AB Science announces results from masitinib phase 2 study on MS

AB Science SA (Paris:AB)(NYSE-Euronext-FR0010557264-AB), a pharmaceutical company specializing in the research, development and commercialization of protein kinase inhibitors, announces the publication of results from the human phase 2 study of masitinib carried-out in the treatment of progressive multiple sclerosis. The article, 'Masitinib treatment in patients with progressive multiple sclerosis: a randomized pilot study', is freely accessible online from BioMed Central's peer-reviewed journal BMC Neurology (http://www.biomedcentral.com/1471-2377/12/36/abstract).

• Phase 2 study establishes proof-of-concept that oral masitinib has potential therapeutic benefits in patients with progressive forms of multiple sclerosis

• Overall, results add new scientific data to the important question of the potential role of anti inflammatory agents in the management of progressive multiple sclerosis

• A phase 3 study has been initiated based upon these promising results

Reported are results from a phase 2 study of 30 patients, conducted by Professor Patrick Vermersch (CHRU Lille - Hôpital Roger Salengro, France) and colleagues from six study centers across France, investigating the hypothesis that masitinib's targeted inhibitory action on mast cells can delay the onset of symptoms associated with progressive forms of multiple sclerosis. There is currently no satisfactory treatment for primary progressive multiple sclerosis or relapse-free secondary progressive multiple sclerosis, which represent approximately 60% of patients diagnosed with multiple sclerosis. Neuroinflammation is thought to be important in progressive multiple sclerosis pathogenesis. Mast cells are a key component of the inflammatory network and participate in the regulation of the blood-brain barrier's permeability. Masitinib is an oral tyrosine kinase inhibitor that effectively down-regulates mast cell functions and therefore, represents a different approach to those therapeutic strategies currently developed. The results showed that for the primary endpoint of Multiple Sclerosis Functional Composite (MSFC) score (which measure symptoms of patients on three aspects: movement of the lower limbs, movement of the upper limbs, and cognitive tests) 32% of patients treated with masitinib were responders against 0% under placebo. Responses were seen in the third month and were more-or-less sustained over the study's 18-month duration. These results suggest that daily administration of masitinib is of therapeutic benefit to progressive forms of multiple sclerosis and could therefore represent an innovative avenue of treatment for this disease.

Professor Vermersch commented: "Masitinib is a selective inhibitor of specific kinases that play a major role in the activation of mast cells, which are involved in the immune response, in the recruitment of lymphocytes to the brain, and also in inflammatory processes associated with multiple sclerosis and many of its resulting symptoms. Masitinib therefore represents an oral treatment different from those drugs already on the market for this indication, with a unique mechanism of action in blocking mast cells. Masitinib showed promising signs of retarding the onset of symptoms associated with progressive multiple sclerosis as compared to placebo, with an acceptable tolerance profile. Although the number of patients in this study was too small to make any definitive conclusions about treatment efficacy, the evidence is sufficiently compelling to warrant further phase 3 investigation."

Professor Olivier Hermine, President of the scientific committee of AB Science and co-corresponding author on this paper declared: "Masitinib differs from those treatments currently available or under development in multiple sclerosis. It has a weak immunosuppressive activity, although by inducing a reduction in the number of lymphocytes infiltrating the brain it helps prevent injuries. Masitinib's characteristic selectivity against mast cells also means that it is not associated to date with major toxicities; for example, cardiac toxicity as seen with mitoxantrone, a drug sometimes used in severe progressive multiple sclerosis, or opportunistic infections as seen with Tysabri or Gilenya, which are associated with an increased risk of infection."