Health-related quality of life (HRQoL) in newly diagnosed patients (pts) with chronic phase chronic myelogenous leukemia (CP CML) treated with bosutinib (BOS) or imatinib (IM).

Abstract

6612 Background: BOS, a dual Src/Abl kinase inhibitor, demonstrated significantly higher response rates versus IM in evaluable pts with CP CML in a phase 3, open-label study. Given the length of time a pt may receive 1st-line treatment for CP CML (>8 yrs), understanding the impact on HRQoL is important, as pts may not present with significant symptom burden. The effect of BOS and IM on HRQoL was an exploratory endpoint. Methods: Pts with newly diagnosed CP CML were randomized 1:1 to BOS or IM. HRQoL was measured using the 44-item Functional Assessment of Cancer Therapy–Leukemia (FACT-Leu). The FACT-Leu is rated on a scale of 0-4 and consists of the Physical Well-being (PWB), Social/Family Well-being (SFWB), Emotional Well-being (EWB), Functional Well-being (FWB), Leukemia Subscale (LeuS), Treatment Outcome Index (TOI), FACT-G Total, and FACT-Leu Total scores; higher scores reflect better HRQoL. Minimal important differences (MID) on the scales range from 2-12 points. The FACT-Leu was completed at baseline (BL), every 3 mo on study, and at treatment completion. Paired t-tests and repeated measures mixed-effects models were used to assess within and between-group differences. Results: Of 250 and 252 pts randomized to BOS and IM, respectively, BL HRQoL data was available for 233 and 235 pts; median follow-up times were 16.0 and 16.5 mo; 71% and 80% of pts remain on treatment. No differences between groups were observed at BL or over the first 12 mo of therapy; however, the study was not powered to detect between-group differences. At 3 mo, significant improvements from BL for BOS and IM pts were observed in EWB (P <0.05 and P <0.001, respectively) and LeuS (P <0.01 and P <0.001); IM pts also reported significant improvements on the FACT-G Total (P <0.05), TOI (P <0.001), and FACT-Leu (P <0.001). At 12 mo, trends noted at 3 mo were evident at the same or greater level of significance, except EWB for BOS pts. None of the changes exceeded the MID. Conclusions: These early HRQoL data suggest both BOS and IM increase several aspects of HRQoL in newly diagnosed CP CML pts. This finding is important given the reported efficacy and manageable, but distinct, safety profiles of BOS and IM.