Impact of lapatinib plus trastuzumab versus single-agent lapatinib on quality of life of patients with trastuzumab-refractory HER2+ metastatic breast cancer

Abstract

Background: Progression-free survival (PFS) was significantly longer for the lapatinib plus trastuzumab (L+T) arm than for L alone in a phase III, randomized, open-label study of women with human epidermal growth factor receptor 2 positive metastatic breast cancer who had documented progression on at least one T-containing regimen in the metastatic setting. This analysis focused on impact of treatments on health-related quality of life (HRQOL).

Methods: HRQOL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire. Changes from baseline and time to deterioration were analyzed in the intent-to-treat population.

Results: Differences between the treatment arms in adjusted mean change from baseline favored the L+T arm, ranging from 0.0 to 4.1 (FACT-B), 1.0-4.0 [Functional Assessment of Cancer Therapy-General (FACT-G)], and 0.5-2.7 (Trial Outcome Index). Most differences were not statistically significant, except for FACT-G at week 12 (delta = 4.0, P = 0.037). Similar results were found in a sensitivity analysis that included HRQOL records up to patient withdrawal from original randomized treatment. The longer time to HRQOL deterioration in the L+T arm was not statistically significant (FACT-B hazard ratio, 0.82; 95% confidence interval 0.56-1.20).

Conclusion: The addition of lapatinib to trastuzumab prolonged PFS while improving or maintaining near-term HRQOL, suggesting a meaningful clinical benefit to patients.