Collaboration agreements - GlaxoSmithKline (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Aug. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Collaboration agreements
Collaboration revenue		$ 7,802	$ 2,036
Deferred revenue		144,351	$ 42,198	$ 147,653	$ 3,944
GSK Agreement
Collaboration agreements
Upfront payment received	$ 100,000
Collaboration arrangement, potential option exercise receivable	$ 90,000
Collaboration revenue		700
Deferred revenue		$ 97,300		$ 98,000