Stock-based compensation - Schedule of stock-based compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 6,381	$ 6,425	$ 12,596	$ 12,676
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2,465	2,644	4,702	5,227
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,916	$ 3,781	$ 7,894	$ 7,449