Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accrued Liabilities And Other Liabilities [Abstract]
Accrued compensation	$ 349	$ 571
Accrued contracted research and development costs	1,162	863
Accrued professional and consulting fees	1,750	863
Accrued other and other current liabilities	50	50
Total accrued and other current liabilities	$ 3,311	$ 2,347