ASH: Higher Imatinib Exposures Associated with Better Chronic-Phase CML Outcomes
ATLANTA — Among chronic myeloid leukemia (CML) patients, higher imatinib exposures were associated with better overall survival (OS) and event-free survival (EFS), according to an analysis of data from the WORLD CML Registry presented during the 54th American Society of Hematology Annual Meeting and Exposition.
“Patients who had higher drug exposure to imatinib had higher estimated OS and EFS rates at 3 years than those who did not,” reported lead author Jorge E. Cortes, MD, of the Department of Leukemia at the MD Anderson Cancer Center in Houston, TX,.
A total of 1,837 evaluable patients with CML from 28 countries were enrolled in the registry during 2008-2010. Median age of enrolled patients was 47 years (range, 16-92 years) and 58% were male, Dr. Cortes and colleagues reported. Median OS and EFS have not been reached, but estimated rates at 3 years for chronic phase (CP) patients were 91.8% OS and 77.3% EFS. Nearly all patients—94%--were initially diagnosed in CP.
“The estimated OS and EFS rates at 3 years in CML-CP patients who received imatinib for ≥85% of total days were higher than those in patients who received imatinib for <85% of days,” the authors reported.
The most common adverse events (AEs) were thrombocytopenia (2.6%) and neutropenia (2.4%). The most common nonhematalogic AEs were rash (0.9%), nausea (0.9%), diarrhea (0.8%) and headache (0.6%).
“Adverse events leading to dose or regimen changes, medication not being taken as prescribed, or death were infrequent in this study,” he noted.“Most patients with CML-CP treated with first-line imatinib did not have cytogenetic or molecular assessments performed at early time points as recommended by the ELN (European LeukemiaNet,” Dr. Cortes said. “One important thing here is that we know that we can have very good outcomes for patients with CML,” Dr. Cortes said. “But it depends on doing things the appropriate way.”