FOLFOX + Panitumumab According to a "Stop and go" Strategy With a Reintroduction Loop After Progression on Fluoropyrimidine as Maintenance Treatment, as the First Line in Patients With Metastatic Colorectal Adenocarcinoma Without a RAS Mutation

Inclusion Criteria: * \- Histologically proven colorectal adenocarcinoma without RAS mutation * Confirmed, non-resectable metastatic disease (Stage IV) * No prior chemotherapy except perioperative or adjuvant chemotherapy discontinued for more than 12 months * At least one measurable metastasis according to the RECIST v1.1 criteria * Age ≥ 18 years * WHO ≤ 2 * Neutrophils \> 1500 /mm3, platelets\> 100 000/mm3, Hb \> 9 g/dL * Creatinine clearance \> 50 mL/min according to the MDRD formula * Serum bilirubin \< 25 µmol/L, AST, ALT, Alk Phos \< 2.5 x ULN or \< 5 x ULN in case of liver metastases * PT \> 60%, albumin ≥ 25g/L * Estimated life expectancy ≥ 3 months * Patient affiliated to a social security scheme * Patient informed and informed consent form signed Exclusion Criteria: * \- Presence of uncontrolled symptomatic brain metastases * RAS mutation (KRAS or NRAS mutation) * Patient taking warfarin. If treated with anticoagulant at the indicated effective dose, this must be replaced with low molecular weight heparin before inclusion * Known DPD deficiency * Peripheral neuropathy \> 1 (NCI CTCAE v4.0) * Patient with interstitial pneumonitis or pulmonary fibrosis * History of chronic diarrhoea or inflammatory disease of the colon or rectum, or obstruction or sub-obstruction during symptomatic treatment * Poorly controlled chronic skin disease * Any known specific contraindication or allergy to the medicinal products used in the study * Patient simultaneously included in another clinical trial involving an investigational drug (example: chemotherapy, targeted therapy, immunotherapy) * Arterial hypertension not controlled by medical treatment (Systolic BP ≥ 160 mmHg end/or diastolic BP ≥ 90 mmHg) * Any progressive pathology not stabilised over the past 6 months: hepatic failure, renal failure, respiratory failure * The following conditions in the 6 months prior to inclusion: myocardial infarction, severe/unstable angina, coronary artery bypass surgery, congestive heart failure NYHA class II, III or IV, stroke or transient ischaemic attack * Patient who has received a transplant, is seropositive for HIV, hepatitis B or hepatitis C or has other immunodeficiency syndromes * History of malignant pathologies during the past 5 years except basal cell carcinoma of the skin or cervical carcinoma in situ, properly treated * QT/QTc interval \> 450 msec for men and \> 470 msec for women * K+ \< LNL, Mg2+ \< LNL, Ca2+ \< LNL * Lack of effective contraception in patients (men and/or women) of childbearing age, pregnant or breastfeeding women, women of childbearing age who have not had a pregnancy test * Persons in custody or under wardship * Impossibility of undergoing medical monitoring during the trial for geographical, social or psychological reasons