Convertible Preferred Stock and Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2026

Convertible Preferred Stock And Stockholders Equity Disclosure [Abstract]

Summary of Stock Option Activity and Related Information Under All Equity Plans

The following table summarizes stock option activity and related information under all equity plans for the period ended September 30, 2026:


		Number of Options				Weighted- Average Price
Balance at December 31, 2025			12,400,620			$	8.36
Granted			4,730,659				1.23
Exercised			(318,033	)			1.38
Forfeited			(689,376	)			7.21
Balance at September 30, 2026			16,123,870			$	6.45

Summary of Restricted Stock Unit Activity Under The Plan

Restricted stock unit activity under all equity and stock option plans is summarized as follows:


		Number of Restricted Stock Units				Weighted- Average Grant Date Fair Value per Share
Balance at December 31, 2025			6,635,820			$	9.78
Granted			3,817,602				1.11
Vested			(3,054,540	)			5.93
Forfeited			(787,757	)			9.45
Balance at September 30, 2026			6,611,125			$	6.59

Schedule of Allocation of Stock-Based Compensation for All Stock Awards

The allocation of stock-based compensation for all stock awards is as follows (in thousands):


		Three Months Ended September 30,								Nine Months Ended September 30,
		2026				2025				2026				2025
Research and development		$	1,349			$	2,448			$	5,375			$	10,146
General and administrative			1,349				2,413				4,770				9,250
Total		$	2,698			$	4,861			$	10,145			$	19,396

Schedule of Weighted-Average Assumptions Used to Determine The Fair Value of Employee and Nonemployee Stock Option Grants

The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee and nonemployee stock option grants were as follows:


		Nine Months Ended September 30,
		2026				2025
Risk-free interest rate			3.9	%			4.4	%
Expected volatility			94.0	%			90.4	%
Expected term (in years)			6.0				6.2
Expected dividend yield			0.0	%			0.0	%

Summary of Changes in Stockholders' Equity

The following table summarizes the Company’s changes in stockholders’ equity accounts for the three and nine months ended September 30, 2026 (in thousands, except share data):


	Convertible Preferred Stock								Common Stock								Additional Paid-in				Accumulated Other Comprehensive				Accumulated				Total Stockholders'
	Shares				Amount				Shares				Amount				Capital				Gain (Loss)				Deficit				Equity
Balance at December 31, 2025		2,755,086			$	3				115,359,735			$	115			$	1,741,259			$	116			$	(1,534,309	)		$	207,184
Issuance of common stock upon vesting of restricted stock units		—				—				912,778				1				(1	)			—				—				—
Stock-based compensation		—				—				—				—				3,929				—				—				3,929
Unrealized loss on investments		—				—				—				—				—				(193	)			—				(193	)
Net loss		—				—				—				—				—				—				(31,213	)			(31,213	)
Balance at March 31, 2026		2,755,086			$	3				116,272,513			$	116			$	1,745,187			$	(77	)		$	(1,565,522	)		$	179,707
Exercise of stock options, net of issuance costs		—				—				293,409				1				411				—				—				412
Issuance of common stock upon vesting of restricted stock units		—				—				128,184				—				—				—				—				—
Stock-based compensation		—				—				—				—				3,518				—				—				3,518
Unrealized loss on investments		—				—				—				—				—				(40	)			—				(40	)
Net loss		—				—				—				—				—				—				(30,159	)			(30,159	)
Balance at June 30, 2026		2,755,086			$	3				116,694,106			$	117			$	1,749,116			$	(117	)		$	(1,595,681	)		$	153,438
Issuance of common stock from ATM offering, net of commissions and issuance costs		—				—				2,801,602				3				7,595				—				—				7,598
Issuance of common stock upon vesting of restricted stock units		—				—				2,013,578				2				(2	)			—				—				—
Exercise of stock options, net of issuance costs		—				—				24,624				—				23				—				—				23
Stock-based compensation		—				—				—				—				2,698				—				—				2,698
Unrealized loss on investments		—				—				—				—				—				(38	)			—				(38	)
Net loss		—				—				—				—				—				—				(30,687	)			(30,687	)
Balance at September 30, 2026		2,755,086			$	3				121,533,910			$	122			$	1,759,430			$	(155	)		$	(1,626,368	)		$	133,032

The following table summarizes the Company’s changes in stockholders’ equity accounts for the three and nine months ended September 30, 2025 (in thousands, except share data):


	Convertible Preferred Stock								Common Stock								Additional Paid-in				Accumulated Other Comprehensive				Accumulated				Total Stockholders'
	Shares				Amount				Shares				Amount				Capital				Gain (Loss)				Deficit				Equity
Balance at December 31, 2024		2,755,086			$	3				113,928,279			$	114			$	1,716,335			$	268			$	(1,397,994	)		$	318,726
Issuance of common stock upon vesting of restricted stock units		—				—				675,631				1				(1	)			—				—				—
Stock-based compensation		—				—				—				—				7,381				—				—				7,381
Unrealized loss on investments		—				—				—				—				—				(77	)			—				(77	)
Net loss		—				—				—				—				—				—				(37,621	)			(37,621	)
Balance at March 31, 2025		2,755,086			$	3				114,603,910			$	115			$	1,723,715			$	191			$	(1,435,615	)		$	288,409
Exercise of stock options, net of issuance costs		—				—				832				—				—				—				—				—
Issuance of common stock upon vesting of restricted stock units		—				—				50,325				—				—				—				—				—
Stock-based compensation		—				—				—				—				7,154				—				—				7,154
Unrealized loss on investments		—				—				—				—				—				(129	)			—				(129	)
Net loss		—				—				—				—				—				—				(34,070	)			(34,070	)
Balance at June 30, 2025		2,755,086			$	3				114,655,067			$	115			$	1,730,869			$	62			$	(1,469,685	)		$	261,364
Issuance of common stock upon vesting of restricted stock units		—				—				681,630				—				—				—				—				—
Stock-based compensation		—				—				—				—				4,861				—				—				4,861
Unrealized gain on investments		—				—				—				—				—				91				—				91
Net loss		—				—				—				—				—				—				(32,250	)			(32,250	)
Balance at September 30, 2025		2,755,086			$	3				115,336,697			$	115			$	1,735,730			$	153			$	(1,501,935	)		$	234,066