Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity and Related Information

A summary of the Company’s stock option activity and related information is as follows:

	Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (in thousands)
Balance as of January 1, 2021		832,868		$	6.83		6.9	$	2
Granted		334,088			2.53
Exercised		-			-
Forfeited		(19,499	)		5.83
Balance as of September 30, 2021		1,147,457		$	5.58		7.1	$	5
Exercisable as of September 30, 2021		657,449		$	7.28		5.9	$	3

Grant Date Fair Value of Employee Stock Options Estimated Using Black-Scholes Option-Pricing Model with Weighted-Average Assumptions

The grant date fair value of employee stock options was estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions:

	Nine Months Ended September 30,
	2021			2020
Expected term (in years)		6.0			6.3
Expected volatility		75	%		75	%
Risk-free interest rate		0.7	%		0.9	%
Expected dividend yield		-	%		-	%

Total Stock-Based Compensation Expense Recognized in Condensed Consolidated Statements of Operations and Comprehensive Loss

Total stock-based compensation expense recognized in the condensed consolidated statements of operations and comprehensive loss is as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Research and development	$	45	$	37	$	118	$	96
General and administrative		111		54		270		565
Total stock-based compensation expense	$	156	$	91	$	388	$	661