Vaccine Therapy, Cyclophosphamide, and Cetuximab in Treating Patients With Metastatic or Locally Advanced Pancreatic Cancer

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