Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating expenses:
General and administrative	$ 24,522,902	$ 11,079,512	$ 1,869,899
Research and development	58,891,667	27,493,460	13,550,422
Total operating expenses	83,414,569	38,572,972	15,420,321
Loss from operations	(83,414,569)	(38,572,972)	(15,420,321)
Other income		84,558
Interest income (expense)	402,765	14,570	(131,527)
Loss from continuing operations, before income taxes	(83,011,804)	(38,473,844)	(15,551,848)
Loss from continuing operations	(83,011,804)	(38,473,844)	(15,551,848)
Loss from discontinued operations, net of tax			(8,729)
Loss from sale of discontinued operations, net of tax			(145,199)
Net loss	(83,011,804)	(38,473,844)	(15,705,776)
Comprehensive loss	$ (83,011,804)	$ (38,473,844)	$ (15,705,776)
Basic and diluted net loss per common share from continuing operations (Note 11)	$ (3.67)	$ (5.43)	$ (2.37)
Basic and diluted net loss per common share from discontinued operations (Note 11)			(0.02)
Basic and diluted net loss per common share (Note 11) (in dollars per share)	$ (3.67)	$ (5.43)	$ (2.39)
Weighted-average basic and diluted common shares outstanding (in shares)	22,647,583	7,087,618	6,916,404