RESUMO
BACKGROUND: Natalizumab is a humanized monoclonal antibody with high efficacy and an acceptable safety profile used in the treatment of patients with multiple sclerosis (MS). OBJECTIVE: Our aim was to report data regarding long-term administration of Natalizumab in patients with Relapsing-Remitting Multiple Sclerosis (RRMS) from our clinic. METHODS: A retrospective observational study was performed including RRMS patients who underwent treatment with ≥ 24 Natalizumab infusions. We analyzed EDSS values, the relapse rate and the rate and type of adverse events related to Natalizumab administration. RESULTS: 51 subjects were included with a predominance of women (62.74%), with an average age of 40.43±1.49 years, a mean disease duration of 9.86±0.7 years and mean number of Natalizumab infusions of 45.58±2.74. An increased number of patients (80.39%) were relapse-free and a mild reduction of the mean EDSS value following Natalizumab initiation in patients who had not been treated with other disease modifying therapies anteriorly was observed. Among the encountered adverse events such as increased liver transaminases (13.72%), local infections (7.84%) and dysmenorrhea in one patient were registered in this study. The rate of severe adverse events was 3.92 and no cases of Progressive Multifocal Leukoencephalopathy (PML) were registered. CONCLUSION: Natalizumab proves to be effective, has an adequate safety profile and can be administered with good tolerability for a rather extended period of time, provided that the patients are closely monitored.