CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Expenses:
Research and development	$ 3,927	$ 3,573
General and administrative	2,187	1,812
Loss from operations	(6,114)	(5,385)
Interest income	116	40
Interest expense		(84)
Other income (expense)	(1)	(9)
Net loss	$ (5,999)	$ (5,438)
Per share information:
Net loss per share of common stock-basic and diluted (in dollars per share)	$ (0.15)	$ (0.26)
Basic and diluted weighted average shares outstanding (in shares)	40,373,083	20,580,558
Net loss	$ (5,999)	$ (5,438)
Other comprehensive loss:
Unrealized loss on available-for-sale securities	(11)
Total comprehensive loss	$ (6,010)	$ (5,438)