Impact of the number of prior chemotherapy regimens on outcomes for patients with metastatic breast cancer treated with eribulin: A post hoc pooled analysis

Eribulin Treatment for Patients with Metastatic Breast Cancer: The UK Experience - A Multicenter Retrospective Study

INTRODUCTION

This study examined real-world data from patients who received eribulin for metastatic breast cancer (MBC) collected from 14 hospitals across the UK.

METHODS

Anonymized data were collected retrospectively from patients with MBC who had received eribulin. The data included the hormone-receptor status, histological diagnosis, age, prior chemotherapy, response to eribulin, progression-free survival (PFS), and overall survival (OS).

RESULTS

Among 577 patients analyzed, the median age was 56 years, and most patients (73%) were estrogen-receptor positive. The median OS was 288 days (95% confidence interval [CI]: 261-315), and the PFS was 117 days (95% CI: 105-129). The median OS was higher among older patients (≥65 vs. <65 years: 325 days [95% CI: 264-385] vs. 285 days [95% CI: 252-317]; p = 0.028). The median OS was also higher in patients who received eribulin after fewer prior lines of chemotherapy (≤2 vs. >2 prior: 328 days [95% CI: 264-385] vs. 264 days [95% CI: 229-298]; p = 0.042).

DISCUSSION/CONCLUSION

These retrospective data suggest that eribulin can be successfully used in older patients with MBC. Eribulin treatment was more effective in earlier-line settings, which, while predictable, supports consideration of eribulin as a second-line treatment option.

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.

The Place of Chemotherapy in The Evolving Treatment Landscape for Patients With HR-positive/HER2-negative MBC

Endocrine therapy (ET) for the treatment of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR-positive/HER2-negative) metastatic breast cancer (MBC) has changed markedly over recent years with the emergence of new ETs and the use of molecularly targeted agents. Cytotoxic chemotherapy continues, however, to have an important role in these patients and it is important to maximize its efficacy while minimizing toxicity to optimize outcomes. This review examines current HR-positive/HER2-negative MBC clinical guidelines and addresses key questions around the use of chemotherapy in the face of emerging therapeutic options. Specifically, the indications for chemotherapy in patients with HR-positive/HER2-negative MBC and the choice of optimal chemotherapy are discussed.

Clinical usefulness of eribulin as first- or second-line chemotherapy for recurrent HER2-negative breast cancer: a randomized phase II study (JBCRG-19)

Background

Anthracycline (A) or taxane T-based regimens are the standard early-line chemotherapy for metastatic breast cancer (BC). A previous study has shown a survival benefit of eribulin in heavily pretreated advanced/recurrent BC patients. The present study aimed to compare the benefit of eribulin with treatment of physician’s choice (TPC) as first- or second-line chemotherapy for recurrent HER2-negative BC.

Methods

Patients with recurrent HER2-negative BC previously receiving anthracycline and taxane AT-based chemotherapy in the adjuvant or first-line setting were eligible for this open-label, randomized, parallel-group study. Patients were randomized 1:1 by the minimization method to receive either eribulin (1.4 mg/m² on day one and eight of each 21-day cycle) or TPC (paclitaxel, docetaxel, nab-paclitaxel or vinorelbine) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included time to treatment failure (TTF), overall response rate (ORR), duration of response, and safety (UMIN000009886).

Results

Between May 2013 and January 2017, 58 patients were randomized, 57 of whom (26 eribulin and 31 TPC) were analyzed for efficacy. The median PFS was 6.6 months with eribulin versus 4.2 months with TPC (hazard ratio: 0.72 [95% confidence interval (CI), 0.40–1.30], p = 0.276). Median TTF was 6.0 months with eribulin versus 3.6 months with TPC (hazard ratio: 0.66 [95% CI, 0.39–1.14], p = 0.136). Other endpoints were also similar between groups. The most common grade ≥ 3 adverse event was neutropenia (22.2% with eribulin versus 16.1% with TPC).

Conclusions

Eribulin seemed to improve PFS or TTF compared with TPC without statistical significance. Further validation studies are needed.

Clinical Utility of Eribulin Mesylate in the Treatment of Breast Cancer: A Chinese Perspective

Eribulin mesylate, a synthetic derivative of the anti-mitotic agent halichondrin B, has a unique tubulin-based mechanism of action that is distinct from other anti-microtubule agents including taxanes and vinca alkaloids. Consistent with this unique activity, eribulin has shown clinical efficacy in patients with metastatic breast cancer (MBC) that progressed following prior taxane and anthracycline therapy. The evidence presented in this review indicates that eribulin represents a treatment option for patients with HER2-negative metastatic breast cancer. Improved survival outcomes and better tolerability compared with vinorelbine supported the first approval of eribulin in China in 2019; eribulin was approved for women with locally advanced/metastatic HER2-negative breast cancer after treatment failure with at least two chemotherapy regimens, including an anthracycline and a taxane. Eribulin has also shown promising efficacy in patients with HER2-positive advanced breast cancer when used in combination with trastuzumab or pertuzumab, and subgroup analyses from the Phase III clinical trials support the continued evaluation of eribulin in patients with triple-negative disease. The unique non-mitotic effects of eribulin, including vascular remodeling, coupled with its clinical efficacy and safety profile, may permit the broader use of this agent in patients with MBC.

An economic evaluation of eribulin for advanced breast cancer treatment based on the Southeast Netherlands advanced breast cancer registry

Background: In 2013, eribulin was reimbursed under a coverage with evidence development (CED) as third or later chemotherapy line for advanced breast cancer (ABC) patients in the Netherlands because of uncertain cost effectiveness. In 2016, the final decision of reimbursing eribulin was taken without considering the evidence collected during CED research. We analysed the cost effectiveness of eribulin versus non-eribulin chemotherapy, using real-world data.Methods: A three health states (progression-free, progressed disease, dead) partitioned survival model was developed. The SOuth East Netherlands Advanced BREast Cancer (SONABRE) registry informed the effectiveness and costs inputs. Health state utility values were obtained from the literature. Incremental cost-effectiveness ratio (ICER) between the eribulin and matched non-eribulin chemotherapy was estimated. Deterministic and probabilistic sensitivity analyses and scenario analyses were performed. The financial risk (i.e., the expected value of perfect information (EVPI) plus the expected monetary loss (eML) associated with reimbursing eribulin) and budget impact associated with reimbursing eribulin were calculated.Results: Eribulin led to higher health benefits (0.07 quality-adjusted life year (QALY)) and costs (€15,321) compared with non-eribulin chemotherapy. This resulted in an ICER of €220,608. At a €80,000 per QALY threshold, the risk of reimbursing eribulin was €9,791 per patient (EVPI €13, eML €9,778). Scaled up to the Dutch population, the estimated annual budget impact was €1.9 million and the annual risk of reimbursing eribulin was €2.7 million.Conclusion: From a Dutch societal perspective, eribulin is not cost effective when considering its list price as third and later chemotherapy line for ABC patients.

Impact of the number of prior chemotherapy regimens on outcomes for patients with metastatic breast cancer treated with eribulin: A post hoc pooled analysis

In a pivotal phase 3 study (Study 305), eribulin mesylate improved overall survival (OS) in patients with previously treated metastatic breast cancer (MBC) compared with treatment of physician's choice (TPC). This post hoc, pooled subgroup analysis of two phase 3 studies (Study 305 and Study 301) reports the influence of the number of prior chemotherapy regimens (0‐6) on OS in patients with locally advanced/MBC randomized to eribulin versus TPC/capecitabine. Patients with ≤ 3 prior chemotherapies for locally advanced/MBC had longer median OS with eribulin (15.3 months) versus control (13.2 months; hazard ratio, 0.858; P = .01).