Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue:
Collaborative revenue		$ 874		$ 1,363
Clinical compound revenue	$ 79		$ 86
Total revenue	79	874	86	1,363
Operating expenses:
Research and development	10,760	4,684	19,305	8,069
General and administrative	2,645	1,922	5,092	3,744
Total operating expenses	13,405	6,606	24,397	11,813
Operating loss	(13,326)	(5,732)	(24,311)	(10,450)
Other income	172	13	321	27
Loss before benefit from income taxes	(13,154)	(5,719)	(23,990)	(10,423)
Benefit from income taxes	79	35	224	50
Net loss	$ (13,075)	$ (5,684)	$ (23,766)	$ (10,373)
Net loss per share -Basic and Diluted	$ (0.48)	$ (0.25)	$ (0.87)	$ (0.45)
Weighted average shares:
Basic and Diluted	27,282,863	22,828,612	27,271,226	22,818,601
Other comprehensive income, net of tax of $0:
Unrealized gains on available-for-sale marketable securities	$ 37		$ 76
Total comprehensive loss	$ (13,038)	$ (5,684)	$ (23,690)	$ (10,373)