Effectiveness and Safety of Cladribine in Relapsing-Remitting Multiple Sclerosis in Clinical Practice: A 2-Year Multicenter Retrospective Open-Label Study

Background and Objectives: Cladribine is an oral immunomodulatory drug approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). The study aimed to evaluate the effectiveness and safety of cladribine in real-world RRMS patients. Methods: A retrospective multicenter study was conducted, including RRMS patients treated with cladribine during a 2-year follow-up period. The endpoints were: Annual relapse rate (ARR), disability progression (according to the Expanded Disability Status Scale, EDSS), absence of new lesions and/or gadolinium enhancement on magnetic resonance imaging, and incidence of adverse events (AEs). Results: A total of 210 patients (74.3% women) were included, with a mean age of 41.96 ± 10.42 years, and 77.6% had received prior treatments. The ARR significantly decreased to 0.16 and 0.16 in the first and second year, respectively ( P < 0.05). Disability, as measured by EDSS, improved during the first year (1.89, P < 0.05) and remained stable in the second year (1.92, P = 0.73). Gadolinium-enhancing lesions improved to 0.14 and 0.26 ( P < 0.05). Mild to moderate AEs were reported in 29% (year 1) and 15% (year 2). One case of prostate cancer and one case of urinary sepsis with a fatal outcome were reported. Conclusions: Cladribine demonstrated clinical and radiological effectiveness in a real-world setting over 2 years, with an acceptable safety profile.