ACCRUED EXPENSES AND OTHER LIABILITIES - Accrued Expenses and Other Liabilities (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Research and development costs and other accrued expenses	$ 3,108,394	$ 3,824,950
Accrued Severance	49,386
Accrued bonus	1,200,633
Professional fees	66,049	314,213
Vacation pay	111,448
Accrued expenses and other liabilities	$ 4,535,910	$ 4,139,163