Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed ductal adenocarcinoma of the pancreas

- Mixed adenocarcinoma tumors eligible provided the predominant invasive component
of the tumor is adenocarcinoma

- The following histologic diagnoses are not eligible:

- Adenosquamous

- Squamous cell

- Colloid

- Islet cell

- Serous or mucinous cystadenoma or cystadenocarcinoma

- Carcinoid

- Small or large cell carcinoma

- Intraductal oncocytic papillary neoplasms

- Osteoclast-like giant cell tumors

- Acinar cell carcinoma

- Pancreatoblastoma

- Solid pseudopapillary tumors

- Undifferentiated small cell carcinoma

- Nonepithelial tumors (sarcoma, gastrointestinal stromal tumor, lymphoma)

- Adenocarcinomas of the ampulla, distal bile duct, or duodenum

- Metastatic or locally advanced disease that is refractory to standard therapy OR for
which patient refused standard therapy

- Measurable disease defined as ≥ 1 lesion unidimensionally measured as ≥ 20 mm by
conventional techniques or ≥ 10 mm by spiral CT scan

- No nonmeasurable disease only including, but not limited to, the following:

- Bone lesions

- Leptomeningeal disease

- Ascites

- Pleural or pericardial effusion

- Inflammatory breast disease

- Lymphangitis cutis/pulmonis

- Abdominal masses that are not confirmed and followed by imaging techniques

- Cystic lesions

- No known active or untreated brain metastases

PATIENT CHARACTERISTICS:

- ECOG performance status 0-1

- WBC ≥ 3,500/mm^3

- Absolute neutrophil count ≥ 1,500/mm^3

- Hemoglobin ≥ 9 g/dL

- Platelet count ≥ 90,000/mm^3

- Creatinine ≤ 2.0 mg/dL

- Bilirubin ≤ 2 mg/dL

- ALT and AST ≤ 5 times upper limit of normal (ULN)

- Alkaline phosphatase ≤ 5 times ULN

- No active infection

- No uncontrolled medical condition that would potentially increase the risk of
toxicities or complications of study therapy

- No gastrointestinal tract disease resulting in an inability to take oral medication
or a requirement for IV alimentation

- No active peptic ulcer disease

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 4 weeks after
completion of study treatment

- No other malignancy within the past 5 years except for nonmelanomatous skin cancer,
superficial bladder cancer, or carcinoma in situ of the cervix

- HIV negative

- No active autoimmune disease or prior autoimmune disease requiring medical treatment
with systemic immunosuppressants including any of the following:

- Inflammatory bowel disease

- Systemic vasculitis

- Scleroderma

- Psoriasis

- Multiple sclerosis

- Hemolytic anemia or immune thrombocytopenia

- Rheumatoid arthritis

- Systemic lupus erythematosus

- Sjögren's syndrome

- Sarcoidosis

- Asthma or chronic obstructive pulmonary disease that does not require systemic
corticosteroids or routine use of inhaled steroids allowed

- No known or suspected hypersensitivity to sargramostim (GM-CSF), cyclophosphamide,
pentastarch, corn, or DMSO

- No prior severe infusion reaction (> grade 3) to a monoclonal antibody

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- More than 1 month since prior adjuvant chemotherapy

- More than 4 weeks since prior surgery except for minor procedures (e.g., dental work,
skin biopsy) and biliary stent placement

- No prior surgical procedures affecting absorption

- More than 4 weeks since prior radiotherapy

- More than 1 month since prior participation in an investigational new drug study

- No unresolved chronic toxicity (except alopecia) from prior anticancer therapy

- More than 28 days since prior systemic steroids

- No concurrent systemic steroids or immunosuppressive drugs

- Topical, inhaled, and intra-articular steroids allowed

- No other concurrent anticancer vaccine therapy

- No other concurrent chemotherapy, immunotherapy, radiotherapy, gene therapy, biologic
therapy, or investigational therapy