Imatinib mesylate therapy improves survival in patients with newly diagnosed Philadelphia chromosome-positive chronic myelogenous leukemia in the chronic phase - Comparison with historic data

BACKGROUND. The (I) under bar nternational <()under bar>andomized study of (I) under bar nterferon-alpha plus cytarabine (IFN-alpha plus ara-C) versus (S) under bar T1571 (imatimb mesylate) [IRIS trial] in patients with newly diagnosed Philadelphia chromosome (Ph)-positive, chronic-phase chronic myelogenous leukemia (CML) has not shown (to date) a survival advantage for imatinib. This was most likely because approximately 90% of patients receiving IFN-alpha plus ara-C changed to imatinib therapy after a median of 8 months into therapy. METHODS. The authors analyzed the results with imatimb therapy in patients with newly diagnosed Ph-positive CML in chronic phase and compared their outcome with patients who received IFN-alpha regimens. A total of 187 patients with Ph-positive CML in early chronic phase treated with imatinib were compared with a historic group of 650 similar patients treated with IFN-a regimens from 1982 until 1997. RESULTS. Patients who received imatimb were significantly older and had significantly more bone marrow basophilia and less leukocytosis. The complete cytogenetic response (Ph 0%) rates were better with imatinib (81% vs. 32%; P < 0.001), as were the survival rates (30-month estimated survival rates 98% vs. 88%; P = 0.01). A multivariate analysis of the total study group of 837 patients identified imatinib therapy to be a significant independent favorable prognostic factor for survival (P = 0.01). CONCLUSIONS. The current Study is the first to indicate the survival advantage of imatinib compared with IFN-alpha, the previous standard of care, in patients with early chronic-phase CML. (C) 2003 American Cancer Society.