Cladribine tablets as therapy for advanced relapsing-remitting multiple sclerosis: a 4-year follow-up real-world, multi-center, retrospective, cohort study

Aleksandra Pogoda-Wesołowska^1*Adam Stepien¹Marcin Wnuk²Monika Marona³Elżbieta Tokarz-Kupczyk⁴Karolina Piasecka-Stryczyńska⁴Konrad Rejdak⁵Anna Jamroz- Wiśniewska⁵Monika Adamczyk-Sowa⁶Katarzyna Kubicka-Bączyk⁶Iwona Kurkowska-Jastrzebska⁷Katarzyna Kurowska⁷Przemysław Puz⁸Alina Kułakowska⁹Monika Chorąży⁹Waldemar Brola¹⁰Halina Bartosik-Psujek¹¹

• ¹Department of Neurology, Military Institute of Medicine (Poland), Warsaw, Poland
• ²Jagiellonian University Medical College, University Hospital in Kraków, Kraków, Poland
• ³Jagiellonian University Medical College, University Hospital in Krakow, Kraków, Poland
• ⁴Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
• ⁵Department of Neurology, Medical University of Lublin, Lublin, Poland
• ⁶Department of Neurology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
• ⁷Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland
• ⁸Department of Neurology, Upper Silesian Medical Centre of the Silesian Medical University in Katowice, Katowice, Poland
• ⁹Department of Neurology, Medical University of Bialystok, Białystok, Poland
• ¹⁰Department of Neurology, Jan Kochanowski University, Kielce, Poland
• ¹¹Department of Neurology, Institute of Medical Sciences, University of Rzeszow, Rzeszów, Poland

Introduction: Cladribine tablets (CladT) are a high-efficacy disease-modifying therapy recommended for the treatment of relapsing-remitting multiple sclerosis (RRMS) particularly in early disease. This study is aimed to evaluate the long-term efficacy of CladT in population of Polish RRMS patients, with more advanced disease.Methods: This retrospective observational study included patients with RRMS who started CladT treatment between December 2019 and November 2023. Collected data included prior treatments, annualized relapse rate (ARR), magnetic resonance imaging (MRI) activity, Expanded Disability Status Scale (EDSS) score, no evidence of disease activity (NEDA-3), lymphocyte counts, and safety outcomes were collected.Results: Of the 230 patients (8.3% treatment-naïve, mean disease duration 9.2 years), follow-up data were available up to year 1 for 222 patients, year 2 for 154 patients, year 3 for 87 patients and year 4 for 31 patients. The ARR decreased from 1.42 at baseline to 0.26, 0.22, and 0.36 in years 1, 2, and 3, respectively. The proportion of relapse-free patients increased from 13.9% at baseline to 76.8% in year 1, 82% in year 2 and 75.4% in year 3 with no relapses reported in year 4. The proportion of patients with active MRI lesions declined from 90.4% at baseline to 36.3% in year 1, 25.2% in year 2, 45.9% in year 3 and 8.3% in year 4. Stable or improved EDSS was observed in 85.9% of patients in year 1, 80.8% in year 2, 73.7% in year 3 and 88.9% in year 4. NEDA-3 status was achieved in 47.4% of patients in year 1, 51.0% in year 2, 40.4% in year 3 and 71.4% in year 4. Adverse events (were reported in 16.7% of patients in years 1-2 and in 6.3% of patients in year 3.The results indicate that CladT is effective and safe in Polish patients with RRMS, characterized by high disease activity, delayed treatment initiation, and multiple number of prior therapies.