ACCOUNTS PAYABLE AND ACCRUED EXPENSES - Summary of accounts payable and accrued expenses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Accounts payable	$ 308	$ 146
Accrued payroll	1,715	2,556
Accrued outsourced pre-clinical and clinical fees	4,996	4,702
Accrued professional fees	492	660
Other accrued expenses	343	406
Accounts payable and accrued expenses, Total	$ 7,854	$ 8,470