Testing the Safety of the Anti-Cancer Drugs Durvalumab and Olaparib During Radiation Therapy for Locally Advanced Unresectable Pancreatic Cancer

This study is being done to answer the following question: What is the dose of durvalumab and olaparib in combination with radiation therapy that can be safely and tolerably taken by patients with pancreatic cancer? It is been done because we want to find out if this approach is better or worse than the usual approach for your pancreatic cancer. The usual approach is defined as care most people get for pancreatic cancer