Masitinib in Patients With Gastrointestinal Stromal Tumour After Progression With Imatinib

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).

Main inclusion criteria include:

- Patient with histological proven metastatic GIST or non-operable locally advanced GIST

- Patient with c-Kit (CD117) positive tumor detected immuno-histochemically

- Patient after at least one progression with imatinib at a dose up to 800mg.
Progression is defined as a RECIST 1.1 and/or CHOI disease progression while receiving
imatinib treatment.

Main exclusion criteria include:

- Patient treated for a cancer other than GIST within 5 years before enrolment, with the
exception of basal cell carcinoma or cervical cancer in situ

- Patient with active central nervous system (CNS) metastasis or with history of CNS
metastasis

- Pregnant, or nursing female patient