Results of Operations and Financial Condition. On August 4, 2026, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended June 30, 2026. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of…

Results of Operations and Financial Condition. On May 5, 2026, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended March 31, 2026. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1…

Entry into a Material Definitive Agreement. On March 10, 2026, Dianthus Therapeutics, Inc. (the “Company”) entered into an underwriting agreement (“Underwriting Agreement”) with Jefferies LLC, TD Securities (USA) LLC, Evercore Group L.L.C., Stifel, Nicolaus & Company, Incorporated and Guggenheim Securities, LLC, as the representatives of the underwriters named therein (the “Underwriters”), to issue and sell 7,313,582 shares of the Company’s common stock at a public offering price of $81.00 pe…

Results of Operations and Financial Condition. On March 9, 2026, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter and full year ended December 31, 2025. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securitie…

Results of Operations and Financial Condition Dianthus Therapeutics, Inc.’s (the “Company”) audited financial statements for the fiscal year ended December 31, 2025 are not yet available. Beginning on January 12, 2026, the Company plans to disclose in a presentation to investors (the "Presentation") that it expects to report cash, cash equivalents, and short-term investments of approximately $514 million as of December 31, 2025. A copy of the Presentation is attached as Exhibit 99.1 to this C…

Results of Operations and Financial Condition. On November 5, 2025, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended September 30, 2025. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange…

Preliminary Financial Information for the Three Months Ended September 30, 2025 In the Presentation, the Company disclosed its estimated cash, cash equivalents and investments as of September 30, 2025. While the Company has not finalized its full financial results for the three months ended September 30, 2025, the Company expects to report that it had approximately $555 million of cash, cash equivalents and investments as of September 30, 2025, with pro forma cash of approximately $525 millio…

Entry into a Material Definitive Agreement License Agreement with Nanjing Leads Biolabs Co. Ltd. On October 16, 2025, Dianthus Therapeutics, Inc. (“ Dianthus ” or the “ Company ”) entered into a License and Collaboration Agreement (the “ License Agreement ”) with Nanjing Leads Biolabs Co. Ltd. (“ Leads ”), pursuant to which Leads granted the Company a royalty-bearing, exclusive license outside of Greater China to develop, manufacture, commercialize or otherwise exploit LBL-047, referred to as…

Results of Operations and Financial Condition The information set forth below under “Preliminary Financial Information for the Three Months Ended September 30, 2025” in

Entry into a Material Definitive Agreement. On September 9, 2025, Dianthus Therapeutics, Inc. (the “Company”) entered into an underwriting agreement (“Underwriting Agreement”) with Jefferies LLC, TD Securities (USA) LLC, Evercore Group L.L.C., and Stifel, Nicolaus & Company, Incorporated, as the representatives of the underwriters named therein (the “Underwriters”), to issue and sell 6,487,879 shares of the Company’s common stock at a public offering price of $33.00 per share and, in lieu of…

Results of Operations and Financial Condition. On August 7, 2025, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended June 30, 2025. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of…

Director — Leon O. Moulder, Jr.: Mr. Moulder resigned from the Board of Directors.

Results of Operations and Financial Condition. On May 12, 2025, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended March 31, 2025. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of…

Results of Operations and Financial Condition. On March 11, 2025, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter and full year ended December 31, 2024. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securiti…

Director — Tomas Kiselak: Mr. Kiselak resigned from the Board and was succeeded by Sujay Kango.

Results of Operations and Financial Condition. On November 7, 2024, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended September 30, 2024. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange…

Class III director and member of the Science and Technology Committee — Steven Romano, M.D.: Dr. Steven Romano was appointed as a Class III director and member of the Science and Technology Committee.

Results of Operations and Financial Condition. On August 8, 2024, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended June 30, 2024. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of…

The filing is about an amendment to a compensatory plan and does not involve any management changes.

Results of Operations and Financial Condition. On May 9, 2024, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended March 31, 2024. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1…

Results of Operations and Financial Condition. On March 21, 2024, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter and full year ended December 31, 2023. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securiti…

Unregistered Sales of Equity Securities. To the extent required by Form 8-K, the disclosures in

Entry into a Material Definitive Agreement. On January 22, 2024, Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), entered into a Securities Purchase Agreement (the “Purchase Agreement”) for a private placement (the “Private Placement”) with certain institutional and accredited investors (each, a “Purchaser” and collectively, the “Purchasers”). The closing of the Private Placement is expected to occur on January 24, 2024. Pursuant to the Purchase Agreement, the Purchasers h…

Results of Operations and Financial Condition. Dianthus Therapeutics, Inc.’s (the “Company”) audited financial statements for the fiscal year ended December 31, 2023 are not yet available. Beginning on January 8, 2024, the Company plans to disclose in a presentation to investors (the "Presentation") that it expects to report cash, cash equivalents, and short-term investments of approximately $173 million as of December 31, 2023. A copy of the Presentation is attached as Exhibit 99.1 to this C…

Results of Operations and Financial Condition. On November 9, 2023, Dianthus Therapeutics, Inc. (the “Company”) issued a press release announcing the Company’s financial results for the quarter ended September 30, 2023. A copy of this press release is furnished as Exhibit 99.1 and is incorporated herein by reference. The information in this Form 8-K (including Exhibit 99.1 attached hereto) is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange…