BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) in Arm A and Arm B only

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) who have not received prior therapy for metastatic disease (1L) in Arm B and Arm C only

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants in Arm A and Arm B only.

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants who have not received prior therapy for metastatic disease (1L)

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed microsatellite instability-high (MSI-H) in Arm A and Arm B only

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed DNA mismatch repairdeficient (dMMR) in Arm A and Arm B only

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed microsatellite instability-high (MSI-H) who have not received prior therapy for metastatic disease (1L) in Arm B and Arm C only

BICR-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed DNA mismatch repairdeficient (dMMR) who have not received prior therapy for metastatic disease (1L) in Arm B and Arm C only

Investigator-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants in Arm A and Arm B only.

Investigator-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) in Arm A and Arm B only.

Investigator-assessed Progression-free survival (PFS) is defined as the time from the randomization date to the date of first objectively documented disease progression per RECIST 1.1 (i.e, radiologic) or death due to any cause, whichever occurs first.

Objective Response Rate (ORR) is defined as the percentage of all randomized participants whose best overall response is either confirmed complete response (CR) or confirmed partial response (PR).

CR= Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to < 10 mm.

PR= At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Progressive disease (PD)=At least a 20% increase in the sum of diameters of target lesions. the sum must also demonstrate an absolute increase of at least 5 mm.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) in Arm A and Arm B only

Objective Response Rate (ORR) is defined as the percentage of all randomized participants whose best overall response is either confirmed complete response (CR) or confirmed partial response (PR).

CR= Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to < 10 mm.

PR= At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Progressive disease (PD)=At least a 20% increase in the sum of diameters of target lesions. the sum must also demonstrate an absolute increase of at least 5 mm.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) who have not received prior therapy for metastatic disease (1L)

Overall Survival (OS) is defined as the time from the randomization date to the date of death due to any cause. A participant who has not died will be censored at last known date alive.

All randomized participants with centrally confirmed DNA mismatch repairdeficient/microsatellite instability-high metastatic colorectal cancer (dMMR/MSI-H mCRC) in Arm A and Arm B only

Overall Survival (OS) is defined as the time from the randomization date to the date of death due to any cause. A participant who has not died will be censored at last known date alive.