Condensed Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended		86 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014
Operating expenses:
Research and development	$ 1,852,116	$ 110,981	$ 18,800,625
General and administrative	1,070,479	221,049	6,019,860
Purchase of in-process research and development			650,000
Total operating expenses	2,922,595	332,030	25,470,485
Loss from operations	(2,922,595)	(332,030)	(25,470,485)
Other income (expense):
Interest income	4,055	1,353	225,155
Interest expense	(36,944)	(39,315)	(402,771)
Change in fair value of preferred stock purchase right			(188,587)
Change in fair value of warrant liability		(124,000)	(54,264)
Grant income			244,000
Total other income (expense)	(32,889)	(161,962)	(176,467)
Net loss and comprehensive loss	$ (2,955,484)	$ (493,992)	$ (25,646,952)
Net loss per common share, basic and diluted	$ (0.49)	$ (0.44)
Weighted-average shares used to compute basic and diluted net loss per share	6,002,936	1,133,375