Abstract P3-11-25: Real-world treatment patterns and clinical outcomes among women with HR+/HER2- advanced or metastatic breast cancer treated in real-world settings in Italy and Germany

Abstract

Abstract Background: Palbociclib is a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) that, when combined with an aromatase inhibitor (AI) or fulvestrant, has been shown in clinical trials to prolong progression-free survival (PFS) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) advanced or metastatic breast cancer (ABC/MBC). This study sought to describe real-world treatment patterns and clinical outcomes among patients with HR+/HER2- ABC/MBC treated with palbociclib in clinical practice settings in Italy and Germany. Methods: MARIA is an ongoing non-interventional, prospective multi-center study that includes women in Italy and Germany initiating their first or second therapy in the HR+/HER2- ABC/mBC setting. Data from 67 sites were used to assess patient and treatment characteristics and progression-free survival (PFS) among patients receiving palbociclib in combination with AI or fulvestrant. Landmark PFS estimates at 6-, 12-, and 18-months were reported by line of therapy (first- and second-line). Results: Overall, 72 patients formed the interim analytic cohort. Among these, 63 (47%) and 9 (7%) received palbociclib + AI as first- and second-line therapy, respectively. Twenty-six (20%) and 37 (27%) of patients received palbociclib + fulvestrant as first- and second-line therapy, respectively. Approximately 96%, 78%, and 64% of patients receiving palbociclib + AI as first-line therapy were progression free at 6-, 12-, and 18-months, respectively. Among patients receiving palbociclib + fulvestrant as first-line therapy, 6-, 12-, and 18-month PFS was 91%, 64%, and 39%, respectively. For second-line therapy, 6-, 12-, and 18-month PFS was 75%, 38%, 38% among palbociclib + AI users and 71%, 54%, and 45% for palbociclib + fulvestrant. Conclusions: This interim analysis indicates that PFS among women with ABC/mBC HR+/HER2-negative breast cancer in Italy and Germany receiving palbociclib, in combination with letrozole or fulvestrant is comparable to published randomized clinical trial results and other real-world observational studies. Further follow-up is required for longitudinal analysis and to estimate overall survival. Funding: Pfizer Citation Format: Michelino De Laurentiis, Nadia Harbeck, Ernest Law, Mayank Ajmera, Debanjali Mitra, Keith Davis, Sara Brucker, Sabino De Placido. Real-world treatment patterns and clinical outcomes among women with HR+/HER2- advanced or metastatic breast cancer treated in real-world settings in Italy and Germany [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 P3-11-25.