This is a multicenter, randomized, open-label, 3-arm Phase 3 study to evaluate encorafenib + cetuximab plus or minus binimetinib versus Investigator's choice of either irinotecan/cetuximab or FOLFIRI/cetuximab, as controls, in patients with BRAFV600E mCRC whose disease has progressed after 1 or 2 prior regimens in the metastatic setting. The study contains a Safety Lead-in Phase in which the safety and tolerability of encorafenib + binimetinib + cetuximab will be assessed prior to the Phase 3 portion of the study.