Abstract PO2-05-12: Retrospective analysis on therapeutic efficacy and predictive indicators of eribulin plus anti-angiogenic drugs for metastatic breast cancer

Abstract Background: Eribulin has been widely used for the treatment of metastatic breast cancer (MBC). It has been found that eribulin can work in synergy with Bevacizumab or Anlotinib to achieve anti-angiogenic effects and possible synergistic enhancement. To optimize the efficacy of eribulin usage in late-line MBC patients, it is essential to delve deeper into the effects of combined treatments and gather more real-world clinical outcomes. Therefore, we evaluated the efficacy and safety of eribulin plus the anti-angiogenic drugs in late-line MBC patients. Objective: This study aims to retrospectively analyze the therapeutic efficacy and safety of eribulin plus anti-angiogenic drugs in treating metastatic breast cancer and explore predictive indicators of the therapeutic efficacy of eribulin in treating MBC. Methods: A retrospective review study was performed. 40 Patients diagnosed with MBC and treated with eribulin in Xi’an international medical center hospital from May 2020 to May 2021 were enrolled in this study. Patients were evaluable for this study and divided into two groups based on whether they received eribulin monotherapy or combined therapy. 22 patients were treated with eribulin monotherapy, and 18 were treated with eribulin and anti-angiogenic drugs (Bevacizumab and Anlotinib). Patients’ treatment parameters and characteristics were recorded. The Kaplan-Meier method was used to calculate the median PFS and corresponding 95% confidence interval (CI), and the Cox regression model was used for multivariate analysis of predictive indicators. The Fisher exact probability test was used to compare the difference in adverse reactions between the two groups, with a level of significance set at p-value 0.05. Results: All study patients have an average of 5 treatment lines and a median progression-free survival (mPFS) of 4.2 months. The eribulin plus anti-angiogenic drug treatment group had a significantly prolonged mPFS compared to the group without anti-angiogenic drug treatment (7.0 months vs 2.0 months, p 0.001, log-rank). Multivariate analysis identified that the combination of anti-angiogenic therapy (HR = 0.043, p = 0.004) and the occurrence of grade 3-4 neutropenia after treatment were two predictive factors for longer PFS (HR = 0.322, p = 0.009). In contrast, prior resistance to taxanes was predictive of shorter PFS (HR = 4.583, p = 0.019). Other factors, including age, Eastern Cooperative Oncology Group (ECOG) performance status, hormone receptor (HR) type, expression status, human epidermal growth factor receptor-2 (HER-2) expression status, Ki-67 level, number of metastatic lesions, and number of prior lines of Eribulin therapy, were not significantly associated with PFS. The results of Fisher’s exact test show that there was no significant increase in treatment-related adverse events (all grades) after combination with anti-angiogenic drugs. Conclusion: A combination of eribulin and anti-angiogenic therapy has significantly prolonged mPFS in the treatment of MBC patients. Other factors such as prior non-taxane resistance, grade 3-4 neutropenia occurrence after treatment, and combined anti-angiogenic therapy can be used as biomarkers for predicting treatment efficacy. The adverse events are manageable and the safety of combined therapy can be guaranteed. Therefore, the eribulin plus anti-angiogenic combination may act as a potential therapy for late-line MBC patients with clinically beneficial therapeutic effects. Keywords: metastatic breast cancer, eribulin, anti-angiogenic therapy, retrospective analysis Citation Format: Junmei Zhang, Xuezheng Wang, Hongjuan Du, Yan Xue. Retrospective analysis on therapeutic efficacy and predictive indicators of eribulin plus anti-angiogenic drugs for metastatic breast cancer abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-05-12.