Phase II, Multicenter, Single-arm Trial of Eribulin as First-line Therapy for Patients With Aggressive Taxane-pretreated HER2-Negative Metastatic Breast Cancer: The MERIBEL Study

Eribulin in breast cancer: Current insights and therapeutic perspectives

Eribulin is a non-taxane synthetic analogue approved in many countries as third-line treatment for the treatment of patients with metastatic breast cancer. In addition to its mitotic property, eribulin has non-mitotic properties including but not limited to, its ability to induce phenotypic reversal of epithelial to mesenchymal transition, vascular remodelling, reduction in immunosuppressive tumour microenvironment. Since approval, there has been a surge in studies investigating the application of eribulin as an earlier-line treatment and also in combination with other agents such as immunotherapy and targeted therapy across all breast cancer sub-types, including hormone receptor positive, HER2 positive and triple negative breast cancer, many demonstrating promising activity. This review will focus on the application of eribulin in the treatment of metastatic breast cancer across all subtypes including its role as an earlier-line agent, its toxicity profile, and potential future directions.

A single-arm study design with non-inferiority and superiority time-to-event endpoints: a tool for proof-of-concept and de-intensification strategies in breast cancer

De-escalation trials in oncology evaluate therapies that aim to improve the quality of life of patients with low-risk cancer by avoiding overtreatment. Non-inferiority randomized trials are commonly used to investigate de-intensified regimens with similar efficacy to that of standard regimens but with fewer adverse effects (ESMO evidence tier A). In cases where it is not feasible to recruit the number of patients needed for a randomized trial, single-arm prospective studies with a hypothesis of non-inferiority can be conducted as an alternative. Single-arm studies are also commonly used to evaluate novel treatment strategies (ESMO evidence tier B). A single-arm design that includes both non-inferiority and superiority primary objectives will enable the ranking of clinical activity and other parameters such as safety, pharmacokinetics, and pharmacodynamics data. Here, we describe the statistical principles and procedures to support such a strategy. The non-inferiority margin is calculated using the fixed margin method. Sample size and statistical analyses are based on the maximum likelihood method for exponential distributions. We present example analyses in metastatic and adjuvant settings to illustrate the usefulness of our methodology. We also explain its implementation with nonparametric methods. Single-arm designs with non-inferiority and superiority analyses are optimal for proof-of-concept and de-escalation studies in oncology.

Eribulin as first-line treatment in older patients with advanced breast cancer: A multicenter phase II trial [SAKK 25/14]

INTRODUCTION

Standard-dose eribulin mesylate (1.4 mg/m² d1 + 8) achieves clinical benefit rates of 26%-52% in patients with metastatic breast cancer (mBC). <10% of patients in the registration trial were ≥ 70 years old; dose reductions were common in these older patients.

MATERIALS AND METHODS

This single-arm phase II trial explored the efficacy of reduced starting dosing of first-line eribulin at 1 mg/m² d1 + 8 q3 weeks in patients with mBC aged ≥70 years. The primary endpoint was a disease control rate (DCR) ≥55%. The secondary endpoints were objective response (OR), progression-free survival (PFS), overall survival (OS), and patient-reported neurotoxicity.

RESULTS

Overall, 77 patients were accrued; their median age was 76 years and Eastern Cooperative Oncology Group performance status was 0-1 in 90%. The DCR was 40% (90% confidence interval [CI]: 31-50); therefore, the primary endpoint was not reached. The overall response rate was 22% (95%CI: 13-33), median PFS 5.4 months (95%CI: 4.5-7.7), and median OS 16.1 months (95%CI: 13.5-26.9). Dose modifications were necessary in 35% of patients. In nine patients, more than fifteen cycles were given; 48 patients (62%) experienced at least one grade 3 toxicity. Median patient-reported neurotoxicity scores remained stable for at least fifteen cycles. The main reason for treatment discontinuation was disease progression (57%).

DISCUSSION

We report the first prospective data on first-line eribulin in older patients. The reduced starting dose of 1.1 mg/m² was safe, with prolonged treatment and DC achieved in a considerable proportion of patients (but less than the 55% assumed), without cumulative neurotoxicity. The reduced dose was apparently within the range of the minimal effective dose, as shown by the efficacy lack in patients requiring further dose reductions. Thus, our results do not support the approach of a reduced starting dose for older patients.

Effectiveness of eribulin as first-line or second-line chemotherapy for HER2-negative hormone-resistant advanced or metastatic breast cancer: findings from the multi-institutional, prospective, observational KBCRN A001: E-SPEC study

BACKGROUND

The optimal positioning of eribulin treatment remains unclear. This study aimed to investigate the effectiveness of eribulin administration as first- and second-line chemotherapy in patients with endocrine-resistant advanced or metastatic breast cancer (AMBC) in the real-world clinical setting.

METHODS

This multi-institutional prospective cohort study enrolled patients with triple-negative AMBC or estrogen receptor-positive AMBC refractory to at least one previous endocrine therapy. The overall survival (OS) from the start of first-line (OS1) and second-line chemotherapy (OS2) was assessed. Data analysis included real-world chemotherapy sequences of first- to third-line chemotherapy regimens. The adjusted hazard ratio (HR) with 95% confidence interval (CI) for treatment regimen comparison was calculated using a stratified proportional hazards model.

RESULTS

Among 201 patients enrolled, 180 were included in the final analysis. Eribulin was administered as first- and second-line chemotherapy to 46 (26.6%) and 70 (47.9%) patients, respectively. Median OS1 and OS2 were 2.25 (95% CI 1.07-2.68) and 1.75 (95% CI, 1.28-2.45) years for first- and second-line eribulin, respectively. Oral 5-FU followed by eribulin had a numerically longer OS1 (2.84 years) than the other sequences. Among patients who proceeded to second-line or later chemotherapy, the median OS1 for those treated with anthracycline or taxane as first- or second-line (n = 98) was 2.56 years (95% CI 2.27-2.74), while it was 2.87 years (95% CI 2.20-4.32) for those who avoided anthracycline and taxane as first- and second-line (n = 48) (adjusted HR, 1.20; 95% CI 0.70-2.06). In the exploratory analysis, OS1 was 2.55 (95% CI 2.14-2.75) and 2.91 years (95% CI 2.61-4.32) for those aged < 65 and ≥ 65 years, respectively (adjusted HR of ≥ 65, 0.91; 95% CI 0.56-1.46).

CONCLUSIONS

Eribulin or oral 5-FU administration in first- and second-line chemotherapy without anthracycline/taxane was acceptable in the real-world setting.

TRIAL REGISTRATION

This study is registered with Clinical Trials.gov (NCT 02,551,263).

Breast cancer treatment-related cardiovascular disturbances: advocacy for a watchful attitude in this never-ending story

INTRODUCTION

Thanks to the emergence of new therapeutics, prognosis and outcome of breast cancer patients (any subtype) have improved significantly. This raises the issue of the interactions and side effects related to the use of multiple drugs. Thus, to decide on a treatment, the optimal benefit risk-ratio should be carefully watched as toxicities such as cardiac ones effect on long-term survival. Indeed, nowadays in France, cardiovascular diseases rank first as causes of death in women.

AREAS COVERED

This non-exhaustive review aims to report the currently available data on cardiac side effects caused by the use of emerging drugs in breast cancer, in localized or metastatic diseases alike. We will focus on HER2-inhibitors, cyclin-dependent-kinase 4/6 and PARP inhibitors, chemotherapy and immunotherapy, before discussing the means of prevention.

EXPERT OPINION

Although this issue has largely been studied, the recent emergence of new drugs emphasizes the necessity for oncologists to adapt their practice to a multidisciplinary model that includes cardio-oncology.

Effectiveness and safety of eribulin for human epidermal growth factor receptor 2 negative metastatic breast cancer in a real-world population

BACKGROUND

Eribulin's clinical benefit remains unclear; so, studies analyzing its effectiveness in routine clinical practice are interesting.

PATIENTS AND METHODS

This is a multicenter, retrospective study including patients with human epidermal growth factor receptor-2-negative metastatic breast cancer which assesses effectiveness and safety of eribulin.

RESULTS

A total of 140 women were included, with a median age of 57 years. The median overall survival and progression-free survival were 8.8 (95% confidence interval: 6.1-11.4) and 2.8 months (95% confidence interval: 2.5-3.1), respectively. For patients with hormonal receptor expression, a significantly longer progression-free survival was observed: 3.4 (95%confidence interval: 2.3-4.5) versus triple negative: 2.0 (95%confidence interval: 1.7-2.3) months, p = 0.003. Also, those who had received capecitabine prior to eribulin had a higher median overall survival than those who had not received it (9.5 months, 95% confidence interval: 6.6-12.5 vs. 4.8 months, 95% confidence interval: 3.4-6.2; p = 0.001). When only triple-negative patients were included, median overall survival was 6.5 (95% confidence interval: 0.1-16.2) for those who had received previous capecitabine versus 4.3 (95% confidence interval: 2.8-5.8) months for patients who had not received it; p =0.006. The safety profile of eribulin was adequate.

CONCLUSION

Effectiveness of eribulin in a real-life human epidermal growth factor receptor-2--negative population is lower than that observed in clinical trials. Its benefit seems to be higher in patients with hormonal receptor expression and patients who had received capecitabine prior to eribulin. The safety profile of eribulin is adequate.

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.

Inclusion of non-inferiority analysis in superiority-based clinical trials with single-arm, two-stage Simon's design

INTRODUCTION

Non-inferiority (NI) analysis is not usually considered in the early phases of clinical development. In some negative phase II trials, a post-hoc NI analysis justified additional phase III trials that were successful. However, the risk of false positive achievements was not controlled in these early phase analyses. We propose to preplan NI analyses in superiority-based Simon's two-stage designs to control type I and II error rates.

METHODS

Simulations have been proposed to assess the control of type I and II errors rates with this method. A total of 12,768 two-stage Simon's design trials were constructed based on different assumptions of rejection response probability, desired response probability, type I and II errors, and NI margins. P-value and type II error were calculated with stochastic ordering using Uniformly Minimum Variance Unbiased Estimator. Type I and II errors were simulated using the Monte Carlo method. The agreement between calculated and simulated values was analyzed with Bland-Altman plots.

RESULTS

We observed the same level of agreement between calculated and simulated type I and II errors from both two-stage Simon's superiority designs and designs in which NI analysis was allowed. Different examples has been proposed to explain the utility of this method.

CONCLUSION

Inclusion of NI analysis in superiority-based single-arm clinical trials may be useful for weighing additional factors such as safety, pharmacokinetics, pharmacodynamic, and biomarker data while assessing early efficacy. Implementation of this strategy can be achieved through simple adaptations to existing designs for one-arm phase II clinical trials.

First-line bevacizumab and eribulin combination therapy for HER2-negative metastatic breast cancer: Efficacy and safety in the GINECO phase II ESMERALDA study

Purpose

Combining bevacizumab with paclitaxel significantly improves progression-free survival (PFS) versus paclitaxel alone in HER2-negative metastatic breast cancer (MBC). Eribulin is active and tolerable in pretreated MBC. To assess whether eribulin may offer a more tolerable yet effective combination partner for bevacizumab, we evaluated a bevacizumab/eribulin combination regimen as first-line therapy for MBC.

Methods

In this single-arm phase II study, patients with histologically confirmed HER2-negative MBC and no prior chemotherapy for MBC received eribulin 1.23 mg/m² on days 1 and 8 every 3 weeks for ≥6 cycles plus bevacizumab 15 mg/kg on day 1 every 3 weeks until disease progression. The primary endpoint was non-progression rate at 1 year. Secondary endpoints included objective response rate (ORR), PFS, and safety.

Results

The median age of the 61 treated female patients was 59 years, 16% had triple-negative MBC, 30% had ≥3 metastatic sites, and 71% had received prior (neo)adjuvant chemotherapy. Patients received a median of six eribulin and nine bevacizumab cycles. The non-progression rate at 1 year was 32% (95% confidence interval [CI]: 20–43%), ORR was 47% (95% CI: 34–60%), and median PFS was 8.3 months (95% CI: 7.0–9.6 months). The only grade ≥3 clinical adverse events in >5% of patients were hypertension (39%), neutropenia (26%), thrombosis (10%), and paresthesia/dysesthesia (7%).

Conclusion

First-line eribulin/bevacizumab combination therapy showed interesting activity in MBC with an acceptable safety profile, including a particularly low incidence of high-grade neuropathy.

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A single-arm study evaluated first-line bevacizumab–eribulin for HER2-negative MBC.

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The primary endpoint was non-progression rate at 1 year.

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The 1-year non-progression rate was 32% (95% CI 20–43%); median PFS was 8.3 months.

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Grade ≥3 clinical AEs in >10% comprised hypertension (39%) and neutropenia (26%).

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Eribulin–bevacizumab showed interesting activity and acceptable safety in MBC.

Eribulin in Triple Negative Metastatic Breast Cancer: Critic Interpretation of Current Evidence and Projection for Future Scenarios

Triple negative breast cancer (TNBC) is characterized by distinctive biological features that confer an aggressive clinical behavior. In TNBC patients, the absence of well-defined driver pathways such as hormonal receptor expression or hyperactivation of the human epidermal growth factor receptor 2 (HER2) significantly reduce the spectrum of therapeutic options, which are currently mainly confined to chemotherapy. Thus far, median overall survival for patients with metastatic TNBC is about 9-12 months with conventional cytotoxic agents. However, the heterogeneity recently revealed at a gene expression level inside the TNBC family may help inform therapeutic decisions concerning the use of chemotherapy and hopefully lead the way to novel targeted options that include immunotherapy. Eribulin, a halichondrin class antineoplastic drug, is currently recommended for treatment of HER2 negative metastatic or recurrent breast cancer (BC) previously exposed to anthracyclines and taxanes, also for patients with a TNBC. It is currently indicated from the second line of treatment. In this review, we aim to analyze a wide range of cumulated evidence on eribulin use in TNBC including preclinical studies, intervention and observational clinical trials. Data from the real-world setting and the emerging evidence increasingly substantiating the rationale for combinations with new generation treatment strategies, e.g., PARP-inhibitors, immune checkpoint inhibitors, will be also discussed.