Stock Option Plans (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Stock Options

Stock option activity for employees and non-employees under the Equity Compensation Plans for the six months ended June 30, 2022 was as follows:

	Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)		Aggregate Intrinsic Value
Outstanding options, December 31, 2021		5,107,672		$	2.44		5.78	$	28,948,535
Granted		528,711		$	2.84
Forfeited		(256,475	)	$	4.81
Exercised		(90,264	)	$	0.85
Outstanding options, June 30, 2022		5,289,644		$	2.64		4.88	$	2,146,863
Options vested and exercisable, June 30, 2022		3,950,063		$	1.34		3.69	$	2,146,863

Summary of Assumptions Used to Calculate Estimated Fair Value of Stock Options

The estimated fair value of stock options granted to employees and consultants during the three and six months ended June 30, 2022 and 2021, were calculated using the Black-Scholes option-pricing model using the following assumptions:

	Three Months Ended June 30,						Six Months Ended June 30,
	2022			2021			2022			2021
Expected volatility	85.4		%	75.9 - 104.3		%	78.0 - 85.4		%	75.9 - 104.3		%
Weighted-average volatility		85.4	%		96.7	%		79.0	%		98.1	%
Expected dividends	—		%	—		%	—		%	—		%
Expected term (in years)	5.89			6.25			5.50 - 6.08			6.25
Risk-free rate	3.03		%	0.14 - 0.59		%	1.38 - 3.03		%	0.14 - 0.59		%

Summary of Restricted Stock

Stock award activity for employees and non-employees under the Equity Compensation Plans for the six months ended June 30, 2022 was as follows:

	Number of shares		Weighted Average Grant Date Fair Value
Unvested as of December 31, 2021		—	$	—
Granted		300,000	$	1.89
Vested		—	$	—
Forfeited		—	$	—
Unvested as of June 30, 2022		300,000	$	1.89

Schedule of Stock-based Compensation Expense

Stock-based compensation expense for the three and six months ended June 30, 2022 and 2021 was as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	149,814	$	303,461	$	518,039	$	514,404
General and administrative		420,047		129,970		949,422		268,142
Total	$	569,861	$	433,431	$	1,467,461	$	782,546