Supplemental Balance Sheet Information - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Supplemental Balance Sheet Information Disclosures [Abstract]
Tax incentive refund	$ 2,662	$ 2,558
Prepaid research and development expenses	4,560	3,145
Prepaid insurance	1,839	973
Prepaid compensation benefits	706	609
Other current assets	522	275
Total	$ 10,289	$ 7,560

Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

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Name:	us-gaap_PrepaidInsurance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant