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

ORR (assessed by BICR per RECIST v1.1) is defined as the proportion of participants with a BOR of confirmed CR or PR. The ORR will be estimated as the number of participants achieving BOR of CR or PR assessed by BICR per RECIST v1.1 divided by the total number of participants.

An AE is any untoward medical occurrence in a patient or clinical study patient, temporally associated with the use of a study intervention, whether or not considered related to the study intervention.

SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires inpatient hospitalization or causes prolongation of existing hospitalization, results in significant disability/incapacity.

ORR (assessed by site Investigator per RECIST v1.1) is defined as the proportion of participants with a BOR of confirmed CR or PR. The ORR will be estimated as the number of participants achieving BOR of CR or PR assessed by site Investigator per RECIST v1.1 divided by the total number of participants.

OS is defined as the time between the date of randomization and the date of death due to any cause.

PFS by BICR is defined as the time from date of randomization to the date of the first documented progressive disease (PD) as determined by BICR per RECIST version 1.1, or the date of death due to any cause, whichever occurs first.

PFS by Investigator assessment is defined as the time from date of randomization to the date of the first documented progressive disease (PD) as determined by site Investigator per RECIST version 1.1, or the date of death due to any cause, whichever occurs first.

BOR is defined as the best response designation, recorded between the start of the study intervention and the date of the initial objectively documented PD per RECIST v1.1 or the date of subsequent anti-cancer therapy, whichever occurs first.

BOR is defined as the best response designation, recorded between the start of the study intervention and the date of the initial objectively documented PD per RECIST v1.1 or the date of subsequent anti-cancer therapy, whichever occurs first.

DOR is defined as the time between the date of first confirmed CR or PR to the date of the first documented PD per RECIST v1.1 or death due to any cause, whichever occurs first.

DOR is defined as the time between the date of first confirmed CR or PR to the date of the first documented PD per RECIST v1.1 or death due to any cause, whichever occurs first.

DCR is defined as the percentage of participants whose BOR is determined to be CR, PR, or stable disease (SD).

DCR is defined as the percentage of participants whose BOR is determined to be CR, PR, or stable disease (SD).

TTR is defined as the time from the date of randomization to the date of first confirmed CR or PR.

TTR is defined as the time from the date of randomization to the date of first confirmed CR or PR.

In participants who have target lesions at baseline and at least 1 post-baseline imaging evaluation, the maximum percent change in the sum of diameters of target lesions is the percent change at the point of the minimum sum of diameters of the target lesions.

In participants who have target lesions at baseline and at least 1 post-baseline imaging evaluation, the maximum percent change in the sum of diameters of target lesions is the percent change at the point of the minimum sum of diameters of the target lesions.

PFS2 is defined as the time from date of randomization to the date of an overall response of PD after subsequent anti-cancer therapy, initiating date of a second subsequent anti-cancer therapy, or date of death from any cause, whichever occurs first.