Multifocal Motor Neuropathy

Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG) ongoing; top-line results on track for 2H’25 Phase 3 CAPTIVATE trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) ongoing; interim responder analysis anticipated in 2H’26 Phase 2 MoMeNtum trial of DNTH103 in Multifocal Motor Neuropathy (MMN) ongoing; top-line results anticipated in 2H’26 $357.0 million of cash provides runway into 2H’27 NEW YORK and WALTHAM, Mass., March 11, 2025 (GLOBE NEWSWIRE) -- Dianthus Therapeutics, Inc. (Nasdaq: DNTH), a clinical-stage biotechnology company dedicated to advancing the next generation of antibody complement therapeutics to treat severe autoimmune diseases, today reported financial results for the fourth quarter and full year ending December 31, 2024 and provided an update on recent business achievements. “We remain on track to report top-line data in 2H’25 from our Phase 2 clinical trial of DNTH103 in gMG, an indication where a best-in-class, potent active C1s and classical pathway inhibitor with the potential for effective and consistent symptom control along with improved safety and convenience could meaningfully advance the standard of care,” said Marino Garcia, Chief Executive Officer of Dianthus Therapeutics. “We are excited to have initiated our pivotal Phase 3 CAPTIVATE trial in CIDP, which is on track for an interim responder analysis in 2H’26, along with top-line results from our Phase 2 trial in MMN.” DNTH103 Clinical Development DNTH103 is an investigational, clinical-stage, potent monoclonal antibody engineered to selectively target the classical pathway by inhibiting only the active form of the C1s protein, a clinically validated complement target. DNTH103 is enhanced with YTE half-life extension technology designed to enable a more convenient subcutaneous, self-administered injection dosed as infrequently as once every two weeks. DNTH103 has the potential to be a best-in-class pipeline-in-a-product across a range of autoimmune disorders with high unmet need. Generalized Myasthenia Gravis (gMG) Phase 2 MaGic gMG trial ongoing: The MaGic trial is a global, randomized, double-blind, placebo-controlled Phase 2 trial in patients with gMG who are acetylcholine receptor (AChR) antibody positive, and it remains on track to report top-line results in 2H’25. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Phase 3 CAPTIVATE CIDP trial ongoing: The CAPTIVATE trial is a single, global, two-part, randomized withdrawal Phase 3 trial in patients with CIDP, and it remains on track for an interim responder analysis in 2H’26. The Company believes this single pivotal trial will support a BLA filing in adult patients with CIDP. Multifocal Motor Neuropathy (MMN) Phase 2 MoMeNtum MMN trial ongoing: The MoMeNtum trial is a global, randomized, double-blind, placebo-controlled Phase 2 trial in patients with MMN, and it remains on track to report top-line results in 2H’26. Corporate Updates On March 5, 2025, John C. King was announced as Chief Commercial Officer and Sujay Kango joined the Company’s Board of Directors. Mr. King brings to Dianthus more than 25 years of global commercial leadership experience in biotechnology, including neuromuscular and hematological rare diseases. Mr. Kango is an experienced executive with more than 26 years of experience in the pharmaceutical and biotechnology sector. Full Year 2024 Financial Results Cash Position - $357.0 million of cash, cash equivalents and investments as of December 31, 2024 is projected to provide runway into the second half of 2027. R&D Expenses - Research and development (R&D) expenses for the year ended December 31, 2024 were $83.1 million, inclusive of $5.6 million of stock-based compensation, compared to $32.8 million for the year ended December 31, 2023, which included $0.9 million of stock-based compensation. This increase in R&D expenses was primarily driven by higher clinical costs, chemistry, manufacturing and controls (CMC) costs and increased headcount to support DNTH103 Phase 2 and Phase 3 development. G&A Expenses - General and administrative (G&A) expenses for the year ended December 31, 2024 totaled $25.0 million, inclusive of stock-based compensation of $7.3 million, compared to $18.2 million for the year ended December 31, 2023, which included $2.0 million of stock-based compensation. This increase in G&A expenses was primarily due to increased headcount and higher professional services costs. Net Loss - Net loss for the year ended December 31, 2024 was $85.0 million or $2.55 per share (basic and diluted) compared to $43.6 million or $8.45 per share (basic and diluted) for the year ended December 31, 2023. Additional Information - For additional information on the Company’s financial results for the year ended December 31, 2024, please refer to the Form 10-K filed with the SEC. About DNTH103DNTH103 is an investigational, clinical-stage, potent monoclonal antibody engineered to selectively target the classical pathway by inhibiting only the active form of the C1s protein, a clinically validated complement target. DNTH103 is enhanced with YTE half-life extension technology designed to enable a more convenient subcutaneous, self-administered injection dosed as infrequently as once every two weeks. Additionally, selective inhibition of the classical complement pathway may lower patient risk of infection from encapsulated bacteria by preserving immune activity of the lectin and alternative pathways. As the classical pathway plays a significant role in disease pathology, DNTH103 has the potential to be a best-in-class pipeline-in-a-product across a range of autoimmune disorders with high unmet need. Dianthus is building a neuromuscular franchise with DNTH103 and anticipates reporting top-line data from the Phase 2 MaGic trial in generalized Myasthenia Gravis in 2H’25, the interim responder analysis of the Phase 3 CAPITIVATE trial in Chronic Inflammatory Demyelinating Polyneuropathy in 2H’26, and top-line data from the Phase 2 MoMeNtum trial in Multifocal Motor Neuropathy in 2H’26. DNTH103 is an investigational agent that is not approved as a therapy in any indication in any jurisdiction worldwide. About Dianthus TherapeuticsDianthus Therapeutics is a clinical-stage biotechnology company dedicated to designing and delivering novel, best-in-class monoclonal antibodies with improved selectivity and potency. Based in New York City and Waltham, Mass., Dianthus is comprised of an experienced team of biotech and pharma executives who are leading the development of next-generation antibody complement therapeutics, aiming to deliver transformative medicines for people living with severe autoimmune and inflammatory diseases. To learn more, please visit www.dianthustx.com and follow us on LinkedIn. Cautionary Statement Regarding Forward-Looking Statements Certain statements in this press release, other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995, express or implied statements regarding future plans and prospects, including statements regarding the expectations or plans for discovery, preclinical studies, clinical trials and research and development programs, in particular with respect to DNTH103, and any developments or results in connection therewith, including the target product profile of DNTH103; the anticipated timing of the initiation and results from those studies and trials; expectations regarding the time period over which the Company’s capital resources are expected to be sufficient to fund its anticipated operations; and expectations regarding the market and potential opportunities for complement therapies, in particular with respect to DNTH103. The words “opportunity,” “potential,” “milestones,” “runway,” “will,” “anticipate,” “achieve,” “near-term,” “catalysts,” “pursue,” “pipeline,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “possible,” “predict,” “project,” “should,” “strive,” “would,” “aim,” “target,” “commit,” and similar expressions (including the negatives of these terms or variations of them) generally identify forward-looking statements, but the absence of these words does not mean that statement is not forward looking. Actual results could differ materially from those included in the forward-looking statements due to various factors, risks and uncertainties, including, but not limited to, that preclinical testing of DNTH103 and data from clinical trials may not be predictive of the results or success of ongoing or later clinical trials, that the development of DNTH103 or the Company's other compounds may take longer and/or cost more than planned, that the Company may be unable to successfully complete the clinical development of the Company’s compounds, that the Company may be delayed in initiating, enrolling or completing its planned clinical trials, and that the Company's compounds may not receive regulatory approval or become commercially successful products. These and other risks and uncertainties are identified under the heading "Risk Factors" included in the Company’s Annual Report on Form 10-K for the period ended December 31, 2024, and other filings that the Company has made and may make with the SEC in the future. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. The forward-looking statements in this press release speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. Dianthus undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. Contact Jennifer Davis RuffDianthus Therapeuticsjdavisruff@dianthustx.com Dianthus Therapeutics, Inc.Consolidated Balance Sheets(in thousands, except share and per share data)(unaudited) ASSETSDecember 31,2024 December 31,2023Current assets: Cash and cash equivalents$22,792 $132,325 Short-term investments 252,449 41,393 Receivable from related party 807 294 Unbilled receivable from related party — 184 Prepaid expenses and other current assets 4,856 3,255 Total current assets 280,904 177,451 Long-term investments 81,728 — Property and equipment, net 194 185 Right-of-use operating lease assets 1,553 615 Other assets and restricted cash 9,629 1,154 Total assets$374,008 $179,405 LIABILITIES AND STOCKHOLDERS’ EQUITY Current liabilities: Accounts payable$4,579 $2,610 Accrued expenses 13,074 6,504 Current portion of deferred revenue 479 — Current portion of deferred revenue – related party — 100 Current portion of operating lease liabilities 320 417 Total current liabilities 18,452 9,631 Deferred revenue 1,908 — Deferred revenue – related party — 736 Long-term operating lease liabilities 1,171 168 Total liabilities 21,531 10,535 Commitments and contingencies Stockholders' equity: Preferred stock — — Common stock 31 15 Additional paid-in capital 526,732 258,231 Accumulated deficit (174,392) (89,423)Accumulated other comprehensive income 106 47 Total stockholders' equity 352,477 168,870 Total liabilities and stockholders' equity$374,008 $179,405 Dianthus Therapeutics, Inc.Consolidated Statements of Operations and Comprehensive Loss(in thousands, except share and per share data)(unaudited) Three Months Ended December 31, Year Ended December 31, 2024 2023 2024 2023 Revenues: License revenue – related party$999 $457 $5,909 $2,826 License revenue 326 — 326 — Total revenues 1,325 457 6,235 2,826 Operating expenses: Research and development 26,413 8,781 83,105 32,841 General and administrative 6,828 4,632 24,994 18,159 Total operating expenses 33,241 13,413 108,099 51,000 Loss from operations (31,916) (12,956) (101,864) (48,174) Other income/(expense): Interest income 3,991 2,444 17,365 4,764 Gain/(loss) on investment in related party (160) — 148 — Gain/(loss) on currency exchange, net 27 (32) (64) (85)Other expense (380) (19) (554) (60)Total other income 3,478 2,393 16,895 4,619 Net loss$(28,438) $(10,563) $(84,969) $(43,555) Net loss per share attributable to common stockholders, basic and diluted$(0.81) $(0.71) $(2.55) $(8.45) Weighted-average number of shares of common stock outstanding, used in computing net loss per share of common stock, basic and diluted 35,033,773 14,817,676 33,313,849 5,153,423 Comprehensive loss: Net Loss$(28,438) $(10,563) $(84,969) $(43,555)Other comprehensive income/(loss): Unrealized gains/(losses) on marketable securities (575) 51 59 208 Total other comprehensive income/(loss) (575) 51 59 208 Total comprehensive loss$(29,013) $(10,512) $(84,910) $(43,347)

Reported $2.2 billion in preliminary* full-year 2024 global product net sales, inclusive of $737 million in fourth quarter sales Pre-filled syringe FDA PDUFA on track for April 2025 to support reaching patients earlier in treatment paradigm 10 ongoing registrational studies in 2025 across efgartigimod and empasiprubart enable next wave of indications Empasiprubart to be evaluated in two head-to-head registrational studies against IVIg to position C2 inhibitor for broad, early-line use in MMN and CIDP Transition to sustainable profitability in 2025 enables continued investment in innovation January 13, 2025, 7:00 AM CET Amsterdam, the Netherlands – argenx SE (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases, today reported preliminary financial results for the full-year 2024, including global product net sales, and announced its strategic priorities for 2025. “2024 was a transformative year as we significantly expanded our global patient reach with VYVGART and advanced a world-class pipeline of precision therapies,” said Tim Van Hauwermeiren, Chief Executive Officer of argenx. “The team’s strong execution has positioned argenx to be a profitable company in 2025, providing us flexibility to invest in the next wave of innovation across the company. Today, we are all in on our innovation mission, applying our successful innovation playbook to bring transformational outcomes to even more patients by unleashing the next wave of autoimmune indications and therapies, and securing our future by advancing multiple programs against first-in-class targets. We are positioned for significant expansion in 2025 with the FDA decision on approval of our pre-filled syringe, global CIDP rollout, and label-expansion studies underway for MG. To further support our growth, we are thrilled to have 10 ongoing registrational and 10 proof-of-concept studies in 2025, teeing us up for several data readouts across our pipeline in the next 12-24 months. “Innovation is the cornerstone of everything we do, from the foundational science all the way to payor negotiations; it is our goal to deliver innovative and disruptive science for the benefit of patients who need better access to transformational safe, effective, and convenient precision therapies. Innovation has no meaning unless it reaches the marketplace, and we will continue to prioritize patient outcomes in all that we do.” 2025 Strategic Priorities argenx established its ‘Vision 2030’ to outline the next phase of growth as part of its long-term commitment to transform the treatment of autoimmune diseases. Through this vision, argenx aims to treat 50,000 patients globally with its medicines, secure 10 labeled indications across all approved medicines, and advance five pipeline candidates into Phase 3 development by 2030. To achieve the goals set out in its ‘Vision 2030’, argenx has set the following priorities for 2025: Expand the global VYVGART opportunity by reaching more patients broadly across MG, CIDP and ITP through additional regulatory approvals and continuous evidence generationLaunch VYVGART SC as a pre-filled syringe to innovate on the patient experience and move earlier in the MG and CIDP treatment paradigmsExecute 10 registrational and 10 proof-of-concept studies to fuel pipeline growth across efgartigimod, empasiprubart and ARGX-119Advance four new molecules into Phase 1 development, expanding the next wave of innovationGenerate sustainable value through continued investment in the Immunology Innovation Program, focused on first-in-class, antibody-based medicines with pipeline-in-a-product potential Expand the global VYVGART opportunity and launch VYVGART SC as a pre-filled syringe VYVGART® (IV: efgartigimod alfa-fcab and SC: efgartigimod alfa and hyaluronidase-qvfc) is a first-in-class FcRn blocker approved in three indications, including generalized myasthenia gravis (gMG) globally, primary immune thrombocytopenia (ITP) in Japan, and chronic inflammatory demyelinating polyneuropathy (CIDP) in the U.S., Japan, and China. Regulatory decisions on approval of VYVGART for gMG expected in first half of 2025, including in Israel (SC), South Korea (IV), and Kuwait (IV)Continued innovation around the patient experience for VYVGART SC, including four key regulatory decisions on approval expected in 2025 FDA review ongoing of pre-filled syringe (PFS) for gMG and CIDP with Prescription Drug User Fee Act (PDUFA) target action date of April 10, 2025PFS decisions on approval for gMG and CIDP expected in Europe in first half of 2025 and Japan and Canada in second half of 2025Autoinjector development underway with launch planned for 2027 Evidence generation through Phase 4 and label-enabling studies in MG, CIDP and ITP Label-enabling studies ongoing to reach broader MG populations, including ADAPT-SERON (seronegative gMG), ADAPT-JR (pediatric) and ADAPT-OCULUS (ocular MG), with topline results expected in second half of 2025 (SERON) and first half of 2026 (OCULUS and JR)Phase 4 switch study ongoing in CIDP to inform treatment decisions when switching a patient on IVIg to VYVGART SCADVANCE-NEXT confirmatory study ongoing of VYVGART IV in primary ITP to support FDA submission with topline results expected in second half of 2026 Execute 10 registrational and 10 proof-of-concept studies across efgartigimod, empasiprubart and ARGX-119 argenx continues to demonstrate breadth and depth within its immunology pipeline, advancing multiple first-in-class product candidates with potential across multiple high-need indications. argenx is solidifying its leadership in FcRn biology with efgartigimod, complement inhibition with empasiprubart and in the role of MuSK at the neuromuscular junction with ARGX-119. In 2025, argenx plans to execute 10 registrational and 10 proof-of-concept studies across efgartigimod, empasiprubart and ARGX-119 to advance its next wave of launches. Efgartigimod DevelopmentEfgartigimod is being evaluated in more than 15 severe autoimmune diseases (including MG, CIDP and ITP), exploring the significance of FcRn biology across neurology and rheumatology indications, as well as new therapeutic areas. To prioritize those indications that can drive transformative benefit, argenx has made the decision to discontinue development of efgartigimod in bullous pemphigoid (BP). Registrational ALKIVIA study ongoing evaluating three myositis subsets (immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and dermatomyositis (DM); topline results expected in second half of 2026Two registrational UplighTED studies ongoing in thyroid eye disease (TED); topline results expected in second half of 2026Registrational UNITY study ongoing in primary Sjögren’s disease; topline results expected in 2027Decision made to discontinue development in BP based on results from 98 patients in the Phase 2 BALLAD studyProof of concept studies ongoing in lupus nephritis (LN), systemic sclerosis (SSc) and antibody mediated rejection (AMR); topline results expected in LN in fourth quarter of 2025, SSc in second half of 2026, and AMR in 2027Two new indications nominated, including autoimmune encephalitis (AIE) and one that will be disclosed later in 2025Externally sponsored research studies ongoing in early MG, MG crisis, Guillain-Barré syndrome (GBS), stiff person syndrome (SPS), and neuromyelitis optica spectrum disorder (NMO-SD) Empasiprubart Development argenx is evaluating empasiprubart in registrational studies in multifocal motor neuropathy (MMN) and CIDP, and proof-of-concept studies in delayed graft function (DGF) and DM. Registrational EMPASSION study ongoing in MMN evaluating empasiprubart head-to-head versus IVIg; topline results expected in second half of 2026Registrational EMVIGORATE study in CIDP evaluating empasiprubart head-to-head versus IVIg to start in first half of 2025Proof of concept studies ongoing in DGF and DM; topline results expected in DGF in second half of 2025 and in DM in first half of 2026 ARGX-119 Developmentargenx is evaluating ARGX-119 in congenital myasthenic syndromes (CMS), amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy (SMA). Phase 1b proof-of-concept study ongoing in CMS; topline results expected in second half of 2025Phase 2a proof-of-concept study ongoing in ALS; topline results expected in first half of 2026SMA nominated as third indication with proof-of-concept study to start in 2025 Advance four new pipeline molecules and generate sustainable value through continued investment in Immunology Innovation Program argenx continues to invest in its Immunology Innovation Program (IIP) to drive long-term sustainable pipeline growth. Through the IIP, four new pipeline candidates have been nominated, including: ARGX- 213, targeting FcRn and further solidifying argenx’s leadership in this new class of medicine; ARGX- 121, a first-in-class molecule targeting IgA; ARGX-109, targeting IL-6, which plays an important role in inflammation, and ARGX-220, a first-in-class sweeping antibody for which the target has not yet been disclosed. Investigational new drug (IND) applications to be filed in 2025 for ARGX-213, ARGX-121, ARGX-109 and ARGX-220; Phase 1 results expected for ARGX-109 in second half of 2025 and for ARGX-213 and ARGX-121 in first half of 2026 Preliminary* Fourth Quarter and Full-Year 2024 Financial Results Today, argenx also announced preliminary* global product net sales for the fourth quarter and full-year 2024 of approximately $737 million and $2.2 billion, respectively. As of December 31, 2024, argenx had approximately $3.4 billion in cash, cash equivalents and current financial assets*. * - The preliminary selected financial information is unaudited, subject to adjustment, and provided as an approximation in advance of the company’s announcement of complete financial results in February 2025. Refer to the Preliminary Financial Results note in this document. 2025 Financial Guidance Based on its current operating plans, argenx expects its combined R&D and SG&A expenses in 2025 to be approximately $2.5 billion. 43rd Annual J.P. Morgan Healthcare Conference Presentation and Webcast Tim Van Hauwermeiren will highlight these updates in a corporate presentation at the 43rd Annual J.P. Morgan Healthcare Conference today, Monday, January 13, 2025, at 9:45 a.m. PT. The live webcast of the presentation may be accessed under Investors on the argenx website. A replay will be available for 30 days following the presentation. About VYVGART and VYVGART SC VYVGART® is a human IgG1 antibody fragment that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG autoantibodies. It is the first approved FcRn blocker for the treatment of generalized myasthenia gravis (gMG), chronic inflammatory demyelinating polyneuropathy (CIDP), and primary immune thrombocytopenia (ITP). VYVGART SC is a subcutaneous combination of efgartigimod alfa and recombinant human hyaluronidase PH20 (rHuPH20), Halozyme’s ENHANZE® drug delivery technology to facilitate subcutaneous injection delivery of biologics. It is marketed as VYVGART® Hytrulo in the U.S., VYVGART SC in Europe, VYVDURA® in Japan, and may be marketed under different proprietary names following approval in other regions. About argenx argenx is a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases. Partnering with leading academic researchers through its Immunology Innovation Program (IIP), argenx aims to translate immunology breakthroughs into a world-class portfolio of novel antibody-based medicines. argenx developed and is commercializing the first approved neonatal Fc receptor (FcRn) blocker, globally in the U.S., Japan, Israel, the EU, the UK, China and Canada. The company is evaluating efgartigimod in multiple serious autoimmune diseases and advancing several earlier stage experimental medicines within its therapeutic franchises. For more information, visit www.argenx.com and follow us on LinkedIn, X (formerly known as Twitter), and Instagram. Media: Ben Petokbpetok@argenx.com Investors: Alexandra Roy (US)aroy@argenx.com Lynn Elton (EU)lelton@argenx.com Preliminary Financial Results The financial information presented in this press release is preliminary, estimated, and unaudited. They are subject to the completion and finalization of argenx’s financial and accounting closing procedures. They reflect management’s estimates based solely upon information available to management as of the date of this press release. Further information learned during that completion and finalization may alter the final results. In addition, the preliminary estimates should not be viewed as a substitute for full quarterly and annual financial statements prepared in accordance with IFRS. There is a possibility that argenx’s financial results for the quarter ended December 31, 2024, and full year financial results for 2024 could vary materially from these preliminary estimates. In addition to the completion of the financial closing procedures, factors that could cause actual results to differ from those described above are set forth below. Accordingly, you should not place undue reliance upon this preliminary information. Additional information regarding the company’s fourth quarter 2024 financial results and full year financial results for 2024 will be available in the company’s annual report and Form 20-F, which will be filed with the Netherlands Authority for the Financial Markets and U.S. Securities and Exchange Commission (the “SEC”), respectively. Forward Looking Statements The contents of this announcement include statements that are, or may be deemed to be, “forward-looking statements.” These forward-looking statements can be identified by the use of forward-looking terminology, including the terms “aim,” “can,” “continue,” “expect,” “goal,” “may,” “ongoing,” “plan,” “possible,” “target,” and “will,” and include statements argenx makes regarding its expected profitability in 2025; its 2025 strategic priorities, including its launch of pre-filled syringes, 10 Phase 3 studies and 10 Phase 2 studies across efgartigimod, empasiprubart and ARGX-119, the advancement of four molecules in Phase 1 studies and the continued investment in the Immunology Innovation Program; its significant expansion in 2025; the continued growth of VYVGART, including its expected autoinjector launch in 2027 and four global decisions in 2025; its expectations regarding the continued growth in CIDP, including its plan to launch multiple CIDP products in 2025 and the expected timing of the EMVIGORATE study; its expectations regarding the growth of the MMN market opportunity, including the expected timing of the EMPASSION study; the anticipated timing of data readouts and regulatory milestones and plans, including the timing of planned clinical trials and regulatory filings and approvals; its vision for 2030, including having 5 new molecules in Phase 3, 10 labeled indications and having 50,000 patients on treatment; the anticipated timing of pending regulatory decisions in Israel, South Korea, Kuwait, the U.S., Europe, Japan and Canada; the expected timing of Phase 4 and label-enabling studies in MG, CIDP and ITP; and its expected 2025 research and development and selling, general and administrative expenses. By their nature, forward-looking statements involve risks and uncertainties and readers are cautioned that any such forward-looking statements are not guarantees of future performance. argenx’s actual results may differ materially from those predicted by the forward-looking statements as a result of various important factors, including the results of argenx's clinical trials; expectations regarding the inherent uncertainties associated with the development of novel drug therapies; preclinical and clinical trial and product development activities and regulatory approval requirements in products and product candidates; the acceptance of argenx's products and product candidates by patients as safe, effective and cost-effective; the impact of governmental laws and regulations on our business; disruptions caused on our reliance of third party suppliers, service providers and manufacturing; inflation and deflation and the corresponding fluctuations in interest rates; and regional instability and conflicts. A further list and description of these risks, uncertainties and other risks can be found in argenx’s U.S. Securities and Exchange Commission (SEC) filings and reports, including in argenx’s most recent annual report on Form 20-F filed with the SEC as well as subsequent filings and reports filed by argenx with the SEC. Given these uncertainties, the reader is advised not to place any undue reliance on such forward-looking statements. These forward-looking statements speak only as of the date of publication of this document. argenx undertakes no obligation to publicly update or revise the information in this press release, including any forward-looking statements, except as may be required by law.

Initiation of a single, two-part, pivotal Phase 3 trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) anticipated by YE’24 Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG) ongoing; top-line results anticipated in 2H’25 Phase 2 MoMeNtum trial of DNTH103 in Multifocal Motor Neuropathy (MMN) ongoing; top-line results anticipated in 2H’26 Approximately $343 million of cash provides runway into 2H’27 NEW YORK and WALTHAM, Mass., Nov. 07, 2024 (GLOBE NEWSWIRE) -- Dianthus Therapeutics, Inc. (Nasdaq: DNTH), a clinical-stage biotechnology company dedicated to advancing the next generation of antibody complement therapeutics to treat severe autoimmune diseases, today reported financial results for the third quarter ending September 30, 2024 and provided an update on recent business achievements. “We are excited to expand DNTH103 beyond gMG and MMN into CIDP before year end. Like gMG and MMN, CIDP has significant unmet needs where a best-in-class, potent classical pathway inhibitor can potentially make a meaningful difference in the lives of patients. We believe this single, two-part, pivotal Phase 3 trial will support BLA filing in adult patients with CIDP and we anticipate initiating the trial by year-end 2024,” said Marino Garcia, Chief Executive Officer of Dianthus Therapeutics. “We continue to be confident in the pipeline-in-a-product potential of DNTH103 across multiple autoimmune diseases, supported by our proof-of-concept in vitro data most recently presented at AANEM and ICNMD and competitor clinical data that further validate targeting the classical pathway and active C1s.” DNTH103 Clinical Development DNTH103 is an investigational, clinical-stage, potent monoclonal antibody engineered to selectively target the classical pathway by inhibiting only the active form of the C1s protein, a clinically validated complement target. DNTH103 is enhanced with YTE half-life extension technology designed to enable a more convenient subcutaneous, self-administered injection dosed as infrequently as once every two weeks. DNTH103 has the potential to be a best-in-class pipeline-in-a-product across a range of autoimmune disorders with high unmet need. Generalized Myasthenia Gravis (gMG) Phase 2 MaGic gMG trial ongoing: The MaGic trial is a global, randomized, double-blind, placebo-controlled Phase 2 trial in patients with gMG who are acetylcholine receptor (AChR) antibody positive, and it remains on track to report top-line results in 2H’25.Poster presentations at AANEM and ICNMD: Encore poster presentations at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting in Savannah, Georgia and at the 18th International Congress on Neuromuscular Diseases (ICNMD) in Perth, Australia highlighted preclinical and in vitro data describing the potentially differentiated profile of DNTH103 in a disease model of gMG. Multifocal Motor Neuropathy (MMN) Phase 2 MoMeNtum MMN trial ongoing: The MoMeNtum trial is a global, randomized, double-blind, placebo-controlled Phase 2 trial designed to evaluate the safety, tolerability, and efficacy of DNTH103 in patients with MMN, and it remains on track to report top-line results in 2H’26. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Initiation of a Phase 3 trial in CIDP anticipated by YE’24: Dianthus plans to initiate a single, two-part, randomized withdrawal Phase 3 trial of DNTH103 in CIDP by YE’24. In the open label Part A of this trial, participants will be administered a loading dose followed by 300mg DNTH103 administered every 2 weeks (Q2W) via subcutaneous (S.C.) injection for up to 13 weeks. Part A includes an interim responder analysis of a pre-defined number of participants. Only participants who respond to DNTH103 in Part A will be randomized into Part B, a double-blind, placebo-controlled treatment period of up to 52 weeks, where they will be assessed for prevention of relapse, safety and tolerability, followed by an open-label extension period. The Company believes this single pivotal trial will support BLA filing in adult patients with CIDP. Additional details regarding Phase 3 trial design and timelines will be provided by YE’24.Poster presentations at AANEM and ICNMD: Encore poster presentations at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting in Savannah, Georgia and at the 18th International Congress on Neuromuscular Diseases (ICNMD) in Perth, Australia highlighted preclinical and in vitro data describing the potentially differentiated profile of DNTH103 in a disease model of CIDP, in addition to head-to-head affinity and pharmacodynamic (PD) potency data for DNTH103 compared to riliprubart. Corporate Updates Effective September 16, 2024, Steven Romano, M.D., was appointed to the Dianthus Therapeutics Board of Directors. Dr. Romano is a pharmaceutical executive with more than 28 years of experience in drug development across a wide range of therapeutic and disease areas. He currently serves as Executive Vice President, Chief Research and Development Officer at Silence Therapeutics. Third-Quarter 2024 Financial Results Cash Position - $342.6 million of cash, cash equivalents and investments as of September 30, 2024 is projected to provide runway into the second half of 2027.R&D Expenses - Research and development (R&D) expenses for the quarter ended September 30, 2024 were $25.5 million, inclusive of $1.7 million of stock-based compensation, compared to $8.0 million for the quarter ended September 30, 2023, which included $0.4 million of stock-based compensation. This increase in R&D expenses was primarily driven by higher clinical costs, chemistry, manufacturing and controls (CMC) costs and increased headcount to support DNTH103 Phase 2 and Phase 3 development.G&A Expenses - General and administrative (G&A) expenses for the quarter ended September 30, 2024 totaled $6.5 million, inclusive of stock-based compensation of $2.2 million, compared to $8.7 million for the quarter ended September 30, 2023, which included $0.8 million of stock-based compensation. This decrease in G&A expenses was primarily due to lower personnel costs.Net Loss - Net loss for the quarter ended September 30, 2024 was $25.2 million or $0.74 per share (basic and diluted) compared to $14.8 million or $3.78 per share (basic and diluted) for the quarter ended September 30, 2023. About DNTH103DNTH103 is an investigational, clinical-stage, potent monoclonal antibody engineered to selectively target the classical pathway by inhibiting only the active form of the C1s protein, a clinically validated complement target. DNTH103 is enhanced with YTE half-life extension technology designed to enable a more convenient subcutaneous, self-administered injection dosed as infrequently as once every two weeks. Additionally, selective inhibition of the classical complement pathway may lower patient risk of infection from encapsulated bacteria by preserving immune activity of the lectin and alternative pathways. As the classical pathway plays a significant role in disease pathology, DNTH103 has the potential to be a best-in-class pipeline-in-a-product across a range of autoimmune disorders with high unmet need. Dianthus is building a neuromuscular franchise with DNTH103 following the initiation of the Phase 2 MaGic trial in generalized Myasthenia Gravis in 1Q’24 and the Phase 2 MoMeNtum trial in Multifocal Motor Neuropathy in 3Q’24, and initiation of a Phase 3 trial in Chronic Inflammatory Demyelinating Polyneuropathy anticipated by YE’24. DNTH103 is an investigational agent that is not approved as a therapy in any indication in any jurisdiction worldwide. About Dianthus TherapeuticsDianthus Therapeutics is a clinical-stage biotechnology company dedicated to designing and delivering novel, best-in-class monoclonal antibodies with improved selectivity and potency. Based in New York City and Waltham, Mass., Dianthus is comprised of an experienced team of biotech and pharma executives who are leading the development of next-generation antibody complement therapeutics, aiming to deliver transformative medicines for people living with severe autoimmune and inflammatory diseases. To learn more, please visit www.dianthustx.com and follow us on LinkedIn. Cautionary Statement Regarding Forward-Looking Statements Certain statements in this press release, other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995, express or implied statements regarding future plans and prospects, including statements regarding the expectations or plans for discovery, preclinical studies, clinical trials and research and development programs, in particular with respect to DNTH103, and any developments or results in connection therewith, including the target product profile of DNTH103; the anticipated timing of the initiation and results from those studies and trials; expectations regarding the time period over which the Company’s capital resources are expected to be sufficient to fund its anticipated operations; and expectations regarding the market and potential opportunities for complement therapies, in particular with respect to DNTH103. The words “opportunity,” “potential,” “milestones,” “runway,” “will,” “anticipate,” “achieve,” “near-term,” “catalysts,” “pursue,” “pipeline,” “believe,” “continue,” “could,” “estimate,” “expect,” “ intend,” “may,” “might,” “plan,” “possible,” “predict,” “project,” “should,” “strive,” “would,” “aim,” “target,” “commit,” and similar expressions (including the negatives of these terms or variations of them) generally identify forward-looking statements, but the absence of these words does not mean that statement is not forward looking. Actual results could differ materially from those included in the forward-looking statements due to various factors, risks and uncertainties, including, but not limited to, that preclinical testing of DNTH103 and data from clinical trials may not be predictive of the results or success of ongoing or later clinical trials, that the development of DNTH103 or the Company's other compounds may take longer and/or cost more than planned, that the Company may be unable to successfully complete the clinical development of the Company’s compounds, that the Company may be delayed in initiating, enrolling or completing its planned clinical trials, and that the Company's compounds may not receive regulatory approval or become commercially successful products. These and other risks and uncertainties are identified under the heading "Risk Factors" included in the Company’s Annual Report on Form 10-K for the period ended December 31, 2023, and other filings that the Company has made and may make with the SEC in the future. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. The forward-looking statements in this press release speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. Dianthus undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. Contact Jennifer Davis RuffDianthus Therapeuticsjdavisruff@dianthustx.com DIANTHUS THERAPEUTICS, INC.Condensed Consolidated Balance Sheets(in thousands, except share and per share data)(unaudited) September 30,2024 December 31,2023 Assets Current assets: Cash and cash equivalents $33,671 $132,325 Short-term investments 247,452 41,393 Receivable from related party 1,390 294 Unbilled receivable from related party 1,293 184 Prepaid expenses and other current assets 3,683 3,255 Total current assets 287,489 177,451 Long-term investments 61,482 — Property and equipment, net 189 185 Right-of-use operating lease assets 352 615 Other assets and restricted cash 4,736 1,154 Total assets $354,248 $179,405 Liabilities and Stockholders’ Equity Current liabilities: Accounts payable $7,572 $2,610 Accrued expenses 7,727 6,504 Current portion of deferred revenue - related party 100 100 Current portion of operating lease liabilities 311 417 Total current liabilities 15,710 9,631 Deferred revenue - related party 640 736 Long-term operating lease liabilities — 168 Total liabilities 16,350 10,535 Commitments and contingencies Stockholders’ equity: Preferred stock — — Common stock 29 15 Additional paid-in capital 483,140 258,231 Accumulated deficit (145,952) (89,423)Accumulated other comprehensive income 681 47 Total stockholders’ equity 337,898 168,870 Total liabilities and stockholders’ equity $354,248 $179,405 DIANTHUS THERAPEUTICS, INC.Condensed Consolidated Statements of Operations and Comprehensive Loss(in thousands, except share and per share data)(unaudited) Three Months EndedSeptember 30, Nine Months EndedSeptember 30, 2024 2023 2024 2023 Revenues: License revenue - related party $2,172 $924 $4,909 $2,369 Operating expenses: Research and development 25,544 7,960 56,692 24,060 General and administrative 6,528 8,723 18,165 13,527 Total operating expenses 32,072 16,683 74,857 37,587 Loss from operations (29,900) (15,759) (69,948) (35,218)Other income/(expense): Interest income 4,445 1,027 13,375 2,320 Gain on investment in related party 307 — 307 — Loss on currency exchange, net (48) (16) (91) (53)Other income/(expense) 22 (15) (172) (41)Total other income 4,726 996 13,419 2,226 Net loss $(25,174) $(14,763) $(56,529) $(32,992)Net loss per share attributable to common stockholders, basic and diluted $(0.74) $(3.78) $(1.73) $(17.40)Weighted-average number of shares of common stock outstanding including shares issuable under equity classified pre-funded warrants, used in computing net loss per share of common stock, basic and diluted 34,236,728 3,906,886 32,614,771 1,896,605 Comprehensive loss: Net loss $(25,174) $(14,763) $(56,529) $(32,992)Other comprehensive income: Change in unrealized gains related to available for-sale debt securities 718 15 634 157 Total other comprehensive income 718 15 634 157 Total comprehensive loss $(24,456) $(14,748) $(55,895) $(32,835)