Stockholders' (Deficit) Equity (Tables)

3 Months Ended

Mar. 31, 2022

Equity [Abstract]

Summary of Option Activity under 2018 Plan, 2013 Plan and 2010 Plan

A summary of option activity under the 2018 Plan, 2013 Plan, and 2010 Plan for the three months ended March 31, 2022, is as follows:

Year-to-Date Activity	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in Millions)
Options outstanding at December 31, 2021		1,954,975		$	8.16		7.8
Granted		853,000		$	2.33
Cancelled/forfeited		(11,875	)	$	3.76
Options outstanding at March 31, 2022		2,796,100		$	6.40		8.2	$	0.6
Options exercisable at March 31, 2022		1,285,645		$	9.72		6.8	$	—

Summary of Stock-Based Compensation Expense

The fair value of shares vested during the three months ending March 31, 2022 and 2021 was $1.2 million and $0.8 million, respectively. The amount of stock-based compensation expense recorded to research and development expenses and to general and administrative expenses is detailed in table below:

	Three Months Ended March 31,
	2022		2021
Stock-based compensation
Research and development	$	140,440	$	168,045
General and administrative		333,657		391,391
Total stock-based compensation expense	$	474,097	$	559,436

Summary of Warrants Issued

	Three Months Ended March 31,
	2022				2021
	Number		Weighted Average Exercise Price		Number		Weighted Average Exercise Price
Granted during the period		150,000	$	2.46		—	$	—
Outstanding at end of the period		150,000	$	2.46		—	$	—
Exercisable at end of the period		150,000	$	2.46
Weighted average remaining life	7.0 years					—