Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Development and clinical manufacturing costs	$ 1,436	$ 598
Payroll and payroll-related costs	2,756	547
Professional fees	184	314
Facility and other	1,147	278
Total Accrued Expenses and Other Current Liabilities	$ 5,523	$ 1,737