Multicentre Placebo-controlled Double-blinded Phase II Study of Lenvatinib Efficacy in Patients With Locally Advanced or Metastatic GIST (Gastrointestinal Stromal Tumor) After Imatinib/Sunitinib Failure

Inclusion Criteria: I1. Male or female ≥ 18 years at the day of consenting to the study. I2. Patient must have histologically confirmed diagnosis of GIST. I3. Disease must be locally advanced or metastatic. I4. Patient who failed (disease progression and/or intolerance) previously at least to imatinib and sunitinib. Nota Bene: patients with more than 2 previous anticancer treatments are eligible. I5. Patient must have evidence of measurable disease as per the RECIST version 1.1 (Appendix 2). I6. Patient must have documented disease progression. I7. ECOG performance status 0, 1 or 2 (Appendix 3). I8. Patient must have normal organ and bone marrow function as defined below: * Hematologic * Absolute neutrophil count (ANC) ≥ 1.5 Gi/L * Haemoglobin ≥ 9 g/dl (5.6 mmol/l) (subjects may not have had a transfusion within 7 days of screening assessment) * Platelets ≥ 100 Gi/l * Coagulation panel * Prothrombin time (PT) or international normalized ratio (INR) ≤ 1.2 X upper limit of normal (ULN) * Partial thromboplastin time (PTT) ≤ 1.2 X ULN Subjects receiving anticoagulant therapy are eligible if their INR is stable and within the recommended range for the desired level of anticoagulation. * Hepatic * Total bilirubin ≤ 1.5 X ULN * AST and ALT ≤ 2.5 X ULN * Renal * Serum creatinine ≤ 1.5 mg/dl (133 µmol/l) Or, if greater than 1.5 mg/dl: calculated creatinine clearance ≥ 50 ml/min * Urine Protein to Creatinine ratio (UPC) \< 1; If UPC \> 1, then a 24-hour u…