Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating expenses:
Research and development	$ 2,848	$ 1,980
General and administrative	1,122	1,372
Total operating expenses	3,970	3,352
Loss from operations	(3,970)	(3,352)
Interest income	14	28
Other expense	(2)	(1)
Net loss and comprehensive loss	$ (3,958)	$ (3,325)
Basic and diluted net loss per share attributable to common stock	$ (0.15)	$ (0.13)
Weighted-average number of common shares outstanding	26,545	26,545