Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Grant	$ 1,479	$ 1,373	$ 2,462	$ 2,232
Operating expenses:
Research and development	5,835	4,420	10,784	8,017
General and administrative	2,364	2,448	4,729	4,277
Total operating expenses	8,199	6,868	15,513	12,294
Loss from operations	(6,720)	(5,495)	(13,051)	(10,062)
Other income (expense):
Interest income	100	74	195	100
Other expense, net	(12)	(9)	(23)	(15)
Total other income	88	65	172	85
Net loss	$ (6,632)	$ (5,430)	$ (12,879)	$ (9,977)
Net loss per share, basic and diluted	$ (0.47)	$ (0.46)	$ (0.94)	$ (1.61)
Weighted-average common shares outstanding, basic and diluted	14,114,101	11,776,058	13,742,029	6,208,379