Abstract P1-13-12: Quality of life and patient-reported outcomes in US patients enrolled in the MONALEESA-2 study
Authors: Tolaney SM , Tan-Chiu E , Truica C , Volas-Redd G , Shtivelband M , Dalal AA , Chandiwana D , Hortobagyi G 
Published: February 2018

Background: Improvement to and maintenance of the highest possible health-related quality of life (QoL), in addition to disease control, are key goals 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 cyclin-dependent kinases 4 and 6 inhibitor ribociclib, in combination with letrozole, significantly extended progression-free survival (PFS) compared with placebo + letrozole in patients with hormone receptor–positive (HR+), human epidermal growth factor receptor 2–negative (HER2−) ABC. Patient-reported outcomes demonstrated similar QoL among patients in both treatment groups. Here, we present data from US patients enrolled in the MONALEESA-2 study on overall QoL as well as individual domains.

Methods: Postmenopausal women (N=668) with HR+, HER2− ABC who did not receive prior systemic treatment for ABC and had an Eastern Cooperative Oncology Group performance status score of ≤1, adequate bone marrow and organ function, and no history of active cardiac dysfunction were randomized 1:1 to receive either ribociclib (600 mg/d, 3 weeks on/1 week off) + letrozole (2.5 mg/d, continuous) or placebo + letrozole. The primary end point was locally assessed PFS. Quality of life was reported using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), the EuroQol 5-domain 5 level (EQ-5D-5L) visual analog scale (VAS) of overall health, and the breast symptom score of the EORTC QLQ-Breast Cancer 23 (EORTC QLQ-BR23) module. Data cutoff in this analysis was January 29, 2016.

Results: Patient characteristics and QoL survey reports were well balanced across treatment groups in US patients (n=213). 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 among treatment groups.

Quality of Life Outcomes of US Patients in the MONALEESA-2 Study at 16 MonthsOutcomeTreatment, nPatients without ≥10% deterioration in score, % (95% CI, %)EORTC QLQ-C30  Global health status/QoLRIB + LET, 2664.0 (49.4–75.4) PBO + LET, 3550.5 (36.2–63.2)Physical functioningRIB + LET, 2175.7 (62.6–84.7) PBO + LET, 1773.1 (57.2–83.9)Emotional functioningRIB + LET, 2271.6 (58.6–81.2) PBO + LET, 3159.7 (45.7–71.2)Social functioningRIB + LET, 1780.1 (68.5–87.8) PBO + LET, 2660.2 (44.1–73.0)EORTC QLQ-BR23 breast symptom scoreRIB + LET, 888.0 (76.6–94.0) PBO + LET, 886.2 (70.6–93.9)EQ-5D-5L VAS of overall healthRIB + LET, 1386.6 (76.9–92.4) PBO + LET, 1873.4 (56.8–84.4)LET, letrozole; PBO, placebo; RIB, ribociclib.

Conclusions: Addition of ribociclib to letrozole in US patients enrolled in MONALEESA-2 led to significant prolongation of PFS while maintaining QoL.

Citation Format: Tolaney SM, Tan-Chiu E, Truica C, Volas-Redd G, Shtivelband M, Dalal AA, Chandiwana D, Hortobagyi G. Quality of life and patient-reported outcomes in US patients enrolled in the MONALEESA-2 study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-12.