Stock-Based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense included in the Company’s condensed consolidated statements of operations and comprehensive loss was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	229	$	165	$	665	$	453
General and administrative		1,510		568		3,025		1,535
Total	$	1,739	$	733	$	3,690	$	1,988

Schedule of Unrecognized Stock-Based Compensation

The following table summarizes the Company’s unrecognized stock-based compensation as of September 30, 2022:

	As of September 30, 2022
	Unrecognized Expense (in thousands)		Period of Recognition (years)
Restricted stock units	$	143		3.3
Stock options		11,198		2.3
Total	$	11,341

Schedule of Fair Value of Stock Option Estimated on Date of Grant Using Black-Scholes Option-Pricing Model or Monte Carlo Simulation in Case of Executive Options

The fair value of each stock option granted to employees, directors and non-employees was estimated on the date of grant using the Black-Scholes option-pricing model, or a Monte Carlo simulation in the case of the Executive Options, with the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Risk-free interest rate		3.2	%		0.9	%		2.6	%		0.7	%
Expected dividend yield		—	%		—	%		—	%		—	%
Expected term (in years)		6.1			6.1			3.7			6.0
Expected volatility		85.2	%		84.2	%		81.4	%		85.0	%

Summary of Restricted Stock Unit Activity

A summary of the restricted stock unit activity under the Plans for the nine months ended September 30, 2022 was as follows:

	Shares			Weighted- Average Grant Date Fair Value
Restricted stock units outstanding as of December 31, 2021		—		$	—
Granted		45,483		$	4.79
Vested		(1,953	)	$	4.89
Forfeited		(8,112	)	$	4.78
Restricted stock units outstanding as of September 30, 2022		35,418		$	4.78

Summary of Stock Option Activity Under Plans

A summary of the stock option activity under the Plans for the nine months ended September 30, 2022 was as follows:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding December 31, 2021		1,662,861		$	10.34		7.6	$	918
Granted		2,765,174			5.21
Exercised		(2,718	)		2.76
Cancelled		(89,053	)		7.29
Outstanding at September 30, 2022		4,336,264		$	7.14		8.5	$	1,917
Exercisable at September 30, 2022		1,245,916		$	9.73		6.7	$	1,102
Vested and expected to vest at September 30, 2022		4,336,264		$	7.14		8.5	$	1,917