Bortezomib With or Without Gemcitabine in Treating Patients With Metastatic Pancreatic Cancer

Inclusion Criteria: Histologically confirmed metastatic ductal or undifferentiated adenocarcinoma consistent with a pancreatic primary for which no standard curative measures exist No locally advanced disease only No islet cell, acinar cell, or cystadenocarcinomas Measurable disease At least one lesion whose longest diameter can be accurately measured as 2 cm or greater by conventional techniques OR 1 cm or greater by spiral CT scan A tumor lesion in a previously irradiated area allowed provided it is histologically confirmed disease with radiographic progression from a post-radiotherapy CT scan No CNS metastasis Performance status - ECOG 0-2 At least 3 months Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hemoglobin at least 9.0 g/dL Bilirubin no greater than 1.5 times upper limit of normal (ULN) (stents allowed) AST no greater than 5 times ULN PT and PTT no greater than ULN* Creatinine no greater than 1.5 times ULN No other prior malignancy within the past 5 years except basal cell or squamous cell skin cancer or carcinoma in situ of the cervix No neuropathy greater than grade 1 No underlying disease state associated with active bleeding Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study participation More than 4 weeks since prior biologic therapy or immunotherapy No concurrent immunotherapy No concurrent colony-stimulating factors during the first course of the study No prior gemcitabine (even as a radiosensitizing agent) No prior chemotherapy Radiosensitizing agent as adjuvant therapy or for locally advanced disease allowed No other concurrent chemotherapy See Disease Characteristics More than 4 weeks since prior radiotherapy No prior radiotherapy to 25% or more of the bone marrow No concurrent radiotherapy No prior bortezomib