Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating expenses:
Research and development	$ 7,137,493	$ 6,951,600
General and administrative	4,093,189	3,592,825
Total operating expenses	11,230,682	10,544,425
Loss from operations	(11,230,682)	(10,544,425)
Other income (expense):
Interest income (expense), net	6,519	(268,029)
Financing costs related to warrant liability		(533,692)
Change in fair value of warrant liability	(1,005,349)	597,615
Total other expense, net	(998,830)	(204,106)
Net loss	$ (12,229,512)	$ (10,748,531)
Net loss per share of common stock, basic	$ (0.82)	$ (1.15)
Net loss per share of common stock, diluted	$ (0.90)	$ (1.15)
Weighted-average shares used to compute basic net loss per share	14,897,885	9,338,068
Weighted-average shares used to compute diluted net loss per share	14,951,036	9,338,068