Nature of the Business and Basis of Presentation	9 Months Ended
Sep. 30, 2022
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Magenta Therapeutics, Inc. (the “Company”) is a clinical-stage biotechnology company developing novel medicines designed to bring the curative power of stem cell transplant to more patients with blood cancers, genetic diseases and autoimmune diseases. The Company was incorporated under the laws of the State of Delaware in June 2015 as HSCTCo Therapeutics, Inc. In February 2016, the Company changed its name to Magenta Therapeutics, Inc. and in June 2018 the Company completed an initial public offering of its common stock. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, the continuing impact of the ongoing coronavirus (“COVID-19”) pandemic and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The Company has a shelf registration statement on Form S-3 (the “Shelf”) on file with the SEC, which covers the offering, issuance and sale of up to an aggregate of $250.0 million of common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. The Company also entered into a sales agreement, as amended, with Cowen and Company, LLC, as sales agent to provide for the issuance and sale by the Company of up to $50.0 million of common stock from time to time in “at-the-market” offerings under the Shelf (the “ATM Program”). The Shelf was declared effective by the SEC on August 12, 2022. During the nine months ended September 30, 2022, the Company sold 1,644,200 shares of its common stock under the ATM program at a weighted average price per share of $1.82 resulting in net proceeds of $2.8 million after commissions and offering costs. As of September 30, 2022, $247.0 million remained available under the Shelf, including up to $47.0 million available for sale under the ATM Program. The Company has incurred recurring losses since inception, including net losses of $56.3 million for the nine months ended September 30, 2022 and $71.1 million the year ended December 31, 2021. As of September 30, 2022, the Company had an accumulated deficit of $381.9 million. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance date of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to raise additional capital to fund its operations. The Company will need to obtain substantial additional funding in connection with continuing operations, particularly as the Company advances its preclinical activities and clinical trials for its product candidates in development. If the Company is unable to raise capital when needed, or on attractive terms, it could be forced to delay, reduce or eliminate its research or drug development programs or any future commercialization efforts. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany balances and transactions have been eliminated. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Nature of the Business and Basis of Presentation

9 Months Ended

Sep. 30, 2022

Nature of the Business and Basis of Presentation

1. Nature of the Business and Basis of Presentation

Magenta Therapeutics, Inc. (the “Company”) is a clinical-stage biotechnology company developing novel medicines designed to bring the curative power of stem cell transplant to more patients with blood cancers, genetic diseases and autoimmune diseases. The Company was incorporated under the laws of the State of Delaware in June 2015 as HSCTCo Therapeutics, Inc. In February 2016, the Company changed its name to Magenta Therapeutics, Inc. and in June 2018 the Company completed an initial public offering of its common stock.

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, the continuing impact of the ongoing coronavirus (“COVID-19”) pandemic and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

The Company has a shelf registration statement on Form S-3 (the “Shelf”) on file with the SEC, which covers the offering, issuance and sale of up to an aggregate of $250.0 million of common stock, preferred stock, debt securities, warrants and/or units of any combination thereof. The Company also entered into a sales agreement, as amended, with Cowen and Company, LLC, as sales agent to provide for the issuance and sale by the Company of up to $50.0 million of common stock from time to time in “at-the-market” offerings under the Shelf (the “ATM Program”). The Shelf was declared effective by the SEC on August 12, 2022. During the nine months ended September 30, 2022, the Company sold 1,644,200 shares of its common stock under the ATM program at a weighted average price per share of $1.82 resulting in net proceeds of $2.8 million after commissions and offering costs. As of September 30, 2022, $247.0 million remained available under the Shelf, including up to $47.0 million available for sale under the ATM Program.

The Company has incurred recurring losses since inception, including net losses of $56.3 million for the nine months ended September 30, 2022 and $71.1 million the year ended December 31, 2021. As of September 30, 2022, the Company had an accumulated deficit of $381.9 million. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance date of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to raise additional capital to fund its operations.

The Company will need to obtain substantial additional funding in connection with continuing operations, particularly as the Company advances its preclinical activities and clinical trials for its product candidates in development. If the Company is unable to raise capital when needed, or on attractive terms, it could be forced to delay, reduce or eliminate its research or drug development programs or any future commercialization efforts. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany balances and transactions have been eliminated. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).