Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($)
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]    
In-process research and development $ 996,154 $ 996,154
Net operating loss carry forward 2,995,024 1,681,549
R&D credit 142,721 60,213
Share-based compensation 2,010,742 841,524
Accrued expenses   17,850
Deferred tax assets gross 6,144,641 3,597,290
Less: valuation allowance (6,144,641) (3,597,290)
Deferred tax assets, net $ 0 $ 0