SHARE-BASED COMPENSATION EXPENSE - Non-Cash Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Total Stock Compensation
Allocated Share-based Compensation Expense	$ 15	$ 35
Research and development expense
Total Stock Compensation
Allocated Share-based Compensation Expense	0	6
Research and development expense | Stock options
Total Stock Compensation
Allocated Share-based Compensation Expense	0	2
Research and development expense | Restricted stock units
Total Stock Compensation
Allocated Share-based Compensation Expense	0	4
General and administrative expense
Total Stock Compensation
Allocated Share-based Compensation Expense	15	29
General and administrative expense | Stock options
Total Stock Compensation
Allocated Share-based Compensation Expense	0	3
General and administrative expense | Restricted stock units
Total Stock Compensation
Allocated Share-based Compensation Expense	$ 15	$ 26