Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Stock-Based Compensation Expense Related to Stock Options

The Company’s stock-based compensation expense related to stock options was recognized in operating expense as follows:

	Three Months Ended June 30,					Six Months Ended June 30,
	2020			2019		2020		2019
	(unaudited)					(unaudited)
Stock-Based Compensation
Research and development	$	53,842		$	9,387	$	106,526	$	450,087
General and administrative		(7,728	)		9,193		64,580		2,323,364
Total	$	46,113		$	18,580	$	171,106	$	2,773,451

Assumptions Used to Value Stock Options Granted

The fair value of options granted during the three and six months ended June 30, 2020 and the three and six months ended June 30, 2019 was estimated using the Black-Scholes option valuation model utilizing the following assumptions.

	Three Months Ended June 30,						Six Months Ended June 30,
	2020			2019			2020			2019
	Weighted Average			Weighted Average			Weighted Average			Weighted Average
	(unaudited)						(unaudited)
Volatility		97.13	%		94.43	%		97.00	%		88.87	%
Risk-Free Interest Rate		0.34	%		2.19	%		0.38	%		2.34	%
Expected Term in Years		6.07			6.08			6.07			6.17
Dividend Rate		0.00	%		0.00	%		0.00	%		0.00	%
Fair Value of Option on Grant Date	$	1.11		$	4.77		$	1.10		$	5.31

Stock Option Activity

The following table summarizes the number of options outstanding and the weighted average exercise price:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value
Options outstanding at December 31, 2019		1,421,797		$	15.95
Granted		319,907			1.43
Exercised		–			–
Forfeited		(84,227	)		41.34
Expired		(17,724	)		4.69
Options outstanding at June 30, 2020		1,639,753		$	11.94		7.17	$	184,693
Vested and expected to vest at June 30, 2020		1,639,753		$	11.94		7.17	$	184,693
Exercisable at June 30, 2020		1,047,284		$	16.73		5.84	$	–