Stockholders Equity (Tables)

3 Months Ended

Mar. 31, 2020


	Three Months Ended March 31,
	2020		2019
Research and development expense	$	736,030	$	507,822
General and administrative expense		1,086,118		874,621
Total stock-based compensation expense	$	1,822,148	$	1,382,443

A summary of the Company’s stock option activity under the 2003 Plan for the three months ended March 31, 2020 is as follows:


				WEIGHTED-	AGGREGATE
		WEIGHTED-		AVERAGE	INTRINSIC
		AVERAGE		REMAINING	VALUE
	OUTSTANDING	EXERCISE		CONTRACTUAL	(IN
	OPTIONS	PRICE		TERM (YEARS)	THOUSANDS)
Outstanding as of December 31, 2019	382,337	$	1.33	1.3
Options exercised	(116,046)		1.12
Options forfeited	—
Outstanding, Vested and Exercisable as of March 31, 2020	266,291		1.43	1.2	$	228

A summary of the Company’s stock option activity under the 2013 Plan for the three months ended March 31, 2020 is as follows:


				WEIGHTED-	AGGREGATE
		WEIGHTED-		AVERAGE	INTRINSIC
		AVERAGE		REMAINING	VALUE
	OUTSTANDING	EXERCISE		CONTRACTUAL	(IN
	OPTIONS	PRICE		TERM (YEARS)	THOUSANDS)
Outstanding as of December 31, 2019	4,399,606	$	10.43	6.8
Options granted	1,334,700		4.64
Options exercised	—		—
Options forfeited	(26,065)		9.11
Outstanding as of March 31, 2020	5,708,241		9.08	7.3	$	-
Vested or expected to vest as of March 31, 2020	5,708,241		9.08	7.3	$	-
Exercisable as of March 31, 2020	3,032,134		9.44	5.7	$	-

The following is a summary of RSU activity under the 2013 Plan for the three months ended March 31, 2020: