Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating expenses:
Research and development	$ 33,014	$ 8,117	$ 644
General and administrative	13,106	4,855	872
Total operating expenses	46,120	12,972	1,516
Loss from operations	(46,120)	(12,972)	(1,516)
Interest expense	(690)	(350)
Other expense, net	(277)
Net loss	$ (47,087)	$ (13,322)	$ (1,516)
Net loss per share, basic and diluted	$ (7.84)	$ (62.19)	$ (7.82)
Weighted-average common shares outstanding, basic and diluted	6,007,027	214,228	193,850