CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating expenses:
Research and development	$ 5,139	$ 5,496	$ 9,285	$ 12,020
General and administrative	2,537	1,839	5,040	4,162
Total operating expenses	7,676	7,335	14,325	16,182
Loss from operations	(7,676)	(7,335)	(14,325)	(16,182)
Other expense	(1)	(14)	(32)	(22)
Interest income	21	463	245	953
Interest expense	(639)	(369)	(1,275)	(723)
Net loss and comprehensive loss	$ (8,295)	$ (7,255)	$ (15,387)	$ (15,974)
Net loss per share — basic and diluted	$ (0.36)	$ (0.39)	$ (0.71)	$ (0.86)
Weighted average common shares outstanding — basic and diluted	23,355,418	18,580,430	21,786,946	18,578,091