Stockholders' Deficit (Tables)

6 Months Ended

Jun. 30, 2023

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 six months ended June 30, 2023 and 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, 2022		2,794,850		$	6.36		7.4
Granted		630,000		$	1.67
Cancelled/forfeited		(369,594	)	$	4.27
Options outstanding at June 30, 2023		3,055,256		$	5.65		7.4	$	—
Options exercisable at June 30, 2023		1,749,361		$	8.18		6.3	$	—
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		958,000		$	2.33
Cancelled/forfeited		(62,188	)	$	4.12
Options outstanding at June 30, 2022		2,850,787		$	6.29		8.0	$	—
Options exercisable at June 30, 2022		1,322,180		$	9.80		6.6	$	—

Summary of Stock-Based Compensation Expense

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 June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Stock-based compensation
Research and development	$	83,998	$	158,880	$	199,578	$	299,320
General and administrative		175,905		301,897		345,834		635,554
Total stock-based compensation expense	$	259,903	$	460,777	$	545,412	$	934,874

Summary of Warrants Issued

	Six Months Ended June 30,
	2023				2022
	Number		Weighted Average Exercise Price		Number		Weighted Average Exercise Price
Outstanding at beginning of the period		250,000	$	2.08		—	$	—
Granted during the period		750,000		1.46		150,000		2.46
Outstanding at end of the period		1,000,000	$	1.62		150,000	$	2.46
Exercisable at end of the period		1,000,000	$	1.62		150,000	$	2.46
Weighted average remaining life	6.4 years				6.8 years

Warrants issued in March 2023 Offering

	Six Months Ended June 30,
	2023
	Number			Weighted Average Exercise Price
Outstanding at beginning of the period		—		$	—
Granted during the period		3,505,612			0.66
Exercised during the period		(585,306	)		—
Outstanding at end of the period		2,920,306		$	0.79
Exercisable at end of the period		2,920,306		$	0.79
Weighted average remaining life	5.2 years