INCOME TAXES - Schedule of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets (liabilities):
Net operating loss carryforwards	$ 9,512	$ 2,904
Research and development tax credits	1,014	459
Accrual to cash adjustment	0	657
Accruals and other	280	0
Stock-based compensation	196	0
Total deferred tax assets	11,002	4,020
Valuation Allowance	(10,995)	(4,010)
Subtotal	7	10
Net fixed assets	(7)	(10)
Net deferred tax assets	$ 0	$ 0