Empasiprubart

$573 million in third quarter global net product sales CIDP global expansion on track, with decisions on approval under review in Japan, Europe, China, and Canada Management to host conference call today at 1:30 PM CET (8:30 AM ET) Regulated information - Inside information October 31, 2024 7:00AM 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 announced its third quarter 2024 financial results and provided a business update. “We delivered significant patient impact with VYVGART over the quarter, expanding our gMG footprint and delivering innovation to CIDP patients three months into launch,” said Tim Van Hauwermeiren, Chief Executive Officer of argenx. “We continued to advance our goal of reaching more gMG patients earlier in their treatment journey, supported by VYVGART’s strong safety and efficacy profile, and real-world data showing the ability to meaningfully reduce steroid use. Expanding upon our leadership in gMG, we are now paving the future in CIDP. The strength of our data, combined with execution across the team to reach key stakeholders, contributed to the initial success of our CIDP launch, with more than 300 patients on therapy at the end of the third quarter. There remains significant opportunity ahead as we work towards achieving our Vision 2030, with innovation implemented across our pipeline to deliver transformative outcomes to more patients.” Advancing ‘Vision 2030’ in Third Quarter 2024 Vision 2030 is the next phase in argenx’s long-term commitment to transform the treatment of autoimmune diseases by strengthening its leadership in FcRn biology, investing in its continuous pipeline of differentiated antibody candidates, and scaling in a disciplined way to ensure innovation remains core to the argenx mission. As a part of this vision, argenx plans to reach at least 50,000 patients globally, advance the pipeline to achieve 10 labeled indications, and bring five new molecules into Phase 3 by 2030. Reaching 50,000 Patients Globally by 2030 VYVGART® (efgartigimod alfa-fcab) is a first-in-class antibody fragment targeting FcRn and is now approved for both intravenous use and subcutaneous injection (SC) (efgartigimod alfa and hyaluronidase-qvfc) in three indications, including generalized myasthenia gravis (gMG) globally, primary immune thrombocytopenia (ITP) in Japan (IV only), and chronic inflammatory demyelinating polyneuropathy (CIDP) in the U.S. (SC only). Generated global net product revenues (inclusive of both VYVGART and VYVGART SC) of $573 million in the third quarter of 2024Multiple VYVGART regulatory submissions completed or underway for gMG, including: Swissmedic approved VYVGART for the treatment of gMG in SwitzerlandRegulatory decisions on approval expected in Australia and Saudi Arabia in 2024, and South Korea in 2025 Multiple VYVGART SC regulatory submissions under review or planned for CIDP, including: Regulatory submissions completed in Japan, Europe, and China with decisions on approval expected in 2025Regulatory submission to be completed in Canada by end of 2024 VYVGART now reimbursed in 11 countries in Europe, with new agreements in place in France, Luxembourg, and BelgiumFDA review of VYVGART SC pre-filled syringe (PFS) for gMG and CIDP ongoing with Prescription Drug User Fee Act (PDUFA) target action date of April 10, 2025 Advancing Pipeline to Achieve 10 Labeled Indications by 2030 argenx continues to demonstrate breadth and depth within its immunology pipeline, advancing multiple pipeline-in-a-product candidates. argenx is solidifying its leadership in FcRn biology, with efgartigimod currently in development in 15 indications. argenx is also advancing its first-in-class C2 inhibitor, empasiprubart, which is being evaluated in multifocal motor neuropathy (MMN), delayed graft function (DGF), dermatomyositis (DM), and CIDP. In addition, argenx is evaluating ARGX-119, a muscle-specific kinase (MuSK) agonist in both congenital myasthenic syndrome (CMS) and amyotrophic lateral sclerosis (ALS). Registrational studies ongoing of efgartigimod in thyroid eye disease (TED)Registrational studies ongoing to support label-expansion into broader MG, including ADAPT SERON in seronegative gMG and ADAPT OCULUS in ocular MGRegistrational study in primary Sjögren’s disease (SjD) on track to start by end of 2024Confirmatory study of efgartigimod in primary ITP to start by end of 2024 to enable registration in U.S.Topline data from seamless Phase 2/3 ALKIVIA study evaluating efgartigimod across three myositis subsets (immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and DM) expected by end of 2024Update on BALLAD study development plan evaluating efgartigimod in bullous pemphigoid (BP) expected by end of 2024Decision made to discontinue development of efgartigimod in membranous nephropathy (MN); proof-of concept study ongoing with efgartigimod in lupus nephritis (LN)Proof-of-concept study ongoing with efgartigimod in antibody mediated rejection (AMR), with systemic sclerosis (SSc) to start by end of 2024Registrational study of empasiprubart in MMN to start by end of 2024Additional proof-of-concept studies of empasiprubart ongoing, including VARVARA study in DGF and EMPACIFIC study in DMRegistrational study of empasiprubart in CIDP to start in 2025Ongoing Phase 1b/2a studies of ARGX-119 to assess early signal in patients with CMS and ALS Investing in Immunology Innovation Program to Support Five New Molecules in Phase 3 by 2030 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. Phase 1 studies of ARGX-213 and ARGX-121 expected to start in second half of 2025Investigational new drug (IND) applications for ARGX-220 and ARGX-109 on track to be filed by end of 2025 THIRD QUARTER 2024 FINANCIAL RESULTS argenx SE UNAUDITED CONDENSED CONSOLIDATED INTERIM STATEMENTS OF PROFIT OR LOSS Three Months Ended Nine Months Ended September 30 September 30(in thousands of $ except for shares and EPS) 2024 2023 2024 2023Product net sales $ 572,997 $ 329,097 $ 1,448,915 $ 816,432 Collaboration revenue 239 692 2,905 3,047 Other operating income 15,642 10,050 38,999 31,275 Total operating income $ 588,878 $ 339,839 $ 1,490,819 $ 850,754 Cost of sales $ (59,072) $ (35,999) $ (154,633) $ (78,358)Research and development expenses (235,940) (191,755) (686,195) (553,119)Selling, general and administrative expenses (277,698) (191,930) (769,392) (503,079)Loss from investment in a joint venture (1,981) (743) (5,294) (2,623)Total operating expenses $ (574,691) $ (420,427) $ (1,615,514) $ (1,137,179) Operating profit/(loss) $ 14,187 $ (80,588) $ (124,695) $ (286,425) Financial income $ 40,586 $ 30,049 $ 118,414 $ 67,078 Financial expense (676) (231) (1,760) (626)Exchange gains/(losses) 33,927 (32,509) 6,712 (23,345) Profit/(loss) for the period before taxes $ 88,024 $ (83,279) $ (1,329) $ (243,318)Income tax (expense)/benefit $ 3,386 $ 10,637 $ 60,208 $ 47,437 Profit/(loss) for the period $ 91,410 $ (72,642) $ 58,879 $ (195,881)Profit/(loss) for the period attributable to: Owners of the parent $ 91,410 $ (72,642) $ 58,879 $ (195,881)Weighted average number of shares outstanding 60,087,498 58,128,233 59,633,179 56,512,254 Basic profit/(loss) per share (in $) 1.52 (1.25) 0.99 (3.47)Diluted profit/(loss) per share (in $) 1.39 (1.25) 0.91 (3.47)Net increase in cash, cash equivalents and current financial assets compared to year-end 2023 and 2022 $ 194,523 $ 993,035 Cash and cash equivalents and current financial assets at the end of the period $ 3,374,367 $ 3,185,583 DETAILS OF THE FINANCIAL RESULTS Total operating income for the third quarter and year-to-date in 2024 was $589 million and $1,491 million, respectively, compared to $340 million and $851 million for the same periods in 2023, and mainly consists of: Product net sales of VYVGART for the three months ended and nine months ended September 30, 2024, were $573 million and $1,449 million, compared to $329 million and $816 million for the same periods in 2023.Other operating income for the third quarter and year-to-date in 2024 was $16 million and $39 million, respectively, compared to $10 million, and $31 million for the same periods in 2023. The other operating income for the three and nine months ended September 30, 2024 primarily relates to research and development tax incentives and payroll tax rebates. Total operating expenses for the third quarter and year-to-date in 2024 were $575 million and $1,616 million, respectively, compared to $420 million and $1,137 million for the same periods in 2023, and mainly consists of: Cost of sales for the third quarter and year-to-date in 2024 was $59 million and $155 million, respectively, compared to $36 million and $78 million for the same periods in 2023. The cost of sales was recognized with respect to the sale of VYVGART and VYVGART Hytrulo.Research and development expenses for the third quarter and year-to-date in 2024 were $236 million and $686 million, respectively, compared to $192 million and $553 million for the same periods in 2023. The research and development expenses mainly relate to external research and development expenses and personnel expenses incurred in the clinical development of efgartigimod in various indications and the expansion of other clinical and preclinical pipeline candidates.Selling, general and administrative expenses for the third quarter and year-to-date in 2024 were $278 million and $769 million, respectively, compared to $192 million and $503 million for the same periods in 2023. The selling, general and administrative expenses mainly relate to professional and marketing fees linked to global commercialization of VYVGART and VYVGART Hytrulo, and personnel expenses. Financial income for the third quarter and year-to-date in 2024 was $41 million and $118 million, respectively, compared to $30 million and $67 million for the same periods in 2023. The increase in financial income is mainly due to an increase in interest income on current financial assets and cash and cash equivalents. Exchange gains for the third quarter and year-to-date in 2024 were $34 million and $7 million respectively, respectively, compared to $(33) million and $(23) million of exchange losses for the same periods in 2023. Exchange gains/losses are mainly attributable to unrealized exchange rate gains or losses on the cash, cash equivalents and current financial assets position in Euro. Income tax for the third quarter and year-to-date in 2024 was $3 million and $60 million of tax benefit, respectively, compared to $11 million and $47 million of tax benefit for the same periods in 2023. Tax benefit for the nine months ended September 30, 2024 consists of $29 million of income tax expense and $89 million of deferred tax income, compared to $24 million of income tax expense and $71 million of deferred tax income for the comparable prior period. Net income for the three and nine month periods ended September 30, 2024, was $91 million and $59 million, respectively, compared to a net loss of $(73) million and $(196) million over the prior year periods. On a per weighted average share basis, the earnings per share was $0.99 for the nine months ended September 30, 2024 and a net loss per share of $(3.47) for the nine months ended September 30, 2023. Cash, cash equivalents and current financial assets totaled $3.4 billion as of September 30, 2024, compared to $3.2 billion as of December 31, 2023. The increases in cash and cash equivalents and current financial assets over the period was from financing activities due to the exercise of stock options which is offset by net cash flows used in operating and investing activities. FINANCIAL GUIDANCE With the increase in cash, cash equivalents and current financial assets in the quarter and year-to-date, the previously issued cash guidance no longer applies. The financial guidance on the combined selling, general and administrative expenses and research and development expenses remains unchanged at approximately $2 billion. EXPECTED 2024 FINANCIAL CALENDAR February 27, 2025: Full-year 2024 financial results and 4Q 2024 business update CONFERENCE CALL DETAILS The third quarter 2024 financial results and business update will be discussed during a conference call and webcast presentation today at 1:30 pm CET/8:30 am ET. A webcast of the live call and replay may be accessed on the Investors section of the argenx website at argenx.com/investors. Dial-in numbers: Please dial in 15 minutes prior to the live call. Belgium 32 800 50 201France 33 800 943355Netherlands 31 20 795 1090United Kingdom 44 800 358 0970United States 1 888 415 4250Japan 81 3 4578 9081Switzerland 41 43 210 11 32 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 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/Twitter, Instagram, Facebook, and YouTube. For further information, please contact: Media: Ben Petokbpetok@argenx.com Investors:Alexandra Roy (US)aroy@argenx.com Lynn Elton (EU)lelton@argenx.com 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,” “achieve,” “advance,” “bring,” “complete,” “expect,” “initiate,” “plan,” “reach,” “start,” “support,” “to be,” or “will,” and include statements argenx makes regarding its goal to reach more gMG patients in an early-line setting; its growth opportunity; its Vision 2030 plan, including (1) transforming the treatment of autoimmune diseases by strengthening its leadership in FcRn biology, (2) investing in its continuous pipeline of differentiated antibody candidates, (3) scaling in a disciplined way to ensure innovation, and (4) reaching 50,000 patients globally with an argenx medicine, 10 labeled indications across all approved assets, and five new molecules in Phase 3 development; the advancement of anticipated clinical development, data readouts and regulatory milestones and plans, including (1) the anticipated timing of additional VYVGART regulatory decisions on approval for gMG in Australia, Saudi Arabia, and South Korea, (2) the anticipated timing of VYVGART SC regulatory submissions for CIDP, including decisions on approval in China, Japan, and Europe and an anticipated regulatory submission filing in Canada, (3) the anticipated timing of the initiation of a registrational study for efgartigimod in primary SjD, (4) the anticipated timing of a confirmatory study of efgartigimod in primary ITP, (5) the anticipated timing of topline data from Phase 2/3 ALKIVIA study evaluating efgartigimod across three myositis subsets, (6) the anticipated timing of an update on the BALLAD study development plan evaluating efgartigimod in BP, (7) the anticipated timing of proof-of-concept study data for efgartigimod in LN, (8) the anticipated timing of the initiation of a study on efgartimod in SSc, (9) the anticipated timing of the initiation of a registrational study of empasiprubart for MMN, (9) the anticipated timing of the initiation of a registrational study of empasiprubart in CIDP, (10) the anticipated timing of the initiation of Phase 1 studies of ARGX-213 and ARGX-121, (11) the anticipated timing of the filing of investigational new drug applications for ARGX-220 and ARGX-109; the advancement of empasiprubart; its 2024 selling, general and administrative expenses and research and development expenses; the anticipated timing of releases of future financial results and business updates; and its goal of translating immunology breakthroughs into a world-class portfolio of novel antibody-based medicines. 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 parties suppliers, service provides 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.

Long-term and real-world data of VYVGART® (efgartigimod alfa-fcab) and VYVGART® Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) demonstrate speed of onset, depth of response, and durability of response VYVGART demonstrates consistent, favorable safety profile from follow-up safety data that totals >8,000 patient years; no vaccinations required and no impact on human serum albumin levels Real-world data show more than 50 percent of gMG patients demonstrate substantial and sustained reduction in steroid use following VYVGART initiation argenx continues to expand its reach in neurology through pipeline programs, including empasiprubart advancing in MMN and ARGX-119 in ALS and CMS October 15, 2024 – 7:00am 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 announced the presentation of clinical and real-world data across its growing immunology pipeline at the 2024 American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting and Myasthenia Gravis Foundation of America (MGFA) Scientific Sessions in Savannah, GA from October 15-18, 2024. “VYVGART continues to deliver impactful benefits to patients in terms of safety, speed of onset, depth of response, and durability of response,” said Luc Truyen, M.D., Ph.D., Chief Medical Officer, argenx. “The robust data we are showing at AANEM and MGFA continue to confirm VYVGART as the leading innovative biologic with an established ability to reduce steroid usage, drive minimal symptom expression for gMG patients, and reduce CIDP symptoms quickly. In addition to VYVGART, we are excited to highlight our growing neurology pipeline, including empasiprubart and ARGX-119, through which we can advance our mission of delivering transformative outcomes for even more patients.” VYVGART and VYVGART Hytrulo Demonstrate Rapid, Deep and Sustained Responses in gMG and CIDP The data presented at AANEM continue to demonstrate the significant impact of VYVGART (including VYVGART Hytrulo), the first-in-class neonatal Fc receptor (FcRn) blocker for people living with generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP). VYVGART is setting a new treatment standard in gMG and has shown rapid, deep and sustained responses, enabling a majority of patients to achieve minimal symptom expression (MSE) with a consistent and favorable safety profile and more than 8,000 patient years of safety data. Based on real-world data, more than half of patients can reduce steroid use by >5mg/day following VYVGART initiation. In CIDP, a majority of patients in the ADHERE trial responded to VYVGART Hytrulo and experienced reduced risk of relapse versus placebo and improvements in motor function and muscle strength, regardless of prior CIDP treatment. Highlights from VYVGART data presented at AANEM and MGFA: Early Line Use and Meaningful Steroid Reduction: VYVGART demonstrates consistent improvement across gMG patient subtypes, including those on mestinon alone, indicating its efficacy in early line use. Real-world gMG data show that at one-year post VYVGART initiation, 55% of patients reduced corticosteroid use by ≥5 mg/day and 42% of patients had achieved steroid doses of ≤5mg/day.Expansion to Seronegative and Ocular MG: argenx is honoring its long-term commitment to the broader MG community with two Phase 3 studies ongoing in additional MG patient populations, including seronegative (ADAPT-SERON) and ocular MG (ADAPT-OCULUS). Seronegative (AChR-) gMG patients evaluated in VYVGART clinical studies experienced consistent and clinically meaningful MG-ADL improvements, including patients achieving MSE.Sustained Functional Benefit in CIDP: VYVGART Hytrulo showed sustained functional benefit in motor function and muscle strength, regardless of prior treatment, which was maintained through ADHERE and the open-label extension study (through week 24).Consistent, Favorable Safety Profile: VYVGART’s consistent and favorable safety profile has been established across multiple autoimmune diseases with no increase in the incidence of adverse events with increased exposure. The unique safety profile of VYVGART is further supported by no black box warnings, no labs or immunoglobulin (Ig) monitoring, and no vaccination requirements. Advancing Immunology Pipeline Across Two First-in-Class Opportunities to Reach New Patients argenx will also highlight two additional pipeline candidates, including Phase 2 ARDA data of empasiprubart (anti-C2 inhibitor) for the treatment of multifocal motor neuropathy (MMN), and clinical trial designs of ARGX-119 (muscle-specific kinase (MuSK) agonist) for the treatment of congenital myasthenic syndromes (CMS) and amyotrophic lateral sclerosis (ALS). Cohort 1 data from the Phase 2 ARDA study will be presented in a poster, showing treatment with empasiprubart for MMN reduced the risk of IVIg retreatment by 91% (HR: 0.09 [95% CI: 0.02–0.44]) and demonstrated significant improvement in grip strength in both hands as compared to placebo. Data from a Patient Global Impression of Change scale show 94.4% of patients said they improved on empasiprubart from the start of the study, compared to 11.1% of placebo patients. As part of its commitment to the MMN community, argenx initiated the iMMersioN longitudinal study of ~150 patients to collect data on the impact of disease and burden of current treatment options on clinical outcomes and quality of life measures. A Phase 3 study of empasiprubart in MMN will start by the end of 2024. argenx posters included in MGFA Scientific Sessions All MGFA posters to be presented on Tuesday, October 15, 12:00 – 12:45pm ETPosters with an asterisk (*) will also be presented in AANEM scientific program Full TitlePresentation DetailsPatterns of Efgartigimod Dosing in Clinical Practice in the United StatesPoster # MG9Real-World Reduction in Oral Glucocorticoid Utilization at 1-Year Following Efgartigimod Initiation*Poster # MG31 / AANEM Poster # 262Efficacy, Safety, and Pharmacodynamics of Efgartigimod PH20 SC Across Bodyweight Quartiles: A Post hoc Analysis of the ADAPT-SC+ TrialPoster # MG32Fixed Cycle and Every-Other-Week Dosing of Intravenous Efgartigimod for Generalized Myasthenia Gravis: Part A of ADAPT NXT*Poster # MG33 /AANEM Poster # 182Design of a Phase 3 Randomized, Double-Blinded, Placebo-Controlled Study Evaluating the Efficacy and Safety of Subcutaneous Efgartigimod PH20 Administered by Prefilled Syringe in Adults with Ocular Myasthenia GravisPoster # MG38Phase 3 Trial Investigating Impact of Intravenous Efgartigimod in Anti-Acetylcholine Receptor Antibody Negative Generalized Myasthenia Gravis*Poster # MG39 / AANEM Poster # 178Observed Efficacy of Efgartigimod in Generalized Myasthenia Gravis Across Patient Subgroups in the ADAPT-SC+ StudyPoster # MG68Exploring the Impact of Non-Steroidal Immunosuppressive Drugs and Steroids on the Development of Comorbidities in Patients with Myasthenia Gravis in the National Veterans Affairs Health NetworkPoster # MG86Quality of Life of Patients with Symptomatic Ocular MG: Comparison with the General PopulationPoster # MG87Steroid Use, Toxicity, and Monitoring in Patients With Generalized Myasthenia Gravis: A Survey Of Neurologists In The United States*Poster # MG89 / AANEM Poster # 235Comparative Risk-Benefit Profiles of Immunomodulatory Therapies for Patients with Generalized Myasthenia GravisPoster # MG98 argenx posters included in AANEM Scientific Program * Session Times: Session I: Wednesday, October 16, 6:15 - 6:45pm ETSession II: Thursday, October 17, 9:30 - 10am ETSession III: Thursday, October 17, 2:45 - 3:15pm ET Full TitlePresentation Details*Long-Term Safety and Efficacy of Efgartigimod PH20 SC in Generalized Myasthenia Gravis: Interim Analysis of Anti-Acetylcholine Receptor Antibody Seronegative Participants in ADAPT-SC+Poster # 144Session I & Session IICombined Analyses of Participants With Anti-Acetylcholine Receptor Seronegative Generalized Myasthenia Gravis Treated With Efgartigimod Across Clinical StudiesPoster # 146Session I & Session IISafety, Tolerability, Pharmacokinetics, Immunogenicity, and Efficacy of ARGX-119 in Participants With DOK7 Congenital Myasthenic Syndromes: Phase 1b Study in ProgressPoster # 165Session I & Session IIIEfficacy and Safety of Subcutaneous Efgartigimod PH20SC in Chronic Inflammatory Demyelinating Polyneuropathy: ADHERE Trial Subgroup AnalysisPoster # 176Session I & Session IIEfficacy and Safety of Subcutaneous Efgartigimod PH20 in Chronic Inflammatory Demyelinating Polyneuropathy: ADHERE/ADHERE+ TrialPoster # 177Session I & Session IIISafety Profile of Intravenous Efgartigimod From Clinical Trials in Immunoglobulin G–Mediated Autoimmune DiseasesPoster # 180Session I & Session IISafety Profile of Subcutaneous Efgartigimod PH20 From Clinical Trials in Immunoglobulin G–Mediated Autoimmune DiseasesPoster # 181Session I & Session IIIEmpasiprubart (ARGX-117) in Multifocal Motor Neuropathy: Initial Safety and Efficacy Data of the Phase 2 ARDA StudyPoster # 198Session I & Session IILong-Term Safety, Tolerability, and Efficacy of Subcutaneous Efgartigimod PH20 in Participants With Generalized Myasthenia Gravis: Interim Results of the ADAPT-SC+ StudyPoster # 212Session I & Session IIISafety, Tolerability, Efficacy, Pharmacokinetics, and Immunogenicity of ARGX-119 in Patients with Amyotrophic Lateral Sclerosis: A Phase 2a Study in ProgressPoster # 237Session I & Session IIRisk of Serious Infections and Malignancies in Adult Myasthenia Gravis Patients: A US Claims Database StudyPoster # 251Session I & Session IIChronic Steroid Toxicity in Adults With Myasthenia Gravis in the United States Based on Electronic Health RecordsPoster # 263Session I & Session IISubcutaneous Efgartigimod PH20 in Chronic Inflammatory Demyelinating Polyneuropathy: Key Secondary Outcomes from the ADHERE TrialPoster # 280Session I & Session IIIEmpasiprubart (ARGX-117) in Multifocal Motor Neuropathy: Baseline Characteristics and MMN Confirmation Committee Outcome of the Phase ARDA Study Cohort 1Poster # 293Session I & Session IICOVID-19 Vaccination Response in Participants Receiving Efgartigimod IV or Efgartigimod PH20 SC in ADAPT+ or ADAPT-SC+Poster # 298Session I & Session IIISteroid Use, Toxicity, and Monitoring in Patients with Chronic Inflammatory Demyelinating Polyneuropathy: A Survey of Neurologists in The United StatesPoster # 306Session I & Session IIIClinical Outcomes, Disease Course, and Quality of Life in Patients With Multifocal Motor Neuropathy: iMMersioN, Study in ProgressPoster # 307Session I & Session II More information on the data presented at the 2024 AANEM Annual Meeting can be found here. See FDA-approved Important Safety Information below, full Prescribing Information for VYVGART and full Prescribing Information for VYVGART Hytrulo for additional information. Important Safety Information What is VYVGART® (efgartigimod alfa-fcab)?VYVGART is a prescription medicine used to treat a condition called generalized myasthenia gravis, which causes muscles to tire and weaken easily throughout the body, in adults who are positive for antibodies directed toward a protein called acetylcholine receptor (anti-AChR antibody positive). IMPORTANT SAFETY INFORMATIONDo not use VYVGART if you have a serious allergy to efgartigimod alfa or any of the other ingredients in VYVGART. VYVGART can cause serious allergic reactions and a decrease in blood pressure leading to fainting. VYVGART may cause serious side effects, including: Infection. VYVGART may increase the risk of infection. The most common infections were urinary tract and respiratory tract infections. Signs or symptoms of an infection may include fever, chills, frequent and/or painful urination, cough, pain and blockage of nasal passages/sinus, wheezing, shortness of breath, fatigue, sore throat, excess phlegm, nasal discharge, back pain, and/or chest pain.Allergic Reactions (hypersensitivity reactions). VYVGART can cause allergic reactions such as rashes, swelling under the skin, and shortness of breath. Serious allergic reactions, such as trouble breathing and decrease in blood pressure leading to fainting have been reported with VYVGART.Infusion-Related Reactions. VYVGART can cause infusion-related reactions. The most frequent symptoms and signs reported with VYVGART were high blood pressure, chills, shivering, and chest, abdominal, and back pain. Tell your doctor if you have signs or symptoms of an infection, allergic reaction, or infusion-related reaction. These can happen while you are receiving your VYVGART treatment or afterward. Your doctor may need to pause or stop your treatment. Contact your doctor immediately if you have signs or symptoms of a serious allergic reaction. Before taking VYVGART, tell your doctor if you: take any medicines, including prescription and non-prescription medicines, supplements, or herbal medicines,have received or are scheduled to receive a vaccine (immunization), orhave any allergies or medical conditions, including if you are pregnant or planning to become pregnant, or are breastfeeding. What are the common side effects of VYVGART?The most common side effects of VYVGART are respiratory tract infection, headache, and urinary tract infection. These are not all the possible side effects of VYVGART. Call your doctor for medical advice about side effects. You may report side effects to the US Food and Drug Administration at 1-800-FDA-1088. Please see the full Prescribing Information for VYVGART and talk to your doctor. What is VYVGART® HYTRULO (efgartigimod alfa and hyaluronidase-qvfc)?VYVGART HYTRULO is a prescription medicine used to treat a condition called generalized myasthenia gravis, which causes muscles to tire and weaken easily throughout the body, in adults who are positive for antibodies directed toward a protein called acetylcholine receptor (anti-AChR antibody positive).VYVGART HYTRULO is a prescription medicine used for the treatment of adult patients with chronic inflammatory demyelinating polyneuropathy (CIDP) IMPORTANT SAFETY INFORMATIONDo not use VYVGART HYTRULO if you have a serious allergy to efgartigimod alfa, hyaluronidase, or any of the other ingredients in VYVGART HYTRULO. VYVGART HYTRULO can cause serious allergic reactions and a decrease in blood pressure leading to fainting. VYVGART HYTRULO may cause serious side effects, including: Infection. VYVGART HYTRULO may increase the risk of infection. The most common infections for efgartigimod alfa-fcab-treated patients were urinary tract and respiratory tract infections. Signs or symptoms of an infection may include fever, chills, frequent and/or painful urination, cough, pain and blockage of nasal passages/sinus, wheezing, shortness of breath, fatigue, sore throat, excess phlegm, nasal discharge, back pain, and/or chest pain.Allergic Reactions (hypersensitivity reactions). VYVGART HYTRULO can cause allergic reactions such as rashes, swelling under the skin, and shortness of breath. Hives were also observed in patients treated with VYVGART HYTRULO. Serious allergic reactions, such as trouble breathing and decrease in blood pressure leading to fainting have been reported with efgartigimod alfa-fcab.Infusion-Related Reactions. VYVGART HYTRULO can cause infusion-related reactions. The most frequent symptoms and signs reported with efgartigimod alfa-fcab were high blood pressure, chills, shivering, and chest, abdominal, and back pain. Tell your doctor if you have signs or symptoms of an infection, allergic reaction, or infusion-related reaction. These can happen while you are receiving your VYVGART HYTRULO treatment or afterward. Your doctor may need to pause or stop your treatment. Contact your doctor immediately if you have signs or symptoms of a serious allergic reaction. Before taking VYVGART HYTRULO, tell your doctor if you: take any medicines, including prescription and non-prescription medicines, supplements, or herbal medicines,have received or are scheduled to receive a vaccine (immunization), orhave any allergies or medical conditions, including if you are pregnant or planning to become pregnant, or are breastfeeding. What are the common side effects of VYVGART HYTRULO?The most common side effects in efgartigimod-alfa-fcab-treated patients were respiratory tract infection, headache, and urinary tract infection. Additional common side effects with VYVGART HYTRULO are injection site reactions, including rash, redness of the skin, itching sensation, bruising, pain, and hives. These are not all the possible side effects of VYVGART HYTRULO. Call your doctor for medical advice about side effects. You may report side effects to the US Food and Drug Administration at 1-800-FDA-1088. Please see the full Prescribing Information for VYVGART HYTRULO and talk to your doctor. About VYVGARTVYVGART 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 in the United States, EU, China and Canada for the treatment of adults with generalized myasthenia gravis (gMG) who are anti- acetylcholine receptor (AChR) antibody positive and in Japan for the treatment of adults with gMG who do not have sufficient response to steroids or non-steroidal immunosuppressive therapies (ISTs). About VYVGART® HytruloVYVGART Hytrulo is a subcutaneous combination of efgartigimod alfa, a human IgG1 antibody fragment marketed for intravenous use as VYVGART®, and recombinant human hyaluronidase PH20 (rHuPH20), Halozyme’s ENHANZE® drug delivery technology to facilitate subcutaneous injection delivery of biologics. In binding to the neonatal Fc receptor (FcRn), VYVGART Hytrulo results in the reduction of circulating IgG. It is the first-and-only approved FcRn blocker administered by subcutaneous injection. VYVGART Hytrulo is the proprietary name in the U.S. for subcutaneous efgartigimod alfa and recombinant human hyaluronidase PH20. It may be marketed under different proprietary names following approval in other regions. About Generalized Myasthenia Gravis (gMG)Generalized myasthenia gravis (gMG) is a rare and chronic autoimmune disease where IgG autoantibodies disrupt communication between nerves and muscles, causing debilitating and potentially life-threatening muscle weakness. Approximately 85% of people with MG progress to gMG within 24 months,1 where muscles throughout the body may be affected. Patients with confirmed AChR antibodies account for approximately 85% of the total gMG population. About Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare and serious autoimmune disease of the peripheral nervous system. Although confirmation of disease pathophysiology is still emerging, there is increasing evidence that IgG antibodies play a key role in the damage to the peripheral nerves. People with CIDP experience fatigue, muscle weakness and a loss of feeling in their arms and legs that can get worse over time or may come and go. These symptoms can significantly impair a person's ability to function in their daily lives. Without treatment, one-third of people living with CIDP will need a wheelchair. About EmpasiprubartEmpasiprubart (ARGX-117) is a first-in-class humanized monoclonal antibody that binds C2 and blocks activation of both the classical and lectin pathways of the complement cascade, leaving the alternative pathway intact for its antimicrobial properties. By blocking complement activity upstream of C3 and C5, empasiprubart has the potential to reduce tissue inflammation and cellular damage, representing a broad pipeline opportunity across multiple severe autoimmune indications. In addition to multifocal motor neuropathy, argenx is evaluating empasiprubart in delayed graft function following kidney transplant, dermatomyositis and chronic inflammatory demyelinating polyneuropathy. About Multifocal Motor NeuropathyMultifocal motor neuropathy (MMN) is a rare, severe, chronic autoimmune disease of the peripheral nervous system. The disease is characterized by slowly progressive, asymmetric muscle weakness mainly of the hands, forearms and lower legs. MMN is often associated with the presence of anti-GM1 IgM autoantibodies, leading to activation of the classical complement pathway, driving subsequent axon damage. High-dose IVIg is the only approved treatment for MMN and patients typically experience disease progression despite therapy, indicating an unmet need for efficacious and better tolerated therapeutic options. About ARGX-119ARGX-119 is a humanized agonistic monoclonal antibody (mAb) that targets and activates muscle-specific kinase (MuSK) to promote maturation and stabilization of the neuromuscular junction (NMJ). MuSK is a receptor kinase that has a critical role in the structure and function of the NMJ. ARGX-119 is being developed as a potential therapy for patients with neuromuscular disease. About Congenital Myasthenic Syndromes (CMS) Congenital Myasthenic Syndromes (CMS) are a heterogenous group of rare genetic disorders of the neuromuscular junction (NMJ) that lead to muscle weakness. CMS cases are classified into subtypes depending on the underlying genetic mutation. While clinical features vary widely across and within subtypes, the predominant manifestation of CMS is fatigable weakness. Age of onset varies widely; while many patients are diagnosed in infancy or early childhood, patients with milder phenotypes may not present or be diagnosed until adulthood. About Amyotrophic Lateral Sclerosis (ALS) ALS is a neurodegenerative disorder of the brain and spinal cord leading to deteriorating muscle function, weakness and atrophy. The multisystemic nature can have impacts throughout the body with specific signs and symptoms associated with lower motor neuron and upper motor neuron loss. Life expectancy is typically 2.5-5 years from diagnosis. About argenxargenx 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 in the U.S., Japan, Israel, the EU, the UK, Canada and China. 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/Twitter, Instagram, Facebook, and YouTube. ContactsMedia:Ben Petokbpetok@argenx.com Investors:Alexandra Roy (US)aroy@argenx.com Lynn Elton (EU)lelton@argenx.com 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,” and “will,” and include statements argenx makes regarding the anticipated timing of the initiation of the Phase 3 clinical trial for empasiprubart in MMN and its goal of translating immunology breakthroughs into a world-class portfolio of novel antibody-based medicines. 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 manufacturers; 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. ###