Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed advanced pancreatic or colorectal
adenocarcinoma Curatively unresectable OR Recurrent following potentially curable
resection OR Pancreatic adenocarcinoma that has been surgically resected within the past
12 months Must have one of the following ras gene mutations at codon 12: Glycine to
cysteine Glycine to aspartic acid Glycine to valine HLA A2 required if evidence of HLA
restriction for peptide presentation

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At
least 3 months Hematopoietic: WBC at least 3,500/mm3 Lymphocyte count at least 500/mm3
Hepatic: Bilirubin no greater than 3 mg/dL Renal: Creatinine no greater than 2 times upper
limit of normal OR Creatinine clearance at least 50 mL/min Other: No active infection
requiring sytemic therapy No history of severe allergy or anaphylaxis No immunodeficiency
(e.g., HIV infection, lupus, or myeloma) Not pregnant Negative pregnancy test Fertile
patients must use effective contraception Women must use contraception for 3 months prior
to, during and for 3 months after study Men must use contraception during and for 3 months
after study

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunologic
therapy No other concurrent systemic immunotherapy for cancer Chemotherapy: At least 4
weeks since prior chemotherapy No concurrent systemic chemotherapy for cancer Endocrine
therapy: At least 4 weeks since prior corticosteroids No concurrent corticosteroids
Radiotherapy: At least 4 weeks since prior radiotherapy Surgery: See Disease
Characteristics Other: At least 4 weeks since prior immunosuppressants (e.g.,
methotrexate) No concurrent immunosuppressants Concurrent nonsteroidal antiinflammatory
drugs for pain palliation allowed