Effectiveness of Eribulin in Metastatic Breast Cancer: 10 Years of Real-World Clinical Experience in the United States

Real-world use patterns, effectiveness, and tolerability of sacituzumab govitecan for second-line and later-line treatment of metastatic triple-negative breast cancer in the United States

PURPOSE

Patients with metastatic triple-negative breast cancer (mTNBC) have poor prognosis and limited treatment options. Sacituzumab govitecan (SG), a Trop-2-directed antibody-drug conjugate, is approved for patients with mTNBC who have received ≥ 2 systemic therapies (≥ 1 in the metastatic setting) based on the ASCENT study (NCT02574455). The current study describes real-world SG use and outcomes in patients with mTNBC in the United States.

METHODS

This retrospective, observational study included adult patients with mTNBC from the ConcertAI Patient360™ database who received SG in the second line (2L) and later from April 2020 to May 2022. SG use patterns, effectiveness, and tolerability are described.

RESULTS

This analysis included 230 patients (median age 60 years, 26% Black, 17% with ECOG performance status ≥ 2, 66% in community settings; median of 2 prior lines of treatment in the metastatic setting); median follow-up was 7.2 months. Median (95% CI) real-world overall survival was 10.0 (8.3-11.1) months for all patients and 13.9 (9.8-not estimable) months in the 2L subgroup (n = 77). Granulocyte-colony stimulating factor (G-CSF) was administered concomitantly with SG in 134 (58%) patients; 35 (15%) received G-CSF for the first time. Median (IQR) time from SG start to G-CSF use was 8.5 (8.0-29.0) days. Seventeen (7%) patients discontinued SG due to toxicity.

CONCLUSIONS

Using a real-world, ethnically diverse population of patients with mTNBC presenting with poor prognosis, these data reinforced the findings from ASCENT. In routine clinical practice, SG is an effective treatment in the 2L setting, consistent with treatment guidelines.

Real-world treatment patterns and clinical outcomes in patients treated with eribulin after prior phosphoinositide 3-Kinase inhibitor treatment for metastatic breast cancer

PURPOSE

In 2010, the US Food and Drug Administration approved eribulin for the treatment of metastatic breast cancer (MBC). Since then, the treatment landscape has evolved with many new therapy classes, a more recent one being the small molecule inhibitors of phosphoinositide 3 kinase (PI3K). We sought to characterize the treatment patterns and clinical outcomes of patients with MBC who received eribulin following prior treatment with a PI3K inhibitor.

METHODS

A retrospective cohort study based on medical record review included MBC patients who initiated eribulin between March 2019 and September 2020 following prior treatment with a PI3K inhibitor was conducted. Patient demographics, treatment characteristics, and clinical outcomes were analyzed descriptively. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated from the initiation of eribulin therapy using Kaplan-Meier analyses.

RESULTS

82 eligible patients were included. Patients' median age at eribulin initiation was 62 years; 86.5% had hormone receptor-positive, human epidermal growth factor receptor 2-negative tumors. Eribulin was most often administered in the second or third line (82.9%) in the metastatic setting. Best overall response on eribulin was reported as complete or partial response in 72% of the patients. The median rwPFS was 18.9 months (95% confidence interval [CI], 12.4-not estimable); median OS was not reached. The estimated rwPFS and OS rates at 12 months were 63.3% (95% CI, 50.5-73.7) and 82.6% (95% CI, 72.4-89.3), respectively.

CONCLUSION

Our real-world study suggests that eribulin may be a potential treatment option for MBC patients who fail a prior PI3K inhibitor.

Cost-benefit evaluation of advanced therapy lines in metastatic triple-negative breast cancer in Germany

BACKGROUND

Triple-negative breast cancer (TNBC) is responsible for 10-20% cases of breast cancer and is resulting in rising healthcare costs. Thus, health-economic evaluations are needed to relate clinical outcomes and costs of treatment options and to provide recommendations of action from a health-economic perspective.

METHODS

We investigated the cost-benefit-ratio of approved treatment options in metastatic TNBC in Germany by applying the efficiency frontier approach. These included sacituzumab-govitecan (SG), eribulin, vinorelbine, and capecitabine. Clinical benefit was measured as (i) median overall survival (mOS) and (ii) health-related quality of life (HRQoL) in terms of time to symptom worsening (TSW). To assess medical benefits, literature was systematically reviewed in PubMed for (i) and (ii), respectively. Treatment costs were calculated considering annual direct outpatient treatment costs from a statutory healthcare payer perspective. It was intended that both, (i) and (ii), yield an efficiency frontier.

RESULTS

Annual direct outpatient treatment costs amounted to EUR 176,415.21 (SG), EUR 47,414.14 (eribulin), EUR 13,711.35 (vinorelbine), and EUR 3,718.84 (capecitabine). Systematic literature review of (i) and statistical analysis resulted in OS values of 14.3, 9.56, 9.44, and 7.46 months, respectively. Capecitabine, vinorelbine, and SG are part of the efficiency frontier including OS. The highest additional benefit per additional cost was determined for vinorelbine, followed by SG. Systematic review of (ii) revealed that no TSW data of TNBC patients receiving vinorelbine were available, preventing the presentation of an efficiency frontier including HRQoL.

CONCLUSIONS

Vinorelbine is most cost-effective, followed by SG. Health-economic evaluations support decision-makers to assess treatment options within one indication area. In Germany, the efficiency frontier can provide decision support for the pricing of innovative interventions. Results of our analysis may thus guide reimbursement determination.

Trabectedin and low-dose radiation therapy in patients with advanced leiomyosarcoma

Background and objectives

Dimensional response is an unmet need in second lines of advanced soft tissue sarcomas (STS). Indeed, the three approved drugs, pazopanib, trabectedin, and eribulin, achieved an overall response rate (ORR) of less than 10%. This fact potentially hinders the options for fast symptomatic relief or surgical rescue. The combination of trabectedin plus low-dose radiation therapy (T-XRT) demonstrated a response rate of 60% in phase I/II trial, while real-life data achieved 32.5% ORR, probably due to a more relaxed timing between treatments. These results were obtained in progressing and advanced STS. In this study, the merged databases (trial plus real life) have been analyzed, with a special focus on leiomyosarcoma patients.

Design and methods

As responses were seen in a wide range of sarcoma histologies (11), this study planned to analyze whether leiomyosarcoma, the largest subtype with 26 cases (30.6%) in this series, exhibited a better clinical outcome with this therapeutic strategy. In addition, four advanced and progressing leiomyosarcoma patients, all with extraordinarily long progression-free survival of over 18 months, were collected.

Results

A total of 847 cycles of trabectedin were administered to 85 patients, with the median number of cycles per patient being 7 (1-45+). A trend toward a longer progression-free survival (PFS) was observed in leiomyosarcoma patients with median PFS (mPFS) of 9.9 months [95% confidence interval (CI): 1.1-18.7] versus 5.6 months (95% CI: 3.2-7.9) for the remaining histologies, p = 0.25. When leiomyosarcoma and liposarcoma were grouped, this difference reached statistical significance, probably due to the special sensitivity of myxoid liposarcoma. The mPFS for L-sarcomas was 12.7 months (95% CI: 7-18.5) versus 4.3 months (95% CI: 3.3-5.3) for the remaining histologies, p = 0.001. Cases with long-lasting disease control are detected among leiomyosarcoma patients.

Conclusion

Even when extraordinarily long-lasting responses do exist among leiomyosarcoma patients treated with T-XR, we were unable to demonstrate a significant difference favoring leiomyosarcoma patients in clinical outcomes.

Early Real-World Treatment Patterns and Clinical Outcomes in Patients with Metastatic Breast Cancer Treated with Eribulin After Prior Immuno-Oncology or Antibody-Drug Conjugate Therapy

Introduction

Eribulin was approved by the FDA in 2010 for the treatment of metastatic breast cancer (MBC) in the United States (US). More recently, several immuno-oncology (IO) and antibody-drug conjugate (ADC) regimens have been approved for MBC. We assessed the treatment patterns and clinical outcomes in MBC patients treated with eribulin following treatment with an IO or ADC in US clinical practice.

Materials and Methods

In a retrospective patient medical chart review study, patients with MBC, aged ≥18 years, who initiated eribulin therapy between March 1, 2019, and September 30, 2020, treated with either prior IO or ADC in the metastatic setting were included. Patient demographics, treatment characteristics, and clinical outcomes were analyzed descriptively. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated using Kaplan-Meier analyses.

Results

In the study population (N=143), median age at eribulin initiation was 62 years; 64% were Caucasian, and 67% had triple-negative MBC (TNBC). Eribulin therapy was used in the second to fifth line of therapy in the metastatic setting; median treatment duration was 7.2 months. The overall response rate for eribulin was 59.4%. Median rwPFS and OS from eribulin initiation were 21.4 months (95% CI, 12.9-not estimable [NE]) and 24.2 months (95% CI, 17.5-NE), respectively. In patients with TNBC, median rwPFS and OS from eribulin initiation were 12.0 months (95% CI, 8.8-NE) and 18.3 months (95% CI, 14.9-NE), respectively.

Conclusion

These real-world data provide evidence for the clinical effectiveness outcomes of eribulin treatment among MBC patients previously treated with an IO or ADC.

Eribulin combined with antiangiogenic agents in women with HER2-negative metastatic breast cancer: a retrospective multicenter study

Background

The relative lack of specifically targeted agents for HER2-negative metastatic breast cancer (MBC) makes the need for new agents or combination therapies to maximize clinical benefit while reducing toxicity critical.

Objectives

To retrospectively analyze the efficacy and safety of eribulin combined with antiangiogenic drugs in the treatment of Chinese women with HER2-negative MBC.

Methods

A total of 85 consecutive MBC patients with HER2-negative who were treated with eribulin + antiangiogenic agents between October 2020 and April 2023 in four institutions were retrospectively included in this study. Patients received eribulin 1.4 mg/m2 (day 1 and 8) plus bevacizumab 7.5 mg/kg (day 1, 64 patients) or anlotinib 10 mg daily (day 1-14, 16 patients) or apatinib 250 mg daily (5 patients) on a 21-day cycle until progression or unacceptable toxicity. The primary end-point was progression-free survival (PFS), according to Response Evaluation Criteria in Solid tumors (RECIST) 1.1. Secondary end-points included toxicities, objective response rate (ORR), disease control rate (DCR), and overall survival (OS). Adverse events (AEs) were graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

Results

The study included 85 HER2-negative MBC patients, with 41 patients (48.2%) in the first to second line group and 44 patients (51.8%) in the greater than or equal to third line group. The median age was 54.0 years. Thirty patients in the first to second line group and 14 patients in the greater than or equal to third line group had triple-negative breast cancer (TNBC). The ORR and DCR were 34.1% (29/85) and 75.3% (64/85). The median PFS (mPFS) of total population was 6.0 months (95% CI: 4.3-7.7), and median OS (mOS) was immature. The mPFS was 7.7 and 4.3 months in the first to second and greater than or equal to third line treatment (p = 0.003), respectively. TNBC patients in first to second line therapy showed a significantly longer PFS (6.5 months versus 2.0 months, p = 0.021) compared to greater than or equal to third line. The incidences of cardiovascular toxicity were 29.4% in grades 1-2 and no grades 3-4. Hematologic toxicity (leukopenia and neutropenia) was the most common grade ⩾3 AEs, and AEs were more common in patients in greater than or equal to third line.

Conclusion

The results suggest that eribulin combined with antiangiogenic therapy has a meaningful clinical activity and an acceptable safety profile in HER2-negative MBC.

Effectiveness, safety, and impact on quality of life of eribulin-based therapy in heavily pretreated patients with metastatic breast cancer: A real-world analysis

INTRODUCTION

Eribulin is currently recommended for the treatment of patients with metastatic breast cancer (MBC) pre-treated with taxanes and anthracyclines. The aim of the present study was to evaluate the effectiveness and safety of eribulin and its impact on health-related quality of life in heavily pre-treated patients with MBC.

METHODS

Data from MBC patients who had received eribulin-based therapy at Beijing Cancer Hospital between January 2020 and July 2022 were analyzed retrospectively. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), adverse effects (AEs) and health-related quality of life (HRQoL) were assessed.

RESULTS

Data from 118 patients who had received eribulin to treat MBC were included. Median PFS was 4.2 months and median OS had not been reached. The ORR was 13.6% (16/118) and DCR was 75.4% (89/118). The median PFS in patients who received eribulin in second-line (26/118), third-line (29/118), or fourth-line or later (63/118) was 4.5, 4.2, and 3.9 months, respectively. The median OS in patients who received eribulin in third- or later line (n = 92) was 14.1 months. Patients who received eribulin combination therapy had a significantly longer median PFS compared with those who received eribulin monotherapy (4.5 vs. 3.4 months, p = 0.007) and there was a trend towards a longer median OS (not reached vs. 12.1 months). The most common grade 3-4 adverse events were neutropenia (22.9%), leukocytopenia (13.6%) and asthenia/fatigue (8.5%), without significant differences in safety between eribulin monotherapy and combination therapy. Quality of life was similar in patients who received eribulin monotherapy and combination therapy, except for cognitive function and nausea and vomiting symptoms, which were better with combination therapy.

CONCLUSIONS

The present study suggests that eribulin-based therapy is an effective treatment option and well tolerated for heavily pre-treated patients with MBC. Eribulin combination therapy might improve PFS and HRQoL compared with eribulin monotherapy.

Eribulin mesylate induces bone mass loss by promoting osteoclastic bone resorption in mice

Over the past few decades, the clinical outcomes of patients with cancer have significantly improved mostly owing to the development of effective chemotherapeutic treatments. However, chronic health conditions such as bone mass loss and risk of fragility fractures caused by chemotherapy have also emerged as crucial issues in patients treated for cancer. In this study, we aimed to understand the effect of eribulin mesylate (ERI), a microtubule-targeting agent currently used to treat metastatic breast cancer and certain subtypes of advanced sarcomas, on bone metabolism in mice. The administration of ERI reduced bone mass in mice, mainly by promoting osteoclast activity. Gene expression analysis of skeletal tissues revealed no change in the expression levels of the transcripts for RANK ligand, one of the master regulators of osteoclastogenesis; however, the transcript levels of osteoprotegerin, which neutralizes RANK ligand, were significantly reduced in ERI-treated mice compared with those in vehicle-treated controls, indicating a relative increase in RANK ligand availability after ERI treatment. In line with the increased bone resorption in ERI-treated mice, we found that zoledronate administration effectively suppressed bone loss in these mice. These results reveal a previously unrecognized effect of ERI on bone metabolism and suggest the application of bisphosphonates for patients with cancer undergoing treatment with ERI.

Combinatorial Strategies With PD-1/PD-L1 Immune Checkpoint Blockade for Breast Cancer Therapy: Mechanisms and Clinical Outcomes

As an emerging antitumor strategy, immune checkpoint therapy is one of the most promising anticancer therapies due to its long response duration. Antibodies against the programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) axis have been extensively applied to various cancers and have demonstrated unprecedented efficacy. Nevertheless, a poor response to monotherapy with anti-PD-1/PD-L1 has been observed in metastatic breast cancer. Combination therapy with other standard treatments is expected to overcome this limitation of PD-1/PD-L1 blockade in the treatment of breast cancer. In the present review, we first illustrate the biological functions of PD-1/PD-L1 and their role in maintaining immune homeostasis as well as protecting against immune-mediated tissue damage in a variety of microenvironments. Several combination therapy strategies for the combination of PD-1/PD-L1 blockade with standard treatment modalities have been proposed to solve the limitations of anti-PD-1/PD-L1 treatment, including chemotherapy, radiotherapy, targeted therapy, antiangiogenic therapy, and other immunotherapies. The corresponding clinical trials provide valuable estimates of treatment effects. Notably, several combination options significantly improve the response and efficacy of PD-1/PD-L1 blockade. This review provides a PD-1/PD-L1 clinical trial landscape survey in breast cancer to guide the development of more effective and less toxic combination therapies.

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.

Regulation of microtubule dynamics, mechanics and function through the growing tip

Microtubule dynamics and their control are essential for the normal function and division of all eukaryotic cells. This plethora of functions is, in large part, supported by dynamic microtubule tips, which can bind to various intracellular targets, generate mechanical forces and couple with actin microfilaments. Here, we review progress in the understanding of microtubule assembly and dynamics, focusing on new information about the structure of microtubule tips. First, we discuss evidence for the widely accepted GTP cap model of microtubule dynamics. Next, we address microtubule dynamic instability in the context of structural information about assembly intermediates at microtubule tips. Three currently discussed models of microtubule assembly and dynamics are reviewed. These are considered in the context of established facts and recent data, which suggest that some long-held views must be re-evaluated. Finally, we review structural observations about the tips of microtubules in cells and describe their implications for understanding the mechanisms of microtubule regulation by associated proteins, by mechanical forces and by microtubule-targeting drugs, prominently including cancer chemotherapeutics.

Eribulin in brain metastases of breast cancer: outcomes of the EBRAIM prospective observational trial

Background: Eribulin shows some activity in controlling brain metastasis in breast cancer. Methods: This observational, multicenter study evaluated brain disease control rates, survival and safety in patients with brain metastatic breast cancer treated with eribulin in clinical practice. Results: A total of 34 patients were enrolled (mean age 49 years, 91% with visceral metastases) and 29 were evaluable for brain disease. Fourteen achieved disease control and showed a longer time without progression: 10 months (95% CI: 2.3-17.7) versus 4 months (95% CI: 3.3-4.7) in the control group (p = 0.029). Patients with clinical benefits at 6 months had longer survival. Leukopenia and neutropenia were the most frequent grade 3-4 toxicities. Conclusion: Eribulin confirms its effectiveness in patients with brain metastatic breast cancer. Further studies on larger cohorts are needed to confirm the results.