First-line treatment of patients with chronic-phase chronic myelogenous leukemia: Progress and remaining questions

Imatinib is the standard first-line therapy for chronic-phase chronic myelogenous leukemia (CP CML). However, only 57% of patients in the key IRIS (International Randomized Study of Interferon and STI571) study now remain on imatinib per protocol with complete cytogenetic response (CCyR), and the lost follow-up on off-protocol patients precludes accurately determining efficacy and long-term survival. The UK front-line study, an intent-to-treat analysis of patients with newly diagnosed CP CML, supports the data generated by IRIS, with follow-up data available for all enrollees. This study suggests that patients who fail to achieve hematologic and cytogenetic responses by specified timepoints have inferior progression-free and overall survival and are thus intriguing targets for therapeutic intervention. This review discusses the results of the UK and other studies and evaluates available second-line treatment options for patients with CP CML.