Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accrued Expenses
Payroll and related costs	$ 420	$ 419
Clinical trials and drug development	2,178	777
Professional fees	196	186
Other	206	121
Accrued expenses	$ 3,000	$ 1,503