Share-based compensation - Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 25,690	$ 15,748
Unrecognized compensation cost	$ 81,500
Recognition period	2 years 10 months 24 days
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 11,193	5,146
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 14,497	$ 10,602