New data support the role of imatinib mesylate (Gleevec) tablets in increasing the 5-year survival rate in adult patients with a newly diagnosed blood cancer, Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML).
Results came from the International Randomized Interferon versus STI571 (IRIS) phase 3 trial, which was the largest trial of its kind for this patient population. Not only did positive patient response to Gleevec increase with each passing year, but progression to an advanced stage of the blood cancer actually declined to 0.6% in the trial's fifth year.
When factoring in mortality from all causes, the survival rate for patients taking Gleevec was 89%. When considering death as a result of causes unrelated to CML or prior transplantation, the survival rate was 95% at 5 years.
Before CML patients had Gleevec as a treatment option, about half of them saw their CML progress to more advanced stages in only 3 to 5 years, with an unpromising survival rate. As Gleevec emerged as a powerful force in combating CML, it has been approved for use in Europe for 6 diseases and in the United States for 7, including 2 solid tumors and 5 blood disorders.
The IRIS study included 1106 patients with Ph+ CML in 177 centers in 16 countries. They were divided into 2 groups: one group received 400 mg/day of Gleevec and the other received 5 milliinternational units/ m2/day of interferon plus Ara-C 20 mg/m2/day for 10 days each month. Due to tolerability concerns and lack/ loss of response, 65% of patients in the interferon group moved into the Gleevec group, and 3% of the Gleevec group moved to the interferon group. In the 5-year treatment period, major cytogenetic responses rose from 85% to 92%; complete cytogenetic response rose from 69% to 87%; and complete hematologic response rose from 96% to 98%.
Results of the study were published in the New England Journal of Medicine.
Ms. Farley is a freelance medical writer based in Wakefield, RI.