Property and equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total, at cost	$ 13,955	$ 13,442
Accumulated depreciation	(7,937)	(7,262)
Total, net	6,018	6,180
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Total, at cost	6,002	5,940
Lab equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	5,996	5,709
Computer equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	994	994
Furniture and office equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	636	472
Vehicles [Member]
Property Plant And Equipment [Line Items]
Total, at cost	305	305
Asset under construction [Member]
Property Plant And Equipment [Line Items]
Total, at cost	$ 22	$ 22