Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Fair Value of Stock Options Issued to Employees

The fair value of stock option issued to employees was estimated at the date of grant using Black-Scholes with the following weighted-average assumptions:

	Year Ended December 31,
	2022		2021
Expected volatility	110.1	%	109.6	%
Expected term (years)	6.0		6.0
Risk-free interest rate	2.4	%	0.8	%
Expected dividend yield	0.0	%	0.0	%

Schedule of Information Related to Stock Options Outstanding

A summary of stock option activity under the Plans is presented below (in thousands, except share and per share data):

				Weighted-Average
		Weighted-		Remaining
	Number of	Average		Contractual Term	Aggregate Intrinsic
	Stock Options	Exercise Price		(Years)	Value
Outstanding, December 31, 2021	2,583,443	$	8.63	5.9	$	8,460
Granted	1,473,427	$	8.48
Exercised	(373,545)	$	2.65
Forfeited or expired	(299,388)	$	8.92
Outstanding, December 31, 2022	3,383,937	$	9.20	5.9	$	25,724
Exercisable, December 31, 2022	1,523,504	$	9.00	5.8	$	12,292
Vested and expected to vest, December 31, 2022	3,197,894	$	9.19	5.9	$	25,724

Summary of Restricted Stock Activity

A summary of restricted stock activities is presented below:

		Weighted-
		average
		Grant Date
	Shares	Fair Value
Unvested, December 31, 2021	74,000	$	3.59
Vested	(74,000)		3.59
Unvested, December 31, 2022	—	$

Schedule of Stock-based Compensation Expense

Stock-based compensation expense is classified in the accompanying consolidated statements of operations and comprehensive loss for the years ended December 31, 2022 and 2021 as follows (in thousands):

	Year Ended December 31,
	2022		2021
Research and development	$	2,835	$	1,656
General and administrative		5,266		3,863
Total	$	8,101	$	5,519

Restricted Stock Units [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Restricted Stock Activity

		Weighted-
		average
		Grant Date
	Shares	Fair Value
Unvested, December 31, 2021	231,928	$	14.53
Granted	285,000		7.11
Vested	(61,028)		14.39
Forfeited or expired	(41,415)		10.95
Unvested, December 31, 2022	414,485	$	9.81