Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets
Federal & State NOL carryforward	$ 25,311,547	$ 16,935,101
Federal & State R&D credit carryforward	3,781,160	2,058,771
Intangibles – net	164,508	325,744
Accounts payable and accrued expenses	1,958,174	615,490
Stock options	3,146,034	2,197,983
Fixed assets – net	10,173	6,409
Gross deferred tax assets	34,371,596	22,139,498
Valuation Allowance	(34,371,596)	(22,123,292)
Net Deferred Tax Assets		16,206
Deferred Tax Liabilities
Note discounts		(16,206)
Gross deferred tax liabilities		(16,206)
TOTAL	$ 0	$ 0