Homoharringtonine and Interferon Alfa in Treating Patients With Chronic Myelogenous Leukemia

DISEASE CHARACTERISTICS: * Chronic myelogenous leukemia (CML) in chronic phase * Clonal evolution (i.e., the presence of clones other than the Ph chromosome) allowed Ph chromosome variants or complex Ph chromosome translocations are not considered disease acceleration * Ineligible for known therapy of higher efficacy or priority * Allogeneic bone marrow transplantation should be considered priority therapy for CML patients with a matched related donor * No blastic phase CML (30% or more blasts in peripheral blood or bone marrow) * No accelerated phase CML, defined as any of the following: 15% or more peripheral or marrow blasts or 30% or more blasts and promyelocytes 20% or more peripheral or marrow basophils * Thrombocytopenia (platelets less than 100,000) unrelated to therapy * Documented extramedullary disease outside of liver or spleen PATIENT CHARACTERISTICS: * Age: 15 and over * Performance status: Zubrod 0-2 * Life expectancy: Sufficient to fully evaluate the effects of 2 courses of therapy * Bilirubin no greater than 2.0 mg/dL * SGOT less than 300 * Creatinine less than 2.0 mg/dL OR creatinine clearance at least 60 mL/min * No severe heart disease (class III/IV) * No pregnant or nursing women * Effective contraception required of fertile women PRIOR CONCURRENT THERAPY: * No prior interferon alpha * At least 2 weeks since antileukemic therapy, with recovery required * Patients who received hydroxyurea within the past 2 weeks and have WBC greater than 50,000 may enter protocol after discussion with the primary investigator