Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Stock-Based Compensation

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:

	For the Year Ended December 31,
	2021		2020
Expected volatility	109.6	%	102.4	%
Expected term (years)	6.0		5.9
Risk-free interest rate	0.8	%	1.2	%
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:

				Weighted-Average
		Weighted-		Remaining
	Number of	Average		Contractual Term	Aggregate Intrinsic
	Stock Options	Exercise Price		(Years)	Value
Outstanding, December 31, 2020	1,626,752	$	4.58	5.9	$	12,234,740
Granted	1,225,700	$	14.34
Exercised	(54,068)	$	3.26
Forfeited or expired	(214,941)	$	11.93
Outstanding, December 31, 2021	2,583,443	$	8.63	5.9	$	8,460,273
Exercisable, December 31, 2021	1,097,101	$	5.66	5.8	$	5,570,354
Vested and expected to vest, December 31, 2021	1,334,735	$	10.81	6.0	$	2,889,919

Summary of Restricted Stock Activity

A summary of restricted stock activities is presented below:

		Weighted-
		average
		Grant Date
	Shares	Fair Value
Unvested, December 31, 2020	169,726	$	4.54
Granted	246,279		14.76
Vested	(85,413)		4.18
Forfeited or expired	(24,664)		16.71
Unvested, December 31, 2021	305,928	$	11.89

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, 2021 and 2020 as follows:

	Year Ended December 31,
	2021		2020
Research and development	$	1,655,982	$	357,762
General and administrative		3,862,908		2,218,244
Total	$	5,518,890	$	2,576,006