Continuous imatinib for chronic myeloid leukaemia

Continuous treatment with imatinib gives a durable response, in the chronic phase of CML, and is associated with a downward trend in the risk of disease progression, a report from the Austrian Breast and Colorectal Cancer Study group suggests. Imatinib inhibits BCR-ABL tyrosine kinase and has activity against chronic myeloid leukaemia (CML). In this randomised trial, 553 patients were randomised to imatinib and 553 to interferon alfa plus cytarabine. The trial was designed as a cross over trial and a large proportion of the patients crossed over to imatinib, and 69% of the imatinib and 3% of the interferon plus cytarabine group continued with their original treatments. This report is of median follow-up of 60 months, and includes the results for the long-term treatment of patients given imatinib. The estimates of cumulative best rates of complete cytogenetic response were 69% at 12 months and 87% at 60 months of imatinib, and of those who were still receiving imatinib at 60 months, 96% had a complete cytogenetic response. The estimated overall survival of patients who received imatinib as initial therapy was 89% at 60 months, and the authors reported that this was higher than any previously reported prospective study. Grade 3 or 4 adverse events decreased over time, and the profile of adverse events was unchanged. The authors concluded that after 5 years of follow-up, continuous treatment with imatinib as initial therapy led to durable responses in a high proportion of patients.Reference...