CONDENSED STATEMENTS OF OPERATIONS (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
License revenue	$ 0	$ 100,000	$ 0	$ 100,000
Expenses:
Research and development	6,167,074	12,452,340	12,934,058	20,604,559
General and administrative	3,137,008	6,128,904	6,116,063	10,087,340
Total expenses	9,304,082	18,581,244	19,050,121	30,691,899
Loss before other income (loss)	(9,304,082)	(18,481,244)	(19,050,121)	(30,591,899)
Other income (loss):
Interest income	90,849	65,436	151,392	127,174
Interest expense	(848,395)	(741,346)	(2,171,110)	(1,158,148)
Other income (loss), net	7,276	(798)	3,504	6,081
Gain (loss) on warrant derivative liabilities	(4,303,945)	877,729	(4,336,066)	693,457
Net loss	$ (14,358,297)	$ (18,280,223)	$ (25,402,401)	$ (30,923,335)
Basic and diluted net loss per share (in dollars per share)	$ (0.10)	$ (0.27)	$ (0.20)	$ (0.46)
Basic and diluted weighted-average shares outstanding (in shares)	139,070,329	67,398,837	126,394,244	66,893,846