Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 333	$ 274
Prepaid insurance	1,144	964
Prepaid research and development expenses	1,899	2,110
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	1,128	0
Other current assets	367	694
Total prepaid expenses and other current assets	$ 4,871	$ 4,042