Progression of a series of patients with relapsing-remitting multiple sclerosis treated for 7 years with natalizumab using the “no evidence of disease activity” parameter

The safety and effectiveness of natalizumab in patients with relapsing-remitting multiple sclerosis (RRMS) has been demonstrated in clinical trials. However, due to the limitations of these trials, it is important to know how the condition behaves under long-term clinical practice conditions. To determine the long-term effectiveness of natalizumab in patients with RRMS by means of annual evaluation of the “no evidence of disease activity” (NEDA) parameter, which includes number of relapses, disability (measured with the Expanded Disability Status Scale), and brain MRI parameters. We performed a retrospective study of patients with RRMS from 3 centres who were treated with one or more doses of natalizumab. Each year, we evaluated NEDA status and safety based on the percentage of patients who discontinued treatment with natalizumab and experienced adverse reactions. The study included 89 patients, most of whom received treatment for 2 to 4 years, with a follow-up period of up to 7 years. Natalizumab significantly reduces the radiological and clinical progression of the disease, as well as the annual rate of relapses. The NEDA parameter demonstrates the effectiveness of the drug, with values of 75.28% for year one and 66.67% for year 7. Twenty-five patients (28.1%) dropped out after a median of 4 years. Fourteen of these patients (56%) dropped out due to the appearance of anti–JC virus antibodies, either in isolation or associated with another cause. Four dropouts (16%) were due to treatment ineffectiveness, with one patient dying due to progressive multifocal leukoencephalopathy. Natalizumab is highly effective as measured by the NEDA long-term remission parameter. La efectividad y seguridad de natalizumab en pacientes con esclerosis múltiple remitente recurrente (EMRR) se demostró en ensayos clínicos. Sin embargo, por las limitaciones de estos, es importante saber cómo se comporta en condiciones de práctica clínica a largo plazo. Conocer la eficacia a largo plazo de natalizumab en pacientes con EMRR mediante la evaluación anual del NEDA (no evidence of disease activity), que incluye número de brotes, discapacidad medida con EDSS y parámetros de RM cerebral. Estudio retrospectivo y multicéntrico (n = 3) de pacientes con EMRR tratados con una o más dosis de natalizumab. Se evaluó el estado NEDA cada año y la seguridad a partir del porcentaje de pacientes que discontinuaron y que presentaron efectos adversos. Incluimos 89 pacientes, la mayoría recibieron trata