Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
License revenue	$ 38,095	$ 38,095	$ 76,190	$ 76,190
Research and development:
Noncash stock expense associated with in- licensing agreement	0	1,211,250	0	1,211,250
Noncash compensation	1,359,446	3,300,111	2,697,354	5,201,721
Other research and development	9,902,214	2,336,771	18,181,645	4,845,029
Total research and development	11,261,660	6,848,132	20,878,999	11,258,000
General and administrative:
Noncash compensation	4,883,540	4,438,735	8,902,660	6,768,563
Other general and administrative	1,004,475	706,725	2,008,962	1,610,249
Total general and administrative	5,888,015	5,145,460	10,911,622	8,378,812
Total costs and expenses	17,149,675	11,993,592	31,790,621	19,636,812
Operating loss	(17,111,580)	(11,955,497)	(31,714,431)	(19,560,622)
Other (income) expense:
Interest income	(31,551)	(12,727)	(53,683)	(26,201)
Other income	0	0	0	(95,427)
Interest expense	246,526	234,787	484,183	461,127
Change in fair value of notes payable	(223,372)	(191,127)	(464,013)	(366,442)
Total other (income) expense	(8,397)	30,933	(33,513)	(26,943)
Net loss	$ (17,103,183)	$ (11,986,430)	$ (31,680,918)	$ (19,533,679)
Basic and diluted net loss per common share (in dollars per share)	$ (0.38)	$ (0.36)	$ (0.73)	$ (0.62)
Weighted average shares used in computing basic and diluted net loss per common share (in shares)	45,320,637	32,985,130	43,216,385	31,546,060