Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Collaboration and license revenue	$ 9,546	$ 8,230
Total revenue	9,546	8,230
Operating expenses:
Research and development	14,742	9,970
General and administrative	4,660	4,573
Total operating expenses	19,402	14,543
Loss from operations	(9,856)	(6,313)
Other income (expense):
Interest income	613	317
Interest expense	(174)
Total other income, net	439	317
Net loss	$ (9,417)	$ (5,996)
Basic and diluted net loss per common share	$ (0.19)	$ (0.12)
Shares used to compute basic and diluted net loss per common share	48,853	48,115