- CETUXIMAB 1st cycle Day 1 400 mg/m2 infusion of 120 min 2 hr before CT infusion 1st cycle Day 8 and subsequent cycles 250 mg/m2 infusion of 60 min 1 hr before CT infusion If cetuximab will be stopped for any of the reasons specified in this protocol, bevacizumab will be administered as defined in arm A of the 1st line study Patients from arm B and Kras Mutant were treated according to arm E. Objectives of study The primary objective of the 1st line study is to determine whether the addition of bevacizumab to a poly-chemotherapy (polyCT) regimen (FOLFIRI or FOLFOX) improves efficacy in terms of progression-free survival (PFS). The secondary objectives of the 1st line study are to determine the Overall Response Rate (ORR) and the safety profile of the treatments administered.