Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued expenses and other current liabilities
Accrued employee compensation and benefits	$ 7,131	$ 9,928
Accrued external research and development expenses	20,629	10,859
Accrued professional fees	1,911	1,068
Current portion of operating lease liabilities	4,680	3,125
Accrued income tax	$ 1,906	$ 970
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Other	$ 1,005	$ 502
Accrued expenses and other current liabilities	$ 37,262	$ 26,452