Inclusion Criteria:  Patients with histologically confirmed metastatic colorectal cancer (CRC) who are planned for, or have received no more than 1 cycle of first-line treatment in the metastatic setting with a fluoropyrimidine and oxaliplatin in combination with bevacizumab Measurable and unresectable disease according to RECIST v1.1 Availability of formalin-fixed paraffin-embedded (FFPE) tumor specimens. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 or equivalent for patients 12 to 17 years of age Patient has adequate organ function in opinion of investigator If women of childbearing potential (WCBP), must be willing to undergo pregnancy testing and agrees to the use at least 1 highly effective contraceptive method during the study treatment period and for 5 months after last investigational study treatment.  Exclusion Criteria:  Patients with microsatellite instability-high disease Patient has a known tumor mutation burden <1 non-synonymous mutations/megabase Known DNA Polymerase Epsilon mutations Patients with known BRAFV600E mutations Bleeding disorder or history of significant bruising or bleeding following IM injections or blood draws Immunosuppression anticipated at time of study treatment History of allogeneic tissue/solid organ transplant Active or history of autoimmune disease or immune deficiency Patient with symptomatic or actively progressing central nervous system (CNS) metastases, carcinomatous meningitis, or has been treated with whole brain radiation History of other cancer within 2 years with the exception of neoplasm that has undergone potentially curative therapy Any severe concurrent non-cancer disease that, in the judgment of the Investigator, would make the patient inappropriate for the current study Active tuberculosis or recent (<2 weeks) clinically significant infection, evidence of active hepatitis B or hepatitis C, or known history of positive test for HIV History of pneumonitis requiring systemic steroids for treatment (with the exception of prior resolved in-field radiation pneumonitis) Myocardial infarction within previous 3 months or prior to study treatment, unstable angina, serious uncontrolled cardiac arrhythmia, history of myocarditis, or congestive heart failure Pregnant, planning to become pregnant, or nursing.