Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues:
Total revenue from sale of therapies	$ 238,735	$ 140,687	$ 4,078
Collaboration revenue	10,693	33,674	32,406
Total revenue	249,428	174,361	36,484
Cost and operating expenses:
Cost of product revenue	(1,037)	(1,089)	0
Research and development expense	(163,545)	(101,921)	(100,248)
Selling, general and administrative expense	(144,495)	(123,059)	(110,823)
Loss from operations	(59,649)	(51,708)	(174,587)
Other (expense) income:
Interest income	17,986	3,756	65
Interest expense	(5,154)	(5,409)	(5,573)
Foreign currency (loss) gain	(13,176)	14,157	289
Other expense, net	(897)	(1,679)	(73)
Net loss before income taxes	(60,890)	(40,883)	(179,879)
Income tax credit (expense)	5,603	(11,660)	(150)
Net loss	(55,287)	(52,543)	(180,029)
Other comprehensive income (loss):
Exchange differences on translation of foreign operations	18,412	(24,358)	(254)
Total comprehensive loss	$ (36,875)	$ (76,901)	$ (180,283)
Basic net loss per share (in dollars per share)	$ (1.13)	$ (1.15)	$ (4.24)
Diluted net loss per share (in dollars per share)	$ (1.13)	$ (1.15)	$ (4.24)
Basic weighted-average number of shares outstanding (in shares)	48,888,975	45,714,923	42,488,579
Diluted weighted-average number of shares outstanding (in shares)	48,888,975	45,714,923	42,488,579
Product Revenue, Net [Member]
Revenues:
Total revenue from sale of therapies	$ 238,735	$ 130,013	$ 0
Pre-Product Revenue, Net [Member]
Revenues:
Total revenue from sale of therapies	$ 0	$ 10,674	$ 4,078