Abstract PS13-37: Effectiveness of eribulin in poor prognosis subgroups of metastatic breast cancer (mBC) patients (elderly, African Americans, and patients with liver metastases) in the United States

Abstract

Abstract Background: Eribulin mesylate was approved in the United States (US) in 2010 as third-line or later treatment (after an anthracycline and a taxane) of mBC. Multiple patient demographic and clinical characteristics have been reported to impact clinical outcomes in mBC patients. The objective of these analyses was to assess real-world clinical outcomes of eribulin therapy in three subgroups that generally have poorer prognoses: elderly (≥65 years), African American, and those with liver metastases in clinical practice in the US. Methods: A retrospective chart review study was conducted across community oncology practices in the US. Adult female patients with mBC who initiated treatment with eribulin as per US prescribing information between 2011 and 2017 were included. Data were extracted by prescribing physicians from individual patient’s electronic health records and captured via an electronic case report form. All patient data were de-identified prior to analyses. Clinical outcomes including objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were assessed in patients who were elderly, African American, or who had liver metastases. Results: Current analyses were based on data from 278 patients including 175 (63%) patients with liver metastases, 98 (35%) elderly patients, and 73 (26%) African American patients. Mean age at initiation of eribulin in each group was: liver metastases, 59; elderly, 71; and African American, 58. Proportion of patients with ECOG-PS ≥2 at initiation of eribulin was: liver metastases, 46%; elderly, 52%; and African American, 47%. The majority of patients received eribulin in 3rd line: liver metastases, 80%; elderly, 87%; and African American, 85%. ORR to eribulin was 34% in patients with liver metastases, 35% in elderly, and 48% in African Americans. Median PFS from initiation of eribulin was 5.2 months in patients with liver metastases, 5.8 months in elderly, and 7.6 months in African Americans. Landmark OS from initiation of eribulin at 6, 12 and 24 months were 71%, 36% and 18%, respectively, in patients with liver metastases, 72%, 35% and 23% in elderly, and 78%, 46%, and 28% in African Americans. Conclusion: Effectiveness of eribulin in clinical practice in patients with liver metastases, elderly, and African Americans was confirmed within this real-world study in the US. Citation Format: Sarah S. Mougalian, Jonathan K. Kish, Jingchuan Zhang, Djibril Liassou, Bruce A. Feinberg. Effectiveness of eribulin in poor prognosis subgroups of metastatic breast cancer (mBC) patients (elderly, African Americans, and patients with liver metastases) in the United States [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-37.