Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued retention bonus	$ 720,398	$ 521,859
Restructuring accrual (see Note 12)	521,848	793,913
Accounts payable	421,120	439,785
Professional fees	412,429	346,999
Accrued project costs	282,765	382,131
Accrued bonus	106,159	689,830
Accrued vacation	65,020	43,470
Other	17,984	13,463
Total accounts payable and accrued expenses	$ 2,547,723	$ 3,231,450