Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Expenses
Payroll and related costs	$ 631	$ 419
Clinical trials and drug development	1,188	777
Professional fees	190	186
Other	152	121
Total accrued expenses	$ 2,161	$ 1,503