Property and equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total, at cost	$ 14,144	$ 14,014
Accumulated depreciation	(11,782)	(10,755)
Total, net	2,362	3,259
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Total, at cost	6,101	6,101
Lab equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	5,975	5,830
Computer equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	1,051	1,051
Furniture and office equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	732	732
Vehicles and equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	281	296
Asset under construction [Member]
Property Plant And Equipment [Line Items]
Total, at cost	$ 4	$ 4