Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity for Awards

A summary of stock option activity for awards is presented below:

	Number of shares			Weighted average exercise price		Weighted average remaining contractual life (years)		Aggregate intrinsic value(1)
Outstanding as of December 31, 2022		8,274,647		$	18.28		7.6	$	20,598
Granted		1,599,227			9.32
Exercised		(145,877	)		2.55
Forfeitures(2)		(1,449,164	)		28.00
Expired(2)		(1,800,770	)		34.88
Outstanding as of December 31, 2023		6,478,063		$	9.64		6.9	$	8,435
Exercisable as of December 31, 2023		4,034,517		$	8.88		5.7	$	8,439

(1)The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that were in the money at December 31, 2023 and 2022.

(2)Options exchanged are classified as either forfeitures or expired based on vesting status at the time of Exchange Offer.

Summary of Restricted Stock Unit Activity

A summary of restricted stock unit activity is presented below:

	Number of shares			Aggregate intrinsic value		Weighted average grant date fair value
Outstanding as of December 31, 2022		—		$	—	$	—
Awarded		807,700					9.04
RSUs in exchange for options as part of option exchange		730,602					3.95
Vested		—					—
Forfeitures		(25,200	)				9.15
Outstanding as of December 31, 2023		1,513,102		$	7,959	$	6.58
Vested or expected to vest as of December 31, 2023		1,513,102		$	7,959	$	6.58

Summary of Stock-based Compensation Expense

Stock-based compensation expense recorded as research and development and general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss is as follows:

	Year ended December 31,
	2023		2022
Research and development	$	9,925	$	8,901
General and administrative		15,332		13,953
	$	25,257	$	22,854

Summary of Fair Values of Options Granted to Employees and Directors

The Company uses the Black-Scholes option pricing model to calculate the grant-date fair value of stock options. The fair values of the options granted to employees and directors were calculated using the following assumptions for the years ended December 31, 2023 and 2022:

	Year ended December 31,
	2023	2022
Risk-free interest rate	3.57-3.94%	1.82-4.15%
Expected dividend yield	0%	0%
Expected life	5.5-6.25 years	5.5-6.25 years
Expected volatility	70-73%	70-71%