Masitinib can help patients by slowing down the progression of Expanded Disability Status Scale (EDSS)-based impairment.
Multiple Sclerosis (MS) is a degenerative, demyelinating, and inflammatory disease of the central nervous system. In terms of medication, the clinical course of MS is diverse, with patients falling into two major categories. The first group, relapsing disease, is connected with inflammatory demyelination processes that result in relapses and remissions. The second group, progressive disease, is characterized by neurodegenerative processes that result in a steady accumulation of neurologic impairment.
Masitinib is a selective tyrosine kinase inhibitor that targets innate immune cells (mast cells and microglia) involved in the pathogenesis of multiple sclerosis progression (MS).
This randomized, double-blind, two parallel-group, placebo-controlled experiment was undertaken to determine if masitinib can slow disability progression in persons with primary progressive MS (PPMS) or nonactive secondary progressive MS (nSPMS). It was conducted across 116 hospital clinics and specialized MS facilities in 20 countries. It was published in the journal Neuroimmunology ＆ Neuroinflammation.
In this study, patients with progressive MS who were not clinically active were administered oral masitinib. Two-to-one randomization with minimization was carried out centrally by an automated system. Patients with primary progressive multiple sclerosis (PPMS) or nonactive secondary progressive multiple sclerosis (nSPMS) without relapse for 2 years, aged 18–75 years, with a baseline Expanded Disability Status Scale (EDSS) score of 2.0–6.0, were treated for 96 weeks, independent of disease onset. In total, 611 individuals were randomized, with 301 in the masitinib 4.5 mg/kg/d parallel group and 310 in the masitinib 6.0 mg/kg/d parallel group.
Masitinib (4.5 mg/kg/d) considerably outperformed placebo based on the primary endpoint, 0.001 versus 0.098, with a between-group difference of 0.097 (97% confidence interval [CI]: 0.192 to 0.002); p = 0.0256. The observed effect of therapy on the primary endpoint was confirmed by convergence in EDSS sensitivity analyses.
In addition, the benefit was demonstrated in a population that included both PPMS and nSPMS subgroups. The safety results of this study were similar to what was already known about masitinib (for example, diarrhea, rash, nausea, peripheral edema, pruritus, and dyspepsia), and no new side effects were found.
This study found that 4.5 mg/kg/d of masitinib can help patients by slowing down the progression of EDSS-based impairment.
A confirmatory Phase 3 clinical trial with neuroimaging data is needed.
Vermersch, P., Brieva-Ruiz, L., Fox, R. J., Paul, F., Ramio-Torrenta, L., Schwab, M., Moussy, A., Mansfield, C., Hermine, O., & Maciejowski, M. (2022). Efficacy and Safety of Masitinib in Progressive Forms of Multiple Sclerosis: A Randomized, Phase 3, Clinical Trial. Neurol Neuroimmunol Neuroinflamm, 9(3). https://doi.org/10.1212/nxi.0000000000001148