Ribociclib Shows Superior QOL With Endocrine Therapy in HR+/HER2- Advanced Breast Cancer

Ribociclib (Kisqali) plus an aromatase inhibitor (AI) elicited improved symptom-related quality of life outcomes compared with abemaciclib (Verzenio) plus an AI as first-line therapy in postmenopausal patients with hormone receptor–positive, HER2–negative advanced breast cancer, according to findings from a matching-adjusted indirect comparison study.

The findings, which were presented during the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting, also showed that the time to first symptom deterioration (TTSD) significantly favored the ribociclib-containing treatment regimen.

“Cyclin-dependent kinases 4 and 6 inhibitors plus endocrine therapy are standards of care in the first-line treatment of patients with hormone receptor-positive, human epidermal growth factor receptor-negative advanced breast cancer,” the study authors wrote in a poster demonstrating the findings. “A statistically significant overall survival benefit with first-line ribociclib plus aromatase inhibitor was recently reported for MONALEESA-2; final [overall survival] results for the MONARCH 3 trial of first-line abemaciclib and aromatase inhibitor are pending.”

The CDK4/6 inhibitor drug class, which both abemaciclib and ribociclib belong to, is associated with various safety profiles. The problem is that many adverse events, even mild, may greatly impact a patient’s quality of life. The study authors noted that results from a previous survey of patients, advocates, nurses and oncologists identified that certain adverse effects — such as diarrhea and appetite loss —that occurred in patients treated with CDK4/6 inhibitors were moderate to severe in nature.

Moreover, the investigators wrote that patient reported outcomes are helpful but head-to-head studies are lacking. As a result, the study authors conducted a matched-adjusted indirect comparison analysis of the patients enrolled into the MONALEESA-2 and MONARCH 3 trials. Quality of life was measured using two questionnaires — the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and BR23. The QLQ-C30 consists of patient reported outcomes on the individuals physical, social, role, cognitive and emotional symptom burden. As for BR23, it assesses questions related to a patient’s side effects, body image and sexual functioning.

The median duration of follow-up for quality of life data was 26.73 months in the MONARCH 3 trial and 79.7 months in the MONALEESA-2 trial.

The findings showed that TTSD in functional and symptomatic scales significantly favored treatment with ribociclib. However, there were no significant differences in any of the functional domains.

In particular, TTSD was significantly better in terms of appetite loss (HR = 0.46; 95% CI, 0.27-0.81), diarrhea (HR = 0.42; 95% CI, 0.23-0.79), fatigue (HR = 0.63; 95% CI, 0.41-0.96) and arm symptoms (HR = 0.49; 95% CI, 0.30-0.79) in those who received the ribociclib-containing regimen.

“Interpretation of these results is limited to the subset of patients in (MONALEESA-2) who were matched to patients in (MONARCH 3),” the authors concluded.

Reference

Rodriguez C, Kaufman JL, Laubach J, et. al. Quality of life (QOL) with ribociclib (RIB) plus aromatase inhibitor (AI) versus abemaciclib (ABE) plus AI as first-line (1L) treatment (tx) of hormone receptor-positive/human epidermal growth factor receptor–negative (HR+/HER2−) advanced breast cancer (ABC), assessed via matching-adjusted indirect comparison (MAIC). J Clin Oncol. 2022;40(suppl 16):1015. doi:10.1200/JCO.2022.40.16_suppl.1015