PREPAID EXPENSES AND OTHER CURRENT ASSETS (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
PREPAID EXPENSES AND OTHER CURRENT ASSETS
Prepaid research and development expenses	$ 5,058	$ 4,483
Insurance premium asset	2,697	1,616
Prepaid rent expenses	120	117
Prepaid insurance expenses	109	105
Prepaid commercial and patient advocacy	302	254
Research and development tax credit receivable	253	502
Interest receivable	35	23
Other prepaid expenses and current assets	602	471
Total prepaid expenses & other current assets	$ 9,176	$ 7,571