Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Summary of Stock Option Activity

A summary of the Company’s stock option activity under its Plans is as follows (in thousands, except share, per share data and years):

	Number of Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Balance at December 31, 2022		7,345,444		$	11.67		8.31	$	29,806
Granted		1,984,650		$	13.90
Exercised		(191,879	)	$	8.65
Forfeited or cancelled		(642,634	)	$	13.71
Balance at September 30, 2023		8,495,581		$	12.10		7.60	$	15,076
Vested and expected to vest at September 30, 2023		8,495,581		$	12.10		7.60	$	15,076
Exercisable at September 30, 2023		5,413,688		$	9.72		7.09	$	14,999

Summary of Fair Value of Stock Option Grants

The assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants under the Plans were as follows:

	Nine Months Ended September 30,
	2023	2022
Risk-free interest rate	3.5% – 4.2%	1.5% – 3.7%
Expected volatility	83% – 87%	81% – 85%
Expected term (in years)	5.3 – 6.1	5.3 – 6.1
Expected dividend yield	—	—

Summary of Stock-Based Compensation Expense

Stock-based compensation expense has been reported in the statements of operations and comprehensive loss as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	1,572	$	2,019	$	6,379	$	5,702
General and administrative		2,976		2,577		9,143		7,296
Total	$	4,548	$	4,596	$	15,522	$	12,998

Summary of Unvested Shares and Unvested Stock Liabilities

A summary of the Company’s unvested shares and unvested stock liabilities is as follows (in thousands, except share data):

	Number of Unvested Shares			Unvested Stock Liabilities
Balance at December 31, 2022		68,406		$	169
Vested shares		(51,403	)		(144	)
Balance at September 30, 2023		17,003		$	25

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	September 30,		December 31,
	2023		2022
Common stock options outstanding		8,495,581		7,345,444
Shares available for issuance under the Plans		4,754,218		4,012,001
Shares available for issuance under the ESPP		1,175,413		816,478
Pre-funded common stock warrants		503,226		—
Total		14,928,438		12,173,923