PROPERTY AND EQUIPMENT, NET - Schedule of Property and Equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 13,276 $ 13,223
Less: Accumulated depreciation and amortization (11,749) (10,786)
Property and equipment, net 1,527 2,437
Furniture and office equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 2,733 2,680
Laboratory equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross 20 20
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 10,523 $ 10,523