum of $ 150.0 million of the maximum aggregate offering price of $ 400.0 million may be issued and sold pursuant to an at-the-market financing facility under a sales agreement dated June 3, 2022, between the Company and Cowen and Company, LLC (Sales Agreement). As of September 30, 2023, all $ 150.0 million remains available for issuance and sale under the Sales Agreement. In September 2022, the Company issued 283,034 shares of Class A common stock to Novartis Pharma AG pursuant to an amendment to a license agreement between the two parties (see Note 11). In February 2023, the Company completed a follow-on public offering pursuant to which the Company issued and sold 16,428,572 shares of its Class A common stock at a public offering price of $ 7.00 per share, including 2,142,857 shares of Class A common stock pursuant to the full exercise of the underwriters’ option to purchase additional shares.

Stock Compensation

Stock Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock Compensation	9. 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 707,942 and 4,650,796 shares of Class A common stock for 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 September 30, 2023 , there were 337,109 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 WEIGHTED- WEIGHTED- AGGREGATE Outstanding as of December 31, 2022 3,821,787 $ 10.30 8.51 $ 35,872 Granted 2,231,000 Exercised ( 93,648 ) Cancelled and forfeited ( 226,958 ) Outstanding as of September 30, 2023 5,732,181 9.39 8.40 31,942 Options exercisable as of September 30, 2023 2,210,094 8.26 7.81 14,537 Vested and expected to vest as of September 30, 2023 5,732,181 9.39 8.40 31,942 The aggregate intrinsic value of stock options exercised during the three and nine months ended September 30, 2023 , was approximately $ 0.6 million and $ 0.8 million, respectively. The weighted-average grant date fair value of options granted during the three and nine months ended September 30, 2023, was $ 13.66 and $ 5.81 per share, respectively. 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 September 30, 2023 , 59,808 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 and nine months ended September 30, 2023. Stock-Based Compensation Expense The following tables summarize the stock-based compensation expense for stock options, restricted stock awards, and restricted stock units granted to employees and nonemployees and for ESPP stock-based compensation that was recorded in the Company’s condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022. Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development $ 1,146 $ 1,255 $ 3,511 $ 3,226 General and administrative 1,777 1,197 4,761 2,913 Total stock-based compensation expense $ 2,923 $ 2,452 $ 8,272 $ 6,139 Three Months Ended Nine Months Ended 2023 2022 2023 2022 Employees $ 2,621 $ 1,637 $ 7,542 $ 3,976 Nonemployees 302 815 730 2,163 Total stock-based compensation expense $ 2,923 $ 2,452 $ 8,272 $ 6,139 As of September 30, 2023 , the Company had $ 24.0 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 2.64 years. The fair value of stock options granted during the three and nine months ended September 30, 2023 and 2022 was estimated using the Black-Scholes option pricing model based on the following weighted-average assumptions. Three Months Ended Nine Months Ended 2023 2022 2023 2022 Expected term (in years) 6.1 6.1 5.5 – 6.1 5.5 – 6.1 Expected volatility 80.2 % 76.7 % – 77.6 % 79.5 % – 80.5 % 75.8 % – 77.6 % Risk-free rate 4.2 % 2.7 % – 4.1 % 3.4 % – 4.2 % 1.8 % – 4.1 % Dividend yield — — — — Restricted Stock Units The Company grants restricted stock units (RSUs) pursuant to the 2021 EIP and satisfies such grants through the issuance of the Company’s Class A common stock. The following table shows RSU activity for the period ending September 30, 2023. NUMBER OF WEIGHTED- Unvested balance at December 31, 2022 204,000 $ 18.37 Granted — Vested ( 65,384 ) 18.40 Cancelled and forfeited ( 6,000 ) 18.60 Unvested balance at September 30, 2023 132,616 18.34 For the nine months ended September 30, 2023, the Company recognized $ 1.0 million of stock-based compensation expense for restricted stock units. As of September 30, 2023, the Company had $ 2.1 million of unrecognized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of approximately 1.04 years.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2023
Retirement Benefits [Abstract]
Employee Benefit Plans	10. 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. The Company contributed $ 12,000 and $ 138,000 to the plan for the three and nine months ended September 30, 2023 , respectively. The Company contributed $ 63,000 to the plan for the three and nine months ended September 30, 2022.

Licenses and Collaborations

Licenses and Collaborations	9 Months Ended
	Sep. 30, 2023
Licenses And Collaborations [Abstract]
Licenses and Collaborations	11. 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 paid a non-refundable license issue fee to Ares in the form of shares of redeemable convertible preferred stock valued at $ 13.1 million, resulting in Ares becoming a related party to the Company. The redeemable convertible preferred stock subsequently converted into 1,913,501 shares of Class A common stock in connection with the IPO. 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. Subsequent to the effective date of the Ares Agreement, Ares is performing manufacturing technology and know-how transfer to the Company. The Company recorded related party expense of $ 0.4 million and $ 0.5 million to Ares for these services during the three months ended September 30, 2023 and 2022, respectively, and $ 2.4 million and $ 2.2 million during the nine months ended September 30, 2023 and 2022, respectively. These amounts are included in research and development expenses on the condensed statements of operations and comprehensive loss. 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 would be 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 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, 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 upon the achievement of specified development, regulatory and commercial milestones. In September 2022, the Company and Novartis entered into an amendment to the Novartis License to modify the terms of future milestone payments. Pursuant to this amendment, the Company issued 283,034 shares of Class A common stock to Novartis in exchange for a reduction of $ 7.0 million in contingent future development milestones, including the $ 2.0 million contingent milestone obligation accrued by the Company in December 2021. The value of the shares issued was $ 5.7 million based on the closing market value of the Company’s Class A common stock as of the effective date of the amendment, and as a result of the amendment the Company recognized $ 3.7 million of research and development expense in 2022. The Company is obligated to make future milestone payments of up to $ 7.0 million and $ 62.0 million to Amplyx and Novartis, respectively, contingent upon the achievement of specified development, regulatory and commercial milestones. In the event that MAU868 is commercialized, the Company will be obligated to pay royalties to Amplyx and Novartis based on net sales by country and by product.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	12. NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS 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 Nine Months Ended 2023 2022 2023 2022 Class A common stock options issued and outstanding 5,732,181 3,766,165 5,732,181 3,766,165 Unvested RSUs 132,616 235,180 132,616 235,180 Total 5,864,797 4,001,345 5,864,797 4,001,345

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	13. 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 11.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
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 unaudited interim condensed financial statements have been prepared in accordance with generally accepted accounting principles in the United States (GAAP), and in the opinion of management, include all adjustments of a normal recurring nature necessary for fair financial statement presentation. Interim results are not necessarily indicative of the results to be expected for the full year ending December 31, 2023, or any other period. The condensed balance sheet as of December 31, 2022 included herein was derived from the audited financial statements as of that date, but may not include all disclosures notes required by GAAP. These unaudited condensed financial statements and other information presented in this Form 10-Q should be read in conjunction with the Company’s audited financial statements and the notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 28, 2023.
Emerging Growth Company Status	Emerging Growth Company Status T he 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 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.
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, cash equivalents and marketable securities. 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, cash equivalents, and marketable securities to the extent recorded in the balance sheet. The Company has not experienced any losses to date related to these concentrations. 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 affect 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.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies from the Company’s Annual Report on Form 10-K for the year ended December 31, 2022.
Recently Adopted Accounting Pronouncements	Recently Adopted 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. Further, the FASB issued ASU No. 2018-19, ASU No. 2019-04, ASU No. 2019-05, ASU 2019-10, ASU 2019-11, ASU 2020-02 and ASU 2020-03 to provide additional guidance on the credit losses standard. The guidance is effective for the annual period beginning after December 15, 2022, with early adoption permitted. The Company adopted the ASUs on January 1, 2023. The ASUs did not have a material impact on the Company’s financial statements.
Recently Issued Accounting Pronouncement Not Yet Adopted	Recently Issued Accounting Pronouncement Not Yet Adopted In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions . This standard clarifies the guidance in Topic 210, when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security and introduces new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The guidance is effective for the annual period beginning after December 15, 2023, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on its financial statements and related disclosures.

Other Financial Statement Inf_2

Other Financial Statement Information (Tables)	9 Months Ended
	Sep. 30, 2023
Other Financial Statement Information [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, Prepaid clinical trial and drug manufacturing expenses $ 8,189 $ 8,487 Prepaid insurance 905 998 Prepaid equity financing costs 409 490 Prepaid rent 256 247 Other 1,922 823 Total prepaid expenses and other current assets $ 11,681 $ 11,045
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, Accrued clinical trial and drug manufacturing expenses $ 4,195 $ 4,334 Accrued payroll 2,645 3,217 Related party payable 2,389 2,780 Accrued legal fees 63 338 Accrued expenses and other 511 295 Total accrued expenses and other current liabilities $ 9,803 $ 10,964

Cash Equivalents And Marketab_2

Cash Equivalents And Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2023
Cash Equivalents And Marketable Securities [Abstract]
Summarizes the Unrealized Gains and Losses in Fair Value of the Company's Investments in Debt Securities	The following table summarizes the unrealized gains and losses in fair value of the Company’s investments in debt securities (in thousands): As of September 30, 2023 Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Level 2: Money market funds $ 26,140 $ - $ - $ 26,140 U.S. Government bonds 132,572 2 ( 76 ) 132,498 Total cash equivalents and marketable securities $ 158,712 $ 2 $ ( 76 ) $ 158,638 As of December 31, 2022 Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Level 2: Money market funds $ 42,495 $ - $ - $ 42,495 U.S. Government bonds 71,418 1 ( 225 ) 71,194 Total cash equivalents and marketable securities $ 113,913 $ 1 $ ( 225 ) $ 113,689
Schedule of Estimated Fair Value of Investments in Available-for-sale Marketable Debt Securities	The following table classifies the estimated fair value of investments in available-for-sale marketable debt securities by effective contractual maturity dates (in thousands): September 30, 2023 Due within one year $ 132,498 Due after one year to two years — Total marketable securities $ 132,498

Non-Marketable Equity Securit_2

Non-Marketable Equity Securities (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Non-marketable Equity Securities	The following table summarizes the value of non-marketable equity securities using the measurement alternative (in thousands): September 30, December 31, Initial cost $ 1,759 $ 1,759 Cumulative net fair value adjustments ( 1,746 ) ( 1,701 ) Total non-marketable equity securities $ 13 $ 58

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases [Abstract]
Schedule of Lease Costs	Net lease costs recognized were as follows (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Operating lease cost $ 644 $ 594 $ 1,933 $ 1,734 Sublease income ( 482 ) ( 482 ) ( 1,446 ) ( 1,446 ) Net lease cost $ 162 $ 112 $ 487 $ 288
Schedule of lease liabilities based on minimum lease commitment	As of September 30, 2023, the maturities of the lease liabilities based on minimum lease commitment amount are as follows (in thousands): 2023 (remaining three months) $ 762 2024 3,022 2025 1,880 2026 - 2027 - Total minimum lease payments 5,664 Less: Imputed interest ( 1,184 ) Present value of operating lease liabilities 4,480 Less: Current portion of operating lease liabilities ( 2,518 ) Non-current operating lease liabilities $ 1,962
Schedule of Receivable Future Annual Sublease Payments	As of September 30, 2023, under the terms of the sublease agreement, the Company is entitled to receive future annual sublease payments as follows (in thousands): 2023 (remaining three months) $ 480 2024 1,954 2025 1,496 Total sublease payments $ 3,930

Note Payable (Tables)

Note Payable (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of Notes Payable	Note payable consists of the following ($ in thousands): September 30, 2023 December 31, 2022 Maturity Effective Amount Effective Amount Collateralized note 2021-12 2027 14.72 % $ 5,000 13.57 $ 5,000 Collateralized note 2022-11 2027 14.86 % 20,000 13.74 20,000 Total borrowings 25,000 25,000 Less: Unamortized debt issuance costs 42 ( 190 ) Net carrying amount of debt $ 25,042 $ 24,810
Schedule Principal Installments Due	Principal installments due on the notes are as follows (in thousands): Remainder of 2023 $ — 2024 — 2025 — 2026 — 2027 25,000 Total long-term debt $ 25,000

Stock Compensation (Tables)

Stock Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
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 WEIGHTED- WEIGHTED- AGGREGATE Outstanding as of December 31, 2022 3,821,787 $ 10.30 8.51 $ 35,872 Granted 2,231,000 Exercised ( 93,648 ) Cancelled and forfeited ( 226,958 ) Outstanding as of September 30, 2023 5,732,181 9.39 8.40 31,942 Options exercisable as of September 30, 2023 2,210,094 8.26 7.81 14,537 Vested and expected to vest as of September 30, 2023 5,732,181 9.39 8.40 31,942
Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount	The following tables summarize the stock-based compensation expense for stock options, restricted stock awards, and restricted stock units granted to employees and nonemployees and for ESPP stock-based compensation that was recorded in the Company’s condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2023 and 2022. Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development $ 1,146 $ 1,255 $ 3,511 $ 3,226 General and administrative 1,777 1,197 4,761 2,913 Total stock-based compensation expense $ 2,923 $ 2,452 $ 8,272 $ 6,139 Three Months Ended Nine Months Ended 2023 2022 2023 2022 Employees $ 2,621 $ 1,637 $ 7,542 $ 3,976 Nonemployees 302 815 730 2,163 Total stock-based compensation expense $ 2,923 $ 2,452 $ 8,272 $ 6,139
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The fair value of stock options granted during the three and nine months ended September 30, 2023 and 2022 was estimated using the Black-Scholes option pricing model based on the following weighted-average assumptions. Three Months Ended Nine Months Ended 2023 2022 2023 2022 Expected term (in years) 6.1 6.1 5.5 – 6.1 5.5 – 6.1 Expected volatility 80.2 % 76.7 % – 77.6 % 79.5 % – 80.5 % 75.8 % – 77.6 % Risk-free rate 4.2 % 2.7 % – 4.1 % 3.4 % – 4.2 % 1.8 % – 4.1 % Dividend yield — — — —
Summary of Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	The following table shows RSU activity for the period ending September 30, 2023. NUMBER OF WEIGHTED- Unvested balance at December 31, 2022 204,000 $ 18.37 Granted — Vested ( 65,384 ) 18.40 Cancelled and forfeited ( 6,000 ) 18.60 Unvested balance at September 30, 2023 132,616 18.34

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2023
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 Nine Months Ended 2023 2022 2023 2022 Class A common stock options issued and outstanding 5,732,181 3,766,165 5,732,181 3,766,165 Unvested RSUs 132,616 235,180 132,616 235,180 Total 5,864,797 4,001,345 5,864,797 4,001,345

Organization and Description _2

Organization and Description of the Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands						1 Months Ended
	Feb. 06, 2023	Feb. 14, 2022	May 20, 2021	May 13, 2021	Oct. 31, 2020	May 31, 2021	Sep. 30, 2023	Dec. 31, 2022
Accumulated deficit							$ (283,447)	$ (213,112)
Cash And Cash Equivalents And Marketable Securities							$ 159,900
Underwriting discounts and commissions	$ 6,900	$ 5,200	$ 3,900
Offering Costs	$ 400	$ 900	2,800
Common Class A [Member]
Stock shares issued during the period new issues shares	2,142,857	748,959
Sale of stock net consideration received on the transaction	$ 107,700	$ 80,000
Common Class A [Member] | IPO [Member]
Conversion of redeemable convertible preferred stock to common stock					1,913,501
Stock shares issued during the period new issues shares				4,350,000
Sale of stock, price per share				$ 11
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	16,428,572	5,742,026
Sale of stock, price per share	$ 7	$ 15
Common Class A [Member] | Over-Allotment Option [Member]
Stock shares issued during the period new issues 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						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						309,238

Other Financial Statement Inf_3

Other Financial Statement Information - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other Financial Statement Information [Abstract]
Prepaid clinical trial and drug manufacturing expenses	$ 8,189	$ 8,487
Prepaid insurance	905	998
Prepaid equity financing costs	409	490
Prepaid rent	256	247
Other	1,922	823
Total prepaid expenses and other current assets	$ 11,681	$ 11,045

Other Financial Statement Inf_4

Other Financial Statement Information - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued clinical trial and drug manufacturing expenses	$ 4,195	$ 4,334
Accrued payroll	2,645	3,217
Accrued legal fees	63	338
Accrued expenses and other	511	295
Total accrued expenses and other current liabilities	9,803	10,964
Related Party [Member]
Related party payable	$ 2,389	$ 2,780

Cash Equivalents And Marketab_3

Cash Equivalents And Marketable Securities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Cash Equivalents And Marketable Securities [Abstract]
Fair value of the debt securities	$ 132.5	$ 71.2

Cash Equivalents And Marketab_4

Cash Equivalents And Marketable Securities - Summarizes the Unrealized Gains and Losses in Fair Value of the Company's Investments in Debt Securities (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Amortized Cost	$ 158,712,000	$ 113,913,000
Unrealized Gains	2,000	1,000
Unrealized Losses	(76,000)	(225,000)
Estimated Fair Value	158,638,000	113,689,000
Money Market Funds
Marketable Securities [Line Items]
Amortized Cost	26,140,000	42,495,000
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	26,140,000	42,495,000
US Government Bonds [Member]
Marketable Securities [Line Items]
Amortized Cost	132,572,000	71,418,000
Unrealized Gains	2,000	1,000
Unrealized Losses	(76,000)	(225,000)
Estimated Fair Value	$ 132,498,000	$ 71,194,000

Cash Equivalents And Marketab_5

Cash Equivalents And Marketable Securities - Schedule of Estimated Fair Value of Marketable Securities by Stated Contractual Maturities (Detail) $ in Thousands	Sep. 30, 2023 USD ($)
Cash Equivalents And Marketable Securities [Abstract]
Due within one year	$ 132,498
Due after one year to two years	0
Total marketable securities	$ 132,498

Non-Marketable Equity Securit_3

Non-Marketable Equity Securities - Summary of Non-marketable Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Initial cost	$ 1,759	$ 1,759
Cumulative net fair value adjustments	(1,746)	(1,701)
Total non-marketable equity securities	$ 13	$ 58

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Leases [Abstract]
Operating lease cost	$ 644	$ 594	$ 1,933	$ 1,734
Sublease income	(482)	(482)	(1,446)	(1,446)
Net lease cost	$ 162	$ 112	$ 487	$ 288

Leases - Schedule of Lease Liab

Leases - Schedule of Lease Liabilities Based on Minimum Lease Commitment (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Leases [Abstract]
2023 (remaining three months)	$ 762
2024	3,022
2025	1,880
2026	0
2027	0
Total minimum lease payments	5,664
Less: Imputed interest	(1,184)
Present value of operating lease liabilities	4,480
Less: Current portion of operating lease liabilities	(2,518)	$ (2,645)
Non-current operating lease liabilities	$ 1,962	$ 3,831

Leases - Schedule of Receivable

Leases - Schedule of Receivable Future Annual Sublease Payments (Detail) $ in Thousands	Sep. 30, 2023 USD ($)
Leases [Abstract]
2023 (remaining three months)	$ 480
2024	1,954
2025	1,496
Total sublease payments	$ 3,930

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	Sep. 30, 2023 USD ($)	Jul. 31, 2022 ft²
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	1 year 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	9.10%
Operating lease minimum future commitments | $	$ 5
Office and Laboratory Space at Brisbane California [Member]
Lessee, Lease, Description [Line Items]
Percentage of increase in rent annually		3%
Office and Laboratory Space at Brisbane California [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Area of real estate availed on lease		9,900
Office and Laboratory Space at Brisbane California [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Area of real estate availed on lease		4,900

Note Payable - Schedule of Note

Note Payable - Schedule of Notes Payable (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total Borrowings	$ 25,000	$ 25,000
Less: Unamortized debt issuance costs	(42)	(190)
Total long-term debt	$ 25,042	$ 24,810
LIBOR (Member)
Debt Instrument [Line Items]
Collateralized debt instrument maturity date	2027
Collateralized note , Effective interest rate	14.72%	13.57%
Collateralized note ,Amount	$ 5,000	$ 5,000
SOFR [Member]
Debt Instrument [Line Items]
Collateralized debt instrument maturity date	2027
Collateralized note , Effective interest rate	14.86%	13.74%
Collateralized note ,Amount	$ 20,000	$ 20,000

Note Payable - Additional Infor

Note Payable - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Nov. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Carrying amount of debt outstanding	$ 25,000
Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	8.25%
Loan Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility with borrowing capacity	$ 25,000		$ 50,000
Additional borrowing capacity		$ 20,000
Carrying amount of debt outstanding	$ 25,000
Debt facility payments description	The interest-only payment period was also extended by 12 months to December 2026.

Note Payable - Schedule Princip

Note Payable - Schedule Principal Installments Due (Detail) $ in Thousands	Sep. 30, 2023 USD ($)
Debt Disclosure [Abstract]
2027	$ 25,000
Total long-term debt	$ 25,000

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($)			1 Months Ended		3 Months Ended	9 Months Ended
	Feb. 06, 2023	Feb. 14, 2022	Sep. 30, 2022	May 31, 2022	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Class of Stock [Line Item]
Maximum aggregate offering price of common stock, preferred stock, debt securities and warrants						$ 400,000,000
Available for Issuance and Sale Under Sales Agreement						150,000,000
Cowen and Company, LLC [Member] | Maximum [Member] | 2022 ATM facility [Member]
Class of Stock [Line Item]
Maximum aggregate offering price of common stock, preferred stock, debt securities and warrants						$ 150,000,000
Common Class A [Member]
Class of Stock [Line Item]
Common stock, shares authorized						500,000,000		500,000,000
Common stock, Par value						$ 0.001		$ 0.001
Common stock conversion basis						one
Cash dividends						$ 0
Stock shares issued during the period new issues shares	2,142,857	748,959
Shares converted			99,238	210,000
Company shares issued					283,034	283,034	283,034
Common Class A [Member] | Follow-on Public Offering [Member]
Class of Stock [Line Item]
Stock shares issued during the period new issues shares	16,428,572	5,742,026
Sale of stock, price per share	$ 7	$ 15
Common Class B [Member]
Class of Stock [Line Item]
Common stock, shares authorized						14,600,000
Common stock, Par value						$ 0.001
Cash dividends						$ 0
Shares converted			99,238	210,000

Stock Compensation - Additional

Stock Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Apr. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, Options exercised in period, Total intrinsic value	$ 600		$ 800
Number of shares issued under share-based payment arrangement			59,808
Stock-based compensation expense	$ 2,923	$ 2,452	$ 8,272	$ 6,139
Employee Stock Purchase Plan ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock capital, Shares reserved for future issuance					707,942
2021 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock capital, Shares reserved for future issuance					4,650,796
Share-based compensation arrangement by share-based payment award, Number of shares available for issuance	337,109		337,109
2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, Options granted in period, Weighted average grant date fair value	$ 13.66		$ 5.81
Unvested Stock Options And Restricted Stock Awards [Member] | 2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized Stock options and equity instruments other than options	$ 24,000		$ 24,000
Share based compensation, Nonvested awards, Compensation cost not yet recognized period of recognition stock options and equity instruments other than options			2 years 7 months 20 days
Unvested Stock Options And Restricted Stock Unit [Member] | 2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized Stock options and equity instruments other than options	$ 2,100		$ 2,100
Restricted Stock [Member] | Unvested Stock Options And Restricted Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, Nonvested awards, Compensation cost not yet recognized period of recognition stock options and equity instruments other than options			1 year 14 days
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock Percent of Fair Market Value			85%
Share purchases funded through payroll deductions for employee's eligible minimum annual compensation, percentage			1%
Share purchases funded through payroll deductions for employee's eligible maximum annual compensation, percentage	15%		15%
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%
Restricted Stock Units (RSUs) [Member] | 2017 and 2021 Amended Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 1,000

Stock Compensation - Summary of

Stock Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Details) - 2017 EIP And 2021 EIP [Member] $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Options, Beginning	3,821,787
Number of Options, Granted	2,231,000
Number of Options, Exercised	(93,648)
Number of Options, Cancelled and forfeited	(226,958)
Number of Options, Ending	5,732,181	3,821,787
Number of Options, Options exercisable	2,210,094
Number of Options, Vested and expected to vest	5,732,181
Weighted average exercise price, Opening balance | $ / shares	$ 10.3
Weighted average exercise price, Ending balance | $ / shares	9.39	$ 10.3
Weighted average exercise price, Option exercisable | $ / shares	8.26
Weighted average exercise price, Vested and expected to vest | $ / shares	$ 9.39
Weighted average remaining contractual term	8 years 4 months 24 days	8 years 6 months 3 days
Weighted average remaining contractual term, Options exercisable	7 years 9 months 21 days
Weighted average remaining contractual term, Vested and expected to vest	8 years 4 months 24 days
Intrinsic Value | $	$ 31,942	$ 35,872
Intrinsic Value, Options exercisable | $	14,537
Intrinsic Value, Vested and expected to vest | $	$ 31,942

Stock compensation - Summary _2

Stock compensation - Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 2,923	$ 2,452	$ 8,272	$ 6,139
Employees [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	2,621	1,637	7,542	3,976
Nonemployees [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	302	815	730	2,163
Research and Development [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	1,146	1,255	3,511	3,226
General and Administrative [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 1,777	$ 1,197	$ 4,761	$ 2,913

Stock Compensation - Schedule o

Stock Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
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
Expected volatility, Minimum		76.70%	79.50%	75.80%
Expected volatility	80.20%
Expected volatility, Maximum		77.60%	80.50%	77.60%
Risk-free rate, Minimum		2.70%	3.40%	1.80%
Risk-free rate	4.20%
Risk-free rate, Maximum		4.10%	4.20%	4.10%
Minimum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected term (in years)			5 years 6 months	5 years 6 months
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

Stock Compensation - Summary _3

Stock Compensation - Summary of Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity (Details) - Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested as of December 31, 2022	204,000
Granted	0
Vested	(65,384)
Cancelled and forfeited	(6,000)
Unvested as of September 30, 2023	132,616
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 18.37
Weighted Average Grant Date Fair Value, Vested | $ / shares	18.4
Weighted Average Grant Date Fair Value, Cancelled and Forfeited | $ / shares	18.6
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 18.34

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Retirement Benefits [Abstract]
Employer contributions	$ 12,000	$ 63,000	$ 138,000	$ 63,000

Licenses and Collaborations - A

Licenses and Collaborations - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2020	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
License and Collaborations [Line Items]
Research and development		$ 16,100	$ 19,656	$ 57,440	$ 42,317
Ares Agreement Member | Ares Trading S A Member
License and Collaborations [Line Items]
Temporary equity shares issued during the period value	$ 13,100
Milestone payments paid							$ 25,000
Related party transaction, expenses from transactions with related party		$ 400	500	2,400	2,200
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			3,700			7,000
Reduction in contingent future development				7,000
Contingent milestone obligation accrued						$ 2,000
Company shares issued				$ 5,700
Amplyx Agreement Member | Amplyx And Novartis Member | Achievement Of Various Clinical Development And Regulatory Milestones Member
License and Collaborations [Line Items]
Milestone payments payable			7,000		7,000
Novartis Member | Amplyx And Novartis Member | Achievement Of Various Clinical Development And Regulatory Milestones Member
License and Collaborations [Line Items]
Milestone payments payable			$ 62,000		$ 62,000
Common Class A [Member]
License and Collaborations [Line Items]
Company shares issued			283,034	283,034	283,034
Common Class A [Member] | IPO [Member]
License and Collaborations [Line Items]
Conversion of redeemable convertible preferred stock to common stock	1,913,501

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Summary of Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	5,864,797	4,001,345	5,864,797	4,001,345
Class A Common Stock Options Issued and Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	5,732,181	3,766,165	5,732,181	3,766,165
Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities	132,616	235,180	132,616	235,180