Condensed consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating expenses
Research and development	$ 6,134	$ 3,687	$ 20,250	$ 11,873
General and administrative	2,149	1,230	5,932	3,874
Total operating expenses	8,283	4,917	26,182	15,747
Other income (expenses) (Note 6)	137	(118)	424	(450)
Net loss before income taxes	(8,146)	(5,035)	(25,758)	(16,197)
Net loss	$ (8,146)	$ (5,035)	$ (25,758)	$ (16,197)
Net loss per common stock - basic and diluted (Note 7)	$ (0.46)	$ (0.43)	$ (1.48)	$ (1.46)
Basic and diluted weighted average number of common stock outstanding	17,690,362	11,841,147	17,372,616	11,096,369
Comprehensive loss:
Net loss	$ (8,146)	$ (5,035)	$ (25,758)	$ (16,197)
Other comprehensive (loss) income - unrealized (loss) gain on available-for-sale securities	(80)	(1)	282	7
Comprehensive loss	$ (8,226)	$ (5,036)	$ (25,476)	$ (16,190)