Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense And Other Assets [Abstract]
Refundable withholding tax	$ 3,375	$ 3,375
Prepaid insurance	359	473
Prepaid clinical costs	188	188
Prepaid manufacturing costs	113	113
Other prepaid expenses and current assets	1,483	1,607
Total prepaid expenses and other current assets	$ 5,518	$ 5,756