Real-world efficacy of ribociclib (RIB) plus aromatase inhibitor (AI)/fulvestrant (FUL), or endocrine monotherapy (ET), or chemotherapy (CT) as first-line (1L) treatment (tx) in patients (pts) with hormone receptor–positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Results of fourth interim analysis (IA) from RIBANNA.
Authors: Lüftner Diana , Brucker Cosima , Decker Thomas , Fasching Peter A. , Göhler Thomas , Jackisch Christian , Janssen Jan , Koehler Andreas , Luedtke-Heckenkamp Kerstin , Mackelenbergh Marion Van , Marmé Frederik , Nusch Arnd , Rautenberg Beate , Reimer Toralf , Schmidt Marcus , Weide Rudolf , Wimberger Pauline , Nabieva Naiba , Roos Christian , Woeckel Achim 
Published: June 2022

1065 Background: RIBANNA is a real-world, noninterventional study conducted in Germany evaluating efficacy, safety, and tolerability of RIB in combination with AI/FUL aiming to gain insights into routine clinical practice for pts with HR+, HER2– ABC. Here, we present results of the fourth IA from RIBANNA. Methods: Pre-, peri- and postmenopausal pts who received 1L tx with RIB+AI/FUL, or ET or CT for HR+, HER2– ABC were included in accordance with the German tx guideline. The effect of baseline demographic characteristics, including histological grade, age, previous adjuvant tx, Eastern Cooperative Oncology Group-performance score (ECOG-PS), and metastatic sites on progression-free survival was evaluated using Cox regression model. Results: At data cutoff October 11, 2021, 2598 pts were enrolled in the study (RIB+AI/FUL, n = 2177; ET, n = 239; CT, n = 182). Data from 1L tx were available for 2492 pts (95.9%), second-line tx for 689 pts (26.5%), third-line tx for 263 pts (10.1%), and fourth-line tx for 94 pts (3.6%). Significant differences were observed in baseline mean age and metastatic sites for pts in RIB+AI/FUL cohort vs ET and CT cohorts (both < 0.001). At baseline, the mean (SD) ages of pts were 65.5 (11.6), 70.7 (11.5) and 61.6 (11.6) years in RIB+AI/FUL, ET, and CT cohorts, respectively. While comparing the performance status, 44.2% of pts in RIB+AI/FUL, 34.7% of pts in ET and 42.1% of pts in CT cohort were fully active with ECOG-PS = 0. CNS, liver, or lung metastases were recorded in 42.6% of pts in RIB+AI/FUL, 26.8% of pts in ET and 67.1% of pts in CT cohort. Bone only metastases were reported in 30.8%, 47.9% and 15.0% of pts in RIB+AI/FUL, ET, and CT cohorts, respectively. Overall, 32.1%, 37.7%, and 52.7% of pts discontinued the study in RIB+AI/FUL, ET, and CT cohorts, respectively, the most common reasons being deaths (16.1%,17.2%, and 31.9%, respectively) and lost to follow-up (5.9%, 8.8%, and 9.3%, respectively). The most common tx-emergent adverse event (grade 3 or 4) observed in RIB+AI/FUL cohort was neutropenia (14.8%), while 6.6% and 6.9% of pts in ET and CT cohorts, respectively, experienced neutropenia. The efficacy results from all 3 cohorts, including Kaplan-Meier curves, will be presented during ASCO 2022. Conclusions: RIBANNA study showed diverse population characteristics among pts who received RIB tx in a real-world setting. Overall higher number of pts were treated in 1L with RIB+AI/FUL followed by ET and CT. The differences in baseline characteristics on metastatic pattern, age, and ECOG-PS reflect different selection strategies for 1L tx decision. No new safety signals were identified. Clinical trial information: CLEE011ADE03.