Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
License and milestone fees		$ 530
Collaborative revenue		313
Clinical compound revenue		68
Total revenue		911
Operating expenses:
Research and development	$ 13,427	20,836
General and administrative	3,697	2,400
Total operating expenses	17,124	23,236
Operating loss	(17,124)	(22,325)
Other income	311	90
Loss before benefit from income taxes	(16,813)	(22,235)
Benefit from income taxes	46	31
Net loss	$ (16,767)	$ (22,204)
Net loss per share:
Basic and Diluted	$ (0.51)	$ (0.81)
Weighted average shares:
Basic and Diluted	32,681,661	27,299,678
Other comprehensive income (loss), net of tax of $0:
Change in unrealized gains (losses) on available-for-sale marketable securities	$ (44)	$ 21
Total comprehensive loss	$ (16,811)	$ (22,183)