PROPERTY AND EQUIPMENT - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment	$ 3,814	$ 3,871
Less: accumulated depreciation and amortization	(3,435)	(3,348)
Property and equipment, net	379	523
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment	2,507	2,507
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	741	741
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment	400	457
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment	$ 166	$ 166

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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