Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue
Contract revenue - related party	$ 1,057,000	$ 0	$ 0
Total revenue	1,057,000	0	0
Expenses:
Research and development	29,092,000	9,944,000	4,362,000
General and administrative	13,934,000	11,396,000	13,579,000
Total expenses	43,026,000	21,340,000	17,941,000
Loss from operations	(41,969,000)	(21,340,000)	(17,941,000)
Other income, net	(57,000)	(27,000)	(6,000)
Net loss	(41,912,000)	(21,313,000)	(17,935,000)
Convertible preferred stock dividends earned	0	0	(801,000)
Net loss attributable to common shareholders	$ (41,912,000)	$ (21,313,000)	$ (18,736,000)
Basic and diluted net loss per share (usd per share)	$ (2.68)	$ (2.00)	$ (12.16)
Shares used in computing basic and diluted net loss per share	15,651	10,667	1,540