Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Operations and Comprehensive Loss
Collaboration revenues	$ 10,390	$ 13,801	$ 7,136
Operating expenses:
Research and development	33,149	25,540	20,761
General and administrative	29,201	14,560	8,121
Total operating expenses	62,350	40,100	28,882
Loss from operations	(51,960)	(26,299)	(21,746)
Other income (expense):
Interest income	683	814	169
Interest expense	(457)
Other expense, net		(5,377)	(665)
Total other income (expense), net	226	(4,563)	(496)
Net loss before income tax provision	(51,734)	(30,862)	(22,242)
(Benefit from) provision for income taxes	(724)	(254)	(396)
Net loss	(51,010)	(30,608)	(21,846)
Net loss attributable to ordinary shareholders	$ (51,010)	$ (30,608)	$ (21,846)
Net loss per share attributable to ordinary shareholders, basic and diluted	$ (2.66)	$ (2.77)	$ (49.78)
Weighted average ordinary shares outstanding, basic and diluted	19,145,938	11,045,370	438,862
Comprehensives Loss:
Net loss	$ (51,010)	$ (30,608)	$ (21,846)
Other comprehensive income (loss):
Foreign currency translation adjustment	(1,658)	216	(1,820)
Total comprehensive loss	$ (52,668)	$ (30,392)	$ (23,666)