374P - 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

Background

European 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.

Methods

HR+/HER2- mBC adults from the Institut de Cancérologie de l'Ouest, France, Charité Universitätsmedizin Berlin and Würzburg University Hospital, Germany, who started 1^st 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 1^st to 4^th CT line.

Results

The 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 1^st CT. Prior to 1^st CT start, 43% received CDK4/6i and ET for mBC. 59%, 32% and 15% had records of subsequent 2^nd, 3^rd and 4^th CT line, respectively, mostly as monotherapy. Median RwOS was 23.5, 12.7, 9.6 and 6.7 months from 1^st, 2^nd, 3^rd and 4^th 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.

Conclusions

HR+/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

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Gilead Sciences, Inc.

Funding

Gilead Sciences, Inc.

Disclosure

M. 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.