STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Licensing revenue	$ 100,000	$ 300,000	$ 100,000
Expenses:
Research and development	36,677,706	17,500,469	12,684,793
General and administrative	12,845,231	10,273,576	8,353,330
Depreciation and amortization	182,927	120,399	113,936
Total expenses	49,705,864	27,894,444	21,152,059
Loss before other income (loss)	(49,605,864)	(27,594,444)	(21,052,059)
Other income (loss):
Interest income	305,331	137,676	131,666
Other income, net	132,114	183,025	191,416
(Gain) loss on warrant liability	19,051,239	(20,210,094)	2,766,704
Loss before provision for income taxes	(30,117,180)	(47,483,837)	(17,962,273)
Income tax expense	(800)	(1,600)	(1,600)
Net loss	$ (30,117,980)	$ (47,485,437)	$ (17,963,873)
Basic and diluted loss per share	$ (0.55)	$ (1.44)	$ (0.78)
Basic weighted average shares outstanding (in shares)	54,371,151	32,891,202	22,973,905
Diluted weighted average shares outstanding (in shares)	54,371,151	32,891,202	22,973,905