Stockholders' Equity - Summary of Non-Cash Share-Based Compensation Expense (Detail) (USD $)	3 Months Ended		86 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 223,310	$ 3,126	$ 458,987
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	92,665	2,501	186,100
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 130,645	$ 625	$ 272,887