Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued research and development	$ 10,010	$ 11,008
Employee compensation and benefits	6,244	10,920
Accrued legal and professional expenses	2,833	1,876
Accrued other	2,128	1,750
Total accrued expenses	$ 21,215	$ 25,554