Pooled Mutant KRAS-Targeted Long Peptide Vaccine Combined With Nivolumab and Ipilimumab for Patients With Resected Mismatch Repair Protein (MMR-p) Colorectal and Pancreatic Cancer

Eligibility Criteria

• * Have histologically or cytologically - proven cancer of the pancreas (PDA) or MSS colorectal (CRC) in one of the following categories:
• * PDAC must have no evidence of disease and last dose of neoadjuvant and/or adjuvant chemotherapy/radiation therapy/or surgery must be \< 6 months from study entry.
• * Metastatic MSS CRC after exposure to 2 more lines of chemotherapy in the metastatic setting including 5-flurouracil, irinotecan, and oxaliplatin exposure. Patients treated with FOLFOXIRI may enroll after progression or intolerance to that regimen.
• * For metastatic MSS CRC cohort, must 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 Principal Investigator).
• * For metastatic MSS CRC patients, must have measurable disease per RECIST 1.1.
• * Have a single site of locoregional recurrence or distant metastasis noted on imaging \> 12 months after the first dose of the mutant KRAS peptide vaccine with poly-ICLC adjuvant.
• * Have completed definitive treatment for solitary recurrence per standard-of-care (e.g. surgical resection, radiation, and/or chemotherapy) \<6 months prior to screening for reinduction treatment.
• * Have sufficient archival tumor 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.
• * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
• * Life expectancy of greater than 6 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 willingness to sign a written informed consent document.
• * If expected to require any other form of systemic or localized antineoplastic therapy while on study.
• * Within 2 weeks prior to first dose of study drug.
• * Systemic or topical steroids corticosteroids at immunosuppressive doses (\> 10 mg/day of prednisone or equivalent). Inhaled or topical steroids, and adrenal replacement steroid doses ≤ 10 mg daily prednisone equivalent, are permitted in the absence of active autoimmune disease.
• * Any palliative or adjuvant radiation or gamma knife radiosurgery.
• * Any chemotherapy.
• * Within 4 weeks prior to first dose of study drug.
• * Any investigational cytotoxic drug.
• * Any investigational device.
• * Has received a live vaccine.
• * Received any allergen hyposensitization therapy.
• * Received any growth factors, e.g. granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), erythropoietin.
• * Any major surgery.
• * PDAC or metastatic MSS CRC Cohort: Prior treatment with immunotherapy agents (including, anti-PD-1, anti-PD-L1, anti-PD-L2, anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4), etc.).
• * Hypersensitivity reaction to any monoclonal antibody.
• * Known history or evidence of brain metastases.
• * Has active autoimmune disease that has required systemic treatment in the past 2 years, or a documented history of clinically severe autoimmune disease, or a syndrome that requires systemic steroids or immunosuppressive agents.
• * Known history or concurrent interstitial lung disease.
• * Has a pulse oximetry \< 92% on room air.
• * Requires the use of home oxygen.
• * Infection with HIV or hepatitis B or C.
• * Uncontrolled intercurrent illness including, but not limited to, uncontrolled infection, symptomatic congestive heart failure, unstable angina, cardiac arrhythmia, metastatic cancer, or psychiatric illness/social situations that would limit compliance with study requirements.
• * Has been diagnosed with another cancer or myeloproliferative disorder within the past 5 year.
• * Has a diagnosis of immunodeficiency.
• * Presence of any tissue or organ allograft, regardless of need for immunosuppression, including corneal allograft. Patients with a history of allogeneic hematopoietic stem cell transplant will be excluded.
• * Any other sound medical, psychiatric, and/or social reason as determined by the Investigator.
• * Unwilling or unable to follow the study schedule for any reason.
• * Are pregnant or breastfeeding.
• * For metastatic MSS CRC and Reinduction Treatment Cohorts, any peritoneal involvement by the tumor.
• * For metastatic MSS CRC and Reinduction Treatment Cohorts, any radiological or clinical pleural effusions or ascites.
• * For metastatic MSS CRC and Reinduction Treatment Cohorts, patients on parenteral nutrition.
• * For metastatic MSS CRC and Reinduction Treatment Cohorts, patients with any single liver metastases greater than 5 cm or greater \> 50% liver involvement.
• * For metastatic MSS CRC and Reinduction Treatment Cohorts, history of malignant bowel obstruction.