Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenues	$ 0	$ 0	$ 0	$ 0
Operating expenses:
Research and development	3,715,379	2,371,058	7,243,529	4,248,236
General and administrative	1,267,364	1,206,995	2,707,876	2,597,233
Total operating expenses	4,982,743	3,578,053	9,951,405	6,845,469
Loss from operations	(4,982,743)	(3,578,053)	(9,951,405)	(6,845,469)
Other income (expense):
Change in fair value of debt conversion feature liability	570,676	412,050	848,374	508,597
Amortization of debt discount	(336,656)	(524,977)	(767,883)	(925,634)
Amortization of financing costs	(421,781)		(519,960)
Interest expense, net	(1,130)	(1,813)	(2,660)	(17,275)
Total other income (expense), net	(188,891)	(114,740)	(442,129)	(434,312)
Net loss	(5,171,634)	(3,692,793)	(10,393,534)	(7,279,781)
Other comprehensive gain (loss), net of tax:
Unrealized gain (loss) on securities	1,500	(6,591)	893	584
Comprehensive loss	$ (5,170,134)	$ (3,699,384)	$ (10,392,641)	$ (7,279,197)
Basic and diluted net loss per share	$ (0.21)	$ (0.22)	$ (0.45)	$ (0.56)
Weighted-average shares used to compute basic and diluted net loss per share	24,118,887	17,105,374	23,240,782	13,060,576