Cover Page
Cover Page - USD ($) | 12 Months Ended | ||
Dec. 31, 2022 | Mar. 31, 2023 | Jun. 30, 2022 | |
Document Information [Line Items] | |||
Document Type | 10-K/A | ||
Amendment Flag | true | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Document Period End Date | Dec. 31, 2022 | ||
Document Fiscal Year Focus | 2022 | ||
Document Fiscal Period Focus | FY | ||
Entity Registrant Name | Magenta Therapeutics, Inc. | ||
Entity Central Index Key | 0001690585 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Ex Transition Period | false | ||
Entity Emerging Growth Company | true | ||
Entity Shell Company | false | ||
Entity Small Business | true | ||
Entity Tax Identification Number | 81-0724163 | ||
Entity Public Float | $ 56.3 | ||
Entity Interactive Data Current | Yes | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Address, Address Line One | 300 Technology Square | ||
Entity Address, Address Line Two | 8th Floor | ||
Entity Address, City or Town | Cambridge | ||
Entity Address, Postal Zip Code | 02139 | ||
Entity Address, State or Province | MA | ||
Entity File Number | 001-38541 | ||
City Area Code | 857 | ||
Local Phone Number | 242-0170 | ||
Entity Common Stock, Shares Outstanding | 60,648,821 | ||
ICFR Auditor Attestation Flag | false | ||
Auditor Name | KPMG LLP | ||
Auditor Firm ID | 185 | ||
Auditor Location | Boston, Massachusetts | ||
Documents Incorporated by Reference [Text Block] | None. | ||
Amendment Description | This Amendment No. 1 on Form 10-K/A (this “Form 10-K/A”) to the Annual Report on Form 10-K of Magenta Therapeutics, Inc. (“Magenta Therapeutics,” “Magenta,” the “Company,” “we,” “us,” “our” and similar references), for the fiscal year ended December 31, 2022, filed with the Securities and Exchange Commission (the “SEC”) on March 23, 2023 (the “Original Form 10-K”) is being filed solely for the purpose of including the information required by Part III of Form 10-K. This information was previously omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K, which permits the information in the above referenced items to be incorporated in the Form 10-K by reference from our definitive proxy statement if such statement is filed no later than 120 days after our fiscal year-end. We are filing this Form 10-K/A to include Part III information in our Form 10-K because we will not file a definitive proxy statement containing such information within 120 days after the end of the fiscal year covered by the Original Form 10-K. In addition, this Form 10-K/A deletes the reference on the cover of the Original Form 10-K to the incorporation by reference of portions of our proxy statement into Part III of the Original Form 10-K. As required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended, in connection with this Form 10-K/A, our President, Chief Financial and Operating Officer is providing a Rule 13a-14(a) certification as included herein. We are amending Item 15 of Part IV solely to reflect the inclusion of this certification. Because no financial statements have been included in this Form 10-K/A and this Form 10-K/A does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted, in accordance with Question 161.01 of the Exchange Act Rules Compliance and Disclosure Interpretations of the Division of Corporation Finance of the SEC. Except as described above, this Form 10-K/A does not modify or update disclosure in, or exhibits to, the Original Form 10-K. Furthermore, this Form 10-K/A does not change any previously reported financial results. Information not affected by this Form 10-K/A remains unchanged and reflects the disclosures made at the time the Original Form 10-K was filed. | ||
Common Stock, $0.001 Par Value [Member] | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Common Stock, $0.001 Par Value | ||
Trading Symbol | MGTA | ||
Security Exchange Name | NASDAQ | ||
Preferred Stock Purchase Rights [Member] | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Preferred Stock Purchase Rights | ||
No Trading Symbol Flag | true | ||
Security Exchange Name | NASDAQ |