| Document and Entity Information | Sep. 11, 2023 |
| Document And Entity Information [Line Items] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Document Period End Date | Sep. 11, 2023 |
| Entity Registrant Name | Dianthus Therapeutics, Inc. /DE/ |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-38541 |
| Entity Tax Identification Number | 81-0724163 |
| Entity Address, Address Line One | 7 Times Square |
| Entity Address, Address Line Two | 43rd Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10036 |
| City Area Code | 929 |
| Local Phone Number | 999-4055 |
| Entity Information, Former Legal or Registered Name | Magenta Therapeutics, Inc. |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Trading Symbol | DNTH |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001690585 |
| Amendment Description | This Amendment No. 1 on Form 8-K/A (this “Amendment”) amends the Current Report on Form 8-K filed by Dianthus Therapeutics, Inc. (formerly Magenta Therapeutics, Inc.) (the “Company”) with the U.S. Securities and Exchange Commission on September 12, 2023 (the “Original Report”), in which the Company reported, among other things, the completion of its previously announced business combination, pursuant to which Dio Merger Sub, Inc. merged with and into Dianthus Therapeutics OpCo, Inc. (formerly Dianthus Therapeutics, Inc.) (“OpCo”), with OpCo surviving as a wholly owned subsidiary of the Company. This Amendment includes (i) the unaudited condensed financial statements of OpCo for the six months ended June 30, 2023 and 2022, (ii) the audited financial statements of OpCo for the years ended December 31, 2022 and 2021, (iii) the unaudited pro forma condensed combined financial information of the Company and OpCo as of June 30, 2023 and for the six months ended June 30, 2023 and for the year ended December 31, 2022, (iv) Management’s Discussion and Analysis of Financial Condition and Results of Operations of OpCo for the six months ended June 30, 2023 and 2022, (v) Management’s Discussion and Analysis of Financial Condition and Results of Operations of OpCo for the years ended December 31, 2022 and 2021, (vi) the Company’s Risk Factors, (vii) the Company’s Business Section and (viii) clarifications regarding the terms of the Class I, Class II and Class III directors of the board of directors of the Company (the “Board”) and the amount of shares of common stock outstanding. Except as described above, this Amendment does not amend or modify any other Item of the Original Report. Except as otherwise indicated herein, this Amendment does not purport to provide an update or a discussion of any developments at the Company or its subsidiaries subsequent to the filing date of the Original Report. The information previously reported in or filed with the Original Report is hereby incorporated by reference to this Amendment. The historical audited and unaudited financial statements of OpCo and the unaudited pro forma condensed combined financial information of the Company and OpCo included herein was excluded from the Original Report in reliance on Items 9.01(a) and 9.01(b). |
| Former Address [Member] | |
| Document And Entity Information [Line Items] | |
| Entity Address, Address Line One | 300 Technology Square |
| Entity Address, Address Line Two | 8th Floor |
| Entity Address, City or Town | Cambridge |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 10036 |
