Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2023

Summary of Assumptions Used in Black-Scholes Option Pricing Model

	Three Months Ended
	March 31,
	2023	2022
Risk-free interest rate	3.62% - 4.22%	1.70% - 2.35%
Expected volatility	76.3% - 81.3%	81.4% - 81.9%
Expected dividend yield	0%	0%
Expected life of employee and Board options (in years)	6.25	6.25

Summary of Compensation Expense Relating to Stock Options

	Three Months Ended
	March 31,
	2023		2022
Research and development	$	1,480	$	1,917
General and administrative		1,241		2,030
Total stock option expense	$	2,721	$	3,947

Summary of Stock Option Activity

		Weighted
	Number of	Average Exercise
	Shares	Price
Outstanding, December 31, 2022	7,689,449	$	14.35
Granted	1,449,154		10.06
Exercised	(93,218)		6.00
Forfeited	(52,626)		11.41
Outstanding, March 31, 2023	8,992,759	$	13.76
Options exercisable, March 31, 2023	5,128,904

Employees And Non-Employee Members Of Board Of Directors [Member]

Summary of Restricted Stock Unit Activity

		Weighted
	Number of	Average Grant
	Units	Date Fair Value
Outstanding, December 31, 2022	372,513	$	13.20
Awarded	407,000		10.06
Vested and released	(83,793)		14.20
Outstanding, March 31, 2023	695,720	$	11.24
Restricted stock units exercisable (vested and deferred), March 31, 2023	—