A Study to Evaluate the Safety and Efficacy of Two Dose Levels of ONO-4578 With Opdivo®, in Combination With mFOLFOX6 and Bevacizumab Versus Standard of Care in Participants With Non-MSI-H/dMMR, PD-L1 Positive Advanced Colorectal Cancer

Who May Qualify: - diagnosed by tissue sample (biopsy-confirmed) advanced (locally advanced or metastatic) colorectal cancer not amenable to curative resection - You should be able to carry out daily activities with 0 level of ability (ECOG 0)-1 - No prior systemic treatment for advanced local or mCRC - Participants whose tumor is positive for PD-L1 expression as determined at a central laboratory Who Should NOT Join This Trial: - Participants with high microsatellite instability (MSI-High), or mismatch repair deficient (dMMR) tumor - Participants with BRAF V600E mutation - Unable to swallow tablets. - Participants with complication or history of interstitial lung disease, pneumonitis or pulmonary fibrosis - Participants with an active, known or suspected autoimmune conditions (where your immune system attacks your own body). - Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T-cell co-stimulation or immune checkpoint pathways. Other protocol-defined inclusion/exclusion criteria apply Always talk to your doctor about whether this trial is right for you.