Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2024

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Summary of Stock Option Activity

The following table summarizes stock option activity:

	Stock Options Outstanding			Weighted-Average Exercise Price
Outstanding - January 1, 2024		5,817,339		$	11.90
Options granted		2,178,094			15.04
Options exercised and vested		(524,502	)		4.42
Options cancelled and forfeited		(6,180	)		18.60
Outstanding - June 30, 2024		7,464,751		$	13.34

Summary of Stock-Based Compensation Expense

The allocation of stock-based compensation expense was as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Research and development	$	2,528	$	2,210	$	4,757	$	2,702
General and administrative		2,616		1,985		4,902		3,755
Total stock-based compensation expense	$	5,144	$	4,195	$	9,659	$	6,457

Summary of Stock-Based Compensation Fair Value Assumptions

The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and stock purchase rights under the ESPP were as follows:

	Six Months Ended June 30,
Stock Options	2024	2023
Expected term (years)	5.7 - 6.1	5.8 - 6.0
Expected volatility	82% - 84%	83% - 84%
Risk-free interest rate	4.0% - 4.6%	3.3% - 4.1%
Expected dividend yield	—%	—%

	Six Months Ended June 30,
ESPP	2024	2023
Expected term (years)	0.5	N/A
Expected volatility	75%	N/A
Risk-free interest rate	5.4%	N/A
Expected dividend yield	—%	N/A

Restricted Stock Units

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Summary of Restricted Stock Award and Restricted Stock Units Activity

Restricted stock units ("RSUs") are valued at the market price of a share of the Company’s common stock on the date of grant. The following table summarizes RSU activity:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested - January 1, 2024		78,505		$	14.28
Granted		20,000			14.85
Vested		(4,437	)		18.82
Forfeited		—			—
Unvested - June 30, 2024		94,068		$	14.19