Health-related quality of life (HRQoL) of bosutinib (SKI-606) in imatinib-resistant (IM-R) or imatinib-intolerant (IM-I) chronic phase chronic myeloid leukemia (CP CML).

Abstract

6620 Background: Bosutinib, a dual Src/Abl tyrosine kinase inhibitor (TKI), has demonstrated efficacy in a phase 1/2 single-arm study of patients (pts) with IM-R or IM-I CP CML. Given the potential for CP CML pts receiving 2nd-generation TKIs to be treated for significant durations, evaluation of concomitant HRQoL is important. The effect of bosutinib on HRQoL was assessed as an exploratory endpoint. Methods: In the phase 2 part of the trial, 253 pts with IM-R (n = 170) or IM-I (n = 83) CP CML were treated with bosutinib 500 mg/d. HRQoL was measured using the 44-item Functional Assessment of Cancer Therapy–Leukemia (FACT-Leu), which consists of 5 domains: Physical Well-being (PWB), Social/Family Well-being (SFWB), Emotional Well-being (EWB), Functional Well-being (FWB), and Leukemia Subscale (LeuS); and 3 summary scales: Treatment Outcome Index (TOI), FACT-General, and FACT-Leu Total. FACT-Leu items are rated on a scale of 0-4. Scores are obtained for each scale by summing item responses; higher scores reflect better HRQoL. The FACT-Leu was completed at baseline, wks 4, 8, and 12, every 12 wks thereafter, and at treatment completion. Within-cohort comparisons were assessed using paired t-tests. Results: In this interim analysis, median follow-up was 97 wks (range, 2-215 wks); 51% of pts were still receiving treatment. At 12 wks, IM-R pts reported significant improvements (P <0.05 to P <0.01) in the PWB, EWB, LeuS, Total, and TOI; IM-I pts reported improvement in the LeuS (P <0.05). At 24 wks, IM-R pts reported improvements from baseline in the EWB, LeuS, Total, and TOI; IM-I pts noted significant improvements (P <0.001 to P <0.05) in the PWB, EWB, LeuS, Total, and TOI. At 48 and 96 wks, the LeuS (P <0.01) and TOI (P <0.05) remained improved for IM-R pts, with additional improvements in PWB, Total (P <0.05), and EWB (P <0.01) observed at 96 wks. EWB, LeuS, Total, and TOI were improved for IM-I pts (P <0.001 to P <0.05) at 48 wks, although not at 96 wks. Conclusions: When examined in the context of previously reported efficacy, these early HRQoL data suggest that bosutinib is associated with improved HRQoL among pts with IM-R or IM-I CP CML who remained on therapy.