Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Number of Shares
Beginning balance (in shares)	6,008,541
Granted (in shares)	6,245,756
Forfeited (in shares)	(670,641)
Ending balance (in shares)	11,583,656	6,008,541
Number of shares Options, Exercisable (in shares)	2,418,389
Number of shares Options, Vested and expected to vest (in shares)	9,206,078
Weighted Average Exercise Price
Beginning balance (in usd per share)	$ 2.97
Granted (in usd per share)	0.98
Forfeited (in usd per share)	1.87
Ending balance (in usd per share)	1.96	$ 2.97
Weighted average exercise price, Exercisable (in usd per share)	5.26
Weighted average exercise price, Vested and expected to vest (in usd per share)	$ 2.19
Weighted average contractual term outstanding (in years)	8 years 9 months 18 days	8 years 7 months 6 days
Weighted average contractual term outstanding, Exercisable (in years)	6 years 8 months 12 days
Weighted average contractual term outstanding, Vested and expected to vest (in years)	8 years 7 months 6 days
Aggregate intrinsic value, Beginning balance	$ 24
Aggregate intrinsic value, Ending balance	0	$ 24
Aggregate intrinsic value, exercisable	0
Aggregate intrinsic value, vested and expected to vest	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period, Intrinsic Value	$ 0