Imatinib Mesylate and Interferon Alfa in Treating Patients With Chronic Myelogenous Leukemia

DISEASE CHARACTERISTICS: Cytogenetically confirmed 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 No leukemia beyond bone marrow, blood, liver, or spleen No chloroma Phase I (closed to accrual as of 7/9/03): Philadelphia (Ph) chromosome-positive CML in chronic phase Phase II: Newly diagnosed Ph chromosome-positive CML in chronic phase Initial diagnosis within 6 months of study No prior therapy for CML except hydroxyurea and/or anagrelide hydrochloride Phase I (closed to accrual as of 7/9/03) and II: No identified sibling donors where allogeneic stem cell transplantation is elected as first-line therapy PATIENT CHARACTERISTICS: Age: 18 and over Performance status: 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 2 methods of effective barrier contraception during and for at least 3 months after study participation No other serious uncontrolled medical condition No autoimmune disease No prior noncompliance to medical regimens or potential unreliability No prior grade 3 or greater non-hematologic toxicity due to prior interferon (phase I [closed to accrual as of 7/9/03]) PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics No prior bone marrow or peripheral blood stem cell transplantation At least 2 weeks since prior interferon alfa (phase I [closed to accrual as of 7/9/03]) Chemotherapy: See Disease Characteristics At least 6 weeks since prior busulfan (phase I [closed to accrual as of 7/9/03] ) At least 2 weeks since prior cytarabine (phase I [closed to accrual as of 7/9/03]) No concurrent chemotherapy Concurrent hydroxyurea allowed during the first 3 months of study Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not specified Other: At least 4 weeks since prior investigational agents other than imatinib mesylate (phase I [closed to accrual as of 7/9/03]) No concurrent grapefruit juice Concurrent anagrelide hydrochloride allowed during the first 3 months of study