Masitinib in First Line Treatment of Gastro-Intestinal Stromal Tumor (GIST)

Masitinib is a selective tyrosine kinase inhibitor with potent activity against wild-type
c-Kit, the juxta membrane domain of c-Kit, and PDGFR. In addition to its direct inhibitory
action against these kinase targets, masitinib is also thought to promote survival via
modulation of immunostimulation-mediated anticancer effects and modulation of the tumor
microenvironment. The objective of this prospective, multicenter, randomized, open-label,
active-controlled study is to compare the efficacy and safety of masitinib with respect to
imatinib in the first line treatment of gastro-intestinal stromal tumor (GIST). Treatment
will be given until disease progression, limiting toxicity or patient consent withdrawal.

Main inclusion criteria include:

- Histologically proven, metastatic or locally advanced non resectable, or recurrent
post-surgery GIST

- Naïve patient or patient previously treated with imatinib as neoadjuvant/adjuvant who
relapsed after imatinib discontinuation

- c-Kit (CD117) positive tumours detected by immuno-histochemically or PDGFR positive if
c-Kit negative

Main exclusion criteria include:

- Patient previously treated by tyrosine kinase inhibitors except imatinib in case of
inclusion criteria

- 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