DETAILED ACCOUNT BALANCES - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Prepaid clinical trial costs	$ 2,280	$ 1,443
Prepaid insurance	837	921
Other prepaid expenses	187	168
Accounts receivable	92	125
Other short-term assets	8	59
Prepaid expenses and other current assets	$ 3,404	$ 2,716