Patient description: The patient is a 57-year-old man with abdominal pain and vomiting. The pain started gradually about 20 hours ago in the epigastric and periumbilical regions, radiating to his back. He drinks around 60 units of alcohol per week and smokes 22 cigarettes per day. He is healthy with no history of allergies or using any medications. His family history is positive for type 2 diabetes (his father and sister). He lives alone and has no children. The abdomen is tender and soft. His bowel sounds are normal. His heart rate is 115/min and blood pressure 110/75 mmHg. The lab results are remarkable for leukocytosis (19.5), urea of 8.5, high CRP (145), high amylase (1200) and Glc level of 15. Cross-sectional imaging was negative for obstructive pancreatitis.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Extrahepatic Bile Duct Adenocarcinoma, Biliary Type Gallbladder Adenocarcinoma, Biliary Type Metastatic Pancreatic Adenocarcinoma Recurrent Cholangiocarcinoma Recurrent Gallbladder Carcinoma Recurrent Hepatocellular Carcinoma Recurrent Intrahepatic Cholangiocarcinoma Recurrent Pancreatic Carcinoma Stage III Gallbladder Cancer AJCC V7 Stage III Hepatocellular Carcinoma AJCC v7 Stage III Intrahepatic Cholangiocarcinoma AJCC v7 Stage III Pancreatic Cancer AJCC v6 and v7 Stage IIIA Gallbladder Cancer AJCC v7 Stage IIIA Hepatocellular Carcinoma AJCC v7 Stage IIIB Gallbladder Cancer AJCC v7 Stage IIIB Hepatocellular Carcinoma AJCC v7 Stage IIIC Hepatocellular Carcinoma AJCC v7 Stage IV Gallbladder Cancer AJCC v7 Stage IV Hepatocellular Carcinoma AJCC v7 Stage IV Pancreatic Cancer AJCC v6 and v7 Stage IVA Gallbladder Cancer AJCC v7 Stage IVA Hepatocellular Carcinoma AJCC v7 Stage IVA Intrahepatic Cholangiocarcinoma AJCC v7 Stage IVB Gallbladder Cancer AJCC v7 Stage IVB Hepatocellular Carcinoma AJCC v7 Stage IVB Intrahepatic Cholangiocarcinoma AJCC v7 Unresectable Gallbladder Carcinoma Unresectable Pancreatic Carcinoma Patients must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 Absolute neutrophil count (ANC) >= 1.5 x 10^9/L (> 1500 per mm^3) except for patients with HCC for whom ANC >= 1000 per mm^3 is allowed Platelet count >= 100 x 10^9/L (> 100,000 per mm^3), except for patients with HCC for whom a platelet count > 60,000 per mm^3 is allowed Hemoglobin >= 8.0 g/dL; if patients have a hemoglobin level below 8, blood transfusion is allowed to meet the as long as post transfusion hemoglobin is maintained at >= 8.0 g/dL for 7 days or longer Aspartate aminotransferase (AST)/serum glutamic-oxaloacetic transaminase (SGOT) and alanine aminotransaminase (ALT)/serum glutamate pyruvate transaminase (SGPT) =< 2.5 x institutional upper limit of normal unless liver metastases are present or unless patient is known to have chronic liver disease (hepatitis) in which case AST and ALT must be =< 5 x institutional upper limit of normal (IULN) Serum bilirubin =< 2.5 x institutional upper limit of normal (ULN) Serum albumin >= 2.5 g/dL Serum creatinine clearance (CL) > 40 mL/min by the Cockcroft-Gault formula or by 24-hour urine collection for determination of creatinine clearance Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 90 days following completion of therapy; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately A female of child-bearing potential is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following  Patients may not be receiving any other investigational agents Patients must not be nursing due to the potential for congenital abnormalities and the potential of this regimen to harm nursing infants Any previous treatment with a hypomethylating agent, or with a PD1 or PD-L1 or anti-PD-L2 or anti-CTLA4 inhibitor, including durvalumab (or any other antibody or drug specifically targeting T-cell costimulation or checkpoint pathways); any immunomodulatory agent that is not described above should be cleared by the principal investigator (PI) History of another primary malignancy except for Malignancy treated with curative intent and with no known active disease >= 3 years before the first dose of study drug Adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease Adequately treated carcinoma in situ without evidence of disease eg, cervical cancer in situ Controlled, superficial bladder carcinoma T1a or T1b or T1c prostate carcinoma treated with radiation >= 1 year prior to study enrollment and prostate specific antigen (PSA) within normal limits (WNL) since treatment T2a or b prostate carcinoma treated curatively >= 1 year prior to study enrollment and PSA undetectable since curative treatment