Imatinib Mesylate Plus Cytarabine in Treating Patients With Chronic Myelogenous Leukemia

DISEASE CHARACTERISTICS: Cytogenetically confirmed chronic phase chronic myelogenous leukemia (CML) Less than 15% blasts in peripheral blood or bone marrow Less than 30% blasts and promyelocytes in peripheral blood or bone marrow Less than 20% basophils in blood or bone marrow Platelet count at least 100,000/mm^3 Philadelphia chromosome positive No more than 6 months since initial diagnosis No presence of leukemia beyond the bone marrow, blood, liver, or spleen (i.e., chloroma) Refused allogeneic stem cell transplantation as first-line therapy PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Eastern Cooperative Oncology Group (ECOG) 0-2 Life expectancy: Not specified Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) AST or ALT no greater than 2 times ULN Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No New York Heart Association class III or IV heart disease Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective barrier contraception during and for at least 3 months after study participation No other serious uncontrolled medical condition No history of noncompliance to medical regimens or potential unreliability PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics No prior biologic therapy for CML Chemotherapy: No prior chemotherapy for CML except hydroxyurea Concurrent hydroxyurea to control blood counts during first 3 months of treatment allowed No other concurrent chemotherapy Endocrine therapy: No prior endocrine therapy for CML Radiotherapy: No prior radiotherapy for CML Surgery: Not specified Other: More than 28 days since prior investigational anticancer agents Prior anagrelide hydrochloride for CML allowed Concurrent anagrelide hydrochloride to control blood counts during first 3 months of treatment allowed No concurrent grapefruit juice or grapefruit