Patient Population and Market Potential - Claseprubart has a target patient population of over 100,000 in the U.S. for generalized myasthenia gravis (gMG), with approximately 85% of these patients having AChR autoantibody-driven disease[4] - The U.S. market for gMG biologics is currently valued at over $3.5 billion, with less than 20% of AChR+ patients treated with biologics, indicating significant growth potential[11] - The company anticipates that self-administered treatments will grow substantially, with expectations for the segment to increase from a small part of the market to approximately 50% in the next three years[10] - The US CIDP market presents a substantial growth opportunity, with current treatments exceeding $3.5 billion and a significant percentage of patients remaining refractory[37] - The US MMN market is projected to grow at ~11% per year, with an opportunity for claseprubart to become the new standard of care[43] - The MMN market has over 10,000 patients in the U.S., with no approved targeted biologic therapies currently available[60] Clinical Trial Results and Efficacy - Claseprubart's Phase 2 trial results demonstrated rapid and sustained symptom improvements, supporting its potential as a best-in-class treatment for gMG[14] - The Phase 2 trial for Claseprubart enrolled 65 participants, exceeding the target enrollment, indicating strong interest and potential for the treatment[15] - Statistically significant improvement in MG-ADL score for both claseprubart arms vs. placebo at Week 13, with mean changes of -1.8 for 300mg/2mL and -2.6 for 600mg/4mL[17] - 60% of participants on claseprubart 300mg/2mL achieved a ≥5 point improvement in MG-ADL at Week 13[21] - Statistically significant improvement in QMG score for both claseprubart arms vs. placebo at Week 13, with mean changes of -2.4 for 300mg/2mL and -2.5 for 600mg/4mL[18] - 37% of 300mg/2mL claseprubart-treated participants achieved Minimal Symptom Expression on MG-ADL at Week 13[23] - Statistically significant improvement in MGC score for both claseprubart arms vs. placebo at Week 13, with mean changes of -5.5 for 300mg/2mL and -5.6 for 600mg/4mL[24] - Statistically significant improvement in MG-QoL-15r score for 300mg/2mL vs. placebo at Week 13, with a mean change of -2.2[25] - Claseprubart demonstrated robust and clinically meaningful responses across key efficacy measures, achieving statistical significance vs. placebo across all five key efficacy measures for the 300mg/2mL treatment arm[26] - Claseprubart demonstrated robust reductions in MG-ADL and QMG scores, with a mean change of -3.0 in MG-ADL from baseline in patients receiving the treatment[32] Safety and Tolerability - Claseprubart was generally well tolerated, with a comparable clinical safety profile to placebo and no significant adverse events reported[29] - The proportion of participants achieving MG-ADL score of 0 or 1 was 14% for placebo, 37% for 300mg/2mL, and 23% for 600mg/4mL[26] - In Phase 1 trials, Claseprubart was generally well tolerated with no serious adverse events reported, and only mild/moderate treatment-related adverse events were observed[73] Dosing and Administration - The company is targeting a dosing regimen of 300mg/2mL every two weeks for Claseprubart, which supports convenient, infrequent self-administration[14] - Claseprubart's target profile aims for a patient-friendly administration with a single 300mg/2mL subcutaneous dose every two weeks, potentially replacing the current standard of care[38] - Claseprubart is designed for Q2W self-administration via a 300mg/2mL subcutaneous autoinjector, enhancing patient convenience[46] - The rationale for Q4W 300mg/2mL dosing is based on potential for enhanced, best-in-class efficacy in generalized Myasthenia Gravis (gMG)[30] Future Trials and Development - Claseprubart is expected to initiate its Phase 3 trial for gMG in 2026, with interim responder analysis planned for Q2 2026 and top-line results for Phase 2 MMN expected in the second half of 2026[3] - The Phase 3 trial design includes a new screening criterion of QMG >10 and MG-ADL >6, aiming to enhance efficacy and dosing convenience[34] - Interim responder analysis for the CIDP pivotal trial is expected to include the first 40 patients by Q2 2026, with a focus on a 52-week placebo-controlled study[40] - The Phase 2 trial for claseprubart in MMN is ongoing, with top-line data expected in the second half of 2026[48] Financial Position - The company has a strong financial position with approximately $514 million in cash, providing a runway into 2028 to fund multiple near-term catalysts[3] - The company has a strong balance sheet with approximately $514 million in cash, providing a runway into 2028[60] Mechanism of Action - The dual mechanism of action of Claseprubart targets both innate and adaptive immune systems, demonstrating superior in vitro efficacy compared to existing treatments[4] - Claseprubart selectively inhibits the classical pathway of the complement system, preserving alternative and lectin pathways, which may lower the risk of infections compared to downstream inhibitors[65] - In vitro studies indicate that Claseprubart maintains bacterial killing against Neisseria meningitidis, suggesting a differentiated safety profile compared to C5 inhibitors[65] - Claseprubart demonstrated superior classical pathway potency with an IC50 of 3.8 ± 0.8 µg/mL, approximately 6 times more potent than empasiprubart at 22.1 ± 5.7 µg/mL[45] - Claseprubart has shown superior affinity and potency compared to riliprubart, with an approximately 8X improvement in blocking the complement cascade[39] Intellectual Property - The expected expiration of the composition of matter patent for DNTH212 is no earlier than 2044, ensuring robust intellectual property protection[58]

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _________________ to _________________ Commission File Number: 001-38541 Dianthus Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) ...

[Filing Information](index=1&type=section&id=Filing%20Information) This section details the registrant's identification, contact information, registered securities, and emerging growth company status [Registrant Details](index=1&type=section&id=Registrant%20Details) This section provides the core identification details for Dianthus Therapeutics, Inc., including its legal name, jurisdiction of incorporation, principal executive offices, and contact information - The exact name of the Registrant is **DIANTHUS THERAPEUTICS, INC.**[2](index=2&type=chunk) - The Registrant's jurisdiction of incorporation is Delaware[2](index=2&type=chunk) - The address of Principal Executive Offices is 7 Times Square, 43rd Floor, New York, New York 10036, with telephone number (929) 999-4055[2](index=2&type=chunk) [Securities and Status](index=1&type=section&id=Securities%20and%20Status) This part outlines the company's registered securities and its status regarding emerging growth company provisions Registered Securities | Title of each class | Symbol(s) | Name of each exchange on which registered | | :------------------ | :-------- | :---------------------------------------- | | Common Stock, $0.001 Par Value | DNTH | The Nasdaq Capital Market | - The registrant indicated it is not an emerging growth company[4](index=4&type=chunk) [Item 1.01 Entry into a Material Definitive Agreement](index=3&type=section&id=Item%201.01%20Entry%20into%20a%20Material%20Definitive%20Agreement) Dianthus Therapeutics, Inc. entered into a significant exclusive license and collaboration agreement with Nanjing Leads Biolabs Co. Ltd. for DNTH212 [License Agreement with Nanjing Leads Biolabs Co. Ltd.](index=3&type=section&id=License%20Agreement%20with%20Nanjing%20Leads%20Biolabs%20Co.%20Ltd.) Dianthus Therapeutics, Inc. entered into an exclusive, royalty-bearing License and Collaboration Agreement with Nanjing Leads Biolabs Co. Ltd. for the development and commercialization of DNTH212 (LBL-047) globally outside of Greater China [Agreement Overview](index=3&type=section&id=Agreement%20Overview) Dianthus secured an exclusive, royalty-bearing license for DNTH212 (LBL-047) from Leads Biolabs, covering development, manufacturing, and commercialization outside Greater China. DNTH212 is an investigational bifunctional fusion protein targeting BDCA2 and inhibiting BAFF/APRIL - On October 16, 2025, Dianthus Therapeutics, Inc. entered into a License and Collaboration Agreement with Nanjing Leads Biolabs Co. Ltd.[6](index=6&type=chunk) - Dianthus obtained a royalty-bearing, exclusive license outside of Greater China to develop, manufacture, commercialize, or otherwise exploit LBL-047, referred to as DNTH212[6](index=6&type=chunk) - DNTH212 is an investigational, extended half-life bifunctional fusion protein targeting plasmacytoid dendritic cell (pDC) BDCA2 to reduce Type 1 interferon production, while simultaneously inhibiting BAFF/APRIL to suppress B cell function[6](index=6&type=chunk) [Financial Terms (Consideration)](index=3&type=section&id=Financial%20Terms%20(Consideration)) Dianthus will make upfront and near-term milestone payments of up to $38 million to Leads, with potential additional payments of up to $962 million for development, regulatory approval, and sales-based milestones across five indications, plus tiered royalties on net sales outside Greater China License Agreement Financial Terms | Payment Type | Amount | | :----------- | :----- | | Upfront and Near-term Milestone Payments | Up to **$38 million** (comprised of $30 million upfront/near-term + $8 million upon Phase 1 study initiation) | | Development and Regulatory Approval Milestones | Up to **$962 million** (across five indications) | | Sales-based Milestones | Included in the $962 million total | | Tiered Royalties | Mid-single digits up to a low double-digit on ex-Greater China net sales | [Governance and Development](index=3&type=section&id=Governance%20and%20Development) A joint steering committee will oversee DNTH212 activities. Leads retains the right to participate in Dianthus's global clinical studies and enroll patients in Greater China, bearing associated costs for those patients - A joint steering committee will oversee manufacturing, development, and commercial activities related to DNTH212[8](index=8&type=chunk) - Leads will have the right to participate in Dianthus's global clinical studies with DNTH212 and enroll patients in Greater China, being responsible for certain costs for those patients[8](index=8&type=chunk) [Non-Competition Clause](index=3&type=section&id=Non-Competition%20Clause) Both Dianthus and Leads are contractually prohibited from engaging in research, development, manufacturing, or commercialization of competing products within Dianthus's licensed territory outside of Greater China - Leads and Dianthus are prohibited from directly or indirectly researching, developing, manufacturing, or commercializing a competing product in Dianthus's territory outside of Greater China[9](index=9&type=chunk) [Term and Termination](index=3&type=section&id=Term%20and%20Termination) The License Agreement remains effective on a country-by-country and product-by-product basis until the expiration of the applicable royalty term, unless terminated earlier. Both parties have customary termination rights, including for material breach, insolvency, patent challenge, or, for Dianthus, for convenience - The License Agreement will remain in effect on a country-by-country and product-by-product basis until the expiration of the applicable royalty term, unless earlier terminated[10](index=10&type=chunk) - Each party has customary termination rights, including for uncured material breach, insolvency, patent challenge, or, in the case of Dianthus, for convenience[10](index=10&type=chunk) [Item 2.02 Results of Operations and Financial Condition](index=3&type=section&id=Item%202.02%20Results%20of%20Operations%20and%20Financial%20Condition) This item incorporates by reference the preliminary financial information for the three months ended September 30, 2025, as disclosed under Item 8.01. It clarifies that such information is 'furnished' rather than 'filed,' limiting its liability and restrictions on incorporation by reference - Preliminary financial information for the three months ended September 30, 2025, set forth under 'Preliminary Financial Information for the Three Months Ended September 30, 2025' in Item 8.01, is incorporated by reference[12](index=12&type=chunk) - This information is 'furnished' and not 'filed,' meaning it is not subject to the liability provisions of Section 18 of the Exchange Act or Sections 11 and 12(a)(2) of the Securities Act, and generally cannot be incorporated by reference into other filings[13](index=13&type=chunk) [Item 8.01 Regulation FD Disclosure and Preliminary Financial Information](index=3&type=section&id=Item%208.01%20Regulation%20FD%20Disclosure%20and%20Preliminary%20Financial%20Information) This section details the public disclosure of the License Agreement and provides preliminary unaudited financial estimates for Q3 2025 [Regulation FD Disclosure](index=3&type=section&id=Regulation%20FD%20Disclosure) On October 16, 2025, Dianthus made a presentation publicly available on its investor relations website, announcing the License Agreement in conjunction with an investor conference call. This presentation is filed as Exhibit 99.1 - On October 16, 2025, Dianthus made a presentation publicly available on its investor relations website, announcing the execution of the License Agreement[14](index=14&type=chunk) - The presentation was in connection with a conference call with investors held at 8:00 a.m. ET on October 16, 2025, and is filed as Exhibit 99.1[14](index=14&type=chunk) [Preliminary Financial Information for the Three Months Ended September 30, 2025](index=5&type=section&id=Preliminary%20Financial%20Information%20for%20the%20Three%20Months%20Ended%20September%2030,%202025) Dianthus disclosed preliminary estimated cash, cash equivalents, and investments of approximately $555 million as of September 30, 2025. Pro forma cash, after deducting $30 million in upfront and near-term milestone payments to Leads, is estimated at $525 million. This information is unaudited and subject to change Preliminary Cash and Investments | Financial Metric | Amount (as of Sept 30, 2025) | | :--------------- | :--------------------------- | | Estimated Cash, Cash Equivalents and Investments | ~**$555 million** | | Pro Forma Cash, Cash Equivalents and Investments | ~**$525 million** (after deducting $30 million in upfront and near-term milestone payments to Leads) | - The disclosed financial information is preliminary, has not been audited, and is subject to change pending completion of the Company's unaudited financial statements[15](index=15&type=chunk) - The Company's independent registered public accounting firm has not audited, reviewed, or performed any procedures with respect to this preliminary information and does not express an opinion or any other form of assurance[15](index=15&type=chunk) [Forward-Looking Statements](index=5&type=section&id=Forward-Looking%20Statements) This section contains a standard disclaimer regarding forward-looking statements, emphasizing that they are based on current estimates and assumptions, subject to various risks and uncertainties, and actual results may differ materially. The company claims Safe Harbor protection and disclaims any obligation to update these statements, except as required by law - This report contains 'forward-looking statements' regarding expected financial results and the License Agreement, identified by specific terminology[16](index=16&type=chunk) - These statements are based on current estimates and assumptions, subject to various risks and uncertainties, many beyond the Company's control, and actual results could be materially different[16](index=16&type=chunk) - The Company claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements and disclaims any obligation to update or alter any statements, except as required by law[16](index=16&type=chunk) [Item 9.01 Financial Statements and Exhibits](index=5&type=section&id=Item%209.01%20Financial%20Statements%20and%20Exhibits) This item lists the exhibits filed as part of this Form 8-K, including the Company Presentation and the Cover Page Interactive Data File Filed Exhibits | Exhibit No. | Description | | :---------- | :---------- | | 99.1 | Company Presentation, dated October 16, 2025 | | 104 | Cover Page Interactive Data File (embedded within the inline XBRL document) | [SIGNATURES](index=6&type=section&id=SIGNATURES) This section confirms the official signing of the report on behalf of Dianthus Therapeutics, Inc. by an authorized officer - The report was signed on October 16, 2025, by Adam M. Veness, Esq., SVP, General Counsel and Secretary of Dianthus Therapeutics, Inc.[21](index=21&type=chunk)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _________________ to _________________ Commission File Number: 001-38541 Dianthus Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) | Del ...

Financial Performance - The net loss for Q2 2025 was $31.6 million, or $0.88 per share, compared to a net loss of $17.6 million, or $0.51 per share, in Q2 2024 [17]. - Total revenues for Q2 2025 were $193,000, a decrease from $1,863,000 in Q2 2024, while total revenues for the six months ended June 30, 2025, were $1,356,000 compared to $2,737,000 in the same period of 2024 [23]. - The net loss for Q2 2025 was $31,629,000, compared to a net loss of $17,607,000 in Q2 2024, resulting in a net loss of $61,140,000 for the six months ended June 30, 2025, versus $31,355,000 in 2024 [23]. - The net loss per share attributable to common stockholders was $(0.88) for Q2 2025, compared to $(0.51) for Q2 2024, with a total of $(1.71) for the six months ended June 30, 2025, versus $(0.99) in 2024 [23]. - Total operating expenses for Q2 2025 were $35,120,000, an increase from $24,067,000 in Q2 2024, with total operating expenses for the six months ended June 30, 2025, reaching $69,460,000 compared to $42,785,000 in 2024 [23]. - Interest and investment income for Q2 2025 was $3,403,000, down from $4,708,000 in Q2 2024, with total interest and investment income for the six months ended June 30, 2025, at $7,194,000 compared to $8,930,000 in 2024 [23]. - The company reported a total comprehensive loss of $31,801,000 for Q2 2025, compared to $17,617,000 in Q2 2024, with a total comprehensive loss of $61,148,000 for the six months ended June 30, 2025, versus $31,439,000 in 2024 [23]. Research and Development - Research and development (R&D) expenses for Q2 2025 were $26.3 million, up from $18.1 million in Q2 2024, primarily due to increased clinical costs and headcount [12][17]. - Research and development expenses increased to $26,251,000 in Q2 2025 from $18,070,000 in Q2 2024, and for the six months ended June 30, 2025, they rose to $53,254,000 from $31,148,000 in 2024 [23]. - Enrollment in the Phase 2 MaGic trial exceeded the target, completing with 65 patients [7]. - The ongoing Phase 3 CAPTIVATE trial in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is on track for an interim responder analysis in the second half of 2026 [8]. - The Phase 2 MoMeNtum trial in Multifocal Motor Neuropathy (MMN) is also ongoing, with top-line results expected in the second half of 2026 [9]. Administrative Expenses - General and administrative (G&A) expenses for Q2 2025 totaled $8.9 million, compared to $6.0 million in Q2 2024, reflecting increased headcount [17]. - General and administrative expenses were $8,869,000 in Q2 2025, up from $5,997,000 in Q2 2024, with a total of $16,206,000 for the six months ended June 30, 2025, compared to $11,637,000 in 2024 [23]. Cash and Investments - The company has $309.1 million in cash, cash equivalents, and investments as of June 30, 2025, projected to provide a runway into the second half of 2027 [2][12]. Product Development - Claseprubart is designed for subcutaneous, self-administered injection, potentially allowing for administration as infrequently as once every two weeks [5][13]. - The company aims to build a neuromuscular franchise with claseprubart, targeting a range of autoimmune disorders with high unmet needs [13].

Financial Performance - Total revenues for the three months ended March 31, 2025, were $1.163 million, an increase from $0.874 million in the same period of 2024, representing a 33% growth[18]. - The net loss for the three months ended March 31, 2025, was $29.511 million, compared to a net loss of $13.748 million in 2024, representing a 115% increase in losses[18]. - The net loss per share attributable to common stockholders was $0.82 for the first quarter of 2025, compared to $0.54 in the same quarter of 2024[18]. - For the three months ended March 31, 2025, the net loss was $29.511 million, compared to a net loss of $13.748 million for the same period in 2024, representing an increase of 114%[24]. - The Company reported net losses of $29.5 million and $13.7 million for the three months ended March 31, 2025 and 2024, respectively, with an accumulated deficit of $203.9 million as of March 31, 2025[44]. - Basic and diluted net loss per share was $(0.82) for the three months ended March 31, 2025, compared to $(0.54) for the same period in 2024[107]. Expenses - Research and development expenses for the same period were $27.003 million, up from $13.078 million in 2024, indicating a 106% increase[18]. - General and administrative expenses rose to $7.337 million from $5.640 million, reflecting a 30% increase year-over-year[18]. - Cash used in operating activities for the three months ended March 31, 2025, was $27.630 million, compared to $14.941 million for the same period in 2024, indicating an 85% increase in cash outflow[24]. - The company incurred stock-based compensation expenses of $5.315 million for the three months ended March 31, 2025, compared to $2.035 million for the same period in 2024, reflecting a 161% increase[24]. - The Company recorded operating lease costs of $135 million for the three months ended March 31, 2025, compared to $111 million for the same period in 2024[66]. Cash and Assets - Cash and cash equivalents decreased to $10.116 million as of March 31, 2025, down from $22.792 million at the end of 2024[16]. - Total current assets were $270.999 million as of March 31, 2025, compared to $280.904 million at the end of 2024[16]. - The company reported cash, cash equivalents, and restricted cash of $10.347 million as of March 31, 2025, down from $329.790 million at the end of the previous year[24]. - As of March 31, 2025, the total cash equivalents amounted to $9,254 million, while total marketable securities were $321,422 million, reflecting a decrease from $334,177 million as of December 31, 2024[57][63]. - The total assets measured at fair value as of March 31, 2025, were $330,819 million, a decrease from $356,271 million as of December 31, 2024[62][63]. Liabilities and Equity - Total liabilities decreased to $19.974 million from $21.531 million at the end of 2024[16]. - The company’s total stockholders' equity as of March 31, 2025, was $328.606 million, compared to $168.870 million as of December 31, 2023, showing a significant increase[24]. Business Developments - The company completed a business combination with Former Dianthus on September 11, 2023, which resulted in Former Dianthus becoming a wholly owned subsidiary[13]. - The company completed a reverse merger on September 11, 2023, resulting in the issuance of 14,817,696 shares of common stock[28]. - The Company raised approximately $72.0 million in pre-closing financing through the issuance of common stock and pre-funded warrants prior to the reverse merger[35]. - The Company raised approximately $230 million through a private placement by issuing 14,500,500 shares of common stock at $12.00 per share and pre-funded warrants for 4,666,332 shares at $11.999 each[36]. Research and Development - The company is focused on advancing the development of DNTH103 and other product candidates, with ongoing preclinical and clinical drug development activities[8]. - The Company has been focusing on developing next-generation complement therapeutics for severe autoimmune and inflammatory diseases, with significant resources allocated to research and development[26][27]. - The Company has not generated any revenue from product sales yet, and its financial performance is assessed based on net loss[54]. - The Company expects to continue incurring significant recurring losses and will rely on outside capital for operations in the foreseeable future[44]. - The Company has potential obligations to pay up to $1.8 million and $11.0 million in development and commercial milestone payments, respectively, to Alloy Therapeutics upon achieving certain milestones[109]. - The Company has potential payments of up to $12.2 million to OmniAb upon achieving certain development milestones[110]. Revenue Recognition - The Company recognized revenue of $1.2 million associated with the Tenacia License Agreement during the three months ended March 31, 2025[106]. - The Company recognized $1.0 million in revenue related to milestones achieved under the Tenacia Agreements during the three months ended March 31, 2025[103]. - The Company has not recorded any royalty revenue to date, as it has not yet satisfied the performance obligations related to its licenses[104]. Stock and Options - The Company issued an aggregate of 11,021,248 shares of common stock to Former Dianthus stockholders during the Reverse Merger on September 11, 2023[72]. - As of March 31, 2025, the company had issued 32,125,933 shares of common stock out of an authorized 150,000,000 shares[74]. - The total common stock reserved for future issuance increased to 11,729,465 shares as of March 31, 2025, up from 11,187,790 shares as of December 31, 2024[75]. - The company had 5,927,868 stock options outstanding as of March 31, 2025, with a weighted average exercise price of $18.50[87]. - The Company reported total stock-based compensation expense of $5.315 million for the three months ended March 31, 2025, compared to $2.035 million for the same period in 2024[91]. - As of March 31, 2025, there was $61.2 million of total unrecognized compensation cost related to granted stock options, expected to be recognized over a remaining weighted-average period of 3.1 years[91]. - The weighted average grant-date fair value per share of stock options granted during the three months ended March 31, 2025, was $16.99[88]. - The Company reported an increase in the number of shares reserved for issuance under the 2018 Amended Plan by 1,555,767 shares on January 1, 2025, due to the Evergreen Provision[81]. Risks and Concerns - The Company is subject to risks including product development uncertainty, dependence on key personnel, and market acceptance of products[38]. - The Company has evaluated its ability to continue as a going concern and expects existing cash and investments to fund obligations for at least twelve months beyond the issuance date[44]. - The Company has experienced negative operating cash flows since its inception, indicating ongoing financial challenges[27]. - The Company has excluded potential dilutive securities from the computation of diluted net loss per share due to their antidilutive effect, totaling 5,932,545 shares for the three months ended March 31, 2025[108].

Exhibit 99.1 DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q1 FINANCIAL RESULTS Completed enrollment in Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG)s Top-line MaGic results anticipated in September 2025 to be the first of three catalysts for the DNTH103 neuromuscular franchise by YE'26 Phase 3 CAPTIVATE trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) ongoing; interim responder analysis anticipated in 2H'26 Phase 2 MoMeNtum tri ...