Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating expenses:
Research and development	$ 8,008	$ 6,636
General and administrative	3,146	3,977
Total operating expenses	11,154	10,613
Loss from operations	(11,154)	(10,613)
Other income	96	83
Loss before provision for income taxes	(11,058)	(10,530)
Provision for income taxes	34	8
Net loss	$ (11,092)	$ (10,538)
Net loss per common share, basic and diluted	$ (0.26)	$ (0.35)
Weighted-average shares used in computing net loss per common share, basic and diluted	42,596,980	30,070,227