Balance Sheet Details - Details of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accrued clinical trial expenses	$ 13,088	$ 18,666
Accrued compensation	8,668	7,179
Other accrued liabilities	10,117	4,074
Common stock warrant liabilities	9	198
Total accrued and other current liabilities	$ 31,882	$ 30,117

Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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