Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating expenses:
Research and development	$ 11,769	$ 8,905	$ 22,524	$ 20,886
General and administrative	15,133	5,215	28,158	9,907
Total operating expenses	26,902	14,120	50,682	30,793
Loss from operations	(26,902)	(14,120)	(50,682)	(30,793)
Other income (expense):
Interest income	797	295	1,355	631
Interest expense	(2,887)	(202)	(3,520)	(478)
Other income (expense), net	112	(158)	83	(360)
Total other income (expense)	(1,978)	(65)	(2,082)	(207)
Net loss	$ (28,880)	$ (14,185)	$ (52,764)	$ (31,000)
Net loss per share basic and diluted	$ (0.91)	$ (0.63)	$ (1.66)	$ (1.40)
Weighted average common shares outstanding, basic and diluted	31,826	22,666	31,765	22,115
Other comprehensive (loss) income:
Unrealized (loss) from available-for-sale securities, net of tax of $0	$ (17)	$ (18)	$ (6)	$ (108)
Total other comprehensive (loss) income	(17)	(18)	(6)	(108)
Comprehensive loss	$ (28,897)	$ (14,203)	$ (52,770)	$ (31,108)