Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of stock-based compensation expense

Stock-based compensation expense is included in the unaudited condensed consolidated statements of operations as follows (in thousands):

	Three Months Ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Research and development	$	471	$	403	$	894	$	791
Selling, general and administrative	1,468		1,585		3,214		3,260
Total	$	1,939	$	1,988	$	4,108	$	4,051

Schedule of stock-based compensation expense by security types

The following table presents total stock-based compensation expense by security type included in the unaudited condensed consolidated statements of operations for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six months ended June 30,
	2020		2019		2020		2019
Stock options	$	575	$	581	$	1,116	$	1,135
RSUs and RSAs	610		386		1,210		847
PSUs	296		316		627		707
PBOs	458		705		1,155		1,362
Total	$	1,939	$	1,988	$	4,108	$	4,051