Abstract P1-19-33: Real-world efficacy of ribociclib + aromatase inhibitor, or endocrine monotherapy, or chemotherapy as first-line treatment in postmenopausal women with HR-positive, HER2-negative locally advanced or metastatic breast cancer: Second interim analysis from the RIBANNA study

Abstract

Abstract Background: Ribociclib (RIB, a selective CDK4/6 inhibitor) plus an aromatase inhibitor (AI) or fulvestrant (FUL) is approved for the treatment of premenopausal and postmenopausal women with HR+/HER2- advanced breast cancer (aBC). Real-world evidence for the effectiveness, safety and tolerability of RIB + AI/FUL in routine clinical practice is needed to support the use of this combination. Methods: RIBANNA is a noninterventional study ongoing in Germany since October 2017. Premenopausal and postmenopausal patients (N=3020) treated with RIB + AI/FUL, or endocrine monotherapy (ET), or chemotherapy (CT) as first-line treatment for HR+/HER2- aBC in accordance with German guidelines were included. Data are being collected from clinical practice in all 3 cohorts. Further lines of treatment are noted to examine outcomes of sequential therapy. Results: For the first interim analysis, 461 patients were enrolled until October 9, 2018, while full analysis set comprised 282 patients (Table 1). The first-line mean daily dose of RIB was 382 mg including and 540 mg excluding dose interruptions, respectively. RIB was prescribed mainly in combination with letrozole (83%), anastrozole (8%), and exemestane (7%); ET included nonsteroidal AI (64%), selective estrogen receptor degrader (25%), selective estrogen receptor modulator (7%), and steroidal AI (5%); CT included taxane-based monotherapy (30%) or combination therapy (27%), other monotherapy (23%) or other combination therapy (13%), and anthracycline-based combination therapy (5%). Conclusion: RIBANNA study showed diverse population characteristics among patients who received RIB treatment in a real-world setting. Based on the baseline demographics data, RIB (CDK4/6 inhibitor) treatment was found to be very well adopted among premenopausal and postmenopausal patients with HR+/HER2- aBC. The second interim analysis is planned for October 2019. Updated baseline data of approximately 1200 to 1300 patients and information on safety and dose modification for first-line patients from all cohorts will be presented. Table 1. Baseline demographic characteristicsTotal (N = 282)RIB + AI (n = 216)Endocrine therapy (n = 26)Chemotherapy (n = 40)Mean age, years (SD)67 (11)67 (10)71 (12)62 (10)Mean time since initial diagnosis, years5.45.56.53.9T stage at initial diagnosis, n (%)T0+T161 (100)48 (79)6 (10)7 (11)T2-T4198 (100)149 (75)17 (9)32 (16)N stage at initial diagnosis, n (%)N0+N1186 (100)144 (77)16 (9)26 (14)N2+N364 (100)48 (75)5 (8)11 (17)M stage at initial diagnosis, n (%)M0156 (100)121 (78)14 (9)21 (13)M1101 (100)75 (74)9 (9)17 (17)Locally advanced, n (%)101 (100)73 (72)9 (9)19 (19)Metastatic, n (%)101 (100)75 (74)9 (9)17 (17)Metastatic location, n (%)CNS, liver, lungs119 (100)96 (81)1 (1)22 (18)Bone only84 (100)62 (74)17 (20)5 (6)Skin, lymph nodes, other52 (100)37 (71)6 (11)9 (17) Citation Format: Achim Wöckel, Pawel Basiora, Michael Bohlmann, Thomas Decker, Jörg Falbrede, Peter Fasching, Helmut Forstbauer, Tobias Hesse, Oliver Hoffmann, Christian Jackisch, Anna Kaczerowsky, Ralf Lorenz, Kerstin Lüdtke-Heckenkamp, Diana Lüftner, Frederik Marmé, Thomas Mueller, Christoph Mundhenke, Arnd Nusch, Volker Petersen, Gabriele Prange-Krex, Toralf Reimer, Thomas Resch, Christian Roos, Oliver Tomé, Anja Weishap. Real-world efficacy of ribociclib + aromatase inhibitor, or endocrine monotherapy, or chemotherapy as first-line treatment in postmenopausal women with HR-positive, HER2-negative locally advanced or metastatic breast cancer: Second interim analysis from the RIBANNA study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-19-33.