Losartan and Nivolumab in Combination With FOLFIRINOX and SBRT in Localized Pancreatic Cancer

This research study is studying a combination of interventions as a possible treatment for pancreatic tumor. The interventions involved in this study are: * FOLFIRINOX which is made up of 4 different drugs: * 5-Fluorouracil (5-FU) * Oxaliplatin * Irinotecan * Leucovorin * Losartan * Nivolumab * Radiation Therapy * Surgery

This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational intervention to learn whether the intervention works in treating a specific disease. "Investigational" means that the intervention is being studied. The FDA (the U.S. Food and Drug Administration) has approved FOLFIRINOX as a treatment option for this disease. The FDA has not approved losartan or nivolumab for this specific disease but they have been approved for other uses. FOLFIRINOX is a combination of 4 chemotherapy agents that may help shrink your tumor before surgery. Losartan is a drug that is used to lower blood pressure. Nivolumab is an antibody (a cell that attaches to other cells to fight off infection) that may cause programmed cell death of cancer cells. Radiation therapy is believed to increase the likelihood of response of immunotherapy (the prevention/treatment of a disease through an immune response).