Equity (Tables)

6 Months Ended

Jun. 30, 2021

Equity Method Investments and Joint Ventures [Abstract]

Summary of warrants outstanding

	Shares of Common Stock Issuable from Warrants Outstanding as of				Weighted
	June 30,		December 31,		Average
Description	2021		2020		Exercise Price		Expiration
Series E		584,416		584,416	$	1.54	September 9, 2021
Series F		7,246		7,246	$	3.45	February 23, 2022 & March 9, 2022
Series G		460,250		460,250	$	2.68	July 21, 2022
Series H		910,000		910,000	$	2.75	October 16, 2022
Series I		10,335,000		10,335,000	$	2.00	November 26, 2025
Total		12,296,912		12,296,912

Summary of stock option activity

	Number of Options			Weighted Average Exercise Price ($)		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value ($)
Outstanding at December 31, 2020		5,895,570			2.45		5.14		3,376,267
Forfeited		(2,805,571	)		2.74
Outstanding at June 30, 2021		3,089,999			2.18		4.96		4,177,775
Vested and exercisable at June 30, 2021		2,427,499			1.90		4.93		3,972,400

Summary of assumption of stock option activity

	Six Months Ended
	June 30, 2020
Risk-free interest rate	0.034%	-	1.67%
Expected term in years	3.25	–	4.98
Weighted Avg. Expected Volatility	105.71%	–	106.88%
Expected dividend yield		0%

The risk-free interest rate assumption is based upon observed interest rates on zero coupon U.S. Treasury bonds whose maturity period is appropriate for the expected term. Estimated volatility is a measure of the amount by which the stock price is expected to fluctuate each year during the term of an award. Our calculation of estimated volatility is based on historical stock prices over a period equal to the term of the awards. The average expected life is based on the contractual terms of the stock option using the simplified method. We utilize a dividend yield of zero based on the fact that we have never paid cash dividends and have no current intention to pay cash dividends. Future stock-based compensation may significantly differ based on changes in the fair value of our Common Stock and our estimates of expected volatility and the other relevant assumptions.

Summary of consolidated statement of operations

	Three Months Ended June 30,					Six Months Ended June 30
	2021			2020		2021			2020
Research and development	$	228,625		$	631,876	$	507,438		$	631,876
General and administrative		(29,026	)		954,646		(1,182,601	)		1,420,409
Total	$	(199,599	)	$	1,586,522	$	(675,163	)	$	2,052,285