PROPERTY AND EQUIPMENT, NET - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,401	$ 5,401
Less: Accumulated depreciation	(4,697)	(4,631)
Property and equipment, net	704	770
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,908	1,908
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	3,473	2,945
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 0	$ 528