Accounts payable and other liabilities - Schedule of Accounts Payable and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Trade accounts payable	$ 1,323	$ 1,604
Accrued clinical and preclinical expenses	1,687	944
Accrued compensation and vacation	3,244	1,238
Other accrued liabilities	927	339
Accounts payable and other liabilities	$ 7,181	$ 4,125