Related Party - Additional Information (Detail) (USD $)				3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Technology Licenses	Mar. 31, 2013 MD Anderson Cancer Center Research and Development Expense	Mar. 31, 2012 MD Anderson Cancer Center Research and Development Expense	Mar. 31, 2013 MD Anderson Cancer Center Research and Development Expense Clinical Trials
Related Party Transaction [Line Items]
Accrued expense - related party	$ 15,000	$ 26,000				$ 26,000
Accrued license payments - related party	50,000	100,000	100,000
Cash paid to MD Anderson Cancer Center for expenses				15,000	11,700
Accounts payable - related party	$ 0	$ 8,582