Income taxes - Summary of Reconciliation of the U.S. Federal Statutory Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory income tax rate	(21.00%)	(21.00%)	(21.00%)
State income taxes, net of federal benefit	(6.50%)	(6.40%)	(6.10%)
Federal and state research and development tax credits	(1.90%)	(4.30%)	(2.30%)
Stock-based compensation expense		1.90%	0.90%
Change in deferred tax asset valuation allowance	29.40%	29.80%	28.50%