STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Expenses:
Research and development	$ 8,690	$ 4,150
General and administrative	3,230	1,229
Loss from operations	(11,920)	(5,379)
Change in fair value of warrant liability	1,192	153
Interest income	12	47
Interest expense	(117)	(91)
Net loss	(10,833)	(5,270)
Cumulative preferred stock dividends	(2,545)	(3,804)
Net loss applicable to common stockholders	$ (13,378)	$ (9,074)
Per share information:
Net loss per share of common stock-basic and diluted (in dollars per share)	$ (2.17)	$ (19.60)
Basic and diluted weighted average shares outstanding (in shares)	6,152,669	462,972