Interferon and GM-CSF Compared With Imatinib Mesylate and Vaccine Therapy in Patients With Chronic Phase CML on a TKI

DISEASE CHARACTERISTICS: * Diagnosis of chronic myelogenous leukemia (CML) in chronic phase based on cytogenetic detection of the Philadelphia chromosome and/or detection of the BCR-ABL rearrangement by any of the following molecular methods: * Recombinant DNA analysis of the BCR-ABL fusion gene * Fluorescence in situ hybridization (FISH) * Polymerase chain reaction detection of the BCR-ABL hybrid mRNA * Documentation of complete cytogenetic response by conventional cytogenetic or FISH analysis while on a stable dose of tyrosine kinase inhibitor * No other phase of CML PATIENT CHARACTERISTICS: * ECG performance status 0-2 * Life expectancy \> 24 months * Not pregnant * Negative pregnancy test * Fertile patients must use effective contraception * Creatinine ≤ 2.0 mg/dL * Bilirubin ≤ 2.0 times upper limit of normal (ULN) * AST and ALT ≤ 2.5 times ULN * No other malignancy within the past 5 years except in situ cervical carcinoma or adequately treated nonmelanoma skin cancer * No other disease requiring long-term corticosteroids or immunosuppressants PRIOR CONCURRENT THERAPY: * At least 28 days since prior investigational agents * No prior bone marrow transplant or other transplant * No concurrent immunosuppressants (e.g., steroids, cyclosporine, azathioprine, mycophenolate mofetil, sirolimus, or tacrolimus) * No concurrent hydroxyurea, busulfan, or cytoreductive agents (other than frontline TKI) * No other concurrent anticancer agents or therapies