Combination Immunotherapy in Colorectal Cancer

Inclusion Criteria:

• 18 years of age or older

• Histologically, cytologically, or clinically confirmed adenocarcinoma of the colonor rectal cancer as long as there is no plans for neoadjuvant radiation for thepatients with rectal cancer. Note: patients can enroll in cohort B while awaitingmismatch repair testing results. If noted to be dMMR/MSI-High, they would be stillconsidered evaluable and moved to cohort C.

• If capable of becoming pregnant, or getting someone else pregnant, must be willingto use highly effective contraception from Screening period through 90 daysfollowing the last dose of study drug

Exclusion Criteria:

• Metastatic cancer (cancer that has spread to other parts of the body)

• Previous treatment with immune checkpoint inhibitors targeting CTLA-4, PD-1 or PD-L1

• Currently participating in another study and receiving a study drug

• History of severe allergic reactions to immunotherapies

• Pregnant or breastfeeding

• Active infection requiring treatment

• On immunosuppressive medications

• Active cardiovascular disease, such as stroke or myocardial infarction within 6months of enrollment, unstable angina, congestive heart failure, or seriousuncontrolled cardiac arrhythmia requiring medication that may prevent surgery

Participants in Cohort C must be dMMR/MSI-High.