Balance Sheet Components - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued research and development costs	$ 17,000	$ 6,360
Professional fees	211	608
Other liabilities	983	726
Total accrued liabilities	$ 18,194	$ 7,694

Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.

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