Effect of lapatinib plus capecitabine (L+C) on quality of life (QOL) compared to capecitabine (C) alone in ErbB2+ metastatic breast cancer (MBC): An exploratory analysis

Abstract

9532 Background: In a phase III randomized open-label multicenter trial, L+C improved time to progression and progression free survival vs C alone in women with ErbB2+ MBC who had received prior therapy including trastuzumab. Per-protocol QOL analyses showed higher point estimates for QOL scores for L+C vs C suggesting no detriment to QOL for patients receiving combination therapy. Here we report exploratory QOL analyses. Materials: QOL outcomes included the Functional Assessment of Cancer Therapy-Breast (FACT-B) total, FACT-general (FACT-G), trial outcome index (TOI), EQ-5D utility, and EQ-5D visual analog scale (VAS) scores assessed at screening, every 6 weeks for the first 24 weeks, every 12 weeks thereafter and at study withdrawal. Higher scores indicate better QOL. Analyses included: comparison of proportions of patients achieving clinically important differences (CID) in QOL scores for L+C vs C with Fisher’s exact test; relationship between QOL and tumor response status using analysis of covariance adjusted for baseline score; and Pearson correlation coefficients (r) between QOL change from baseline scores and % tumor size reduction. Results: The study randomized 198 subjects to L+C and 201 subjects to C with nearly 50% completing Week 12 and 20% completing Week 24. A greater proportion of patients receiving L+C vs C achieved the CID for all 5 QOL scores (greater by 3 - 12 % points, although the differences in proportions were not statistically significant). Patients who showed a tumor response had higher adjusted mean QOL change from baseline scores compared to those showing disease progression (significant at Week 12, FACT-B total by 7.3, FACT-G 6.1, TOI 5.7, EQ-5D utility 0.11, and ED-5D VAS 10.7). Also, reductions in tumor sizes were associated with improvement in the 5 QOL scores (ranging from r = 0.15 to 0.19, p = 0.02 to 0.07). Conclusions: A greater proportion of patients receiving lapatinib in combination with capecitabine achieved clinically important improvements in QOL scores versus capecitabine alone. These QOL benefits were positively related to the clinical benefits. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration GlaxoSmithKline GlaxoSmithKline GlaxoSmithKline GlaxoSmithKline