Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued compensation	$ 394,773	$ 444,786
Accrued research and development	550,323	313,642
Accrued general & administrative	192,676	101,457
Accrued other	48,657	48,839
Accrued expenses	$ 1,186,429	$ 908,724