STOCK-BASED COMPENSATION - Share-based compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Stock options
Stock-based compensation (in dollars)	$ 38	$ 17	$ 100	$ 73
Expected term			10 years
Vesting period			48 months
Cumulative Adjustment on adoption of ASU 2016-09.	11,577	12,814	$ 11,577	12,814	$ 13,476	$ 15,746	$ 15,516	$ 18,115
Research and development
Stock options
Stock-based compensation (in dollars)		(17)	1	(11)
General and administrative
Stock options
Stock-based compensation (in dollars)	38	34	99	84
Stock Options
Stock options
Stock-based compensation (in dollars)	$ 38	$ 29	$ 100	$ 77