Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board

The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis:

	Year Ended December 31,
	2023			2022
Expected option life (years)		6.00			5.98
Risk-free interest rate		3.82	%		2.47	%
Expected volatility		83.36	%		80.43	%
Expected dividend yield		—	%		—	%

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the year ended December 31, 2023:

	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2022		9,423,271		$	7.26		8.14	$	22
Granted		123,501		$	1.09
Exercised		(297,604	)	$	0.79
Cancelled or forfeited		(4,106,896	)	$	7.44
Outstanding as of December 31, 2023		5,142,272		$	7.33		6.24	$	663
Exercisable as of December 31, 2023		3,670,053		$	8.84		5.44	$	376

Summary of Restricted Stock Award and Restricted Stock Unit Activity

The following table summarizes the Company’s restricted stock award and restricted stock unit activity for the year ended December 31, 2023:

	Number of Shares			Weighted- Average Grant Date Fair Value
Issued and unvested as of December 31, 2022		940,392		$	3.62
Granted		1,548,117			1.65
Vested		(305,502	)		4.74
Forfeited, cancelled or expired		(1,246,649	)		2.02
Issued and unvested as of December 31, 2023		936,358		$	2.13

Schedule of Stock-based Compensation Expense

Stock-based compensation expense was allocated as follows:

	Year Ended December 31,
	2023		2022
Research and development	$	1,927	$	2,785
General and administrative		4,964		8,737
Total stock-based compensation expense	$	6,891	$	11,522