Accrued Expenses - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Accrued Liabilities And Other Liabilities [Abstract]
Accrued professional services	$ 489,836	$ 1,350,194
Accrued payroll and employee benefits	1,661,708	2,351,599
Accrued interest	16,456	13,016
Accrued research and development	5,074,045	7,316,876
Lease obligation, current portion (see Note 6)	374,502	356,716
Deferred revenue	57,989	19,753
Total accrued expenses	$ 7,674,536	$ 11,408,154