MDX-010 in Treating Patients With Stage IV Pancreatic Cancer That Cannot Be Removed By Surgery

DISEASE CHARACTERISTICS: Histologically confirmed pancreatic adenocarcinoma Stage IV disease Locally (invasion of adjacent structures, including mesenteric arteries or organs) or distantly metastatic disease Unresectable disease Pancreatic adenocarcinoma with intraductal papillary mucinous neoplasm allowed The following diagnoses are not allowed: Acinar cell carcinoma Pancreaticoblastoma Malignant cystic neoplasms Endocrine neoplasms Squamous cell carcinoma Vater and periampullary duodenal or common bile duct malignancies Clinically evaluable disease with ≥ 1 site of measurable disease Biliary or gastric outlet obstruction allowed provided it is effectively drained by endoscopic, operative, or interventional means Pancreatic, biliary, or enteric fistulae allowed provided they are controlled with an appropriate drain PATIENT CHARACTERISTICS: Age 18 and over Performance status ECOG 0-2 Life expectancy At least 3 months Hematopoietic WBC ≥ 2,500/mm^3 Absolute neutrophil count ≥ 1,500/mm^3 Platelet count ≥ 100,000/mm^3 Hemoglobin ≥ 9 g/dL Hematocrit ≥ 27% Hepatic Hepatitis B surface antigen negative Hepatitis C virus antibody negative OR Hepatitis C RNA negative by polymerase chain reaction Renal Creatinine < 2.0 mg/dL Immunologic HIV negative No history of or active autoimmune disease, including uveitis or autoimmune inflammatory eye disease No active uncontrolled infection Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the cervix No underlying medical condition that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy No prior anti-cytotoxic T-lymphocyte-associated antigen-4 monoclonal antibody (MDX-010) Chemotherapy At least 3 weeks since prior chemotherapy for pancreatic adenocarcinoma and recovered No concurrent chemotherapy Endocrine therapy More than 4 weeks since prior corticosteroids No concurrent systemic or topical corticosteroids Radiotherapy At least 3 weeks since prior radiotherapy for pancreatic adenocarcinoma and recovered Surgery See Disease Characteristics Other At least 3 weeks since other prior therapy for pancreatic adenocarcinoma and recovered No concurrent immunosuppressants (e.g., cyclosporin or its analog)