Condensed Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating expenses:
Research and development	$ 1,669	$ 1,387
General and administrative	1,108	1,241
Total operating expenses	2,777	2,628
Loss from operations	(2,777)	(2,628)
Investment income	3	1
Other (expense) income, net	2	(3)
Net loss and comprehensive loss	$ (2,772)	$ (2,630)
Basic and diluted net loss per share attributable to common stock	$ (0.13)	$ (0.29)
Weighted-average number of common shares outstanding	21,095	9,054