Nature of Business	9 Months Ended
Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Background Atea Pharmaceuticals, Inc., together with its subsidiary Atea Pharmaceuticals Securities Corporation, is referred to on a consolidated basis as the “Company”. The Company is a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing antiviral therapeutics to improve the lives of patients suffering from life-threatening viral infections. The accompanying unaudited consolidated financial statements are presented as of September 30, 2020 and for the three-month and nine-month periods then ended. As discussed further in Note 13, there were several material events that occurred after September 30, 2020 which are described below: Series D-1 Convertible Preferred Stock In October 2020, the Company issued 8,973,261 shares of Series D-1 Convertible Preferred Stock at a purchase price of $11.98 per share for gross proceeds of $107,500 (the “Series D-1 Closing”). Roche License Agreement In October 2020, the Company entered into the Roche License Agreement, granting Roche an exclusive license to develop and commercialize AT-527 outside of the United States (other than for certain use in connection with the hepatitis C indication). The Company also granted Roche a global license to manufacture AT-527 and agreed that Roche would manufacture the global commercial supply of AT-527 for uses other than the hepatitis C indication. As part of the consideration, Roche agreed to pay the Company an upfront payment of $350,000 (the “Roche Upfront Payment”), which was received in November 2020. Initial Public Offering In November 2020, the Company completed an initial public offering of its common stock (the “IPO”). In connection with the IPO, the Company issued 14,375,000 shares of its common stock, including the exercise in full of the underwriters’ option to purchase up to 1,875,000 shares, at $24.00 per share for aggregate gross proceeds of $345,000 before deducting underwriting discounts and commissions of $24,150 and offering expenses of approximately $3,200. As a result of the IPO, all shares of Series A, B, C, D and D-1 convertible preferred stock converted into 57,932,090 shares of common stock. Risks and Uncertainties The Company is subject to risks and uncertainties common to clinical stage biopharmaceutical companies. These risks include, but are not limited to, potential failure of preclinical and clinical studies, uncertainties associated with research and development activities generally, competition from technical innovations of others, dependence upon key personnel, compliance with governmental regulations, the need to obtain marketing approval for any product candidate that the Company may discover and develop, the need to gain broad acceptance among patients, payers and health care providers to successfully commercialize any product for which marketing approval is obtained and the need to secure and maintain adequate intellectual property protection for the Company’s proprietary technology and products. Further, the Company is currently dependent on third-party service providers for much of its preclinical research, clinical development and manufacturing activities. Product candidates currently under development will require significant amounts of additional capital, additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. Even if the Company is able to generate revenues from the sale of its product candidates, if approved, it may not become profitable. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations. The Company is also subject to risks associated with the COVID-19 global pandemic, including actual and potential delays associated with certain of its ongoing and anticipated trials, and potential negative impacts on the Company’s business operations and its ability to raise additional capital to finance its operations. Through September 30, 2020, the Company financed its operations from the sale of convertible preferred stock. Since its inception, the Company has incurred recurring operating losses and negative cash flows from operations. As of September 30, 2020, the Company had an accumulated deficit of $85,816. The Company expects to continue to generate operating losses for the foreseeable future. The Company believes that its cash and cash equivalents of $105,383 as of September 30, 2020, together with the net proceeds from the Series D-1 Closing, the Roche Upfront Payment and the net proceeds from the IPO will be sufficient to fund its operations as currently planned through at least 2023. The Company may seek additional capital through one or more of a combination of financing through the sale of additional equity securities, debt financing, or funding in connection with any additional collaborative relationships it may enter into or other arrangements. There can be no assurance that the Company will be able to obtain such additional funding, on terms acceptable to the Company, on a timely basis or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s existing shareholders.

Nature of Business

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Nature of Business

Background

Atea Pharmaceuticals, Inc., together with its subsidiary Atea Pharmaceuticals Securities Corporation, is referred to on a consolidated basis as the “Company”.

The Company is a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing antiviral therapeutics to improve the lives of patients suffering from life-threatening viral infections.

The accompanying unaudited consolidated financial statements are presented as of September 30, 2020 and for the three-month and nine-month periods then ended. As discussed further in Note 13, there were several material events that occurred after September 30, 2020 which are described below:

Series D-1 Convertible Preferred Stock

In October 2020, the Company issued 8,973,261 shares of Series D-1 Convertible Preferred Stock at a purchase price of $11.98 per share for gross proceeds of $107,500 (the “Series D-1 Closing”).

Roche License Agreement

In October 2020, the Company entered into the Roche License Agreement, granting Roche an exclusive license to develop and commercialize AT-527 outside of the United States (other than for certain use in connection with the hepatitis C indication). The Company also granted Roche a global license to manufacture AT-527 and agreed that Roche would manufacture the global commercial supply of AT-527 for uses other than the hepatitis C indication. As part of the consideration, Roche agreed to pay the Company an upfront payment of $350,000 (the “Roche Upfront Payment”), which was received in November 2020.

Initial Public Offering

In November 2020, the Company completed an initial public offering of its common stock (the “IPO”). In connection with the IPO, the Company issued 14,375,000 shares of its common stock, including the exercise in full of the underwriters’ option to purchase up to 1,875,000 shares, at $24.00 per share for aggregate gross proceeds of $345,000 before deducting underwriting discounts and commissions of $24,150 and offering expenses of approximately $3,200. As a result of the IPO, all shares of Series A, B, C, D and D-1 convertible preferred stock converted into 57,932,090 shares of common stock.

Risks and Uncertainties

The Company is subject to risks and uncertainties common to clinical stage biopharmaceutical companies. These risks include, but are not limited to, potential failure of preclinical and clinical studies, uncertainties associated with research and development activities generally, competition from technical innovations of others, dependence upon key personnel, compliance with governmental regulations, the need to obtain marketing approval for any product candidate that the Company may discover and develop, the need to gain broad acceptance among patients, payers and health care providers to successfully commercialize any product for which marketing approval is obtained and the need to secure and maintain adequate intellectual property protection for the Company’s proprietary technology and products. Further, the Company is currently dependent on third-party service providers for much of its preclinical research, clinical development and manufacturing activities. Product candidates currently under development will require significant amounts of additional capital, additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. Even if the Company is able to generate revenues from the sale of its product candidates, if approved, it may not become profitable. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations. The Company is also subject to risks associated with the COVID-19 global pandemic, including actual and potential delays associated with certain of its ongoing and anticipated trials, and potential negative impacts on the Company’s business operations and its ability to raise additional capital to finance its operations.

Through September 30, 2020, the Company financed its operations from the sale of convertible preferred stock. Since its inception, the Company has incurred recurring operating losses and negative cash flows from operations. As of September 30, 2020, the Company had an accumulated deficit of $85,816. The Company expects to continue to generate operating losses for the foreseeable future. The Company believes that its cash and cash equivalents of $105,383 as of September 30, 2020, together with the net proceeds from the Series D-1 Closing, the Roche Upfront Payment and the net proceeds from the IPO will be sufficient to fund its operations as currently planned through at least 2023.

The Company may seek additional capital through one or more of a combination of financing through the sale of additional equity securities, debt financing, or funding in connection with any additional collaborative relationships it may enter into or other arrangements. There can be no assurance that the Company will be able to obtain such additional funding, on terms acceptable to the Company, on a timely basis or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s existing shareholders.