Imatinib mesylate in Philadelphia chromosome-positive, chronic-phase myeloid leukemia after failure of interferon alpha.

Imatinib mesylate (STI 571; Glivec) is a potent and selective tyrosine kinase inhibitor. The introduction of imatinib has chanced the philosophy of mechanisms of cancer therapy and already changed current management of patients with chronic myeloid leukemia (CML). A total of 49 patients with later chronic phase CML in whom previous therapy with interferon alpha had failed were treated with 400 mg of oral imatinib daily. Patients were evaluated for hematologic and cytogenetic responses. Time to progression, survival, and toxic effects were also evaluated. Complete hematologic responses were reported for 48 of 49 patients studied (98 percent). The median time to a complete hematologic response was 1.2 month; 89% of patients who had a response did so within 4 months. Imatinib induced major cytogenetic responses in 73%; 62% had a complete responses. After a median follow-up of 18 months, CML had not progressed to the accelerated or blast phases in an estimated 98% of patients, and 100 percent of the patients were alive. Grade 3 or 4 nonhematologic toxic effects were manageable. No one of patients discontinued treatment due to of drug-related adverse events, and no treatment-related deaths occurred. The results of current study indicate that imatinib has a significant therapy benefit in CML patients in whom treatment with IFN alpha had failed. Therefore, has favorably changed the prognosis for patients with chronic myelogenous leukemia.