SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accrued Expenses (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Accrued compensation and benefits	$ 574,332	$ 697,334
Accrued Clinical Expenses, Current	4,143,269	58,151
Other accrued expenses	30,150	70,842
Total	$ 4,747,751	$ 826,327