Stock-based Compensation - Summary of Stock Option Activity for Employees and Nonemployees (Detail) - Employee and Nonemployee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Aggregate Intrinsic Value,Granted
Shares, Outstanding, Beginning balance	13,026,359
Shares, Granted	306,000
Shares, Exercised	(13,193)
Shares, Forfeited	(1,120,412)
Shares, Expired	(3,577,944)
Shares, Outstanding, Ending balance	8,620,810	13,026,359
Shares, Exercisable	6,739,120
Weighted-Average Exercise Price Per Share, Outstanding, Beginning balance	$ 11.46
Weighted-Average Exercise Price Per Share, Granted	2.23
Weighted-Average Exercise Price Per Share, Exercised	3.46
Weighted-Average Exercise Price Per Share, Forfeited	10.31
Weighted-Average Exercise Price Per Share, Expired	12.65
Weighted-Average Exercise Price Per Share, Outstanding, Ending balance	10.79	$ 11.46
Weighted-Average Exercise Price Per Share, Exercisable	$ 11.59
Weighted-Average Remaining Contractual Term (years), Outstanding	5 years 3 months 18 days	5 years 3 months 18 days
Weighted-Average Remaining Contractual Term (years), Exercisable	4 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 0	$ 6
Aggregate Intrinsic Value, Exercisable	$ 0