AB-GIST: A Prospective, Multicenter, Randomized, Open-Label, Active-Controlled, 2-parallel Group, Phase III Study to Compare Efficacy and Safety of Masitinib at 7.5 mg/kg/day to Imatinib at 400 or 600 mg in Treatment of Patients With Gastro-intestinal Stromal Tumor in First Line Medical Treatment.

Summary:
This study will compare the safety and the efficacy of two oral medications, masitinib at 7.5 mg/kg/day and imatinib at 400 or 600 mg, in patients with gastro-intestinal stromal tumor (GIST) in initial treatment or treatment for relapse. Imatinib is a medication approved by the FDA for treatment of GIST.

In order to determine eligibility for this study, the genetic features of your cancer will be studied.

Treatment Plan
Subjects will be randomly assigned to one of two groups:

• Group 1: patients will receive masitinib at 7.5 mg/kg/day
• Group 2:  patients will receive imatinib at 400 or 600 mg per day

Eligibility Participants:

1. Diagnosis of GIST that is metastatic or locally advanced and not eligible for surgery or recurred after surgery.
2. Subjects previously untreated or treated initially with imatinib who relapsed after imatinib discontinuation.
3. Subjects without  serious heart disease, such as congestive heart failure, or myocardial infarction within 6 months