Second-line FOLFIRI + Panitumumab in Subjects With Wild Type RAS Metastatic Colorectal

To estimate progression-free-survival at 6 months in subjects treated in first-line with panitumumab and FOLFOX and with wild type RAS mCRC (metastatic colorectal cancer) confirmed in liquid biopsies before starting second line treatment will be screened for this trial and who have interrupted panitumumab for \<3 months (panitumumab continuation). Control arm of subjects treated with FOLFIRI alone will be included. The combinations of 5-fluorouracil (5-FU) with oxaliplatin (FOLFOX)are considered the backbone chemotherapy for mCRC. Clinical trials have shown the benefit of adding monoclonal antibodies to subjects without mutations in RAS, directed against the epidermal growth factor receptor (EGFR) (cetuximab and panitumumab) to conventional chemotherapy as first-line treatment of mCRC. This trial purposes to study the treatment beyond progression with panitumumab in subjects treated in first-line with an anti-EGFR monoclonal antibody, or rather,the re-introduction of the same targeted therapy after progression to first line. The clinical hypothesis of this study is that the second-line regimen FOLFIRI + panitumumab, is sufficiently active (defined as a 6-months PFS higher than 30% \[based on prior results with second-line FOLFIRI alone\] and of at least 50%), justifying further study in this population.