Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Stock-Based Compensation Expense Recorded in Statements of Operations and Allocated

Total stock-based compensation expense related to the Company’s equity incentive plan and employee stock purchase plan was recorded in the statements of operations and allocated as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2023		2022		2023		2022
Research and development	$	1,650	$	1,253	$	3,124	$	2,265
General and administrative		1,786		1,306		3,545		2,624
Total stock-based compensation expense	$	3,436	$	2,559	$	6,669	$	4,889

As of June 30, 2023, there was $30.0 million of total unrecognized stock-based compensation expense which is expected to be recognized over a weighted-average period of 2.5 years.

Summary of Stock Option Activity

The following table summarizes stock option activity:

	Outstanding Options
	Shares			Weighted- Average Exercise		Weighted- Average Remaining Contractual Term (Years)
Balance, December 31, 2022		5,341,975		$	8.79		8.6
Granted		1,916,895			9.17
Exercised		(76,061	)		8.19
Cancelled		(150,343	)		9.29
Balance, June 30, 2023		7,032,466			8.89		8.6
Exercisable, June 30, 2023		2,622,543		$	8.82		8.2

Summary of Fair Value of Stock Options Estimated using Weighted-Average Assumptions

The Company estimates the fair value of stock options using the Black-Scholes option pricing model and the fair value of these stock options was estimated using the following weighted-average assumptions:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2023			2022			2023			2022
Expected term in years		5.9			5.9			6.0			6.0
Expected volatility		79	%		95	%		79	%		93	%
Risk-free interest rate		4.0	%		3.4	%		3.6	%		2.9	%
Dividend yield		—			—			—			—
Weighted average fair value of share-based awards granted	$	21.74		$	3.93		$	6.44		$	4.31

Summary of Restricted Stock Activity

The following table summarizes the restricted stock activity:

	Number of Restricted Stock Awards			Weighted-Average Grant Date Fair Value
Balance, December 31, 2022		292,236		$	4.04
Granted		—			—
Released		(90,159	)		4.02
Forfeited		—			—
Balance, June 30, 2023		202,077		$	4.05