Accrued Expense - Additional Information (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Accounts Payable and Accrued Liabilities [Line Items]
Accrued expense	$ 539,668	$ 253,445
Accrued expense - related party	0	67,050
MD Anderson Cancer Center | Expenses
Accounts Payable and Accrued Liabilities [Line Items]
Accrued expense - related party		100,000
MD Anderson Cancer Center | Clinical Trials
Accounts Payable and Accrued Liabilities [Line Items]
Accrued expense - related party		$ 67,050