A nationwide, multicenter retrospective study on the effectiveness and safety of eribulin in Korean breast cancer patients (REMARK)

Average duration of prior treatment lines predicts clinical benefit to eribulin chemotherapy in patients with metastatic breast cancer

Purpose

The aim of this study was to identify factors associated with progression-free survival (PFS) and overall survival (OS) in patients with metastatic breast cancer (MBC) treated with eribulin in a real-world setting, to improve information provision in those considering treatment.

Methods

Patients treated with eribulin for MBC at The Christie NHS Foundation Trust, Manchester, UK, between August 2011 and December 2018 were included (n = 439). Data were collected by retrospective review of medical records and electronic prescribing systems. Factors such as biological subtype, distant recurrence-free interval, previous lines of chemotherapy and the ‘average duration of previous treatment lines’ (ADPT) (calculated as: (date of initiation of eribulin–date of MBC) / the number of previous treatment lines in the metastatic setting) were evaluated for prognostic impact using Cox proportional hazards regression.

Results

In the full cohort, the median PFS and OS were 4.1 months (95% CI 3.7–4.4) and 8.6 months (95% CI 7.4–9.8), respectively. Outcomes were significantly inferior for those with triple-negative breast cancer (TNBC) (n = 92); PFS_TNBC: 2.4 months (95% CI 2.1–3.0), p =  < 0.001 and OS_TNBC: 5.4 months (95% CI 4.6–6.6), p =  < 0.001. ADPT was the only factor other than subtype significantly associated with PFS and OS. Longer ADPT was also significantly associated with PFS and OS in those with TNBC. For example, women in the lowest ADPT tertile (< 5.0 months) achieved a median OS of only 4.3 months, whereas those in the upper ADPT tertile (> 8.7 months) had a median OS of 12.1 months (p = 0.004).

Conclusion

Our results indicate that the ADPT lines is an important factor when predicting the outcome with eribulin chemotherapy in a palliative setting and that quantitative guidance on the likely PFS and OS with treatment can be provided using ADPT. Validation in additional cohorts is warranted.

Real-world effectiveness of eribulin in heavily pretreated patients with metastatic breast cancer in China: a multicenter retrospective study

Background:

Eribulin is a nontaxane microtubule inhibitor approved in China for patients with advanced breast cancer who show progression after ⩾2 lines of chemotherapy. The aim of this study was to determine the efficacy and safety profile of eribulin and explore potential predictive factors for the efficacy of eribulin among Chinese women with metastatic breast cancer (MBC) in real-world practice.

Patients and Methods:

A total of 272 consecutive MBC patients who were treated with eribulin between November 2019 and October 2020 in 9 institutions nationwide were included in this study. Eribulin was administered intravenously at a dose of 1.4 mg/m² on days 1 and 8 of a 21-day cycle. Efficacy outcomes included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and clinical benefit rate (CBR). Adverse events (AEs) were graded according to The National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 5.0.

Results:

Eribulin showed a median PFS of 4.1 months (95% confidence interval [CI] 3.6–4.6); however, the OS data were immature. The ORR was 17.6% and the CBR was 24.6%. A total of 51.8% of patients received eribulin monotherapy, while 48.2% of patients were treated with eribulin plus targeted therapy or other chemotherapy. The number of metastatic sites, duration of previous taxane treatment for MBC, and combination with bevacizumab were significant in Cox multivariate analysis (p = 0.023, p = 0.048, and p = 0.046, respectively) and were significantly associated with PFS of eribulin. The most common AEs with eribulin treatment were hematological toxicities, including neutropenia, leukopenia, and anemia.

Conclusion:

Eribulin was effective with a manageable toxicity profile in clinical practice. Furthermore, when prescribed in combination with other agents, eribulin did not increase the toxic effects of each agent. Eribulin monotherapy or plus other agents is an alternative for the heavily pretreated patients with MBC.