Bortezomib in Treating Patients With Chronic Myelogenous Leukemia

DISEASE CHARACTERISTICS: Diagnosis of Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) in chronic or accelerated phase, defined as having any of the following: Peripheral blood (PB) or bone marrow (BM) blasts at least 10% but less than 30% PB or BM blasts and promyelocytes at least 20% PB or BM basophils at least 20% Progressive splenomegaly (at least 10 cm confirmed twice at least 4 weeks apart or 50% increase in splenomegaly over 4 weeks) Clonal evolution defined as the presence of additional cytogenetic abnormalities other than the Ph chromosome Thrombocytopenia (platelet count less than 100,000/mm^3) unrelated to therapy Hemoglobin less than 7 g/dL unrelated to therapy or bleeding Failed prior treatment with imatinib mesylate or intolerant, unable, or unwilling to receive it Ineligible for higher-priority or higher-efficacy regimens or protocols No blastic phase CML PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Eastern Cooperative Oncology Group (ECOG) 0-2 Life expectancy: At least 18 weeks Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 1.5 mg/dL Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 60 mL/min Other: No other concurrent illness that would preclude study entry Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No more than 2 prior cytotoxic regimens in addition to imatinib mesylate and/or hydroxyurea At least 4 weeks since prior chemotherapy and recovered Concurrent hydroxyurea and/or anagrelide allowed during first 2 courses Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy and recovered Surgery: Not specified Other: See Disease Characteristics See Chemotherapy At least 24 hours since prior imatinib mesylate No other concurrent investigational agents