Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of allocation of total stock-based compensation expense

The following table reflects stock-based compensation expense recognized for the three and six months ended June 30, 2017 and 2016 (in thousands):

	Three Months Ended  June 30,				Six Months Ended  June 30,
	2017		2016		2017		2016
Research and development:
Employees	$	849	$	691	$	1,624	$	1,276
Non-employee consultants	46		40		92		122
General and administrative:
Employees	2,870		1,877		4,921		3,710
Non-employee consultants	—		23		12		76
Total expense	$	3,765	$	2,631	$	6,649	$	5,184