Annexon (ANNX) 10-Q 12 Aug 24 2024 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2024	Aug. 08, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Jun. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Trading Symbol	ANNX
Entity Registrant Name	ANNEXON, INC.
Entity Central Index Key	0001528115
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-39402
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-5414423
Entity Address, Address Line One	1400 Sierra Point Parkway
Entity Address, Address Line Two	Bldg C
Entity Address, Address Line Three	Suite 200
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	822-5500
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		105,653,962
Prefunded Warrant [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		41,283,052

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 157,304	$ 225,110
Short-term investments	211,395	34,606
Prepaid expenses and other current assets	5,270	4,144
Total current assets	373,969	263,860
Restricted cash	1,032	1,032
Property and equipment, net	13,702	14,773
Operating lease right-of-use assets	17,382	18,009
Total assets	406,085	297,674
Current liabilities:
Accounts payable	4,126	5,487
Accrued liabilities	10,657	10,235
Operating lease liabilities, current	2,345	2,165
Other current liabilities	20	41
Total current liabilities	17,148	17,928
Operating lease liabilities, non-current	27,858	29,190
Total liabilities	45,006	47,118
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock	106	78
Additional paid-in capital	988,347	823,029
Accumulated other comprehensive loss	(89)	(52)
Accumulated deficit	(627,285)	(572,499)
Total stockholders’ equity	361,079	250,556
Total liabilities and stockholders’ equity	$ 406,085	$ 297,674

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Operating expenses:
Research and development	$ 25,026	$ 30,251	$ 45,989	$ 62,596
General and administrative	8,554	7,440	16,163	16,337
Total operating expenses	33,580	37,691	62,152	78,933
Loss from operations	(33,580)	(37,691)	(62,152)	(78,933)
Interest and other income, net	3,970	2,503	7,366	5,069
Net loss	$ (29,610)	$ (35,188)	$ (54,786)	$ (73,864)
Net loss per share, basic	$ (0.23)	$ (0.47)	$ (0.43)	$ (0.99)
Net loss per share, diluted	$ (0.23)	$ (0.47)	$ (0.43)	$ (0.99)
Weighted-average shares used in computing net loss per share, basic	130,132,960	75,230,003	126,403,081	74,546,995
Weighted-average shares used in computing net loss per share, diluted	130,132,960	75,230,003	126,403,081	74,546,995

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (29,610)	$ (35,188)	$ (54,786)	$ (73,864)
Other comprehensive income (loss):
Foreign currency translation adjustment	1	(1)	(11)	(6)
Unrealized gain (loss) on available-for-sale securities	12	47	(26)	207
Comprehensive loss	$ (29,597)	$ (35,142)	$ (54,823)	$ (73,663)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Related Party [Member]	Common Stock [Member]	Common Stock [Member] Related Party [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Related Party [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Beginning Balance, Values at Dec. 31, 2022	$ 231,194		$ 48		$ 669,780		$ (372)	$ (438,262)
Beginning Balance, Shares at Dec. 31, 2022			47,722,995
Exercise of stock options	111				111
Exercise of stock options, Shares			55,605
Exercise of pre-funded warrants, Value			$ 3		(3)
Exercise of pre-funded warrants, Shares			2,582,557
Issuance of common stock, net of issuance costs, Value		$ 17,470		$ 2		$ 17,468
Issuance of common stock, net of issuance costs, Shares				2,646,458
Restricted stock vested in the period			73,058
Stock-based compensation	4,607				4,607
Other comprehensive income (loss)	155						155
Net loss	(38,676)							(38,676)
Ending Balance, Values at Mar. 31, 2023	214,861		$ 53		691,963		(217)	(476,938)
Ending Balance, Shares at Mar. 31, 2023			53,080,673
Beginning Balance, Values at Dec. 31, 2022	231,194		$ 48		669,780		(372)	(438,262)
Beginning Balance, Shares at Dec. 31, 2022			47,722,995
Net loss	(73,864)
Ending Balance, Values at Jun. 30, 2023	184,724		$ 53		696,968		(171)	(512,126)
Ending Balance, Shares at Jun. 30, 2023			53,151,111
Beginning Balance, Values at Mar. 31, 2023	214,861		$ 53		691,963		(217)	(476,938)
Beginning Balance, Shares at Mar. 31, 2023			53,080,673
Exercise of stock options, Shares			283
Issuance of common stock per Employee Stock Purchase Plan purchase , Shares			70,155
Issuance of common stock per Employee Stock Purchase Plan purchase , Value	345				345
Stock-based compensation	4,660				4,660
Other comprehensive income (loss)	46						46
Net loss	(35,188)							(35,188)
Ending Balance, Values at Jun. 30, 2023	184,724		$ 53		696,968		(171)	(512,126)
Ending Balance, Shares at Jun. 30, 2023			53,151,111
Beginning Balance, Values at Dec. 31, 2023	250,556		$ 78		823,029		(52)	(572,499)
Beginning Balance, Shares at Dec. 31, 2023			78,369,099
Exercise of stock options	217				217
Exercise of stock options, Shares			105,526
Exercise of pre-funded warrants, Value			$ 5		(5)
Exercise of pre-funded warrants, Shares			5,243,400
Issuance of common stock, net of issuance costs, Value	32,198		$ 7		32,191
Issuance of common stock, net of issuance costs, Shares			6,639,348
Restricted stock vested in the period			124,695
Stock-based compensation	4,660				4,660
Other comprehensive income (loss)	(50)						(50)
Net loss	(25,176)							(25,176)
Ending Balance, Values at Mar. 31, 2024	262,405		$ 90		860,092		(102)	(597,675)
Ending Balance, Shares at Mar. 31, 2024			90,482,068
Beginning Balance, Values at Dec. 31, 2023	$ 250,556		$ 78		823,029		(52)	(572,499)
Beginning Balance, Shares at Dec. 31, 2023			78,369,099
Exercise of stock options, Shares	141,440
Net loss	$ (54,786)
Ending Balance, Values at Jun. 30, 2024	361,079		$ 106		988,347		(89)	(627,285)
Ending Balance, Shares at Jun. 30, 2024			105,539,683
Beginning Balance, Values at Mar. 31, 2024	262,405		$ 90		860,092		(102)	(597,675)
Beginning Balance, Shares at Mar. 31, 2024			90,482,068
Exercise of stock options	171				171
Exercise of stock options, Shares			35,914
Exercise of pre-funded warrants, Value			$ 1		(1)
Exercise of pre-funded warrants, Shares			965,427
Exercise of common warrants , Shares			19,901
Issuance of common stock, net of issuance costs, Value	6,126		$ 1		6,125
Issuance of common stock per Employee Stock Purchase Plan purchase , Shares			98,534
Issuance of common stock and pre-funded warrants, net of issuance costs of $8,183, Value	116,817		$ 13		116,804
Issuance of common stock and pre-funded warrants, net of issuance costs of $8,183, Shares			13,001,120
Issuance of common stock, net of issuance costs, Shares			936,719
Issuance of common stock per Employee Stock Purchase Plan purchase , Value	215		$ 1		214
Stock-based compensation	4,942				4,942
Other comprehensive income (loss)	13						13
Net loss	(29,610)							(29,610)
Ending Balance, Values at Jun. 30, 2024	$ 361,079		$ 106		$ 988,347		$ (89)	$ (627,285)
Ending Balance, Shares at Jun. 30, 2024			105,539,683

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Mar. 31, 2023
Stock issuance costs	$ 480	$ 933
Common Stock and Prefunded Warrants [Member]
Stock issuance costs	$ 8,183
Related Party [Member]
Stock issuance costs			$ 525

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities:
Net loss	$ (54,786)	$ (73,864)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,075	1,072
Accretion of discount on available-for-sale securities	(2,932)	(1,695)
Stock-based compensation	9,602	9,267
Reduction in the carrying amount of right-of-use assets	627	538
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,126)	818
Accounts payable	(1,457)	(152)
Accrued liabilities	194	(4,495)
Operating lease liabilities	(1,152)	(844)
Other current liabilities	(21)	(19)
Net cash used in operating activities	(49,976)	(69,374)
Investing activities:
Purchases of property and equipment		(167)
Purchases of available-for-sale securities	(266,183)	(69,875)
Proceeds from maturities of available-for-sale securities	92,300	95,090
Net cash (used in) provided by investing activities	(173,883)	25,048
Financing activities:
Proceeds from the exercise of common stock options	388	111
Proceeds from Employee Stock Purchase Plan purchases	215	345
Proceeds from the issuance of common stock, including related party of zero and $17,995 for the six months ended June 30, 2024 and 2023, respectively	39,737	17,995
Proceeds from the issuance of common stock and pre-funded warrants, net of commissions	117,500
Payment of financing costs	(1,776)	(525)
Net cash provided by financing activities	156,064	17,926
Decrease in cash, cash equivalents and restricted cash	(67,795)	(26,400)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(11)	(6)
Cash, cash equivalents and restricted cash
Beginning of period	226,142	141,052
End of period	158,336	114,646
Supplemental disclosure of cash flow information:
Cash paid for amounts included in the measurement of lease liability	2,432	$ 2,350
Non-cash investing and financing activities:
Deferred offering costs included in accounts payable and accrued liabilities	$ 320

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from the issuance of common stock including related party	$ 0	$ 17,995

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (29,610)	$ (25,176)	$ (35,188)	$ (38,676)	$ (54,786)	$ (73,864)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Trading Arrangements of Section 16 Reporting Persons. During the Company’s last fiscal quarter, the Company’s directors and officers (as defined in Rule 16a-1(f) under the Exchange Act) adopted or terminated the contracts, instructions or written plans for the purchase or sale of the Company’s securities set forth in the table below. Types of Trading Arrangement Name and Position Action Adoption Date Rule Non-Rule 10b5-1** Total Shares of Common Stock to be Sold Total Shares of Common Stock to be Purchased Expiration Date Jennifer Lew , Chief Financial Officer Adopt 4/10/2024 X 23,505 4/14/2025 Douglas Love , Chief Executive Officer Adopt 4/12/2024 X 37,994 1/22/2025 Ted Yednock , Executive Vice President and Chief Innovation Officer Adopt 4/12/2024 X 324,042 6/30/2025 __________________ * Contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act. ** “Non-Rule 10b5-1 trading arrangement” as defined in Item 408(a) of Regulation S-K under the Exchange Act.
Jennifer Lew [Member]
Trading Arrangements, by Individual
Name	Jennifer Lew
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	4/10/2024
Expiration Date	4/14/2025
Arrangement Duration	370 days
Aggregate Available	23,505
Douglas Love [Member]
Trading Arrangements, by Individual
Name	Douglas Love
Title	Chief Executive Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	4/12/2024
Expiration Date	1/22/2025
Arrangement Duration	286 days
Aggregate Available	37,994
Ted Yednock [Member]
Trading Arrangements, by Individual
Name	Ted Yednock
Title	Executive Vice President and Chief Innovation Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	4/12/2024
Expiration Date	6/30/2025
Arrangement Duration	436 days
Aggregate Available	324,042

Organization

Organization	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Organization	1. Organization Annexon, Inc., or the Company, is a clinical-stage biopharmaceutical company pioneering a new class of complement medicines for people living with devasting inflammatory-related diseases. The Company is located in Brisbane, California and was incorporated in Delaware in March 2011. The Company’s wholly-owned subsidiary, Annexon Biosciences Australia Pty Ltd, or the Subsidiary, is a proprietary limited company incorporated in 2016 and domiciled in Australia. Liquidity Since inception, the Company has been involved primarily in performing research and development activities, conducting clinical trials, hiring personnel, and raising capital to support and expand these activities. The Company has experienced losses and negative cash flows from operations since its inception and, as of June 30, 2024, had an accumulated deficit of $ 627.3 million and cash and cash equivalents and short-term investments of $ 368.7 million. The Company has historically funded its operations through the issuance of shares of its common stock and warrants. Based on projected activities, management projects that existing cash and cash equivalents and short-term investments will enable the Company to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these financial statements. The Company’s future viability beyond that point is dependent on its ability to achieve development milestones and obtain additional funding. Management expects to continue to incur losses and negative cash flows from operations for at least the next several years. There are uncertainties associated with the Company’s ability to (1) obtain additional equity or debt financing on terms that are favorable to the Company, (2) enter into collaborative agreements with strategic partners, and (3) succeed in its future operations. If the Company is not able to obtain the required funding for its operations or is not able to obtain funding on terms that are favorable to the Company, it could be forced to delay, reduce or eliminate its research and development programs and its business could be materially harmed.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
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 consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP, and applicable rules and regulations of the SEC regarding interim financial reporting. The condensed consolidated balance sheet as of June 30, 2024, the condensed consolidated statements of operations, comprehensive loss, stockholders’ equity for the three and six months ended June 30, 2024 and 2023 and the condensed consolidated statements of cash flows for the six months ended June 30, 2024 and 2023 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position, results of operations and cash flows for the interim period presented. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three-month periods are also unaudited. The results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2023 included herein was derived from the audited financial statements as of that date. These unaudited condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 26, 2024. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, or GAAP, 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 financial statements and the reported expenses during the reporting period. Management evaluates its estimates, including but not limited to the fair value of investments, operating lease right-of-use assets and liabilities, valuation of deferred tax assets and uncertain tax positions (including valuation allowance), clinical trial accruals and stock-based compensation. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates. Principles of Consolidation The condensed consolidated financial statements include the operations of Annexon, Inc. and its wholly-owned subsidiary and include the results of operations and cash flows of these entities. All intercompany balances and transactions have been eliminated in consolidation. Summary of Significant Accounting Policies Reference is made to Note 2, Summary of Significant Accounting Policies, in the Company’s 2023 Form 10-K filed on March 26, 2024 for a detailed description of significant accounting policies. There have been no significant changes to the Company’s accounting policies as disclosed in its 2023 Form 10-K. Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting: Improvements to Reportable Segment Disclosures , which requires disclosure of incremental segment information on an interim and annual basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal periods beginning after December 15, 2024, and requires retrospective application to all prior periods presented in the financial statements. The Company adopted annual requirements under ASU 2023-07 on January 1, 2024 and plans to adopt interim requirements under ASU 2023-07 on January 1, 2025. The Company will begin including financial statement disclosures in accordance with ASU 2023-07 in its Annual Report on Form 10-K for the year ended December 31, 2024. The Company is evaluating the impact of this guidance on its financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes: Improvements to Income Tax Disclosures , which requires enhanced annual disclosures regarding the rate reconciliation and income taxes paid information. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 and may be adopted on a prospective or retrospective basis. Early adoption is permitted. The Company is evaluating the impact of this guidance on its financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines fair value based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: • Level 1 Inputs: Unadjusted quoted prices in active markets for identical assets or liabilities accessible to the reporting entity at the measurement date. • Level 2 Inputs: Other than quoted prices included in Level 1 inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. • Level 3 Inputs: Unobservable inputs for the asset or liability used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at measurement date. On a recurring basis, the Company measures certain financial assets and liabilities at fair value. The following tables summarize the fair value of the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2024 Valuation Amortized Gross Gross Aggregate Assets: Cash equivalents: Money market funds Level 1 $ 36,226 $ — $ — $ 36,226 Government bonds Level 2 118,139 1 ( 1 ) 118,139 Total cash equivalents 154,365 1 ( 1 ) 154,365 Short-term investments: Government bonds Level 2 211,402 4 ( 11 ) 211,395 Total short-term investments 211,402 4 ( 11 ) 211,395 $ 365,767 $ 5 $ ( 12 ) $ 365,760 December 31, 2023 Valuation Amortized Gross Gross Aggregate Assets: Cash equivalents: Money market funds Level 1 $ 143,933 $ — $ — $ 143,933 Government bonds Level 2 72,689 — — 72,689 Total cash equivalents 216,622 — — 216,622 Short-term investments: Government bonds Level 2 34,596 10 — 34,606 Total short-term investments 34,596 10 — 34,606 $ 251,218 $ 10 $ — $ 251,228 For the three and six months ended June 30, 2024 and 2023, the Company recognized no material realized gains or losses on financial instruments.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2024
Disclosure Of Balance Sheet Components [Abstract]
Balance Sheet Components	4. Balance Sheet Components Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid instruments with an original maturity of three months or less at time of purchase to be cash equivalents. Cash equivalents, which include amounts invested in money market funds, are stated at fair value. Restricted cash as of June 30, 2024 relates to the letters of credit established for the Company’s office leases. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the condensed consolidated statements of cash flows (in thousands): June 30, December 31, Cash $ 2,939 $ 8,488 Cash equivalents 154,365 216,622 Cash and cash equivalents 157,304 225,110 Restricted cash 1,032 1,032 Cash, cash equivalents and restricted cash $ 158,336 $ 226,142 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Prepaid research and development costs $ 4,130 $ 2,617 Prepaid insurance 309 704 Other prepaid expenses 831 760 Other current assets — 63 Total prepaid expenses and other current assets $ 5,270 $ 4,144 Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): June 30, December 31, Leasehold improvements $ 17,245 $ 17,245 Laboratory equipment 1,832 1,832 Furniture and fixtures 692 692 Computer equipment and software 33 33 Construction in progress 4 — Total property and equipment, gross 19,806 19,802 Less: accumulated depreciation ( 6,104 ) ( 5,029 ) Total property and equipment, net $ 13,702 $ 14,773 The Company recognized depreciation for property and equipment of $ 0.5 million for each of the three months ended June 30, 2024 and 2023, and $ 1.1 million for each of the six months ended June 30, 2024 and 2023. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): June 30, December 31, Accrued research and development expenses $ 6,538 $ 4,027 Accrued compensation 2,766 5,607 Accrued professional services 1,240 501 Other accrued expenses 113 100 Total accrued liabilities $ 10,657 $ 10,235

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and Contingencies Leases The Company leases its offices and laboratory in Brisbane, California, or the Brisbane Lease, under a ten-year noncancelable lease agreement that ends in October 2031 with a ten-year renewable option. In November 2021, the Company subleased unoccupied space from December 2021 through November 2023 , for aggregate sublease payments of $ 3.4 million. The sublease income, while it reduces the rent expense, is not considered in the value of the right-of-use assets or lease liabilities. The Company’s sublease income was zero and $ 0.6 million for the three months ended June 30, 2024 and 2023, respectively, and zero and $ 1.1 million for the six months ended June 30, 2024 and 2023, respectively. As of June 30, 2024, the operating lease right-of-use assets were $ 17.4 million and lease liabilities were $ 30.2 million on the condensed consolidated balance sheet. The weighted-average remaining lease term is 7.3 years. The weighted-average incremental borrowing rate used to measure the operating lease liability is 8.4 % . Operating lease costs were $ 1.0 million and $ 0.5 million for the three months ended June 30, 2024 and 2023, respectively, and $ 1.9 million and $ 1.1 million for the six months ended June 30, 2024 and 2023, respectively. Variable lease payments were $ 0.6 million and $ 0.4 million for the three months ended June 30, 2024 and 2023, respectively, and $ 1.2 million and $ 0.7 million for the six months ended June 30, 2024 and 2023, respectively. Future minimum lease payments and related lease liabilities as of June 30, 2024, were as follows: (in thousands) 2024 (remaining six months) $ 2,461 2025 5,065 2026 5,242 2027 5,425 2028 and thereafter 22,600 Total undiscounted lease payments 40,793 Less: Imputed interest ( 10,590 ) Total $ 30,203 Guarantees and Indemnifications In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. To date, the Company has no t paid any claims or been required to defend any action related to its indemnification obligations. As of June 30, 2024, the Company did no t have any material indemnification claims that were probable or reasonably possible and consequently has not recorded related liabilities.

Stockholder's Equity

Stockholder's Equity	6 Months Ended
	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	6. Stockholders’ Equity 2024 Financing In June 2024, the Company raised net proceeds of approximately $ 116.8 million after deducting underwriting discounts and offering expenses through the sale of 13,001,120 shares of the Company’s common stock, par value $ 0.001 per share at a price of $ 6.25 per share and pre-funded warrants to purchase an aggregate of 7,000,000 shares of common stock at a price of $ 6.249 per share, which equals the per share offering price for the shares of common stock less the $ 0.001 exercise price for each pre-funded warrant. The pre-funded warrants are immediately exercisable, subject to certain beneficial ownership limitations. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital in the amount of $ 43.7 million. 2023 Financing In December 2023, the Company raised net proceeds of approximately $ 117.0 million after deducting underwriting discounts and offering expenses through the sale of 25,035,000 shares of the Company’s common stock, par value $ 0.001 per share at a price of $ 2.880 per share and pre-funded warrants to purchase an aggregate of 18,379,861 shares of common stock at a price of $ 2.879 per share, which equals the per share offering price for the shares of common stock less the $ 0.001 exercise price for each pre-funded warrant. An entity related to one of the Company’s directors participated in the public offering and purchased 350,000 shares of common stock for an aggregate price of approximately $ 1.0 million. The pre-funded warrants are immediately exercisable, subject to certain beneficial ownership limitations. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital in the amount of $ 52.9 million. T he Company issued an aggregate of 5,243,400 shares and 965,427 shares of common stock upon the cashless and cash exercise of these pre-funded warrants in February 2024 and April 2024, respectively. 2022 Financing In July 2022, the Company raised net proceeds of approximately $ 122.5 million after deducting fees and expenses through the sale of an aggregate of 9,013,834 shares of common stock, pre-funded warrants to purchase up to 24,696,206 shares of its common stock and accompanying common warrants to purchase up to 8,427,508 shares of its common stock. The offering price per share and accompanying common warrant was $ 3.87125 per share and the offering price per pre-funded warrant and accompanying common warrant was $ 3.87025 per share, which equals the per share offering price for the shares of common stock less the $ 0.001 exercise price for each such pre-funded warrant. The pre-funded warrants remain exercisable until exercised in full. The common warrants have an exercise price of $ 5.806875 per share and expire on June 30, 2025 . Both the pre-funded and common warrants are immediately exercisable, subject to beneficial ownership limitations. The warrants meet the criteria for equity classification and were therefore recorded at fair value as of the grant date as a component of stockholders’ equity within additional paid-in capital. The Company issued an aggregate of 2,582,557 shares of common stock upon the cashless exercise of the pre-funded warrants in March 2023. The Company issued an aggregate of 19,901 shares of common stock upon the cashless exercise of the common warrants in June 2024. Pre-Funded and Common Warrants The following summarizes warrant activity during the six months ended June 30, 2024 and 2023: Number of Common Warrants Number of Pre-funded Warrants Weighted-Average Exercise Price Balances as of December 31, 2023 8,427,508 40,492,923 Issued — 7,000,000 $ 0.001 Exercised ( 322,893 ) ( 6,209,871 ) $ 0.307 Balances as of June 30, 2024 8,104,615 41,283,052 Number of Common Warrants Number of Pre-funded Warrants Weighted-Average Exercise Price Balances as of December 31, 2022 8,427,508 24,696,206 Exercised — ( 2,583,144 ) $ 0.001 Balances as of June 30, 2023 8,427,508 22,113,062 2024 ATM Program In March 2024, the Company entered into a sales agreement with TD Cowen, as sales agent, or 2024 ATM program, pursuant to which the Company may issue and sell shares of its common stock for an aggregate maximum offering of $ 100.0 million. TD Cowen is entitled to compensation up to 3 % of the aggregate gross proceeds for the common stock sold through the 2024 ATM program. As of June 30, 2024, the Company has no t made any sales under the 2024 ATM program. 2021 At-the-Market (ATM) Program In August 2021, the Company entered into a sales agreement with Cowen and Company LLC, or TD Cowen, as sales agent, pursuant to which the Company may issue and sell shares of its common stock for an aggregate maximum offering of $ 100.0 million under an at-the-market offering program, or 2021 ATM program. TD Cowen is entitled to compensation up to 3 % of the aggregate gross proceeds for the common stock sold through the 2021 ATM program. During the six months ended June 30, 2024 and 2023, the Company sold 7,576,067 shares and 2,646,458 shares of common stock, respectively, under the 2021 ATM program for net proceeds of approximately $ 38.4 million and $ 17.5 million, respectively, after deducting commissions paid to TD Cowen. As of June 30, 2024 and December 31, 2023, approximately $ 42.3 million and $ 82.0 million, respectively, remained available for the offer and sale of shares of common stock under the 2021 ATM program. The Form S-3 registration statement pursuant to which the 2021 ATM Program is registered will expire on August 15, 2024 , and no shares of common stock may be sold under the 2021 ATM Program after that date. Common Stock The Company reserved the following shares of common stock for issuance as follows: June 30, December 31, Stock options issued and outstanding 11,937,414 9,208,970 Stock options reserved for 2020 Incentive Award Plan 1,861,959 1,988,340 Unvested restricted stock units outstanding 867,298 495,579 Common stock reserved for 2021 ATM program 25,043,404 2,619,471 Common stock reserved for 2024 ATM program 25,000,000 — Common stock reserved for Employee Stock Purchase Plan 2,023,537 1,338,381 Common stock reserved for 2022 Employment Inducement 1,502,930 758,084 Common stock reserved for pre-funded warrants 41,283,052 40,493,510 Common stock reserved for common warrants 8,104,615 8,427,508 Total common stock reserved 117,624,209 65,329,843

Equity Incentive Plans

Equity Incentive Plans	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Equity Incentive Plans	7. Equity Incentive Plans In July 2020, the Company’s board of directors and stockholders adopted and approved the 2020 Incentive Award Plan, or the 2020 Plan, and the Employee Stock Purchase Plan, or the ESPP, which became effective in connection with the Company’s initial public offering, or the IPO. The Company may not grant any additional awards under the 2011 Equity Incentive Plan, or the 2011 Plan. The 2011 Plan will continue to govern outstanding equity awards granted thereunder. 2020 Equity Incentive Plan The number of shares of common stock reserved for issuance under the 2020 Plan automatically increases on the first day of January, in an amount equal to 4 % of the total number of shares of the Company’s capital stock outstanding on the last day of the preceding year, or a lesser number of shares determined by the Company’s board of directors. Awards granted under the 2020 Plan expire no later than ten years from the date of grant. For Incentive Stock Options, or ISOs, and Nonstatutory Stock Options, or NSOs, the option price shall not be less than 100 % of the estimated fair value on the date of grant. Options granted typically vest over a four-year period but may be granted with different vesting terms. As of June 30, 2024, there were 1,861,959 shares available for issuance under the 2020 Plan. 2022 Employment Inducement Award Plan In July 2022, the Company’s board of directors adopted the Annexon, Inc. 2022 Employment Inducement Award Plan, or the Inducement Plan, and together with the 2011 Plan and the 2020 Plan, the Plans. The Inducement Plan was adopted by the Company’s board of directors without stockholder approval pursuant to Nasdaq Marketplace Rule 5635(c)(4), or Rule 5635(c)(4). In accordance with Rule 5635(c)(4), awards made under the Inducement Plan may only be granted to newly hired employees as an inducement material to the employees entering into employment with the Company. Awards granted under the Inducement Plan expire no later than ten years from the date of grant. An aggregate of 2,850,000 shares of common stock were reserved for issuance under the Inducement Plan. As of June 30, 2024, there were 1,502,930 shares available for issuance under the Inducement Plan. Stock Options The following table presents stock option activity under the Plans for the period: Number of Weighted- Weighted- Aggregate Balances as of December 31, 2023 9,208,970 $ 10.31 7.53 $ 2,930 Stock options granted 3,596,114 $ 5.26 Stock options exercised ( 141,440 ) $ 2.74 Stock options forfeited ( 726,230 ) $ 10.08 Balances as of June 30, 2024 11,937,414 $ 8.89 7.77 $ 3,355 Exercisable as of June 30, 2024 6,002,916 $ 11.62 6.51 $ 1,739 The total intrinsic value of options exercised was $ 0.1 million and zero for the three months ended June 30, 2024 and 2023, respectively, and $ 0.4 million and $ 0.3 million for the six months ended June 30, 2024 and 2023, respectively. The intrinsic value is the difference between the fair value of the Company’s common stock at the time of exercise and the exercise price of the stock option. The weighted-average grant date fair value of options granted to employees during the six months ended June 30, 2024 and 2023 was $ 4.17 and $ 4.18 per share, respectively. As of June 30, 2024, the total unrecognized stock-based compensation cost related to outstanding unvested stock options was $ 26.6 million, which the Company expects to recognize over an estimated weighted-average period of 2.5 years. Restricted Stock Units RSUs are share awards that entitle the holder to receive freely tradeable shares of the Company’s common stock upon vesting. The RSUs cannot be transferred and the awards are subject to forfeiture if the holder’s employment terminates prior to the release of the vesting restrictions. The RSUs generally vest over a three-year period in equal amounts on an annual basis, provided the employee remains continuously employed with the Company. The fair value of the RSUs is equal to the closing price of the Company’s common stock on the grant date. A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: Number of Shares Weighted-Average Grant Date Fair Value Per Share Unvested as of December 31, 2023 495,579 $ 5.69 Granted 602,600 5.13 Vested ( 124,695 ) 6.44 Cancelled ( 106,186 ) 5.29 Unvested as of June 30, 2024 867,298 $ 5.24 As of June 30, 2024, unrecognized stock-based compensation expense related to outstanding unvested RSUs was $ 3.6 million, which is expected to be recognized over a weighted-average period of 2.2 years. Employee Stock Purchase Plan The ESPP enables eligible employees to purchase shares of the Company’s 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 business day or the last business 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, by a number equal to, 1 % of the shares of common stock outstanding on the last day of the immediately preceding fiscal year, or such number of shares determined by the Company’s board of directors. As of June 30, 2024, 2,023,537 shares were available for future purchase. The ESPP generally provides for six-month consecutive offering periods beginning on May 16 th and November 16 th of each year. 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 six months ended June 30, 2024. The stock-based compensation expense related to the ESPP was $ 41,000 and $ 0.1 million for the three months ended June 30, 2024 and 2023, respectively, and $ 0.1 million for each of the six months ended June 30, 2024 and 2023. Stock-Based Compensation Expense The total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended Six Months Ended 2024 2023 2024 2023 Research and development $ 2,311 $ 2,307 $ 4,593 $ 4,558 General and administrative 2,631 2,353 5,009 4,709 Total stock-based compensation expense $ 4,942 $ 4,660 $ 9,602 $ 9,267 To determine the value of stock option awards for stock-based compensation purposes, the Company uses the Black-Scholes option pricing model and the assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment. Fair Value of Common Stock —The fair value of each share of underlying common stock is based on the closing price of the Company’s common stock as reported on the date of grant on the Nasdaq Global Select Market. Expected Term —The expected term represents the period that the stock-based awards are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term). The Company continues using the simplified method as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term due to the limited period of time its equity shares have been publicly traded. Expected Volatility —Beginning in 2024, the expected volatility was estimated based on a weighted volatility using both the Company’s trading history for its common stock and the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. Prior to 2024, the expected volatility was estimated based on the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on the similar size, stage in life cycle or area of specialty. Risk-Free Interest Rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the option. Dividend Yield —The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. The fair value of each stock option issued was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions: Three Months Ended Six Months Ended 2024 2023 2024 2023 Expected term (in years) 6.08 5.50 - 6.08 6.02 - 6.08 5.50 - 6.08 Expected volatility 96.20 % - 97.80 % 81.50 % - 82.40 % 95.90 % - 97.80 % 81.20 % - 82.40 % Risk-free interest rate 4.22 % - 4.65 % 3.47 % - 3.86 % 4.22 % - 4.65 % 3.47 % - 4.02 % Dividend yield — — — —

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	8. Net Loss Per Share The Company calculates basic net loss per share by dividing net loss by the weighted-average number of shares of common stock outstanding, excluding restricted common stock. The weighted-average number of shares of common stock used in the basic and diluted net loss per share calculation include pre-funded warrants to purchase up to 41,283,052 shares of common stock, as the pre-funded warrants are exercisable at any time for nominal cash consideration. The Company has generated a net loss in all periods presented, so the basic and diluted net loss per share are the same, as the inclusion of the potentially dilutive securities would be anti-dilutive. The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Six Months Ended 2024 2023 Stock options to purchase common stock 11,937,414 9,187,093 Shares subject to Employee Stock Purchase Plan 7,850 15,031 Unvested restricted stock units 867,298 660,031 Common warrants 8,104,615 8,427,508 Total 20,917,177 18,289,663

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP, and applicable rules and regulations of the SEC regarding interim financial reporting. The condensed consolidated balance sheet as of June 30, 2024, the condensed consolidated statements of operations, comprehensive loss, stockholders’ equity for the three and six months ended June 30, 2024 and 2023 and the condensed consolidated statements of cash flows for the six months ended June 30, 2024 and 2023 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position, results of operations and cash flows for the interim period presented. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three-month periods are also unaudited. The results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2023 included herein was derived from the audited financial statements as of that date. These unaudited condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 26, 2024.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, or GAAP, 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 financial statements and the reported expenses during the reporting period. Management evaluates its estimates, including but not limited to the fair value of investments, operating lease right-of-use assets and liabilities, valuation of deferred tax assets and uncertain tax positions (including valuation allowance), clinical trial accruals and stock-based compensation. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the operations of Annexon, Inc. and its wholly-owned subsidiary and include the results of operations and cash flows of these entities. All intercompany balances and transactions have been eliminated in consolidation.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting: Improvements to Reportable Segment Disclosures , which requires disclosure of incremental segment information on an interim and annual basis. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal periods beginning after December 15, 2024, and requires retrospective application to all prior periods presented in the financial statements. The Company adopted annual requirements under ASU 2023-07 on January 1, 2024 and plans to adopt interim requirements under ASU 2023-07 on January 1, 2025. The Company will begin including financial statement disclosures in accordance with ASU 2023-07 in its Annual Report on Form 10-K for the year ended December 31, 2024. The Company is evaluating the impact of this guidance on its financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes: Improvements to Income Tax Disclosures , which requires enhanced annual disclosures regarding the rate reconciliation and income taxes paid information. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 and may be adopted on a prospective or retrospective basis. Early adoption is permitted. The Company is evaluating the impact of this guidance on its financial statements and related disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on a Recurring Basis	The following tables summarize the fair value of the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): June 30, 2024 Valuation Amortized Gross Gross Aggregate Assets: Cash equivalents: Money market funds Level 1 $ 36,226 $ — $ — $ 36,226 Government bonds Level 2 118,139 1 ( 1 ) 118,139 Total cash equivalents 154,365 1 ( 1 ) 154,365 Short-term investments: Government bonds Level 2 211,402 4 ( 11 ) 211,395 Total short-term investments 211,402 4 ( 11 ) 211,395 $ 365,767 $ 5 $ ( 12 ) $ 365,760 December 31, 2023 Valuation Amortized Gross Gross Aggregate Assets: Cash equivalents: Money market funds Level 1 $ 143,933 $ — $ — $ 143,933 Government bonds Level 2 72,689 — — 72,689 Total cash equivalents 216,622 — — 216,622 Short-term investments: Government bonds Level 2 34,596 10 — 34,606 Total short-term investments 34,596 10 — 34,606 $ 251,218 $ 10 $ — $ 251,228

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2024
Disclosure Of Balance Sheet Components [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the condensed consolidated statements of cash flows (in thousands): June 30, December 31, Cash $ 2,939 $ 8,488 Cash equivalents 154,365 216,622 Cash and cash equivalents 157,304 225,110 Restricted cash 1,032 1,032 Cash, cash equivalents and restricted cash $ 158,336 $ 226,142
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Prepaid research and development costs $ 4,130 $ 2,617 Prepaid insurance 309 704 Other prepaid expenses 831 760 Other current assets — 63 Total prepaid expenses and other current assets $ 5,270 $ 4,144
Summary of Property and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): June 30, December 31, Leasehold improvements $ 17,245 $ 17,245 Laboratory equipment 1,832 1,832 Furniture and fixtures 692 692 Computer equipment and software 33 33 Construction in progress 4 — Total property and equipment, gross 19,806 19,802 Less: accumulated depreciation ( 6,104 ) ( 5,029 ) Total property and equipment, net $ 13,702 $ 14,773
Summary of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): June 30, December 31, Accrued research and development expenses $ 6,538 $ 4,027 Accrued compensation 2,766 5,607 Accrued professional services 1,240 501 Other accrued expenses 113 100 Total accrued liabilities $ 10,657 $ 10,235

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments and Related Lease Liabilities	Future minimum lease payments and related lease liabilities as of June 30, 2024, were as follows: (in thousands) 2024 (remaining six months) $ 2,461 2025 5,065 2026 5,242 2027 5,425 2028 and thereafter 22,600 Total undiscounted lease payments 40,793 Less: Imputed interest ( 10,590 ) Total $ 30,203

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	6 Months Ended
	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Summary of Warrants Activity	The following summarizes warrant activity during the six months ended June 30, 2024 and 2023: Number of Common Warrants Number of Pre-funded Warrants Weighted-Average Exercise Price Balances as of December 31, 2023 8,427,508 40,492,923 Issued — 7,000,000 $ 0.001 Exercised ( 322,893 ) ( 6,209,871 ) $ 0.307 Balances as of June 30, 2024 8,104,615 41,283,052 Number of Common Warrants Number of Pre-funded Warrants Weighted-Average Exercise Price Balances as of December 31, 2022 8,427,508 24,696,206 Exercised — ( 2,583,144 ) $ 0.001 Balances as of June 30, 2023 8,427,508 22,113,062
Schedule of Common Stock Reserved for Future Issuance	The Company reserved the following shares of common stock for issuance as follows: June 30, December 31, Stock options issued and outstanding 11,937,414 9,208,970 Stock options reserved for 2020 Incentive Award Plan 1,861,959 1,988,340 Unvested restricted stock units outstanding 867,298 495,579 Common stock reserved for 2021 ATM program 25,043,404 2,619,471 Common stock reserved for 2024 ATM program 25,000,000 — Common stock reserved for Employee Stock Purchase Plan 2,023,537 1,338,381 Common stock reserved for 2022 Employment Inducement 1,502,930 758,084 Common stock reserved for pre-funded warrants 41,283,052 40,493,510 Common stock reserved for common warrants 8,104,615 8,427,508 Total common stock reserved 117,624,209 65,329,843

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The following table presents stock option activity under the Plans for the period: Number of Weighted- Weighted- Aggregate Balances as of December 31, 2023 9,208,970 $ 10.31 7.53 $ 2,930 Stock options granted 3,596,114 $ 5.26 Stock options exercised ( 141,440 ) $ 2.74 Stock options forfeited ( 726,230 ) $ 10.08 Balances as of June 30, 2024 11,937,414 $ 8.89 7.77 $ 3,355 Exercisable as of June 30, 2024 6,002,916 $ 11.62 6.51 $ 1,739
Summary of RSU Activity under 2020 Plan	A summary of RSU activity under the Company’s equity incentive plan and related information is as follows: Number of Shares Weighted-Average Grant Date Fair Value Per Share Unvested as of December 31, 2023 495,579 $ 5.69 Granted 602,600 5.13 Vested ( 124,695 ) 6.44 Cancelled ( 106,186 ) 5.29 Unvested as of June 30, 2024 867,298 $ 5.24
Summary of Stock-Based Compensation Expense	The total stock-based compensation expense recognized was as follows (in thousands): Three Months Ended Six Months Ended 2024 2023 2024 2023 Research and development $ 2,311 $ 2,307 $ 4,593 $ 4,558 General and administrative 2,631 2,353 5,009 4,709 Total stock-based compensation expense $ 4,942 $ 4,660 $ 9,602 $ 9,267
Summary of Fair Value of Each Award Issued Estimated on the Date of Grant Using the Black-Scholes Option Pricing Model	The fair value of each stock option issued was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions: Three Months Ended Six Months Ended 2024 2023 2024 2023 Expected term (in years) 6.08 5.50 - 6.08 6.02 - 6.08 5.50 - 6.08 Expected volatility 96.20 % - 97.80 % 81.50 % - 82.40 % 95.90 % - 97.80 % 81.20 % - 82.40 % Risk-free interest rate 4.22 % - 4.65 % 3.47 % - 3.86 % 4.22 % - 4.65 % 3.47 % - 4.02 % Dividend yield — — — —

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Summary of Outstanding Potentially Dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Six Months Ended 2024 2023 Stock options to purchase common stock 11,937,414 9,187,093 Shares subject to Employee Stock Purchase Plan 7,850 15,031 Unvested restricted stock units 867,298 660,031 Common warrants 8,104,615 8,427,508 Total 20,917,177 18,289,663

Organization - Additional Infor

Organization - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Accumulated deficit	$ 627,285	$ 572,499
Cash and cash equivalents and short-term investments	$ 368,700

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 365,767	$ 251,218
Gross Unrealized Holding Gains	5	10
Gross Unrealized Holding Losses	(12)
Aggregate Fair Value	365,760	251,228
Level 1 [Member] | Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	36,226	143,933
Aggregate Fair Value	36,226	143,933
Level 2 [Member] | Cash and Cash Equivalents [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	154,365	216,622
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	(1)
Aggregate Fair Value	154,365	216,622
Level 2 [Member] | Cash and Cash Equivalents [Member] | Government Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	118,139	72,689
Gross Unrealized Holding Gains	1
Gross Unrealized Holding Losses	(1)
Aggregate Fair Value	118,139	72,689
Level 2 [Member] | Short-Term Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	211,402	34,596
Gross Unrealized Holding Gains	4	10
Gross Unrealized Holding Losses	(11)
Aggregate Fair Value	211,395	34,606
Level 2 [Member] | Short-Term Investments [Member] | Government Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	211,402	34,596
Gross Unrealized Holding Gains	4	10
Gross Unrealized Holding Losses	(11)
Aggregate Fair Value	$ 211,395	$ 34,606

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash	$ 2,939	$ 8,488
Cash equivalents	154,365	216,622
Cash and cash equivalents	157,304	225,110
Restricted cash	1,032	1,032
Cash, cash equivalents and restricted cash	$ 158,336	$ 226,142

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid research and development costs	$ 4,130	$ 2,617
Prepaid insurance	309	704
Other prepaid expenses	831	760
Other current assets		63
Total prepaid expenses and other current assets	$ 5,270	$ 4,144

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 19,806	$ 19,802
Less: accumulated depreciation	(6,104)	(5,029)
Total property and equipment, net	13,702	14,773
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	17,245	17,245
Laboratory Equipment [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	1,832	1,832
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	692	692
Computer Equipment and Software [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	33	$ 33
Construction in Progress [Member]
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 4

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Depreciation expense	$ 0.5	$ 0.5	$ 1.1	$ 1.1

Balance Sheet Components - Su_3

Balance Sheet Components - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Accrued research and development expenses	$ 6,538	$ 4,027
Accrued compensation	2,766	5,607
Accrued professional services	1,240	501
Other accrued expenses	113	100
Total accrued liabilities	$ 10,657	$ 10,235

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	3 Months Ended		6 Months Ended		24 Months Ended
	Nov. 30, 2021	Jun. 30, 2024 USD ($) Claim	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) Claim	Jun. 30, 2023 USD ($)	Nov. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Gain Contingencies [Line Items]
Aggregate sublease payment receivable						$ 3,400,000
Sublease income		$ 0	$ 600,000	$ 0	$ 1,100,000
Operating lease right-of-use asset		17,382,000		17,382,000			$ 18,009,000
Lease liabilities		$ 30,203,000		$ 30,203,000
Weighted average incremental borrowing rate		8.40%		8.40%
Operating lease costs		$ 1,000,000	500,000	$ 1,900,000	1,100,000
Variable lease payments		600,000	$ 400,000	1,200,000	$ 700,000
Loss contingency accrual		$ 0		$ 0
Indemnification Agreement [Member]
Gain Contingencies [Line Items]
Loss contingency pending claims | Claim		0		0
Brisbane, California [Member]
Gain Contingencies [Line Items]
Operating lease, term of contract		10 years		10 years
Operating lease, expiration month and year				2031-10
Operating lease, renewal term		10 years		10 years
Lessee, Operating Sublease Commencement Year and Month	2021-12
Lessee operating sublease expiration year and month	2023-11
Operating lease right-of-use asset		$ 17,400,000		$ 17,400,000
Lease liabilities		$ 30,200,000		$ 30,200,000
Weighted average remaining lease term		7 years 3 months 18 days		7 years 3 months 18 days

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Lease Payments and Related Lease Liabilities (Detail) $ in Thousands	Jun. 30, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024 (remaining six months)	$ 2,461
2025	5,065
2026	5,242
2027	5,425
2028 and thereafter	22,600
Total undiscounted lease payments	40,793
Less: Imputed interest	(10,590)
Lease liabilities	$ 30,203

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended								3 Months Ended				6 Months Ended
	Jun. 30, 2024	Apr. 30, 2024	Mar. 31, 2024	Feb. 29, 2024	Dec. 31, 2023	Mar. 31, 2023	Jul. 31, 2022	Aug. 31, 2021	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Class Of Stock [Line Items]
Net proceeds from private placement							$ 122,500
Share option expired													141,440
Common stock	$ 106				$ 78				$ 106				$ 106
Net proceeds from sale of common stock													$ 39,737	$ 17,995
Common Stock [Member]
Class Of Stock [Line Items]
Sale of shares									936,719	6,639,348
Common stock shares issued for exercise of warrants	19,901	965,427		5,243,400		2,582,557
Share option expired									35,914	105,526	283	55,605
Pre-funded Warrants [Member]
Class Of Stock [Line Items]
Purchase of shares	7,000,000				18,379,861				7,000,000				7,000,000
Offering price per share	$ 6.249				$ 2.879		$ 3.87025
Pre-funded warrants were recorded at fair value	$ 43,700				$ 52,900
Pre-funded Warrants [Member] | Maximum [Member]
Class Of Stock [Line Items]
Purchase of shares							24,696,206
Purchase price per share	$ 0.001				$ 0.001		$ 0.001		$ 0.001				$ 0.001
Warrants or Common Warrants [Member]
Class Of Stock [Line Items]
Offering price per share							3.87125
Purchase price per share							$ 5.806875
Warrant expiration date							Jun. 30, 2025
Warrants or Common Warrants [Member] | Maximum [Member]
Class Of Stock [Line Items]
Purchase of shares							8,427,508
Private Placement [Member]
Class Of Stock [Line Items]
Sale of shares							9,013,834
Underwriting agreement [Member]
Class Of Stock [Line Items]
Sale of shares	13,001,120				25,035,000
Common stock, par value per share	$ 0.001				$ 0.001				0.001				0.001
Exchange value					$ 1,000
Shares issued price per share	$ 6.25				$ 2.88				$ 6.25				$ 6.25
Net proceeds from sale of common stock	$ 116,800				$ 117,000
Underwriting agreement [Member] | Director [Member]
Class Of Stock [Line Items]
Sale of shares					350,000
Sales Agreement with Cowen and Company LLC [Member] | 2021 ATM Program [Member]
Class Of Stock [Line Items]
Common stock								$ 100,000
Percentage of gross proceeds of common stock to be paid								3%
Common stock, shares issued	7,576,067								7,576,067		2,646,458		7,576,067	2,646,458
Net proceeds from sale of common stock													$ 38,400	$ 17,500
Remains available for offer and sales of shares of common stock	$ 42,300								$ 42,300		$ 82,000		$ 42,300	$ 82,000
Common stock sales agreement expiration date								Aug. 15, 2024
Number of common stock sold after expiration date								0
Sales Agreement with Cowen and Company LLC [Member] | 2024 ATM Program [Member]
Class Of Stock [Line Items]
Common stock			$ 100,000							$ 100,000
Common stock, shares issued	0								0				0
Sales Agreement with Cowen and Company LLC [Member] | 2024 ATM Program [Member] | Maximum [Member]
Class Of Stock [Line Items]
Percentage of gross proceeds of common stock to be paid			3%

Stockholder's Equity - Summary

Stockholder's Equity - Summary of Warrants Activity (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Number of Common Warrants [Member]
Class of Warrant or Right [Line Items]
Beginning Balance	8,427,508	8,427,508
Exercised	(322,893)
Ending Balance	8,104,615	8,427,508
Number of Pre-funded Warrants [Member]
Class of Warrant or Right [Line Items]
Beginning Balance	40,492,923	24,696,206
Issued	7,000,000
Exercised	(6,209,871)	(2,583,144)
Ending Balance	41,283,052	22,113,062
Common Warrant and Pre-funded Warrants [Member]
Class of Warrant or Right [Line Items]
Weighted-Average Exercise Price, Issued	$ 0.001
Weighted-Average Exercise Price, Exercised	$ 0.307	$ 0.001

Stockholder's Equity - Schedule

Stockholder's Equity - Schedule of Common Stock Reserved for Future Issuance (Detail) - shares	Jun. 30, 2024	Dec. 31, 2023
Class Of Stock [Line Items]
Common stock reserved	11,937,414	9,208,970
Common stock reserved	1,861,959
Common stock reserved	117,624,209	65,329,843
Employee Stock Option [Member]
Class Of Stock [Line Items]
Common stock reserved	11,937,414	9,208,970
Stock Options Reserved for 2020 Incentive Award Plan [Member]
Class Of Stock [Line Items]
Common stock reserved	1,861,959	1,988,340
Unvested Restricted Stock Units Outstanding [Member]
Class Of Stock [Line Items]
Common stock reserved	867,298	495,579
Common Stock Reserved for Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common stock reserved	2,023,537	1,338,381
2022 Employment Inducement Award Plan [Member]
Class Of Stock [Line Items]
Common stock reserved	1,502,930	758,084
Pre-Funded Warrants [Member]
Class Of Stock [Line Items]
Common stock reserved	41,283,052	40,493,510
Common Warrants [Member]
Class Of Stock [Line Items]
Common stock reserved	8,104,615	8,427,508
2021 ATM Program [Member]
Class Of Stock [Line Items]
Common stock reserved	25,043,404	2,619,471
2024 ATM Program [Member]
Class Of Stock [Line Items]
Common stock reserved	25,000,000

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Mar. 31, 2024	Dec. 31, 2023	Jul. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of number of shares of capital stock outstanding on last day of preceding year			4%
Stock option grants description			Awards granted under the 2020 Plan expire no later than ten years from the date of grant. For Incentive Stock Options, or ISOs, and Nonstatutory Stock Options, or NSOs, the option price shall not be less than 100% of the estimated fair value on the date of grant. Options granted typically vest over a four-year period but may be granted with different vesting terms.
Option expiry period			10 years
Vesting Period			4 years
Options available for future grant	1,861,959		1,861,959
Intrinsic value of options exercised	$ 100,000	$ 0	$ 400,000	$ 300,000
Weighted- average exercise price per share, Stock options granted			$ 5.26
Unrecognized stock-based compensation cost expected period for recognition			2 years 6 months
Common stock for future issuance	117,624,209		117,624,209			65,329,843
Total stock-based compensation expense	$ 4,942,000	4,660,000	$ 9,602,000	$ 9,267,000
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted- average exercise price per share, Stock options granted			$ 4.17	$ 4.18
2022 Employment Inducement Award Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options available for future grant	1,502,930		1,502,930				2,850,000
Incentive Stock Options, or ISOs, and Nonstatutory Stock Options, or NSOs [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase of Common stock at end of each offering period at price equal to percentage of fair market value of shares			100%
Employee Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation cost	$ 26,600,000		$ 26,600,000
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation cost	$ 3,600,000		$ 3,600,000
Unrecognized stock-based compensation cost expected period for recognition			2 years 2 months 12 days
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase of Common stock at end of each offering period at price equal to percentage of fair market value of shares			85%
Share purchases funded through payroll deductions minimum percentage of employee's eligible compensation					1%
Share purchases funded through payroll deductions maximum percentage of employee's eligible compensation	15%		15%
Common stock for future issuance	2,023,537		2,023,537			1,338,381
Percentage of shares of common stock outstanding on last day of immediately preceding fiscal year			1%
Total stock-based compensation expense	$ 41,000	$ 100,000	$ 100,000	$ 100,000

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of shares, Beginning balance | shares	9,208,970
Number of shares, Stock options granted | shares	3,596,114
Number of shares, Stock options exercised | shares	(141,440)
Number of shares, Stock options forfeited | shares	(726,230)
Number of shares, Ending balance | shares	11,937,414	9,208,970
Number of shares, Exercisable | shares	6,002,916
Weighted- average exercise price per share, Beginning balance | $ / shares	$ 10.31
Weighted- average exercise price per share, Stock options granted | $ / shares	5.26
Weighted- average exercise price per share, Stock options exercised | $ / shares	2.74
Weighted- average exercise price per share, Stock options forfeited | $ / shares	10.08
Weighted- average exercise price per share, Ending balance | $ / shares	8.89	$ 10.31
Weighted- average exercise price per share, Exercisable | $ / shares	$ 11.62
Weighted- average remaining contractual term	7 years 9 months 7 days	7 years 6 months 10 days
Weighted- average remaining contractual term, Exercisable	6 years 6 months 3 days
Aggregate intrinsic value | $	$ 3,355	$ 2,930
Aggregate intrinsic value, Exercisable | $	$ 1,739

Equity Incentive Plans - Summ_2

Equity Incentive Plans - Summary of RSU Activity under 2020 Plan (Detail)	6 Months Ended
	Jun. 30, 2024 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of Shares, Unvested as of December 31, 2023 | shares	495,579
Number of Shares, Granted | shares	602,600
Number of Shares, Vested | shares	(124,695)
Number of Shares, Cancelled | shares	(106,186)
Number of Shares, Unvested as of March 31, 2024 | shares	867,298
Weighted-Average Grant Date Fair Value Per Share, Granted Unvested as of December 31, 2023 | $ / shares	$ 5.69
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	5.13
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	6.44
Weighted-Average Grant Date Fair Value Per Share, Cancelled | $ / shares	5.29
Weighted-Average Grant Date Fair Value Per Share, Granted Unvested as of March 31, 2024 | $ / shares	$ 5.24

Equity Incentive Plans - Summ_3

Equity Incentive Plans - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 4,942	$ 4,660	$ 9,602	$ 9,267
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,311	2,307	4,593	4,558
General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,631	$ 2,353	$ 5,009	$ 4,709

Equity Incentive Plans - Summ_4

Equity Incentive Plans - Summary of Fair Value of Each Award Issued Estimated on the Date of Grant Using the Black-Scholes Option Pricing Model (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days
Expected volatility, Minimum	96.20%	81.50%	95.90%	81.20%
Expected volatility, Maximum	97.80%	82.40%	97.80%	82.40%
Risk-free interest rate, Minimum	4.22%	3.47%	4.22%	3.47%
Risk-free interest rate, Maximum	4.65%	3.86%	4.65%	4.02%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		5 years 6 months	6 years 7 days	5 years 6 months
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		6 years 29 days	6 years 29 days	6 years 29 days

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail)	Jun. 30, 2024 shares
Maximum [Member] | Common Stock [Member]
Class of Warrant or Right [Line Items]
Warrants exercised	41,283,052

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Outstanding Potentially Dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share (Detail) - shares	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	20,917,177	18,289,663
Shares Subject to Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	7,850	15,031
Stock Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	11,937,414	9,187,093
Unvested Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	867,298	660,031
Common Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	8,104,615	8,427,508