Compared to abemaciclib, treatment with ribociclib was associated with better symptom-related quality of life (QoL) in patients with HR+/HER2- advanced breast cancer. Researchers shared their findings at the 2022 ASCO Annual Meeting.

Using matching-adjusted indirect comparison, which “allows for comparative effectiveness in the absence of head-to-head trial data,” study authors compared patient-reported QoL outcomes from the MONALEESA-2 and MONARCH 3 studies.

MONALEESA-2 evaluated treatment with ribociclib plus an aromatase inhibitor, while MONARCH 3 involved treatment with abemaciclib plus an aromatase inhibitor. Ribociclib and abemaciclib are both cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, which are recommended in combination with endocrine therapy as first-line treatment for HR+/HER2- advanced breast cancer.

“QoL is an important endpoint that affects [treatment] decisions,” said Hope S Rugo, MD, professor, Department of Medicine, University of California San Francisco, and coinvestigators. “All available QoL data were used in this analysis; the median follow-up for MONALEESA-2 was 79.7 months, and the median duration of follow-up at which QoL data were reported for MONARCH 3 was 26.73 months.”

Data on patient QoL was self-reported in EORTC QLQ-C30 and BR-23 questionnaires.

In MONALEESA-2, 205 patients received treatment with ribociclib plus endocrine therapy, and 149 patients received placebo. Patients were weighted to match the baseline characteristics of MONARCH 3 participants, of whom there were 328 patients receiving abemaciclib plus endocrine therapy and 165 patients receiving placebo.

Time to sustained deterioration was “calculated as the time from randomization to a ≥10-point deterioration with no later improvement above this threshold,” Dr Rugo and coauthors said.

Ribociclib was superior to abemaciclib for time to sustained duration in appetite loss (HR, 0.46; 95% CI, 0.27-0.81), diarrhea (HR, 0.42; 95% CI, 0.23-0.79), and fatigue (HR, 0.63; 95% CI, 0.41-0.96). Time to sustained duration did not significantly favor abemaciclib over ribociclib in function or symptoms on either questionnaire, researchers said.

Better symptom-related QoL is associated with ribociclib vs abemaciclib, both in combination with endocrine therapy, as a first-line treatment for HR+/HER2- advanced breast cancer, investigators concluded.

Reference:
Rugo HS, O’Shaughnessy J, Jhaveri KL, 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):abstr 1015. doi:10.1200/JCO.2022.40.16_suppl.1015