The long-term outcomes of imatinib treatment for chronic myeloid leukemia (CML) were evaluated in a multicenter, open-label, crossover trial. Patients with newly diagnosed CML in the chronic phase were randomly assigned to receive either imatinib or interferon alfa plus cytarabine. The median follow-up was 10.9 years. The estimated overall survival rate at 10 years was 83.3% for patients treated with imatinib, with a complete cytogenetic response rate of 82.8%. Serious adverse events were uncommon and mostly occurred during the first year of treatment. The results indicate that imatinib remains effective over time and is not associated with unacceptable cumulative or late toxic effects.The long-term outcomes of imatinib treatment for chronic myeloid leukemia (CML) were evaluated in a multicenter, open-label, crossover trial. Patients with newly diagnosed CML in the chronic phase were randomly assigned to receive either imatinib or interferon alfa plus cytarabine. The median follow-up was 10.9 years. The estimated overall survival rate at 10 years was 83.3% for patients treated with imatinib, with a complete cytogenetic response rate of 82.8%. Serious adverse events were uncommon and mostly occurred during the first year of treatment. The results indicate that imatinib remains effective over time and is not associated with unacceptable cumulative or late toxic effects.