Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 352	$ 333
Prepaid insurance	385	1,144
Prepaid research and development expenses	2,047	1,899
Australia research and development refundable tax credit	1,558	1,128
Other current assets	487	367
Total prepaid expenses and other current assets	$ 4,829	$ 4,871