KRAS-Targeted Vaccine Combined With Balstilimab and Botensilimab for Patients With Stage IV MMR-p Colorectal Cancer and Pancreatic Ductal Cancer

Inclusion Criteria: * Age ≥18 years. * Have histologically or cytologically - proven cancer of the pancreas or colon. * Have tumor lesions amenable to repeated biopsy, and patient's acceptance to have a tumor biopsy of an accessible lesion at baseline and on treatment if the lesion can be biopsied with acceptable clinical risk (as judged by the investigator). * Measurable disease as per RECIST 1.1. * Have sufficient and accessible tissue for next generation sequencing (NGS) and immune-phenotyping. * Have one of the KRAS mutations included in the vaccine at the time of vaccination expressed in tumor. * Cohort A: Have received 4-6 months of FOLFIRINOX or gemcitabine+nab-paclitaxel for the 1st line treatment of metastatic unresectable PDAC. * Cohort B: Have received 4-6 months of 1st line SOC chemotherapy per NCCN guidelines (FOLFIRINOX, FOLFOX, FOLFIRI +/- targeted therapy with VEGFi or EGFRi) of metastatic CRC. * Cohort C: Have received no more than 3 lines of systemic chemotherapy, including prior KRAS inhibitor. * Eastern Cooperative Oncology Group (ECOG) performance status 0. * Life expectancy of greater than 3 months. * Patients must have adequate organ and marrow function defined by study-specified laboratory tests prior to initial study drug. * Woman of childbearing potential must have a negative pregnancy test and follow contraceptive guidelines as defined per protocol. * Men must use acceptable form of birth control while on study. * Ability to understand and willingn…