STOCK OPTIONS (Tables)

9 Months Ended

Sep. 30, 2022

Stock-based compensation expense was classified in the consolidated statements of operations and comprehensive loss as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021

Research and development expenses	$	141,933	$	986,406	$	465,777	$	2,786,486
General and administrative expenses		1,203,593		1,612,841		3,984,584		4,900,435
Total stock-based compensation	$	1,345,526	$	2,599,247	$	4,450,361	$	7,686,921

The weighted average assumptions used principally in determining the fair value of options granted to employees were as follows:

A summary of option activity for the nine months ended September 30, 2022 and is presented below:


Options	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term in Years		Aggregate Intrinsic Value
Outstanding at December 31, 2021		15,326,105		$	4.06
Granted		5,298,503			0.44
Forfeited		(1,404,071	)		3.97
Expired		(305,432	)		4.34
Outstanding at September 30, 2022		18,915,105		$	3.05		6.89	$	10,981,693
Vested at September 30, 2022		10,619,178		$	4.33		5.33	$	3,055,619
Vested and expected to vest at September 30, 2022		17,740,623		$	3.19		6.75	$	9,640,583