Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Prepaid Expense and Other Assets [Abstract]
Prepaid manufacturing costs	$ 930	$ 351
Prepaid clinical costs	820	3,051
Prepaid insurance	505	415
Other prepaid expenses and current assets	1,133	650
Total prepaid expenses and other current assets	$ 3,388	$ 4,467