INCOME TAXES - Schedule of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred income tax assets:
Federal and state net operating loss carryovers	$ 23,376	$ 22,167
Capitalized research costs	859	608
Stock-based compensation	283	260
Compensation accruals and other	45	59
Operating leases related to ROU assets	0	54
Deferred revenue	3	4
Depreciation	13	11
Other	0	2
Total deferred income tax assets	24,579	23,165
Valuation allowance for deferred income tax assets	(24,579)	(23,113)
Deferred income tax assets, net of valuation allowance	0	52
Deferred income tax liabilities:
ROU assets	0	(52)
Total deferred income tax liabilities	0	(52)
Deferred income tax assets, net	$ 0	$ 0