Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Grant revenue			$ 1,000	$ 1,022
Operating expenses:
Research and development	$ 4,161	$ 6,011	12,725	19,782
General and administrative	1,631	1,384	4,853	4,638
Total operating expenses	5,792	7,395	17,578	24,420
Loss from operations	(5,792)	(7,395)	(16,578)	(23,398)
Other income (expense):
Interest income, net	6	90	77	275
Share of loss from equity method investment		(282)	(9)	(910)
Net loss	$ (5,786)	$ (7,587)	$ (16,510)	$ (24,033)
Weighted-average common shares outstanding used in computing net loss, basic and diluted	8,923,374	8,694,104	8,922,052	8,304,510
Net loss per share, basic and diluted	$ (0.65)	$ (0.87)	$ (1.85)	$ (2.89)