Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Summary of Share-based Compensation Expense

Share-based compensation expense for options granted under the 2011 Plan and the 2016 Plan is reflected in the statements of operations as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Research and development	$	290	$	243	$	881	$	1,066
General and administrative		384		543		1,176		2,166
Total	$	674	$	786	$	2,057	$	3,232

Stock Options

Summary of Activity Related to Stock Options

The following table summarizes the activity related to stock options during the nine months ended September 30, 2020:

				Weighted
	Number of			Average
	Shares			Exercise Price
Options outstanding at December 31, 2019		4,104,450		$	4.63
Granted		1,100,250			2.31
Exercised		(253,216	)		0.89
Forfeited		(702,041	)		6.49
Options outstanding at September 30, 2020		4,249,443			3.95
Options exercisable at December 31, 2019		2,452,764			5.44
Options exercisable at September 30, 2020		2,225,536			4.97

Restricted Stock Units (RSUs)

Summary of the Activity Related to RSUs

The following table summarizes the activity related to RSUs during the nine months ended September 30, 2020:

				Weighted Average
	Number of			Grant Date
	Shares			Fair Value
Non-vested RSUs outstanding at December 31, 2019		1,269,300		$	0.87
Granted		486,000			2.39
Vested		(887,575	)		0.93
Forfeited		(6,700	)		0.91
Non-vested RSUs outstanding at September 30, 2020		861,025			1.67