Patients receive cytarabine and homoharringtonine concurrently by continuous intravenous infusion for 7 days. Courses repeat every 28 days. Patients receive a minimum of 9 courses of therapy in the absence of disease progression and unacceptable toxicity. Patients who are major cytogenetic responders at 9 months may continue therapy or switch to interferon. Minor cytogenetic responders are switched to interferon, and nonresponders are removed from therapy and given the option to switch to interferon.