Income taxes - Schedule of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Net operating losses	$ 62,429	$ 61,036
Capitalized research and experimental expenditures	68,370	51,401
Operating lease liability	19,083	20,611
R&D and investment tax credits	23,646	18,049
Stock-based compensation	11,003	9,061
Deferred revenue	6,671	3,881
Foreign tax credit	0	1,204
Capitalized start-up costs	392	555
Other	25	27
Total gross deferred tax assets	191,619	165,825
Deferred tax liabilities:
Right-of-use asset	(16,697)	(18,573)
Fixed assets	(1,382)	(1,663)
Less: valuation allowance	(173,540)	(145,589)
Net deferred taxes	$ 0	$ 0