Common Stock and Stock-Based Awards - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Equity [Abstract]
Number of Shares, Beginning Balance	14,844,112
Number of Shares, Granted	6,743,362
Number of Shares, Exercised	0
Number of Shares, Forfeited	(2,428,857)
Number of Shares, Ending Balance	19,158,617	14,844,112
Number of Shares, Vested or expected to vest	19,158,617
Number of Shares, Options exercisable	9,026,731
Weighted Average Exercise Price, Beginning Balance	$ 9.64
Weighted Average Exercise Price, Granted	1.07
Weighted Average Exercise Price, Exercised	0
Weighted Average Exercise Price, Forfeited	8.93
Weighted Average Exercise Price, Ending Balance	6.72	$ 9.64
Weighted Average Exercise Price, Vested or expected to vest	6.72
Weighted Average Exercise Price, Options exercisable	$ 10.16
Weighted Average Remaining Contractual Term, Outstanding	7 years 7 months 2 days	5 years 8 months 15 days
Weighted Average Remaining Contractual Term, Vested or expected to vest	7 years 7 months 2 days
Weighted Average Remaining Contractual Term, Options exercisable	5 years 8 months 4 days
Aggregate Intrinsic Value, Outstanding	$ 0	$ 0
Aggregate Intrinsic Value, Vested or expected to vest	0
Aggregate Intrinsic Value, Options exercisable	$ 0