DARMSTADT, GERMANY -- Merck, a leading science and technology company, 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 41st 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