Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid research fees	$ 303,898	$ 334,565
Prepaid insurance	457,487	598,909
Prepaid pre-commercialization fees		35,500
Prepaid subscription fees	91,095	22,770
Prepaid rent	19,906	19,756
Other	57,476	36,444
Total prepaid expenses and other current assets	$ 929,862	$ 1,047,944