Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Accrued Liabilities [Line Items]
Legal and accounting fees	$ 255	$ 118
Accrued compensation	377	604
Accrued clinical trial costs	426
Other	7	7
Total	$ 1,065	$ 729