Oral Masitinib Effective in Progressive Multiple Sclerosis

February 26, 2020

The orally administered tyrosine kinase inhibitor was shown to delay disability progression in patients with primary progressive multiple sclerosis.

Olivier Hermine

AB Science SA has announced that oral masitinib met its primary end point in a phase 2b/3 study (AB07002) of patients with primary progressive multiple sclerosis (PPMS) and nonactive secondary progressive MS (SPMS).

“While numerous treatments based on targeting of B-cells and T-cells of the adaptive immune system are available for patients with relapsing forms of MS, these strategies have failed or had inconclusive results in PPMS and nSPMS,” Patrick Vermersch, MD, PhD, professor of neurology at Lille University in France and coordinate investigator of study AB07002, said in a statement. “Masitinib does not target the adaptive immune system and the results from this study represent a scientific breakthrough because this is the first time that the novel strategy of targeting the innate immune system via mast cells and microglia has been able to significantly slow progression of clinical disability in progressive forms of MS. These data are extremely encouraging and may provide new hope for progressive MS patients.”

The multicenter, double-blind, placebo-controlled phase 2b/3 trial enrolled 611 participants and compared the efficacy and safety of masitinib 4.5 mg/kg/day or 6.0 mg/kg/day versus placebo.

Patients included in the study (age 18-75) had an Expanded Disability Status Scale (EDSS) score between 2 and 6. Investigators used change in EDSS from week 12 to week 96 as the primary end point of the study.

A modified intent-to-treat population that included all randomized patients who took at least one dose of study treatment was used for efficacy analysis.

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The investigators reported that the masitinib 4.5 mg/kg/day group (n = 200) achieved the primary end point (P = .0256), demonstrating a significant delayed disease progression as measured by the time to reach an EDSS score of 7.0. Notably, the investigators concluded that the 6.0 mg/kg/day dose of masitinib (n = 203) did not demonstrate any significant improvement in comparison with placebo.

Safety analysis showed that 95% of patients who received 4.5 mg/kg/day of masitinib had at least 1 adverse event compared to 87.1% of patients in the placebo group. Masitinib was generally tolerated throughout the study.

“This is the second piece of supportive evidence delivered by the masitinib clinical program. The first one was the positive phase 2b/3 study with masitinib in amyotrophic lateral sclerosis. The second one is this new positive phase 2b/3 study in progressive forms of MS, which share similar characteristics with other neurodegenerative diseases,” professor Olivier Hermine, president of the Scientific Committee of AB Science and member of the Academie des Sciences in France, said in a statement. “The two studies taken together clearly demonstrate that targeting the innate immune system via macrophage/microglia and mast cells, as masitinib does, is one of the right strategies to treat neurodegenerative disorders.”

Detailed study results will be presented at an upcoming medical meeting.

REFERENCE

AB Science announces positive top-line phase 2B/3 results for oral masitinib in progressive forms of multiple sclerosis [news release]. Paris, France: AB Science SA. February 20, 2020. globenewswire.com/news-release/2020/02/20/1988146/0/en/AB-Science-announces-positive-top-line-Phase-2B-3-results-for-oral-masitinib-in-progressive-forms-of-multiple-sclerosis.html. Accessed February 20, 2020.