CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Revenue	$ 13,369	$ 2,437	$ 45,706	$ 6,565
Operating expenses:
Research and development, net	37,688	45,398	120,770	141,127
General and administrative	12,488	10,860	34,211	30,645
Total operating expenses	50,176	56,258	154,981	171,772
Loss from operations	(36,807)	(53,821)	(109,275)	(165,207)
Gain (loss) from equity-method investment		(250)	(515)	670
Gain from foreign currency	1,862	506	3,237	923
Finance expense, net	(321)	(519)	(1,445)	(1,397)
Net loss	$ (35,266)	$ (54,084)	$ (107,998)	$ (165,011)
Net loss per share, basic	$ (1.33)	$ (2.05)	$ (4.09)	$ (6.27)
Net loss per share, diluted	$ (1.33)	$ (2.05)	$ (4.09)	$ (6.27)
Weighted-average shares outstanding, basic	26,467	26,338	26,423	26,302
Weighted-average shares outstanding, diluted	26,467	26,338	26,423	26,302
Comprehensive loss:
Net loss	$ (35,266)	$ (54,084)	$ (107,998)	$ (165,011)
Comprehensive loss	$ (35,266)	$ (54,084)	$ (107,998)	$ (165,011)