Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating expenses:
Research and development	$ 2,832	$ 2,075	$ 8,699	$ 6,429
General and administrative	708	1,187	2,707	3,855
Total operating expenses	3,540	3,262	11,406	10,284
Loss from operations	(3,540)	(3,262)	(11,406)	(10,284)
Interest income	7	26	33	84
Other expense	(3)		(5)	(1)
Net loss and comprehensive loss	$ (3,536)	$ (3,236)	$ (11,378)	$ (10,201)
Basic and diluted net loss per share attributable to common stock	$ (0.13)	$ (0.12)	$ (0.43)	$ (0.38)
Weighted-average number of common shares outstanding	26,545	26,545	26,545	26,545