Real-world (Rw) outcomes in patients (pts) with hormone receptor-positive and human epidermal growth factor receptor-2 negative (HR+/HER2-) metastatic breast cancer (mBC) treated with chemotherapy (CT) in France and Germany

BackgroundEuropean guidelines recommend endocrine therapy (ET) with CDK4/6 inhibitors (CDK4/6i) as the standard of care for HR+/HER2- (immunohistochemistry [IHC] 0, 1+, 2+/in situ IHC-) mBC. Despite its efficacy, most pts develop ET resistance, after which treatment (Tx) options are limited to CT. Antibody-drug conjugates have recently been added as Tx option in later lines. This study described patient characteristics, Tx patterns and survival outcomes of HR+/HER2- mBC pts initiating CT using Rw data from France and Germany, separately.MethodsHR+/HER2- mBC adults from the Institut de Cancérologie de l'Ouest, France, Charité Universitätsmedizin Berlin and Würzburg University Hospital, Germany, who started 1st CT for mBC from Jan 2016 to Feb 2023, were analysed. Baseline characteristics and Txs were described using descriptive statistics. Kaplan-Meier method was used to describe Rw overall survival (OS) from start of each line for 1st to 4th CT line.ResultsThe study included 339 patients from France and 157 patients from Germany. Of the German cohort: 99% were female, 32% had de novo mBC, with median age of 57 years at 1st CT. Prior to 1st CT start, 43% received CDK4/6i and ET for mBC. 59%, 32% and 15% had records of subsequent 2nd, 3rd and 4th CT line, respectively, mostly as monotherapy. Median RwOS was 23.5, 12.7, 9.6 and 6.7 months from 1st, 2nd, 3rd and 4th CT line, respectively (Table). The German results presented are aligned with those observed and previously presented for France1. 1 Campone M et al. ESMO BC Congress 2024, Berlin.ConclusionsHR+/HER2- mBC pts initiating CT in France and Germany showed poor prognosis with median survival decreasing with each subsequent CT line. The consistent findings in both countries demonstrate continued high unmet need for improved treatment options for this population in Europe. Table: 374P RwOS by CT line 1st CT 2nd CT 3rd CT 4th CT N Pts 157 92 51 23 N Deaths 75 46 25 11 Median rwOS in months (mo) (IQR) 23.5 (9.0-NR) 12.7 (6.2-NR) 9.6 (4.9-NR) 6.7 (2.3-NR) 6 mo N 110 58 30 - % Survival [95% CI] 82% [76-89] 76% [67-86] 73% [62-88] - 12 mo N 76 29 10 - % Survival [95% CI] 66% [59-75] 54% [43-67] 42% [29-62] - 18 mo N 55 19 - - % Survival [95% CI] 57% [49-67] 40% [29-54] - 24 mo N 39 12 - - Legal entity responsible for the studyGilead Sciences, Inc.FundingGilead Sciences, Inc.DisclosureM. Campone: Financial Interests, Institutional, Advisory Board: Astrazeneca, Novartis, Sanofi, Daiichi Sankyo, Lilly, Stemline, Gilead, Seagen; Financial Interests, Institutional, Invited Speaker: Novartis, Lilly. J. Frenel: Financial Interests, Personal, Advisory Board: Pfizer, Novocure, Pierre Fabre, Eisai, Seagen, Gilead; Financial Interests, Personal, Invited Speaker: GSK, Amgen, Eisai; Financial Interests, Institutional, Advisory Board: Exactscience, Lilly, Daiichi Sankyo, AstraZeneca, Clovis Oncology; Financial Interests, Institutional, Invited Speaker: Novartis, MSD; Financial Interests, Coordinating PI: AstraZeneca, Seagen; Financial Interests, Local PI: MSD, Daiichi Sankyo; Non-Financial Interests, Principal Investigator: Novartis, Lilly, AstraZeneca, Pfizer, Daiichi Sankyo, MSD. V.I.I. Kiver: Financial Interests, Personal, Advisory Board: Gilead, Lilly; Financial Interests, Personal, Invited Speaker: Novartis, Pfizer, Roche, Eisei, AstraZeneca; Financial Interests, Personal and Institutional, Research Grant: Novartis; Non-Financial Interests, Principal Investigator: Novartis, Pfizer, AstraZeneca; Non-Financial Interests, Personal, Training: Novartis. A. Woeckel: Financial Interests, Personal, Advisory Board: AstraZeneca, • Novartis, Pfizer, Roche, MSD, Stemline; Financial Interests, Personal, Invited Speaker: Lilly, Novartis, Pfizer, Gilead, Dajichi Sanko. A.G. Kerscher: Financial Interests, Institutional, Other, IT-Infrastructure: Janssen; Other, Consulting: IQVIA. M. Krebs: Financial Interests, Personal, Advisory Board: Janssen, IQVIA, GSK Oncology; Financial Interests, Personal, Stocks/Shares: General Electric. C.S. Leal: Financial Interests, Personal, Full or part-time Employment, Epidemiologist: IQVIA. V.M. Saglimbene: Financial Interests, Personal, Full or part-time Employment: IQVIA Solutions. N. Trankov: Financial Interests, Personal, Full or part-time Employment: IQVIA. N. Sadetsky: Financial Interests, Personal, Full or part-time Employment: Gilead; Financial Interests, Personal, Stocks/Shares: gilead, Roche/Genentech. N. Sjekloca: Financial Interests, Personal, Stocks or ownership: Gilead Sciences Europe Ltd.; Financial Interests, Personal, Full or part-time Employment: Gilead Sciences Europe Ltd. O. Libert: Financial Interests, Personal, Full or part-time Employment, Medical Affairs: Gilead Sciences; Financial Interests, Personal, Stocks/Shares: Gilead Sciences. A.G. Kaushik: Financial Interests, Institutional, Full or part-time Employment: Employee of Gilead Sciences; Financial Interests, Institutional, Stocks/Shares: Stockholder of Gilead Sciences. All other authors have declared no conflicts of interest.