Masican (masitinib) filed with EMA for adults with severe systemic mastocytosis- AB Science

AB Science has filed for registration with the European Medicines Agency (EMA) for Masican (masitinib) in the treatment of adult patient with severe systemic mastocytosis unresponsive to optimal symptomatic treatment, with date of review process starting on 26 April 2016. Top-line results from this phase III were previously announced on 30 November 2015. EMA decision should be known during the first half of 2017.

Filing to EMA for the Marketing Authorization of masitinib in severe systemic mastocytosis was done on the basis of results from a phase III study showing that masitinib was superior to optimal symptomatic treatment on the primary efficacy analysis as well as secondary efficacy analyses. This study compared masitinib plus optimal symptomatic treatment versus placebo plus optimal symptomatic treatment in adult patients with severe systemic mastocytosis, with or without D816V mutation of c-Kit. Study results showed that masitinib administered at 6 mg/kg/day was superior to the comparator, as measured by the cumulative 75% response rate until week 24 on the handicaps of pruritus or flushes or depression or fatigue (4H75% response). The 4H75% response was 18.7% for the masitinib treatment-arm versus 7.4% for the placebo treatment-arm in the mITT population (primary analysis). According to protocol, the primary efficacy analysis was performed in the modified intent-to-treat population (mITT), yet the study was also successful on the sensitivity analysis performed in the intent-to-treat population (18.7% versus 7.6%). Success in the primary analysis was also supported by positive outcomes in all secondary analyses.

Comment: Comment: Mastocytosis is an orphan disease characterized by an abnormal proliferation or activation of mast cells either in the skin or in bone marrow or other organs. Mastocytosis comes in two main forms: indolent and aggressive. Indolent forms of mastocytosis can be either cutaneous or systemic. The prevalence of indolent systemic mastocytosis, including smoldering systemic mastocytosis, is estimated to be 1/26,000 in Europe. The symptoms and handicaps are severe in about one third of the patients; hence, an estimated target population for masitinib of approximately 1/78,000 of the general population.