CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenue from collaboration and licensing	$ 11,942	$ 7,629
Operating expenses:
Research and development	(46,312)	(21,965)	$ (9,772)
General and administrative	(16,715)	(6,844)	(4,385)
Total operating expenses	(63,027)	(28,809)	(14,157)
Loss from operations	(51,085)	(21,180)	(14,157)
Other income (expense):
Grant income	6,737	5,612	2,069
Interest income	1,587	0
Interest expense	(877)	(778)	(606)
Other income and expenses, net	601	133	(25)
Total other income, net	8,048	4,967	1,438
Net loss before tax	(43,037)	(16,213)	(12,719)
Income tax expense	0	(24)	(4)
Net loss	(43,037)	(16,237)	(12,723)
Other comprehensive loss:
Foreign currency translation gain (loss), net of tax	(933)	(2,358)	1,764
Comprehensive loss	$ (43,970)	$ (18,595)	$ (10,959)
Net loss per share—basic and diluted	$ (2.41)	$ (17.76)	$ (13.95)
Weighted average common shares outstanding — basic and diluted	17,859,935	914,375	911,777