Tenaya Therapeutics (TNYA) 10-Q 8 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 02, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Registrant Name	TENAYA THERAPEUTICS, INC.
Entity Central Index Key	0001858848
Entity File Number	001-40656
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-3789973
Entity Address, Address Line One	171 Oyster Point Boulevard
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	825-6990
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	TNYA
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		68,111,019

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 82,153	$ 95,272
Short-term investments in marketable securities	39,600	91,255
Prepaid expenses and other current assets	5,075	7,227
Total current assets	126,828	193,754
Property and equipment, net	45,131	51,032
Operating lease right-of-use assets	9,337	11,663
Long-term investments in marketable securities	6,367	17,703
Other noncurrent assets	5,734	4,793
Total assets	193,397	278,945
Current liabilities:
Accounts payable	5,902	9,578
Accrued and other current liabilities	10,321	10,664
Operating lease liabilities, current	3,154	4,006
Total current liabilities	19,377	24,248
Operating lease liabilities, noncurrent	8,890	11,093
Other noncurrent liabilities	246	228
Total liabilities	28,513	35,569
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock	7	7
Additional paid-in capital	538,485	522,945
Accumulated other comprehensive loss	(261)	(378)
Accumulated deficit	(373,347)	(279,198)
Total stockholders' equity	164,884	243,376
Total liabilities and stockholders' equity	$ 193,397	$ 278,945

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - 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	$ 23,091	$ 23,758	$ 75,173	$ 68,789
General and administrative	7,829	7,540	24,574	22,282
Total operating expenses	30,920	31,298	99,747	91,071
Loss from operations	(30,920)	(31,298)	(99,747)	(91,071)
Other income, net:
Interest income	1,776	596	5,586	917
Other income, net	1	6	12	5
Total other income, net	1,777	602	5,598	922
Net loss before income tax expense	(29,143)	(30,696)	(94,149)	(90,149)
Net loss	(29,143)	(30,696)	(94,149)	(90,149)
Other comprehensive income (loss):
Net unrealized gain (loss) on marketable securities	72	(28)	117	(626)
Comprehensive loss	$ (29,071)	$ (30,724)	$ (94,032)	$ (90,775)
Net loss per share, basic	$ (0.39)	$ (0.74)	$ (1.28)	$ (2.18)
Net loss per share, diluted	$ (0.39)	$ (0.74)	$ (1.28)	$ (2.18)
Weighted-average shares used in computing net loss per share, basic	73,924,937	41,358,296	73,579,200	41,309,812
Weighted-average shares used in computing net loss per share, diluted	73,924,937	41,358,296	73,579,200	41,309,812

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	At The Market Sales	Common Stock	Common Stock At The Market Sales	Additional Paid-In Capital	Additional Paid-In Capital At The Market Sales	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2021	$ 278,526		$ 4		$ 434,196		$ (141)	$ (155,533)
Balance, shares at Dec. 31, 2021			41,291,374
Issuance of common stock upon exercise of stock options	17				17
Issuance of common stock upon exercise of stock options, shares			7,652
Vesting of early exercised stock options	6				6
Stock-based compensation	2,094				2,094
Other comprehensive income (loss)	(490)						(490)
Net loss	(31,056)							(31,056)
Balance at Mar. 31, 2022	249,097		$ 4		436,313		(631)	(186,589)
Balance, shares at Mar. 31, 2022			41,299,026
Balance at Dec. 31, 2021	278,526		$ 4		434,196		(141)	(155,533)
Balance, shares at Dec. 31, 2021			41,291,374
Net loss	(90,149)
Balance at Sep. 30, 2022	196,328		$ 4		442,773		(767)	(245,682)
Balance, shares at Sep. 30, 2022			41,374,689
Balance at Mar. 31, 2022	249,097		$ 4		436,313		(631)	(186,589)
Balance, shares at Mar. 31, 2022			41,299,026
Issuance of common stock upon exercise of stock options	28				28
Issuance of common stock upon exercise of stock options, shares			13,186
Issuance of common stock pursuant to employee stock purchase plan	230				230
Issuance of common stock pursuant to employee stock purchase plan, shares			51,608
Vesting of early exercised stock options	5				5
Stock-based compensation	3,012				3,012
Other comprehensive income (loss)	(108)						(108)
Net loss	(28,397)							(28,397)
Balance at Jun. 30, 2022	223,867		$ 4		439,588		(739)	(214,986)
Balance, shares at Jun. 30, 2022			41,363,820
Issuance of common stock upon exercise of stock options and vesting of restricted stock units	6				6
Issuance of common stock upon exercise of stock options and vesting of restricted stock units, shares			10,869
Vesting of early exercised stock options	5				5
Stock-based compensation	3,174				3,174
Other comprehensive income (loss)	(28)						(28)
Net loss	(30,696)							(30,696)
Balance at Sep. 30, 2022	196,328		$ 4		442,773		(767)	(245,682)
Balance, shares at Sep. 30, 2022			41,374,689
Balance at Dec. 31, 2022	243,376		$ 7		522,945		(378)	(279,198)
Balance, shares at Dec. 31, 2022			66,857,113
Issuance of common stock upon exercise of stock options and vesting of restricted stock units, shares			8,311
Vesting of early exercised stock options	1				1
Stock-based compensation	3,514				3,514
Other comprehensive income (loss)	258						258
Net loss	(31,737)							(31,737)
Balance at Mar. 31, 2023	215,412		$ 7		526,460		(120)	(310,935)
Balance, shares at Mar. 31, 2023			66,865,424
Balance at Dec. 31, 2022	243,376		$ 7		522,945		(378)	(279,198)
Balance, shares at Dec. 31, 2022			66,857,113
Net loss	(94,149)
Balance at Sep. 30, 2023	164,884		$ 7		538,485		(261)	(373,347)
Balance, shares at Sep. 30, 2023			68,111,019
Balance at Mar. 31, 2023	215,412		$ 7		526,460		(120)	(310,935)
Balance, shares at Mar. 31, 2023			66,865,424
Issuance of common stock upon exercise of stock options	29				29
Issuance of common stock upon exercise of stock options, shares			10,875
Issuance of common stock in connection with at-the-market sales, net of issuance costs		$ 3,868				$ 3,868
Issuance of common stock in connection with at-the-market sales, net of issuance costs, shares				535,767
Issuance of common stock upon exercise of pre-funded warrants, shares			302,517
Issuance of common stock pursuant to employee stock purchase plan	282				282
Issuance of common stock pursuant to employee stock purchase plan, shares			150,575
Stock-based compensation	3,831				3,831
Other comprehensive income (loss)	(213)						(213)
Net loss	(33,269)							(33,269)
Balance at Jun. 30, 2023	189,940		$ 7		534,470		(333)	(344,204)
Balance, shares at Jun. 30, 2023			67,865,158
Issuance of common stock upon vesting of restricted stock units, shares			245,861
Stock-based compensation	4,015				4,015
Other comprehensive income (loss)	72						72
Net loss	(29,143)							(29,143)
Balance at Sep. 30, 2023	$ 164,884		$ 7		$ 538,485		$ (261)	$ (373,347)
Balance, shares at Sep. 30, 2023			68,111,019

Condensed Statements of Stock_2

Condensed Statements of Stockholders' Equity (Unaudited) (Parenthetical) $ in Thousands	3 Months Ended
	Jun. 30, 2023 USD ($)
At The Market Sales
Stock issuance costs	$ 120

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Cash flows from operating activities:
Net loss	$ (94,149)	$ (90,149)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,506	4,350
Amortization (accretion) of premium (discount) on marketable securities	(1,371)	76
Stock-based compensation	11,360	8,280
Non-cash operating lease expense	2,326	1,510
Other	157	27
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	2,013	(3,278)
Other noncurrent assets	(658)	(672)
Accounts payable	(2,977)	(1,803)
Accrued and other current liabilities	(300)	2,051
Operating lease liabilities	(3,055)	(2,147)
Other noncurrent liabilities		13
Net cash used in operating activities	(80,148)	(81,742)
Cash flows from investing activities:
Purchases of property and equipment	(845)	(19,835)
Purchases of marketable securities	(40,998)	(108,737)
Proceeds from maturities of marketable securities	105,484	206,250
Other	(7)
Net cash provided by investing activities	63,634	77,678
Cash flows from financing activities:
Proceeds from at-the-market sales, net of issuance costs	3,868
Payment of accrued offering costs	(501)
Proceeds from exercise of stock options and employee stock purchase plan	311	281
Net cash provided by financing activities	3,678	281
Net change in cash, cash equivalents and restricted cash	(12,836)	(3,783)
Cash and cash equivalents and restricted cash at beginning of period	95,671	38,676
Cash and cash equivalents and restricted cash at end of period	82,835	34,893
Components of cash, cash equivalents and restricted cash:
Cash and cash equivalents	82,153	34,494
Restricted cash included in other noncurrent assets	682	399
Cash, cash equivalents and restricted cash	82,835	34,893
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment included in accounts payable and accrued and other current liabilities	$ 309	$ 263

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 the Business Tenaya Therapeutics, Inc. (the Company) was incorporated in the state of Delaware in August 2016 and is headquartered in South San Francisco, California. The Company is a clinical-stage biotechnology company focused on discovering, developing and delivering curative therapies that address the underlying drivers of heart disease. The Company’s lead product candidates include, TN-201, a gene therapy for myosin binding protein C3-associated hypertrophic cardiomyopathy, TN-401, a gene therapy for plakophilin 2-associated arrhythmogenic right ventricular cardiomyopathy and TN-301, a small molecule for heart failure with preserved ejection fraction. Liquidity The Company has incurred net losses since inception and expects such losses to continue in the future as it conducts research and development activities. As of September 30, 2023, the Company had an accumulated deficit of $ 373.3 million. The Company incurred a net loss of $ 94.1 million and $ 90.1 million during the nine months ended September 30, 2023 and 2022, respectively. The Company had $ 128.1 million of cash, cash equivalents and investments in marketable securities as of September 30, 2023. Management recognizes the need to raise additional capital to fully implement its business plan. The Company may seek to raise capital through equity financings, debt financings, license agreements, collaborative agreements or other sources of financing. Management believes that its existing cash, cash equivalents and investments in marketable securities as of September 30, 2023 will be sufficient to fund the Company’s operations for at least the next twelve months following the date these condensed financial statements are filed with the Securities and Exchange Commission (SEC).

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and follow the requirements of the SEC for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. The interim condensed balance sheet as of September 30, 2023, the interim condensed statements of operations and comprehensive loss, stockholders’ equity and cash flows for the nine months ended September 30, 2023 and 2022 are unaudited. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and reflect all adjustments that are necessary for the fair statement of the Company’s financial position, results of operations and cash flows for the interim periods presented. The condensed results of operations for the nine months ended September 30, 2023, are not necessarily indicative of the results to be expected for the full year or for any other future annual or interim period. The condensed balance sheet as of December 31, 2022, included herein was derived from the audited financial statements as of that date. These condensed financial statements should be read in conjunction with the Company’s audited financial statements and the related notes thereto for the year ended December 31, 2022, included in Company’s Annual Report on Form 10-K, filed with the SEC on March 8, 2023. Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to clinical trial accrued liabilities, income tax valuation allowance and stock-based compensation. Management bases its estimates on historical experience, the current economic environment, and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions. Significant Accounting Policies Except for the changes below, there have been no material revisions to the Company’s significant accounting policies described in Note 2 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. Marketable Securities The Company invests in marketable securities, primarily securities issued by the U.S. government and its agencies, commercial paper and corporate bonds. All marketable securities have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its marketable debt securities at the time of purchase and reevaluates such designation at each balance sheet date. The Company evaluates securities for impairment at the end of each reporting period. Factors considered in the evaluation include whether a decline in fair value below the amortized cost basis is due to credit-related factors or non-credit-related factors, the financial condition and near-term prospect of the issuer, and the Company’s intent and ability to hold the investment to allow for anticipated recovery in fair value. A credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings. Any impairment that is not credit-related is reported as a component of other comprehensive loss. Realized gains and losses are included in other income (expense), net. The cost of securities sold is based on the specific-identification method. Interest earned on marketable securities is included in interest income. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which replaces the existing incurred loss impairment model with an expected credit loss model. This standard requires companies to recognize an allowance for credit losses on available-for-sale debt securities rather than the prior approach of recording a reduction to the carrying value of the asset. ASU 2016-13 became effective for the Company beginning January 1, 2023 . The adoption of this standard did no t have a material impact on the Company's financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: Level 1 - Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2 - Inputs other than quoted market prices included in Level 1 are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life. Level 3 - Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy: September 30, 2023 Valuation Amortized Unrealized Unrealized Fair Value (In thousands) Assets: Cash equivalents: Money market funds Level 1 1,261 — — 1,261 U.S. treasuries Level 1 43,859 6 — 43,865 Commercial paper Level 2 18,026 — ( 6 ) 18,020 Government agencies bonds Level 2 18,417 2 — 18,419 Marketable securities: U.S. treasuries Level 1 8,307 — ( 34 ) 8,273 Government agencies bonds Level 2 37,922 — ( 228 ) 37,694 Total financial assets $ 127,792 $ 8 $ ( 268 ) $ 127,532 December 31, 2022 Valuation Amortized Unrealized Unrealized Fair Value (In thousands) Assets: Cash equivalents: Cash equivalents Level 1 $ 20,532 $ — $ — $ 20,532 Money market funds Level 1 7,203 — — 7,203 Commercial paper Level 2 11,972 — ( 4 ) 11,968 Government agencies bonds Level 2 54,569 12 — 54,581 Marketable securities: U.S. treasuries Level 1 25,273 1 ( 147 ) 25,127 Commercial paper Level 2 43,605 4 ( 125 ) 43,484 Corporate bonds Level 2 2,696 — ( 18 ) 2,678 Government agencies bonds Level 2 37,770 9 ( 110 ) 37,669 Total financial assets $ 203,620 $ 26 $ ( 404 ) $ 203,242 Money market funds and U.S. treasury securities are classified as Level 1 because they are valued using quoted market prices in active markets for identical assets. Financial instruments classified within Level 2 of the fair value hierarchy are valued based on observable inputs or can be derived from non-binding quotes from the Company’s investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers. The Company believes it is more likely than not that its marketable securities in an unrealized loss position will be held until maturity or the recovery of the cost basis of the investment. To date, the Company has no t recorded any allowance for credit losses on its investment securities. Based upon its quarterly impairment review, the Company determined that the unrealized losses were not attributed to credit risk, but were primarily driven by the broader change in interest rates. As of September 30, 2023, the fair value of available-for-sale marketable securities was $ 46.0 million. $ 39.6 million of available-for-sale marketable securities had remaining maturities of less than one year. The remaining $ 6.4 million of marketable securities had remaining maturities between one and two years . The carrying amount of the Company’s remaining financial assets and liabilities, which include cash, receivables and payables, approximate their fair values due to their short-term nature.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Property and Equipment, Net Property and equipment, net consists of the following: September 30, December 31, (In thousands) Leasehold improvements $ 25,603 $ 23,605 Laboratory equipment 19,770 20,537 Manufacturing equipment 17,716 17,468 Construction in progress 1,658 3,128 Computer equipment and software 1,591 1,060 Furniture and fixtures 975 910 Total property and equipment $ 67,313 $ 66,708 Less: accumulated depreciation and amortization ( 22,182 ) ( 15,676 ) Total property and equipment, net $ 45,131 $ 51,032 Depreciation and amortization expense for the three months ended September 30, 2023 and 2022 was $ 2.2 million and $ 2.1 million, respectively. Depreciation and amortization expense for the nine months ended September 30, 2023 and 2022 was $ 6.5 million and $ 4.3 million, respectively. Accrued and Other Current Liabilities Accrued and other current liabilities consist of the following: September 30, December 31, (In thousands) Accrued compensation and related expenses $ 6,362 $ 6,299 Accrued research and development expenses 2,361 3,214 Accrued professional services 518 482 ESPP deduction liability 441 124 Accrued facility management services 181 — Other current liabilities 458 545 Total accrued and other current liabilities $ 10,321 $ 10,664

License Agreements

License Agreements	9 Months Ended
	Sep. 30, 2023
License Agreements [Abstract]
License Agreements	5. License Agreements Gladstone License Agreement In October 2016, the Company entered into a license agreement with the J. David Gladstone Institute (Gladstone), pursuant to which Gladstone granted the Company a worldwide, royalty-bearing exclusive patent license and a non-exclusive technology license to develop and commercialize certain products for certain diseases (Gladstone License Agreement). Pursuant to the Gladstone License Agreement, the Company is obligated, among other things, to pay Gladstone (i) annual license maintenance fees ranging from $ 25,000 up to $ 0.1 million per year, which will be creditable against royalties paid in the following twelve month period, (ii) milestone payments up to $ 4.1 million for royalty-bearing products directed to a particular target, which are contingent upon achieving specific clinical and commercialization milestone events, and (iii) tiered low-single digit royalties on future net sales of each royalty-bearing product. Under the agreement, the Company is subject to diligence requirements to develop and commercialize at least one royalty-bearing product. The Company may pay $ 50,000 to $ 100,000 to extend the deadline for its diligence milestone obligations for up to four additional one-year terms. Dr. Deepak Srivastava, M.D., a member of the Company’s board of directors, serves as President of Gladstone. As of September 30, 2023, the Company has no t recognized any milestone and royalty payments under the Gladstone License Agreement. During the three and nine months ended September 30, 2023 and 2022, there were no material amounts recorded related to annual license fees payable pursuant to the Gladstone License Agreement. University of Texas Southwestern License Agreements In January 2020, the Company entered into a license agreement with the University of Texas Southwestern (UTSW License), pursuant to which UTSW granted the Company a royalty-bearing exclusive and sublicensable patent license and a non-exclusive, non-sublicensable license for certain materials. Under the UTSW License, the Company is obligated to pay UTSW (i) a non-refundable upfront license fee of $ 0.1 million, (ii) milestone payments up to a total of $ 14.8 million in aggregate, which are contingent upon achieving specific development and commercialization milestone events, and (iii) royalties on future net sales of each royalty-bearing product ranging in the low-single digits. As of September 30, 2023, the Company has no t recognized any milestone and royalty payments under the UTSW License. Other License Agreements In addition, the Company has other license agreements with various institutions and business entities, none of which are material individually or in the aggregate.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Facility Leases In December 2016, the Company entered into a lease agreement for office and laboratory space in South San Francisco, California. The lease expires in May 2025 and the Company may renew the lease term for two additional five-year periods. In February 2021, the Company entered into a lease agreement for the Union City Facility. The lease commenced in May 2021 and has a ten-year term with one five-year renewal option. In November 2021, the Company entered into a short-term sublease agreement for additional office and laboratory space in South San Francisco, California with a lease term that was initially set to expire on June 30, 2022 . In May 2022, the Company entered into an amendment to extend the term for the existing sublease premise through December 31, 2022 . Under the amendment, the Company also subleased additional office and laboratory space at the same sublease premise through November 30, 2023. In October 2023, the Company entered into a second amendment for additional laboratory space and to extend the term of the sublease premise through November 30, 2024 . Total lease payment under the sublease extension is $ 1.5 million. Information related to operating lease activity during the three and nine months ended September 30, 2023 was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (In thousands) Operating lease cost $ 1,090 $ 1,090 $ 3,271 $ 2,624 Variable lease cost 324 319 919 910 Short-term lease cost — 244 5 709 Total lease cost $ 1,414 $ 1,653 $ 4,195 $ 4,243 Operating lease right-of-use assets obtained in exchange for lease obligations $ — $ 2,224 Cash paid for amounts included in the measurement of lease liabilities $ 4,000 $ 2,978 As of September 30, 2023, the Company’s operating leases had a weighted average remaining lease term of 5.6 years and a weighted average discount rate of 9.6 %. Future minimum lease payments under the Company’s operating leases as of September 30, 2023 were as follows: Amount (In thousands) 2023 (remaining 3 months) $ 1,223 2024 3,910 2025 2,445 2026 1,386 2027 1,428 Thereafter 5,477 Total undiscounted future minimum lease payments $ 15,869 Imputed interest ( 3,825 ) Total operating lease liabilities $ 12,044 Asset Retirement Obligation Under the lease agreement for the manufacturing and office facility in Union City, the Company is contractually obligated to remove constructed leasehold improvements related to capitalized machinery and equipment (see Note 4) and to restore the leased space to its original condition upon termination of the lease agreement. As of September 30, 2023, the balance of the asset retirement obligation liability was not material. Purchase Commitments The Company enters into contractual agreements with various suppliers in the normal course of its business, including vendors that provide machinery and equipment. All contracts are terminable, with varying provisions regarding termination. If a contract with a specific vendor were to be terminated, the Company would only be obligated for the products or services that the Company had received through the time of termination. Indemnification From time to time, the Company may become involved in litigation and other legal actions. The Company estimates the range of liability related to any pending litigation where the amount and range of loss can be estimated. The Company records its best estimate of a loss when the loss is considered probable. Where a liability is probable and there is a range of estimated loss with no best estimate in the range, the Company records a charge equal to at least the minimum estimated liability for a loss contingency when both of the following conditions are met: (i) information available prior to issuance of the consolidated financial statements indicates that it is probable that a liability had been incurred at the date of the consolidated financial statements and (ii) the range of loss can be reasonably estimated. The Company was not involved in any material litigation as of September 30, 2023. In the normal course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amounts of future payments the Company could be required to make under these provisions is not determinable. In addition, the Company has entered into indemnification agreements with its directors and certain officers that may require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. As of September 30, 2023, the Company did not have any material indemnification claims that were probable or reasonably possible and, consequently, has not recorded any related liabilities .

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	7. Stock-Based Compensation 2021 Equity Incentive Plan Under the Company's 2021 Equity Incentive Plan (2021 Plan), 4,000,000 shares of the Company’s common stock were initially reserved for issuance of equity awards to employees, directors, and consultants, under terms and provisions established by the board of directors. The number of shares of common stock available for issuance under the 2021 Plan automatically increases on the first day of January for a period of ten years , commencing on January 1, 2022, in an amount equal to the lesser of: 4,000,000 shares; 4 % of the outstanding shares of the Company’s common stock as of the last day of the immediately preceding year; or such other amount as the board of directors may determine. In addition, the Company’s 2016 Equity Incentive Plan (2016 Plan) was terminated in connection with the IPO. Shares subject to awards granted under the 2016 Plan that are repurchased by or forfeited to the Company will be reserved for issuance under the 2021 Plan. Total shares reserved and available for grant under the 2021 Plan as of September 30, 2023 are 1,078,248 . Stock Option Activity The following table summarizes stock option activity: Shares Weighted- (in dollars) Outstanding as of December 31, 2022 5,210,182 $ 10.01 Granted 3,148,158 $ 3.43 Exercised ( 10,875 ) $ 2.71 Cancelled ( 123,119 ) $ 5.64 Outstanding as of September 30, 2023 8,224,346 $ 7.57 Stock option awards granted to employees generally vest over a four-year period. The contractual term of stock option awards is generally 10 years from the grant date. Stock Option Valuation The fair value of the Company’s stock option awards is estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Expected term (in years) 6.1 5.5 – 6.1 5.5 – 6.1 5.5 – 6.1 Expected volatility 94 % 96 % – 97 % 94 % – 95 % 96 % – 97 % Risk-free interest rate 4.0 % – 4.4 % 2.9 % – 3.6 % 3.4 % – 4.4 % 1.6 % – 3.6 % Expected dividend yield — % — % — % — % Restricted Stock Units (RSUs) RSUs are awards that entitle the holder to receive freely tradable shares of the Company’s common stock upon the completion of a specific period of continued service. RSUs generally vest over a two - to four-year period and are subject to forfeiture if employment terminates prior to the release of vesting restrictions. RSUs are valued at the market price of the underlying common stock on the date of grant. The Company recognizes noncash compensation expense for the fair value of RSUs on a straight-line basis over the requisite service period of the awards. The following table summarizes activity of RSUs granted to employees with service-based vesting under the 2021 Plan. Shares Weighted (in dollars) Unvested as of December 31, 2022 459,192 $ 4.07 Granted 911,813 $ 3.06 Vested ( 254,172 ) $ 3.61 Forfeited ( 22,052 ) $ 3.82 Unvested as of September 30, 2023 1,094,781 $ 3.34 2021 Employee Stock Purchase Plan Under the Company's 2021 Employee Stock Purchase Plan (ESPP), the Company initially reserved 800,000 shares for future issuance. The number of shares of common stock available for issuance under the ESPP automatically increases on the first day of each fiscal year beginning with 2022 in an amount equal to the lesser of: 800,000 shares; 1 % of the outstanding shares of the Company’s common stock as of the last day of the immediately preceding year; or such other amount as the board of directors may determine. As of September 30, 2023, 1,624,717 shares were reserved for future issuance under the ESPP. Under the Company’s ESPP, employees are generally eligible to participate and can purchase shares on each purchase date established semi-annually through payroll deductions at the lower of 85 % of the fair market value of the Company’s stock at the commencement of the offering period or each purchase date of the offering period. Each offering period spans 6 months . The ESPP permits eligible employees to purchase common stock through payroll deductions for up to 15 % of qualified compensation, up to an annual limit of $ 25,000 per the Internal Revenue Service. The first offering period commenced in January 2022. For the nine months ended September 30, 2023 and 2022, the stock-based compensation expense for ESPP was no t material. Stock-Based Compensation The following table summarizes stock-based compensation recognized in the Company’s condensed statements of operations and comprehensive loss: Three Months Ended Nine Months Ended 2023 2022 2023 2022 (In thousands) Research and development $ 1,861 $ 1,344 $ 5,204 $ 3,777 General and administrative 2,154 1,830 6,156 4,503 Total stock-based compensation $ 4,015 $ 3,174 $ 11,360 $ 8,280

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders' Equity	8. Stockholders' Equity “At-the-Market” Equity Offering On August 10, 2022, the Company entered into a sales agreement (Sales Agreement) with SVB Securities LLC to establish an at-the-market (ATM) offering defined in Rule 415 under the Securities Act. Pursuant to the Sales Agreement, the Company is permitted to offer and sell, from time to time, shares of its common stock having a maximum aggregate offering price of up to $ 75.0 million. During the three and nine months ended September 30, 2023, the Company sold 535,767 shares under the ATM, resulting in proceeds of $ 3.9 million, after deducting commissions of $ 0.1 million pursuant to the Sales Agreement. Follow-On Offering On November 21, 2022, the Company completed an underwritten public offering of 22,613,307 shares of its common stock at a price of $ 2.60 per share and, to certain investors in lieu of common stock, pre-funded warrants to purchase 6,236,693 shares of its common stock at a price of $ 2.599 per pre-funded warrant. The pre-funded warrants can be exercised at any time after issuance for an exercise price of $ 0.001 per share, subject to certain ownership limitations. In addition, the Company granted the underwriters a 30-day option to purchase up to an additional 4,327,500 shares of its common stock to cover overallotments, if any, at $ 2.60 per share. On November 29, 2022, the underwriters partially exercised the option and purchased an additional 2,816,409 shares of Company ’s common stock. As of September 30, 2023, pre-funded warrants for 302,517 shares of common stock have been exercised. As of September 30, 2023, total shares of common stock reserved for issuance, on an as-if converted basis, are as follows: September 30, Outstanding stock options and awards 9,319,127 Outstanding pre-funded warrants 5,934,176 Stock options and awards available for future grant 1,078,248 Shares available for further issuance under the employee stock purchase plan 1,624,717 Total 17,956,268

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes For the nine months ended September 30, 2023 and 2022, the Company did no t record any income tax expense or benefit. The Company has recorded a full valuation allowance against its U.S. federal and state deferred tax assets as the Company believes it is more likely than not that the benefit will not be realized.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	10. Net Loss Per Share Basic and diluted loss per share are computed by dividing net loss by the weighted-average number of common shares outstanding during the reporting period. Basic weighted-average shares of common stock outstanding includes the weighted-average effect of the Company’s pre-funded warrants. The following potentially dilutive securities were not included in the calculation of diluted net loss per share as of the periods presented because the effect would have been anti-dilutive: September 30, 2023 2022 Outstanding stock options and awards 9,319,127 5,266,152 Restricted stock subject to future vesting — 7,773 Total 9,319,127 5,273,925

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and follow the requirements of the SEC for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. The interim condensed balance sheet as of September 30, 2023, the interim condensed statements of operations and comprehensive loss, stockholders’ equity and cash flows for the nine months ended September 30, 2023 and 2022 are unaudited. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and reflect all adjustments that are necessary for the fair statement of the Company’s financial position, results of operations and cash flows for the interim periods presented. The condensed results of operations for the nine months ended September 30, 2023, are not necessarily indicative of the results to be expected for the full year or for any other future annual or interim period. The condensed balance sheet as of December 31, 2022, included herein was derived from the audited financial statements as of that date. These condensed financial statements should be read in conjunction with the Company’s audited financial statements and the related notes thereto for the year ended December 31, 2022, included in Company’s Annual Report on Form 10-K, filed with the SEC on March 8, 2023.
Use of Estimates	Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to clinical trial accrued liabilities, income tax valuation allowance and stock-based compensation. Management bases its estimates on historical experience, the current economic environment, and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.
Marketable Securities	Marketable Securities The Company invests in marketable securities, primarily securities issued by the U.S. government and its agencies, commercial paper and corporate bonds. All marketable securities have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its marketable debt securities at the time of purchase and reevaluates such designation at each balance sheet date. The Company evaluates securities for impairment at the end of each reporting period. Factors considered in the evaluation include whether a decline in fair value below the amortized cost basis is due to credit-related factors or non-credit-related factors, the financial condition and near-term prospect of the issuer, and the Company’s intent and ability to hold the investment to allow for anticipated recovery in fair value. A credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings. Any impairment that is not credit-related is reported as a component of other comprehensive loss. Realized gains and losses are included in other income (expense), net. The cost of securities sold is based on the specific-identification method. Interest earned on marketable securities is included in interest income.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which replaces the existing incurred loss impairment model with an expected credit loss model. This standard requires companies to recognize an allowance for credit losses on available-for-sale debt securities rather than the prior approach of recording a reduction to the carrying value of the asset. ASU 2016-13 became effective for the Company beginning January 1, 2023 . The adoption of this standard did no t have a material impact on the Company's financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Fair Value of Financial Assets Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy: September 30, 2023 Valuation Amortized Unrealized Unrealized Fair Value (In thousands) Assets: Cash equivalents: Money market funds Level 1 1,261 — — 1,261 U.S. treasuries Level 1 43,859 6 — 43,865 Commercial paper Level 2 18,026 — ( 6 ) 18,020 Government agencies bonds Level 2 18,417 2 — 18,419 Marketable securities: U.S. treasuries Level 1 8,307 — ( 34 ) 8,273 Government agencies bonds Level 2 37,922 — ( 228 ) 37,694 Total financial assets $ 127,792 $ 8 $ ( 268 ) $ 127,532 December 31, 2022 Valuation Amortized Unrealized Unrealized Fair Value (In thousands) Assets: Cash equivalents: Cash equivalents Level 1 $ 20,532 $ — $ — $ 20,532 Money market funds Level 1 7,203 — — 7,203 Commercial paper Level 2 11,972 — ( 4 ) 11,968 Government agencies bonds Level 2 54,569 12 — 54,581 Marketable securities: U.S. treasuries Level 1 25,273 1 ( 147 ) 25,127 Commercial paper Level 2 43,605 4 ( 125 ) 43,484 Corporate bonds Level 2 2,696 — ( 18 ) 2,678 Government agencies bonds Level 2 37,770 9 ( 110 ) 37,669 Total financial assets $ 203,620 $ 26 $ ( 404 ) $ 203,242

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consists of the following: September 30, December 31, (In thousands) Leasehold improvements $ 25,603 $ 23,605 Laboratory equipment 19,770 20,537 Manufacturing equipment 17,716 17,468 Construction in progress 1,658 3,128 Computer equipment and software 1,591 1,060 Furniture and fixtures 975 910 Total property and equipment $ 67,313 $ 66,708 Less: accumulated depreciation and amortization ( 22,182 ) ( 15,676 ) Total property and equipment, net $ 45,131 $ 51,032
Summary of Accrued and Other Current Liabilities	Accrued and other current liabilities consist of the following: September 30, December 31, (In thousands) Accrued compensation and related expenses $ 6,362 $ 6,299 Accrued research and development expenses 2,361 3,214 Accrued professional services 518 482 ESPP deduction liability 441 124 Accrued facility management services 181 — Other current liabilities 458 545 Total accrued and other current liabilities $ 10,321 $ 10,664

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Operating Lease Activity	Information related to operating lease activity during the three and nine months ended September 30, 2023 was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (In thousands) Operating lease cost $ 1,090 $ 1,090 $ 3,271 $ 2,624 Variable lease cost 324 319 919 910 Short-term lease cost — 244 5 709 Total lease cost $ 1,414 $ 1,653 $ 4,195 $ 4,243 Operating lease right-of-use assets obtained in exchange for lease obligations $ — $ 2,224 Cash paid for amounts included in the measurement of lease liabilities $ 4,000 $ 2,978
Summary of Future Minimum Lease Payments Under Operating Lease	Future minimum lease payments under the Company’s operating leases as of September 30, 2023 were as follows: Amount (In thousands) 2023 (remaining 3 months) $ 1,223 2024 3,910 2025 2,445 2026 1,386 2027 1,428 Thereafter 5,477 Total undiscounted future minimum lease payments $ 15,869 Imputed interest ( 3,825 ) Total operating lease liabilities $ 12,044

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity: Shares Weighted- (in dollars) Outstanding as of December 31, 2022 5,210,182 $ 10.01 Granted 3,148,158 $ 3.43 Exercised ( 10,875 ) $ 2.71 Cancelled ( 123,119 ) $ 5.64 Outstanding as of September 30, 2023 8,224,346 $ 7.57
Summary of Fair Value of Stock Option Awards	The fair value of the Company’s stock option awards is estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Expected term (in years) 6.1 5.5 – 6.1 5.5 – 6.1 5.5 – 6.1 Expected volatility 94 % 96 % – 97 % 94 % – 95 % 96 % – 97 % Risk-free interest rate 4.0 % – 4.4 % 2.9 % – 3.6 % 3.4 % – 4.4 % 1.6 % – 3.6 % Expected dividend yield — % — % — % — %
Summary of Restricted Stock Activity	The following table summarizes activity of RSUs granted to employees with service-based vesting under the 2021 Plan. Shares Weighted (in dollars) Unvested as of December 31, 2022 459,192 $ 4.07 Granted 911,813 $ 3.06 Vested ( 254,172 ) $ 3.61 Forfeited ( 22,052 ) $ 3.82 Unvested as of September 30, 2023 1,094,781 $ 3.34
Summary of Stock-based Compensation	The following table summarizes stock-based compensation recognized in the Company’s condensed statements of operations and comprehensive loss: Three Months Ended Nine Months Ended 2023 2022 2023 2022 (In thousands) Research and development $ 1,861 $ 1,344 $ 5,204 $ 3,777 General and administrative 2,154 1,830 6,156 4,503 Total stock-based compensation $ 4,015 $ 3,174 $ 11,360 $ 8,280

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Schedule of Common Stock Reserved for Issuance	As of September 30, 2023, total shares of common stock reserved for issuance, on an as-if converted basis, are as follows: September 30, Outstanding stock options and awards 9,319,127 Outstanding pre-funded warrants 5,934,176 Stock options and awards available for future grant 1,078,248 Shares available for further issuance under the employee stock purchase plan 1,624,717 Total 17,956,268

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share	The following potentially dilutive securities were not included in the calculation of diluted net loss per share as of the periods presented because the effect would have been anti-dilutive: September 30, 2023 2022 Outstanding stock options and awards 9,319,127 5,266,152 Restricted stock subject to future vesting — 7,773 Total 9,319,127 5,273,925

Organization and Description _2

Organization and Description of the Business - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ (373,347)						$ (373,347)		$ (279,198)
Net loss	(29,143)	$ (33,269)	$ (31,737)	$ (30,696)	$ (28,397)	$ (31,056)	(94,149)	$ (90,149)
Cash, cash equivalents and investments in marketable securities	$ 128,100						$ 128,100

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - ASU 2016-13	Sep. 30, 2023
Significant Accounting Policies [Line Items]
Accounting standards update, adopted [true false]	true
Accounting standards update, immaterial effect [true false]	true
Accounting standards update, adoption date	Jan. 01, 2023

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 127,792	$ 203,620
Unrealized Gain	8	26
Unrealized Loss	(268)	(404)
Fair Value	127,532	203,242
Cash Equivalents | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		20,532
Fair Value		20,532
Money Market Funds | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	1,261	7,203
Fair Value	1,261	7,203
U.S. Treasuries | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	43,859
Unrealized Gain	6
Fair Value	43,865
Commercial Paper | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	18,026	11,972
Unrealized Loss	(6)	(4)
Fair Value	18,020	11,968
Government Agencies Bonds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	18,417	54,569
Unrealized Gain	2	12
Fair Value	18,419	54,581
U.S. Treasuries | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	8,307	25,273
Unrealized Gain		1
Unrealized Loss	(34)	(147)
Fair Value	8,273	25,127
Commercial Paper | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		43,605
Unrealized Gain		4
Unrealized Loss		(125)
Fair Value		43,484
Corporate Bonds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		2,696
Unrealized Loss		(18)
Fair Value		2,678
Government Agencies Bonds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	37,922	37,770
Unrealized Gain		9
Unrealized Loss	(228)	(110)
Fair Value	$ 37,694	$ 37,669

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charges on marketable securities related to other-than-temporary	$ 0
Available-for-sale marketable securities	39,600
Available-for-sale marketable securities maturities between one and two Years	6,400
Marketable Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale marketable securities	$ 46,000
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale marketable securities contractual maturities term	2 years
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale marketable securities contractual maturities term	1 year

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Total property and equipment	$ 67,313	$ 66,708
Less: accumulated depreciation and amortization	(22,182)	(15,676)
Total property and equipment, net	45,131	51,032
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	25,603	23,605
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	19,770	20,537
Manufacturing Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	17,716	17,468
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment	1,658	3,128
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Total property and equipment	1,591	1,060
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	$ 975	$ 910

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense	$ 2.2	$ 2.1	$ 6.5	$ 4.3

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and related expenses	$ 6,362	$ 6,299
Accrued research and development expenses	2,361	3,214
Accrued professional services	518	482
ESPP deduction liability	441	124
Accrued facility management services	181
Other current liabilities	458	545
Total accrued and other current liabilities	$ 10,321	$ 10,664

License Agreements (Details)

License Agreements (Details)	1 Months Ended		9 Months Ended
	Jan. 31, 2020 USD ($)	Oct. 31, 2016 USD ($) Option	Sep. 30, 2023 USD ($)
University of Texas Southwestern License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone and royalty payments recognized			$ 0
Non-refundable upfront license fee	$ 100,000
University of Texas Southwestern License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments contingent upon achieving specific development and commercialization milestone events	$ 14,800,000
Gladstone | Gladstone License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone and royalty payments recognized			$ 0
Number of additional option to extend milestone payment | Option		4
Milestone obligation additional extended payment terms		1 year
Gladstone | Gladstone License Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Annual license maintenance fees		$ 25,000
Milestone obligation amount		50,000
Gladstone | Gladstone License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Annual license maintenance fees		100,000
Milestone payments for royalty-bearing products contingent upon achieving specific clinical and commercialization milestone events		4,100,000
Milestone obligation amount		$ 100,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended
	Oct. 31, 2023 USD ($)	Sep. 30, 2023	May 31, 2022	Nov. 30, 2021	Feb. 28, 2021 RenewalOption	Dec. 31, 2016 RenewalOption
Commitments And Contingencies [Line Items]
Weighted-average remaining lease term		5 years 7 months 6 days
Weighted-average discount rate		9.60%
South San Francisco, California | Subsequent Event
Commitments And Contingencies [Line Items]
Lease payment related to sublease extension | $	$ 1.5
Union City Facility
Commitments And Contingencies [Line Items]
Number of lease renewal term					1
Lease renewal term					5 years
Lease commenced month and year					2021-05
Term of lease					10 years
Office and Laboratory Space | South San Francisco, California
Commitments And Contingencies [Line Items]
Lease expiration month and year						2025-05
Number of lease renewal term						2
Lease renewal term						5 years
Additional Office and Laboratory Space | South San Francisco, California
Commitments And Contingencies [Line Items]
Lease Expiration Date			Dec. 31, 2022	Jun. 30, 2022
Second Amendment | South San Francisco, California
Commitments And Contingencies [Line Items]
Lease Expiration Date		Nov. 30, 2024

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Operating Lease Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,090	$ 1,090	$ 3,271	$ 2,624
Variable lease cost	324	319	919	910
Short-term lease cost		244	5	709
Total lease cost	$ 1,414	$ 1,653	4,195	4,243
Operating lease right-of-use assets obtained in exchange for lease obligations				2,224
Cash paid for amounts included in the measurement of lease liabilities			$ 4,000	$ 2,978

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Future Minimum Lease Payments Under Operating Leases (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2023 (remaining 3 months)	$ 1,223
2024	3,910
2025	2,445
2026	1,386
2027	1,428
Thereafter	5,477
Total undiscounted future minimum lease payments	15,869
Imputed interest	(3,825)
Total operating lease liabilities	$ 12,044

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jul. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for issuance	17,956,268		17,956,268
Contractual term of stock option awards			10 years
Vesting period			4 years
Stock-based compensation	$ 4,015	$ 3,174	$ 11,360	$ 8,280
Restricted Stock | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period			2 years
Restricted Stock | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period			4 years
2021 Employee Stock Purchase Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for issuance	1,624,717		1,624,717		800,000
Participants to purchase common stock through payroll deduction maximum percentage of eligible compensation			15%
Participants to purchase shares through payroll deduction at lower percentage of fair market value			85%
Number of shares of common stock that may be issued in accordance with the plan			800,000
Percentage of shares of common stock outstanding on last day of immediately preceding year			1%
Stock-based compensation			$ 0	$ 0
Participants to purchase common stock through payroll deduction annual limit of eligible compensation			$ 25,000
Offering period			6 months
2021 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock reserved for issuance	4,000,000		4,000,000
Common stock shares available for issuance period			10 years
Number of shares of common stock that may be issued in accordance with the plan			4,000,000
Percentage of shares of common stock outstanding on last day of immediately preceding year			4%
Shares reserved and available for grant	1,078,248		1,078,248

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - 2021 Equity Incentive Plan	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares, Outstanding Beginning Balance | shares	5,210,182
Granted | shares	3,148,158
Exercised | shares	(10,875)
Cancelled | shares	(123,119)
Shares, Outstanding Ending Balance | shares	8,224,346
Weighted-Average Exercise Price Per Share, Outstanding Beginning Balance | $ / shares	$ 10.01
Granted | $ / shares	3.43
Exercised | $ / shares	2.71
Cancelled | $ / shares	5.64
Weighted-Average Exercise Price Per Share, Outstanding Ending Balance | $ / shares	$ 7.57

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Fair Value of Stock Option Awards (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected volatility, minimum	94%	96%	94%	96%
Expected volatility, maximum		97%	95%	97%
Risk-free interest rate, minimum	4%	2.90%	3.40%	1.60%
Risk free interest rate, maximum	4.40%	3.60%	4.40%	3.60%
Expected dividend yield	0%	0%	0%	0%
Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	5 years 6 months	5 years 6 months	5 years 6 months
Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)		6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) - 2021 Equity Incentive Plan - Restricted Stock	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares
Unvested as of December 31, 2022 | shares	459,192
Granted | shares	911,813
Vested | shares	(254,172)
Forfeited | shares	(22,052)
Unvested as of September 30, 2023 | shares	1,094,781
Weighted Average Grant Date Fair Value per Share
Unvested as of December 31, 2022 | $ / shares	$ 4.07
Granted | $ / shares	3.06
Vested | $ / shares	3.61
Forfeited | $ / shares	3.82
Unvested as of September 30, 2023 | $ / shares	$ 3.34

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation	$ 4,015	$ 3,174	$ 11,360	$ 8,280
Research and Development
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation	1,861	1,344	5,204	3,777
General and Administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total stock-based compensation	$ 2,154	$ 1,830	$ 6,156	$ 4,503

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended	9 Months Ended
	Nov. 29, 2022	Nov. 21, 2022	Aug. 10, 2022	Sep. 30, 2023	Sep. 30, 2023
Class of Stock [Line Items]
Proceeds from issuance of common stock at the market					$ 3,868
Pre-funded warrants, shares of common stock exercised				302,517	302,517
At-the-Market Equity Offering
Class of Stock [Line Items]
Proceeds from issuance of common stock at the market				$ 3,900	$ 3,900
Commission on sale of stock				$ 100	$ 100
Follow On Offering
Class of Stock [Line Items]
Number of common shares	2,816,409	22,613,307
Common stock, per share		$ 2.6
Warrant purchase common stock		4,327,500
Follow On Offering | Pre Funded Warrant
Class of Stock [Line Items]
Warrants issued to purchase shares of common stock		6,236,693
Class of warrant price per share		$ 2.599
Warrants, exercise price		$ 0.001
Common Stock | At-the-Market Equity Offering
Class of Stock [Line Items]
Maximum aggregate offering price			$ 75,000
Issuance of common stock in connection with at-the-market sales, net of issuance costs, shares				535,767	535,767

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Common Stock Reserved for Issuance (Details)	Sep. 30, 2023 shares
Class Of Stock [Line Items]
Common stock reserved for issuance	17,956,268
Outstanding Pre-Funded Warrants
Class Of Stock [Line Items]
Common stock reserved for issuance	5,934,176
Outstanding Stock Options and Awards
Class Of Stock [Line Items]
Common stock reserved for issuance	9,319,127
Stock Options and Awards Available for Future Grant
Class Of Stock [Line Items]
Common stock reserved for issuance	1,078,248
Shares Available for Further Issuance Under the Employee Stock Purchase Plan | Employee Stock Purchase Plan
Class Of Stock [Line Items]
Common stock reserved for issuance	1,624,717

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities were not included in the calculation of diluted net loss per share	9,319,127	5,273,925
Outstanding Stock Options and Awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities were not included in the calculation of diluted net loss per share	9,319,127	5,266,152
Restricted Stock Subject to Future Vesting
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities were not included in the calculation of diluted net loss per share		7,773