Stock compensation - Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	$ 1,662	$ 404
Employees [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	1,014	399
Nonemployees [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	648	5
Research and development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	902	60
General and administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Arrangement, Expense	$ 760	$ 344