Quality of Life in Patients With Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia on Imatinib Versus Interferon Alfa Plus Low-Dose Cytarabine: Results From the IRIS Study

Abstract

Purpose: Quality of life (QOL) outcomes in patients with chronic myeloid leukemia (CML) were evaluated in an international phase III study. Patients and Methods: Newly diagnosed patients with chronic phase CML were randomly assigned to imatinib or interferon alfa plus subcutaneous low-dose cytarabine (IFN+LDAC). Cross-over to the other treatment was permitted because of intolerance or lack of efficacy. Patients completed cancer-specific QOL (Functional Assessment of Cancer Therapy–Biologic Response Modifiers) and utility (Euro QoL-5D) questionnaires at baseline and during treatment (n = 1,049). The primary QOL end point was the Trial Outcome Index (TOI; a measure of physical function and well-being). Secondary end points included social and family well-being (SFWB), emotional well-being (EWB), and the utility score. Primary analyses were intention to treat with secondary analyses accounting for cross-over. Results: Patients receiving IFN+LDAC experienced a large decline in the TOI, whereas those receiving imatinib maintained their baseline level. Treatment differences at each visit were significant (P < .001) and clinically relevant in favor of imatinib. Mean SFWB, EWB, and utility scores were also significantly better for those patients taking imatinib. Patients who crossed over to imatinib experienced a large increase in TOI; significant (P < .001) differences were observed between patients who did and did not cross over in favor of imatinib. Conclusion: Imatinib offers clear QOL advantages compared with IFN+LDAC as first-line treatment of chronic phase CML. In addition, patients who cross over to imatinib from IFN+LDAC experience a significant improvement in QOL compared with patients who continue to take IFN+LDAC.