Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue
Total revenue	$ 4,753	$ 1,371
Type of Revenue [Extensible List]	us-gaap:GrantMember	us-gaap:GrantMember
Operating expenses
Research and development	$ 12,836	$ 11,075
Write-off of acquired in-process research and development		38,313
General and administrative	13,691	27,395
Total operating expenses	26,527	76,783
Loss from operations	(21,774)	(75,412)
Interest income	1,022	989
Interest expense		(2,429)
Other income (expense), net	2,534	519
Net loss	$ (18,218)	$ (76,333)
Net loss per share- basic and diluted	$ (1.57)	$ (10.64)
Weighted-average common shares used to compute net loss per share- basic and diluted	11,589	7,171