Significant agreements - Novartis Collaboration Agreement (Details) $ in Thousands		12 Months Ended
	Mar. 27, 2023 USD ($) item	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum days allowed for cancellation of contracts prior written notice		90 days
Revenue from collaborative arrangement		$ 26,976	$ 14,463	$ 11,697
Termination in entirety or product by product or target by target basis
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Threshold period of notice required for termination of agreement	90 days
Completion of all milestones for targets
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone payments receivable	$ 800,000
Novartis
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of collaboration targets | item	2
Additional research term	1 year
Upfront cash payment	$ 50,000
Milestone payments receivable	210,000
Milestone payments, receivable	$ 840,000
Maximum days allowed for cancellation of contracts prior written notice	30 days
Total transaction price initially determined	$ 50,000
Expected period for satisfaction of performance obligations	3 years
Material rights exercise period	6 years
Revenue from collaborative arrangement		$ 1,909
Novartis | Termination based on other party's uncured material breach or insolvency
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Threshold period of notice required for termination of agreement	60 days
Novartis | Termination if safety or regulatory issue exists
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Threshold period of notice required for termination of agreement	30 days
Novartis | Achievement of specified levels of net sales
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Milestone payments receivable	$ 200,000