Vaccine Therapy in Treating Patients With Philadelphia Chromosome-Positive Chronic Myelogenous Leukemia

DISEASE CHARACTERISTICS: * Diagnosis of chronic myelogenous leukemia (CML) meeting the following criteria: * Philadelphia chromosome positive disease * b3a2 breakpoint mutation * Prior treatment with conventional imatinib mesylate for ≥ 18 months required * Complete cytogenetic response documented on ≥ 2 different examinations * Persistence of molecularly detectable residual disease (any level of bcr-abl transcript) * Patients continue to receive imatinib mesylate at the same dose (conventional treatment) during study treatment PATIENT CHARACTERISTICS: * WHO performance status 0-1 * Bilirubin ≤ 2 times upper limit of normal (ULN) * AST and ALT ≤ 2.5 times ULN * Creatinine ≤ 1.5 times ULN * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No severe active infection or other serious medical illness that would preclude study completion * No known immunodeficiency * No autoimmune disorders PRIOR CONCURRENT THERAPY: * No concurrent immunosuppression or systemic immunosuppressive medication * No concurrent dose escalation of imatinib mesylate * No other concurrent investigational products