Study Evaluating Neurotoxicity in Patients With Metastatic Gastro Intestinal Cancer Taking Phycocare® or Placebo During Oxaliplatin Based Chemotherapy

Inclusion Criteria: * Male or female with the age \> or = to 18 years old. * Negative pregnancy test for women with child-bearing potential if applicable (without hysterectomy for example) * Information given to the patient who must have signed informed consent * Patient with Histologically or cytologically proven gastro intestinal cancer including oesogastric, colo-rectal, pancreatic cancers, locally advanced pancreatic cancers and planned to be treated with oxaliplatin * Patient with metastatic disease not previously treated * Patient willing not to take any plant-based therapy during the study (including phytotherapy and gemmotherapy) * Previous radiotherapy is authorized if discontinued ≥15 days prior to randomization * Sites of disease evaluated within 42 days prior C1 day 1 of chemotherapy with thoracic-abdominal-pelvic CT scan (or abdominal-pelvic MRI and chest X-ray) * Patient with ECOG Performance status 0 or 1 * Patients with a Life expectancy ≥12 weeks * Laboratory results: Hematologic function: polynuclear neutrophils ≥ 1.5.109/L platelets ≥100.109/L haemoglobin ≥9 g/dL Hepatic function: transaminases ≤2.5 times upper limit of normal (ULN) (≤5 ULN in case of hepatic metastases), alkaline phosphatases ≤2.5 x ULN (≤5 ULN in case of hepatic metastases), total bilirubin ≤1.5 x ULN Renal function: creatinemia clearance \>50 ml/min (Cockcroft and Gault) \- Patient with Public Health insurance coverage Exclusion Criteria: * Patients with phenylketonuria * Patie…