Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

Stock-Based Compensation

Summary of Stock-Based Compensation Expense Recognized

The following table presents stock-based compensation expense recognized for stock options, restricted stock units, or RSUs, performance-based restricted stock units, or PRSUs, and the Company’s employee stock purchase program, or ESPP, in the Company’s statements of operations (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Research and development	$	983	$	1,414	$	1,890	$	2,445
General and administrative		1,620		1,376		3,138		2,454
Total	$	2,603	$	2,790	$	5,028	$	4,899