Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating expenses:
Research and development	$ 4,197	$ 5,247
General and administrative	2,137	2,392
Total operating expenses	6,334	7,639
Loss from operations	(6,334)	(7,639)
Other income (expense):
Interest expense		(57)
Interest and investment income	226	32
Other income, net	70	12
Total other income (expense), net	296	(13)
Net loss	$ (6,038)	$ (7,652)
Net loss per share - basic and diluted (in dollars per share)	$ (0.62)	$ (2.88)
Weighted-average common shares outstanding used in net loss per share - basic and diluted (in shares)	9,686,224	2,655,584