XENOX - Evaluation of the Efficacy of Xaliproden in Reducing the Neurotoxicity of the Oxaliplatin + 5-FU/LV Chemotherapy

Inclusion Criteria: * Histologically or cytologically proven adenocarcinoma of the colon or the rectum * age \> 18 years * WHO performance status : 0,1,2 * Signed written informed consent prior to study entry * Disease stage : metastatic disease not amenable to potentially curative treatment (eg : inoperable metastatic disease) * Measurable disease * No prior chemotherapeutic regimen for metastatic disease ; prior adjuvant chemotherapy allowed (disease free interval from end of adjuvant therapy of at least 6 months) * Prior radiotherapy permitted, if completed at least 3 weeks before randomization, and if not administered to target lesions identified for the study Exclusion Criteria: * Chemotherapeutic agents other than 5-FU/LV or 5-FU/Levamizole as part of adjuvant therapy * Prior therapy with Oxaliplatin * History of cardiac toxicities under 5-FU/LV therapy or myocardial infarction within the 6 months before study entry ; Known Dihydropyrimidine Dehydrogenase deficiency * History of intolerance to appropriate antiemetics * Concurrent active cancer originating from a primary site other than colon or rectum * Presence of any symptom suggesting brain metastasis * Known peripheral neuropathy * Interstitial pneumonia or extensive and symptomatic fibrosis of the lung * Allergy to Xaliproden/excipients