Real-world efficacy of ribociclib (RIB) + aromatase inhibitor (AI)/fulvestrant (FUL), or endocrine monotherapy (ET), or chemotherapy (CT) as first-line (1L) treatment (tx) in elderly patients (pts; > 75 years) with hormone receptor–positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Results of fifth interim analysis (IA) from RIBANNA.

e13050 Background: RIB+ET has demonstrated a statistically significant survival benefit across three phase 3 MONALEESA trials, irrespective of menopausal status, line of therapy, or combination partner. RIBANNA (CLEE011ADE03), a prospective, noninterventional study assessing the efficacy and safety of RIB+ET, or ET alone or CT in 1L setting in pre-, peri- and postmenopausal women with HR+, HER2– ABC is ongoing in Germany since October 2017. In this 5 th IA from RIBANNA, efficacy, safety, and tolerability for exclusively elderly pts ( > 75 years) will be presented. Methods: Pts were included in accordance with the German tx guideline. The following analysis will be performed exclusively for pts > 75 years. Effectiveness analysis for PFS will be performed including propensity score matched (PSM) and Cox Proportional Hazards Regression (CPHR) analysis. Data for patient-reported outcomes (PRO) were collected at baseline and every 3 months until the end of treatment and will be evaluated using the Morisky Medication Adherence Scale (MMAS-8), questionnaires related to quality-of-life (EORTC QLQ-C30) and its breast cancer–specific module (EORTC QLQ-BR23) as well as the Hospital Anxiety and Depression Scale (HADS). Results: At data cutoff Sep 6, 2022, 2581 pts were enrolled in the study (RIB+AI/FUL, n = 2163; ET, n = 237; CT, n = 181). For pts > 75 years data from n = 434 (RIB+AI/FUL), n = 83 (ET) and n = 20 (CT) are available. In the overall population at baseline, the mean age (standard deviation [SD]) of patients was 65.5 (11.6), 70.8 (11.3), and 61.8 (11.6) years in the RIB + AI/FUL, ET, and CT cohorts, respectively. The unadjusted KM estimate for median PFS was 32.2 months (95% CI, 29.3–34.8) in the RIB + AI/FUL cohort, 35.2 months (95% CI, 23.9–44.2) in the ET cohort, and 16.7 months (95% CI, 9.9–17.5) in the CT cohort. Multivariate analysis showed that PFS was independently affected by several baseline parameter. After CPHR Analysis RIB + AI/FUL was associated with prolonged PFS compared with ET or CT. These results could be confirmed using PSM. The most frequent treatment-emergent adverse events (AEs) (all grade) in the RIB + AI/FUL cohort were neutropenia (25.8%), nausea (25.1%), fatigue (24.2%), and leukopenia (19.8%). Nausea and fatigue were the most common treatment-emergent AE (all grade) in both the CT and ET cohorts. Conclusions: RIBANNA study showed diverse population characteristics among pts who received RIB tx in a real-world setting. In the overall population Ribociclib showed superiority over ET and CT in the clinical routine, without new safety signals. Data for exclusively elderly pts ( > 75 years) will be presented.