Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Consolidated Statements of Operations
Revenues	$ 250		$ 250
Operating expenses:
Research and development	4,776	$ 5,936	14,693	$ 19,190
General and administrative	2,426	2,347	7,189	7,695
Total operating expenses	7,202	8,283	21,882	26,885
Loss from operations	(6,952)	(8,283)	(21,632)	(26,885)
Other (expense) income:
Interest expense	(105)	(199)	(381)	(662)
Interest and investment income	45	50	128	183
Other (expense) income, net	(5)	13	18	82
Total other expense, net	(65)	(136)	(235)	(397)
Net loss	$ (7,017)	$ (8,419)	$ (21,867)	$ (27,282)
Net loss per share - basic and diluted (in dollars per share)	$ (0.31)	$ (0.54)	$ (1.03)	$ (1.77)
Weighted-average common shares outstanding used in net loss per share - basic and diluted (in shares)	22,563,174	15,512,608	21,163,591	15,407,747