Consolidated Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenue	$ 143,000	$ 103,000	$ 347,000	$ 308,000
Operating expenses
Research and development	728,000	1,793,000	2,777,000	4,692,000
General and administrative	1,554,000	1,701,000	4,568,000	5,289,000
Severance expense	289,000	1,840,000	289,000	1,840,000
Total operating expenses	2,571,000	5,334,000	7,634,000	11,821,000
Loss from operations	(2,428,000)	(5,231,000)	(7,287,000)	(11,513,000)
Other income (expense)
Change in fair value of warrant liability	693,000	7,079,000	607,000	9,245,000
Change in fair value of Preferred B stock derivative liability	7,045,000	19,359,000	8,697,000	26,041,000
Other income	129,000
Other expense			(302,000)
Total other income	7,867,000	26,438,000	9,002,000	35,286,000
Net income	5,439,000	21,207,000	1,715,000	23,773,000
Accretion of Series B redeemable convertible preferred stock	(7,163,000)	(323,000)	(9,329,000)	(955,000)
Net (loss) income attributable to common stockholders	$ (1,724,000)	$ 20,884,000	$ (7,614,000)	$ 22,818,000
Per share information:
Net (loss) income per share of common stock - basic	$ (0.30)	$ 5.58	$ (1.45)	$ 6.19
Weighted average number of shares of common stock outstanding - basic	5,813,063	3,743,182	5,247,508	3,688,903
Net (loss) income per share of common stock - diluted	$ (0.30)	$ 3.30	$ (1.45)	$ 3.53
Weighted average number of shares of common stock outstanding - diluted	5,813,063	6,319,802	5,247,508	6,472,093