Masitinib is a selective tyrosine kinase inhibitor with potent activity against wild-type c-Kit, the juxta membrane domain of c-Kit, and PDGFR. Masitinib is also thought to promote survival via modulation of immunostimulation-mediated anticancer effects and modulation of the tumor microenvironment. The objective is to compare the efficacy and safety of masitinib at 12 mg/kg/day with respect to sunitinib at 50 mg/day in the treatment of imatinib-resistant gastro-intestinal stromal tumor (GIST).