Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Accrued expenses and other current liabilities
Accrued manufacturing and clinical expenses		$ 2,997	$ 2,097
Accrued board of director compensation		9	19
Accrued bonus		1,925	539
Accrued payroll and employee benefits		928	653
Accrued professional fees		1,270	1,108
Accrued leasehold improvements			1,163
Accrued other		932	1,433
Total	$ 7,012	$ 8,061	$ 7,012