Income taxes - Deferred tax assets (liabilities) and unrecognized tax benefits (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Income taxes
Unrecognized tax benefits	$ 0	$ 0
Amounts in uncertain tax position	0
Accrued interest	0	0
Deferred tax assets:
Net operating loss carryforwards	4,244	13,724
Tax credit carryforwards	34,424	28,427
Lease liability	11,946	5,544
Deferred revenue	7,867	1,675
Stock-based compensation	5,328	5,157
Non-deductible accruals and reserves	2,435	2,613
Capitalized research expenses	50,974	31,347
Intangibles	499	554
Total deferred tax assets	117,717	89,041
Less valuation allowance	(105,854)	(82,612)
Net deferred tax assets	11,863	6,429
Deferred tax liabilities
Right of use assets	(9,111)	(3,691)
Depreciation and amortization	$ (2,752)	$ (2,738)