Olaparib in Treating Patients With Stage IV Pancreatic Cancer

PRIMARY OBJECTIVES: I. To determine the efficacy of olaparib monotherapy in stage IV pancreatic ductal adenocarcinoma (PDAC) with breast cancer, early onset (BRCA)ness. SECONDARY OBJECTIVES: I. To further determine the efficacy of olaparib in the study population. SAFETY OBJECTIVES: I. To assess the safety and tolerability of olaparib. EXPLORATORY OBJECTIVES: I. To identify tissue based biomarkers of defective homologous recombination repair (HRD). OUTLINE: Patients receive olaparib orally (PO) twice daily (BID) on days 1-28. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days and then every 8 weeks thereafter.