Health-related quality of life with pertuzumab retreatment: Secondary analysis of the PRECIOUS trial.

BACKGROUND

Retreatment with pertuzumab has demonstrated survival benefit in previously treated human epidermal growth factor receptor 2 (HER2)-positive locally advanced or metastatic breast cancer, but its effect on health-related quality of life (HRQoL) is not well established.

METHODS

This secondary analysis of the randomized, open-label phase III PRECIOUS trial evaluated HRQoL in women previously treated with pertuzumab, trastuzumab, and chemotherapy. Patients were randomized 1:1 to pertuzumab plus trastuzumab plus chemotherapy (PTC) or trastuzumab plus chemotherapy (TC). HRQoL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B). The primary endpoint was time-to-deterioration (TTD) in the Breast-Trial Outcome Index (B-TOI), defined as a ≥5-point decline. Secondary endpoints included TTD in the FACT-B total score, General Subscale, and Breast Cancer Subscale. Longitudinal changes were analyzed using linear mixed-effects models.

RESULTS

Of 217 eligible patients, 178 were included in the HRQoL analysis (median age: 57 years in PTC and 60 years in TC). No significant between-group differences in TTD for B-TOI were observed (hazard ratio, 1.22; 95% CI, 0.86-1.90; p = 0.23). Secondary TTD endpoints also showed no differences. Mixed-effects models indicated that TC had better B-TOI and Breast Cancer Subscale scores at week 6, but these early differences were not sustained beyond week 12.

CONCLUSION

Pertuzumab retreatment was not associated with clinically meaningful deterioration in HRQoL. These findings support the use of dual HER2 blockade beyond progression in appropriately selected patients.