Collaboration agreements - Merck Immunosythen Agreement (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2023 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) target performanceObligation	Dec. 31, 2021 USD ($)
Collaboration agreements
Collaboration revenue		$ 7,802	$ 2,036
Deferred revenue		144,351	$ 42,198	$ 147,653	$ 3,944
2022 Merck Research Collaboration & License Agreement
Collaboration agreements
Number of targets designated | target				2
Upfront payment received	$ 30,000
Performance obligations identified | performanceObligation				4
Collaboration revenue		3,100
Deferred revenue		$ 26,900		$ 30,000