Common Stock - Summary of Reserved Shares of Common Stock for Future Issuance (Detail)	Sep. 30, 2022 shares
Class Of Stock [Line Items]
Total shares reserved	10,368,861
Pre-funded warrants issued and outstanding
Class Of Stock [Line Items]
Total shares reserved	4,000,000
2019 Equity Incentive Plan and 2015 Stock Plan \| Options Issued and Outstanding
Class Of Stock [Line Items]
Total shares reserved	2,972,047
2019 Equity Incentive Plan \| Restricted Stock Units Issued and Outstanding
Class Of Stock [Line Items]
Total shares reserved	27,000
2019 Equity Incentive Plan \| Options Available for Future Grants
Class Of Stock [Line Items]
Total shares reserved	2,850,944
2019 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Total shares reserved	518,870