Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
License and milestone fees			$ 530
Collaborative revenue			313
Clinical compound revenue		$ 79	68	$ 86
Total revenue		79	911	86
Operating expenses:
Research and development	$ 6,961	10,760	27,797	19,305
General and administrative	2,672	2,645	5,072	5,092
Total operating expenses	9,633	13,405	32,869	24,397
Operating loss	(9,633)	(13,326)	(31,958)	(24,311)
Other income	331	172	421	321
Loss before benefit from income taxes	(9,302)	(13,154)	(31,537)	(23,990)
Benefit from income taxes	2	79	33	224
Net loss	$ (9,300)	$ (13,075)	$ (31,504)	$ (23,766)
Net loss per share -Basic and Diluted	$ (0.29)	$ (0.48)	$ (1.06)	$ (0.87)
Weighted average shares:
Basic and Diluted	32,239,877	27,282,863	29,783,424	27,271,226
Other comprehensive income, net of tax of $0:
Unrealized gains (losses) on available-for-sale marketable securities	$ (37)	$ 37	$ (16)	$ 76
Total comprehensive loss	$ (9,337)	$ (13,038)	$ (31,520)	$ (23,690)