BUSINESS WIRE: Merck to Present New Data Highlighting Durable Effects of MAVENCLAD® in Relapsing Multiple Sclerosis (RMS) at ECTRIMS 2025

ANNOUNCEMENT TRANSMITTED BY BUSINESS WIRE. THE CONTENT IS THE SOLE RESPONSIBILITY OF THE REPORTING COMPANY.

• Four-year data show nearly 9 in 10 RMS patients remained free from progression independent of relapse activity (PIRA)
• Results highlight the potential of MAVENCLAD to reduce neurodegeneration and neuroinflammation beyond established clinical efficacy outcomes in RMS
• Evidence suggests that MAVENCLAD effectiveness could be driven by peripheral and central effects without requiring continuous immunosuppression

DARMSTADT, Germany --(BUSINESS WIRE)-- 17.09.2025 --

Not intended for UK-, US- or Canada-based media

Merck, a leading science and technology company, today announced the presentation of over 30 abstracts from its multiple sclerosis (MS) portfolio. New four-year data from two large Phase 4 studies highlight the long-term efficacy, favorable disability outcomes and durable impact of MAVENCLAD^® (cladribine tablets) in people living with relapsing multiple sclerosis (RMS). These findings are to be presented at the 41^st Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), being held September 24-26 in Barcelona.

“As the only high-efficacy short-course oral treatment, MAVENCLAD has demonstrated sustained benefits across a variety of outcomes—extending beyond relapses and MRI—without requiring continuous immunosuppression,” said Alex Kulla, Senior Vice President & Global Head of the Neurology & Immunology Medical Unit for the Healthcare business of Merck. “With over two decades of clinical experience and substantial real-world data, MAVENCLAD has been utilized to treat more than 130,000 individuals, amounting to over 360,000 patient-years of exposure. The comprehensive data presented at ECTRIMS 2025 reinforces its role in delivering durable, effective care for individuals with RMS—supporting them from early diagnosis through later stages of life.”

Key MAVENCLAD data:

• An integrated analysis of four-year data from CLARIFY-MS (n=482) and MAGNIFY-MS (n=270), including their extension studies, showed low rates of disability accumulation and progression independent of relapse activity (PIRA) in patients treated with MAVENCLAD, especially those who initiated treatment in the early stages of their disease.
  • At Year 4, 83.4% of patients were free from confirmed disability progression (CDP) and 89.2% were free from PIRA.
  • 15.4% experienced confirmed disability improvement (CDI).
  • Patients aged ≤40 experienced lower rates of PIRA compared to those over 40 (7.6% vs. 15.4%, respectively).
  • The analysis demonstrated that MAVENCLAD provided durable efficacy after short-course treatment, with long-term control over both inflammatory and non-inflammatory components of MS-related disability.
• Data from MAGNIFY-MS showed MAVENCLAD reduced serum and cerebrospinal fluid (CSF) biomarkers of neuroinflammation, suggesting a broader central nervous system (CNS) benefit.
  • At Year 2, reductions were observed in key biomarkers, including serum glial fibrillary acidic protein (GFAP), immunoglobulin G (IgG) index, and C-X-C motif chemokine ligand 13 (CXCL-13) levels.
• Brain imaging data from MAGNIFY-MS indicated that the brain atrophy rate in MAVENCLAD-treated patients was comparable to that observed in the healthy population, reinforcing the importance of brain volume (BV) preservation as a therapeutic goal in MS.
  • From Years 2 to 4, annualized percent BV change remained below 0.4%, across all subgroups.
  • Patients with low brain atrophy rates at Year 4 had markedly lower annualized relapse rate (ARR) (0.04 ±0.12 vs. 0.16 ±0.26) and less clinical deterioration compared to those with annualized percentage BV change exceeding -0.4%.

Additional MAVENCLAD presentations:

• Poster Presentation Title: Treatment Continuation With Cladribine Tablets Beyond Year 4: Analysis of Longitudinal Prescription Data From Germany
  • Lead Author: David Kormann, Real World Data Analytics, IQVIA Commercial GmbH & Co. OHG, Frankfurt, Germany
• Poster Presentation Title: Treatment continuation with cladribine tablets (CladT) beyond year 4– second interim analysis of the CLIP-5 study
  • Lead Author: Catharina Korsukewitz, University Hospital Muenster, Muenster, Germany
• Poster Presentation Title: Incidence Rate of Malignancies in People with Multiple Sclerosis Newly Initiating Cladribine Tablets or Fingolimod: Second Interim Results from CLARION
  • Lead Author: Anna Glaser, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
• Poster Presentation Title: Clinical Outcomes of Cladribine Tablets in Aging (≥50 years) Patients with Relapsing Multiple Sclerosis in a Real-World Setting: Insights From the ‘Aging’ Study
  • Lead Author: Joshua Katz, Elliot Lewis Center for Multiple Sclerosis Care, Wellesley, MA, United States

Below is the full list of MAVENCLAD abstracts accepted for presentation at ECTRIMS 2025:

About MAVENCLAD^®

MAVENCLAD, approved by the U.S. Food and Drug Administration (FDA) on March 29, 2019, is the first and only short-course oral therapy for the treatment of adults with relapsing-remitting disease (RRMS) and active secondary progressive disease (SPMS). Because of its safety profile, use of MAVENCLAD is generally recommended for patients who have had an inadequate response to, or are unable to tolerate, an alternate drug indicated for the treatment of multiple sclerosis (MS), and MAVENCLAD is not recommended for use in patients with clinically isolated syndrome (CIS). Patients should follow healthcare provider instructions including cancer screening, contraception, and blood tests. The approved dose of MAVENCLAD is 3.5 mg per kg body weight over two years, administered as one treatment course of 1.75 mg per kg per year, each consisting of two treatment weeks. The mechanism by which cladribine exerts its therapeutic effects in patients with multiple sclerosis has not been fully elucidated but is thought to involve cytotoxic effects on B and T lymphocytes through impairment of DNA synthesis, resulting in depletion of lymphocytes. MAVENCLAD causes a dose-dependent reduction in lymphocyte counts followed by recovery.

Because cladribine is cytotoxic, special handling and disposal instructions should be followed.

More than 130,000 patients have been treated with MAVENCLAD since its launch in 2019. MAVENCLAD has been approved in over 80 countries, including the European Union (EU), Canada, Australia and Switzerland, for various relapsing MS indications. Visit www.MAVENCLAD.com for more information.

About Multiple Sclerosis

Multiple sclerosis (MS) is a chronic, inflammatory condition of the central nervous system and is the most common non-traumatic, disabling neurological disease in young adults. It is estimated that approximately 2.9 million people have MS worldwide. While symptoms can vary, the most common symptoms of MS include blurred vision, numbness or tingling in the limbs and problems with strength and coordination. The relapsing forms of MS are the most common.

Merck in Neurology and Immunology

Merck has a long-standing legacy in neurology and immunology, with significant R&D and commercial experience in multiple sclerosis (MS). The company’s current MS portfolio includes two products for the treatment of relapsing MS – Rebif^® (interferon beta-1a) and MAVENCLAD^® (cladribine tablets). Merck aims to improve the lives of patients by addressing areas of unmet medical needs. In addition to Merck’s commitment to MS, the company also has a pipeline focusing on discovering new therapies that have potential in other neuroinflammatory and immune-mediated diseases, including systemic lupus erythematosus (SLE), cutaneous lupus erythematosus (CLE) and generalized myasthenia gravis (gMG).

About Merck

Merck, a leading science and technology company, operates across life science, healthcare and electronics. More than 62,000 employees work to make a positive difference to millions of people’s lives every day by creating more joyful and sustainable ways to live. From providing products and services that accelerate drug development and manufacturing as well as discovering unique ways to treat the most challenging diseases to enabling the intelligence of devices – the company is everywhere. In 2024, Merck generated sales of € 21.2 billion in 65 countries.

Scientific exploration and responsible entrepreneurship have been key to Merck’s technological and scientific advances. This is how Merck has thrived since its founding in 1668. The founding family remains the majority owner of the publicly listed company. Merck holds the global rights to the Merck name and brand. The only exceptions are the United States and Canada, where the business sectors of Merck operate as MilliporeSigma in life science, EMD Serono in healthcare, and EMD Electronics in electronics.

All Merck press releases are distributed by e-mail at the same time they become available on the Merck website. Please go to www.merckgroup.com/subscribe to register online, change your selection or discontinue this service.

View source version on businesswire.com: https://www.businesswire.com/news/home/20250917717443/en/

Media Relations
Flavia.felix@emdserono.com
Phone: +1 781 427 1892