Condensed consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating expenses
Research and development	$ 9,235	$ 3,619	$ 14,116	$ 8,186
General and administrative	1,830	1,173	3,783	2,646
Total operating expenses	11,065	4,792	17,899	10,832
Other income (expenses) (Note 6)	164	42	287	(330)
Net loss before income taxes	(10,901)	(4,750)	(17,612)	(11,162)
Net loss	$ (10,901)	$ (4,750)	$ (17,612)	$ (11,162)
Net loss per common stock - basic and diluted (Note 7)	$ (0.63)	$ (0.44)	$ (1.02)	$ (1.04)
Basic and diluted weighted average number of common stock outstanding	17,212,007	10,723,584	17,211,997	10,717,808
Comprehensive loss:
Net loss	$ (10,901)	$ (4,750)	$ (17,612)	$ (11,162)
Other comprehensive income - unrealized gain on available-for-sale securities	119	1	362	8
Comprehensive loss	$ (10,782)	$ (4,749)	$ (17,250)	$ (11,154)