Results from a recent Brazilian study, published in the journal Arquivos de Neuro-Psiquiatria, revealed that natalizumab is an effective treatment for multiple sclerosis (MS) patients. The study is entitled “Natalizumab treatment in multiple sclerosis: the experience from two Brazilian MS centers“.
MS is a demyelinating, inflammatory disease of the central nervous system, presumably with an autoimmune etiopathogenesis. First line therapies developed for the relapsing-remitting form of MS (RRMS) include disease modifying treatments (DMTs), such as interferons (IFNs) beta and glatiramer acetate. However, these treatment options have been shown to be only partially effective, with 20 – 50% of the treated patients experiencing a relapse or disability progression in a short period of time.
Natalizumab is a humanized monoclonal antibody that blocks the α-4 integrin, VLA-4, an adhesion molecule present on the surface of leukocytes (white blood cells), inhibiting their migration into the central nervous system.
To analyze the demographics and clinical characteristics, as well as the efficacy and safety profile of natalizumab treatment, researchers conduced a retrospective analysis on Brazilian patients with RRMS in two tertiary MS clinical centers in São Paulo, Brazil. In total, the team reviewed medical records of 75 RRMS patients treated for at least 12 months with natalizumab (Tysabri). A subgroup analysis was performed to evaluate the efficacy of natalizumab treatment in patients with Expanded Disability Status Scale (EDSS) ≤ 3.0 vs patients with EDSS > 3. The EDSS is a quantification method for disability in MS patients, where the higher the score, the higher is the degree of disability.
The results showed that RRMS patients treated for at least one year with natalizumab had a 91% reduction in the annualized relapse rate and a general improvement in their neurological disability. The impact of natalizumab treatment was greater in patients with EDSS < 3.0. Overall, natalizumab was safe, although one patient developed progressive multifocal leukoencephalopathy, a life-threatening condition that affects the brain.
Based on their findings, the research team suggests that the positive impact of natalizumab treatment on patients with mild neurological disability should prompt neurologists to consider, in cases of treatment failure, an early therapeutic switch to natalizumab, which is currently mostly used as a 3rd line therapy.