Masitinib is a selective tyrosine kinase inhibitor that modulates mast cell activity via inhibition of c-Kit, Lyn and Fyn kinase signaling pathways. This is a multicenter, randomized, double-blind, placebo-controlled, 2-parallel-group, trial comparing oral masitinib versus placebo in the treatment of patients suffering from smouldering or indolent systemic mastocytosis with severe symptoms of mast cell mediator release (also referred to as handicaps), unresponsive to optimal symptomatic treatment. The treatment period is 24 weeks. Participants receive masitinib (3.0 mg/kg/day), given orally twice daily, with a dose escalation to 4.5 mg/kg/day after 4 weeks of treatment, followed by dose escalation to 6.0 mg/kg/day after 4 weeks of treatment. Each ascending dose titration is subjected to a safety control.
The purpose of this study is to evaluate the efficacy and safety of oral masitinib versus placebo in the treatment of patients suffering from smouldering or indolent systemic mastocytosis with severe symptoms of mast cell mediator release, unresponsive to optimal symptomatic treatment.