Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Accounts Payable And Accrued Liabilities Current [Line Items]
Accounts payable and accrued expenses	$ 1,055,738	$ 2,278,398
Research and Development Expenses [Member]
Accounts Payable And Accrued Liabilities Current [Line Items]
Accounts payable and accrued expenses	470,824	1,339,851
Professional Fees [Member]
Accounts Payable And Accrued Liabilities Current [Line Items]
Accounts payable and accrued expenses	201,146	735,990
General and Administrative Expenses [Member]
Accounts Payable And Accrued Liabilities Current [Line Items]
Accounts payable and accrued expenses	307,883	121,554
Compensation Related Expenses [Member]
Accounts Payable And Accrued Liabilities Current [Line Items]
Accounts payable and accrued expenses	$ 75,885	$ 81,003