PREPAID EXPENSES AND OTHER CURRENT ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
PREPAID EXPENSES AND OTHER CURRENT ASSETS
Prepaid research and development expenses	$ 4,996	$ 4,483
Insurance premium asset	1,914	1,616
Prepaid rent expenses	86	117
Prepaid insurance expenses	89	105
Prepaid commercial and patient advocacy	167	254
Research and development tax credit receivable	252	502
Interest receivable	24	23
Other prepaid expenses and current assets	604	471
Total prepaid expenses & other current assets	$ 8,132	$ 7,571