Improvement of health-related quality of life (QOL), in addition to disease control, is a key goal of treatment in patients with advanced breast cancer (ABC). Endocrine therapy is preferred as first-line therapy in ABC because of its preferable safety profile compared with chemotherapy. In the MONALEESA-2 study, the CDK4/6 inhibitor ribociclib, in combination with letrozole, significantly extended progression-free survival (PFS) compared with placebo plus letrozole in postmenopausal women with hormone receptor (HR)-positive/HER2-negative ABC.1 Patient-reported outcomes demonstrated similar QOL among patients in both treatment groups. At SABCS 2017, data were presented from US patients enrolled in the MONALEESA-2 study on overall QOL, as well as individual domains.2
Postmenopausal women with HR-positive/HER2-negative ABC who did not receive prior systemic treatment for ABC and had an Eastern Cooperative Oncology Group performance status ≤1, adequate bone marrow and organ function, and no history of active cardiac dysfunction were randomized 1:1 to receive either ribociclib + letrozole or placebo + letrozole. The primary end point was locally assessed PFS. QOL was reported using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), the EuroQol 5-Dimension 5-Level visual analog scale of overall health, and the breast symptom score of the EORTC QLQ-Breast Cancer 23 module. Data cutoff in this analysis was January 4, 2017.
The global health status/QOL scores of the EORTC QLQ-C30 were maintained between groups, and improved over time in the ribociclib group (mean ± standard deviation [SD] score at baseline, 69.1 ± 19.0; at 8 months, 71.3 ± 18.2; and at 16 months, 73.0 ± 16.0) and the placebo group (mean ± SD score at baseline, 69.9 ± 20.0; at 8 months, 75.9 ± 19.2; and at 16 months, 77.0 ± 15.0), which was consistent with scores in the overall population. At 16 months, the proportion of patients who did not experience ≥10% deterioration of all QOL scores was similar between treatment groups.
The authors concluded that the addition of ribociclib to letrozole in patients enrolled in MONALEESA-2 led to significant prolongation of PFS while maintaining QOL. Moreover, a clinically meaningful reduction in pain score was observed at 8 weeks in the ribociclib + letrozole group, with greater average pain reduction in the ribociclib + letrozole group compared with the placebo + letrozole group.
1. Sonke GS, et al. Breast Cancer Res Treat. 2017 Oct 22. doi: 10.1007/s10549-017-4523-y. Epub ahead of print.
2. Tolaney SM, et al. SABCS 2017. Abstract P1-13-12.