Stock-Based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Stock-Based Compensation Expense

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

	Year Ended December 31,
	2021		2020
Research and development	$	508	$	229
General and administrative		2,262		1,584
Total	$	2,770	$	1,813

Schedule of Fair Value of Stock Option Estimated on Date of Grant Using Black-Scholes Option-Pricing Model

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, with the following weighted-average assumptions:

	Year Ended December 31,
	2021			2020
Risk-free interest rate		0.7	%		0.6	%
Expected dividend yield		—	%		—	%
Expected term (in years)		6.0			6.0
Expected volatility		85.0	%		80.7	%

Summary of Stock Option Activity Under Plans

A summary of the stock option activity under the Plans for the year ended December 31, 2021 was as follows:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding December 31, 2020		1,428,886		$	10.41		7.7	$	5,165
Granted		428,500			9.72
Exercised		(72,201	)		8.36
Cancelled		(122,324	)		10.14
Outstanding at December 31, 2021		1,662,861		$	10.34		7.6	$	918
Exercisable at December 31, 2021		856,363		$	9.85		6.7	$	732
Vested and expected to vest at December 31, 2021		1,662,861		$	10.34		7.6	$	918