Organization and Basis of Presentation	12 Months Ended
Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Description of Business 89bio, Inc. (“89bio” or the “Company”) is a clinical-stage biopharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of liver and cardio-metabolic diseases. The Company’s lead product candidate, pegozafermin (previously BIO89-100), a specifically engineered glycoPEGylated analog of fibroblast growth factor 21, is currently being developed for the treatment of nonalcoholic steatohepatitis and for the treatment of severe hypertriglyceridemia. 89bio, Inc. was formed as a Delaware corporation in June 2019 to carry on the business of 89Bio Ltd., which was incorporated in Israel in January 2018. Liquidity The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and liquidation of liabilities in the normal course of business. To date, the Company has not generated revenues from its activities and has incurred substantial operating losses. Management expects the Company to continue to generate substantial operating losses for the foreseeable future until it completes development of its products and seeks regulatory approvals to market such products. The Company had cash and cash equivalents and short-term available-for-sale securities of $188.2 million as of December 31, 2022. The Company expects that its cash and cash equivalents and short-term available-for-sale securities as of December 31, 2022, together with proceeds received in January and February 2023 from its ATM Facility (see Note 7 and Note 11), and proceeds available from the 2023 Loan Agreement (see Note 6 and Note 11), will be sufficient to fund operating expenses and capital expenditure requirements for a period of at least one year from the date these audited consolidated financial statements are filed with the Securities and Exchange Commission.

Organization and Basis of Presentation

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Organization and Basis of Presentation

Description of Business

89bio, Inc. (“89bio” or the “Company”) is a clinical-stage biopharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of liver and cardio-metabolic diseases. The Company’s lead product candidate, pegozafermin (previously BIO89-100), a specifically engineered glycoPEGylated analog of fibroblast growth factor 21, is currently being developed for the treatment of nonalcoholic steatohepatitis and for the treatment of severe hypertriglyceridemia.

89bio, Inc. was formed as a Delaware corporation in June 2019 to carry on the business of 89Bio Ltd., which was incorporated in Israel in January 2018.

Liquidity

The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and liquidation of liabilities in the normal course of business. To date, the Company has not generated revenues from its activities and has incurred substantial operating losses. Management expects the Company to continue to generate substantial operating losses for the foreseeable future until it completes development of its products and seeks regulatory approvals to market such products. The Company had cash and cash equivalents and short-term available-for-sale securities of $188.2 million as of December 31, 2022.

The Company expects that its cash and cash equivalents and short-term available-for-sale securities as of December 31, 2022, together with proceeds received in January and February 2023 from its ATM Facility (see Note 7 and Note 11), and proceeds available from the 2023 Loan Agreement (see Note 6 and Note 11), will be sufficient to fund operating expenses and capital expenditure requirements for a period of at least one year from the date these audited consolidated financial statements are filed with the Securities and Exchange Commission.