Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Development and manufacturing costs	$ 2,093	$ 1,436
Payroll and payroll-related costs	1,187	2,756
Professional fees	498	184
Facility	3,128	1,053
Other	153	94
Total Accrued Expenses and Other Current Liabilities	$ 7,059	$ 5,523