Accounts payable and other liabilities - Schedule of Accounts Payable and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Trade accounts payable	$ 526	$ 1,323
Accrued clinical and preclinical expenses	2,399	1,687
Accrued compensation and vacation	3,263	3,244
Other accrued liabilities	1,227	927
Accounts payable and other liabilities	$ 7,415	$ 7,181