In vivo imaging of eribulin-induced reoxygenation in advanced breast cancer patients: a comparison to bevacizumab

Comparison of Lipid and Water Contents by Time-domain Diffuse Optical Spectroscopy and Dual-energy Computed Tomography in Breast Cancer Patients

We previously compared time-domain diffuse optical spectroscopy (TD-DOS) with magnetic resonance imaging (MRI) using various water/lipid phantoms. However, it is difficult to conduct similar comparisons in the breast, because of measurement differences due to modality-dependent differences in posture. Dual-energy computed tomography (DECT) examination is performed in the same supine position as a TD-DOS measurement. Therefore, we first verified the accuracy of the measured fat fraction of fibroglandular tissue in the normal breast on DECT by comparing it with MRI in breast cancer patients (n = 28). Then, we compared lipid and water signals obtained in TD-DOS and DECT from normal and tumor-tissue regions (n = 16). The TD-DOS breast measurements were carried out using reflectance geometry with a source–detector separation of 3 cm. A semicircular region of interest (ROI), with a transverse diameter of 3 cm and a depth of 2 cm that included the breast surface, was set on the DECT image. Although the measurement area differed between the modalities, the correlation coefficients of lipid and water signals between TD-DOS and DECT were rs = 0.58 (p < 0.01) and rs = 0.90 (p < 0.01), respectively. These results indicate that TD-DOS captures the characteristics of the lipid and water contents of the breast.

Microtubule-Targeting Drugs: More than Antimitotics

Nature has yielded numerous compounds that bind to tubulin/microtubules and disrupt microtubule function. Even with the advent of targeted therapies for cancer, natural products and their derivatives that target microtubules are some of the most effective drugs used in the treatment of solid tumors and hematological malignancies. For decades, these drugs were thought to work solely through their ability to inhibit mitosis. Accumulating evidence demonstrates that their actions are much more complex, in that they also have significant effects on microtubules in nondividing cells that inhibit a diverse range of signaling events important for carcinogenesis. The abilities of these drugs to inhibit oncogenic signaling likely underlies their efficacy, especially in solid tumors. In this review, we describe the role of microtubules in cells, the proliferation paradox of cells in culture as compared to cancers in patients, and evidence that microtubule-targeting drugs inhibit cellular signaling pathways important for tumorigenesis. The potential mechanisms behind differences in the clinical indications and efficacy of these natural-product-derived drugs are also discussed. Microtubules are an important target for structurally diverse natural products, and a fuller understanding of the mechanisms of action of these drugs will promote their optimal use.

Significant Association Between Low Baseline Neutrophil-to-Lymphocyte Ratio and Improved Progression-free Survival of Patients With Locally Advanced or Metastatic Breast Cancer Treated With Eribulin But Not With Nab-Paclitaxel

INTRODUCTION

Although eribulin and nab-paclitaxel are chemotherapy agents widely used for locally advanced or metastatic breast cancer (MBC), their predictive factors remain unknown. Because the absolute neutrophil-to-lymphocyte ratio (NLR) is a significant prognostic factor for early-stage breast cancer, we investigated its usefulness in terms of the eribulin or nab-paclitaxel treatment efficacy for MBC.

PATIENTS AND METHODS

A total of 85 patients with MBC treated with eribulin (n = 59) or nab-paclitaxel (n = 26) were recruited. NLR values were collected at baseline, after 1 cycle, after 2 cycles, and at the end of treatment. The NLR cutoff value was set at 3.

RESULTS

The progression-free survival (PFS) of patients with an NLR < 3 at baseline (median, 242 days; n = 24) was significantly better than that of patients with an NLR of ≥ 3 (median, 98 days; n = 35; hazard ratio, 0.37, 95% confidence interval, 0.18-0.71; P = .0032). Similarly, the overall survival was marginally significantly better in patients with an NLR < 3 who were treated with eribulin (P = .058). However, the NLR was not significantly associated with PFS or overall survival for patients treated with nab-paclitaxel. No significant association was found between the NLR during treatment and PFS in the eribulin group. The significance of the NLR for the efficacy of eribulin was consistent, irrespective of estrogen receptor status, previous anthracycline or endocrine use, and the number of previous chemotherapy regimens.

CONCLUSION

A low NLR at baseline was significantly associated with improved PFS in patients treated with eribulin but not in those treated with nab-paclitaxel. Therefore, the baseline NLR might be clinically useful for selecting patients who would benefit from eribulin.

MORAb-202, an Antibody-Drug Conjugate Utilizing Humanized Anti-human FRα Farletuzumab and the Microtubule-targeting Agent Eribulin, has Potent Antitumor Activity

Microtubule-targeting agents (MTA) have been investigated for many years as payloads for antibody-drug conjugates (ADC). In many cases, these ADCs have shown limited benefits due to lack of efficacy or significant toxicity, which has spurred continued investigation into novel MTA payloads for next-generation ADCs. In this study, we have developed ADCs using the MTA eribulin, a derivative of the macrocyclic polyether natural product halichondrin B, as a payload. Eribulin ADCs demonstrated in vitro potency and specificity using various linkers and two different conjugation approaches. MORAb-202 is an investigational agent that consists of the humanized anti-human folate receptor alpha (FRA) antibody farletuzumab conjugated via reduced interchain disulfide bonds to maleimido-PEG₂-valine-citrulline-p-aminobenzylcarbamyl-eribulin at a drug-to-antibody ratio of 4.0. MORAb-202 displayed preferable biophysical properties and broad potency across a number of FRA-positive tumor cell lines as well as demonstrated improved specificity in vitro compared with farletuzumab conjugated with a number of other MTA payloads, including MMAE, MMAF, and the reducible maytansine linker-payload sulfo-SPDB-DM4. A single-dose administration of MORAb-202 in FRA-positive human tumor cell line xenograft and patient-derived tumor xenograft models elicited a robust and durable antitumor response. These data support further investigation of MORAb-202 as a potential new treatment modality for FRA-positive cancers, using the novel MTA eribulin as a payload.

Outcome of eribulin as a late treatment line for Thai metastatic breast cancer patients

Background

We report the safety and efficacy of eribulin as a late treatment line in Thai metastatic breast cancer (MBC) patients.

Patients and methods

A total of 30 MBC patients treated with eribulin between January 2014 and January 2017 were retrospectively analyzed. The patients were scheduled to receive 1.4 mg/m² of eribulin on day 1, day 8 and subsequently every 21 days. All patients had previously received at least three chemotherapy regimens including anthracycline and taxane. Response rate and progression-free survival (PFS) were analyzed.

Results

The median age was 56 years (range, 40–74 years), with a median follow-up time of 5.7 months (range, 0.2–25 months). The overall response rate was 30% (nine patients): four patients had triple-negative breast cancer, three patients had luminal B breast cancer and two patients had luminal A breast cancer. The median PFS was 2.9 months (range, 0.2–14 months). The median number of previous chemotherapy regimens was 4 (range, 3–9). Univariate analysis showed that the number of regimens (four or fewer) prior to eribulin was statistically associated with superior PFS (P = 0.009). Multivariate analysis also showed similar statistical association between number of prior regimens (four or fewer) and better PFS adjusted by age group (≥50 years; hazard ratio = 1.29; 95% CI: 1.0–1.65; P = 0.046). There were no toxic deaths or grade 4 toxicities. Nine (30%) patients had grade 3 anemia toxicities, and the other common toxicities were leukopenia and neutropenia. Four (13%) patients required dose reduction and 16 (53%) patients required dose delay because of toxicities.

Conclusion

Eribulin is an effective drug for heavily pretreated MBC patients with tolerable toxicities. The benefit was superior in patients who received fewer than four previous chemotherapy regimens.

Phase II trial of eribulin mesylate as a first- or second-line treatment for locally advanced or metastatic breast cancer: a multicenter, single-arm trial

Background

Eribulin mesylate is currently indicated as a sequential monotherapy to be administered after two chemotherapeutic regimens, including anthracycline and taxane treatments, for treatment of metastatic breast cancer. This open-label, multicenter phase II study was designed to evaluate the efficacy and safety of eribulin as a first- or second-line treatment for patients with metastatic breast cancer.

Methods

The primary objective was to determine the overall response rate. Secondary objectives were to evaluate progression-free survival and the safety profile. Patients were scheduled to receive eribulin mesylate 1.4 mg/m² intravenously on days 1 and 8 of a 21-day cycle. Patients received the study treatment unless disease progression, unacceptable toxicity, or a request to discontinue from the patient and/or investigator eventuated.

Results

Between December 2012 and September 2015, 32 patients with metastatic breast cancer were enrolled at 10 participating clinical institutions in Japan, and toxicity and response rates were evaluated. The overall response rate was 43.8% (95% confidence interval [CI] 26.5–61.0). The clinical benefit and tumor control rates were 56.3% (95% CI 39.0–73.5) and 78.1% (95% CI 63.8–92.5), respectively. Median progression-free survival was 8.3 months (95% CI 7.1–9.4). A subgroup analysis did not identify any factors affecting the efficacy of eribulin. The most common adverse events were neutropenia (71.9%), alopecia (68.7%), and peripheral neuropathy (46.9%). As a first- or second-line therapy, eribulin showed sufficient efficacy for metastatic breast cancer compared with taxane and capecitabine treatment in previous clinical trials. The safety profile of eribulin was acceptable.

Conclusions

Eribulin may be another option for first-line chemotherapeutic regimens for metastatic breast cancer.

Trial registrations

This trial was retrospectively registered at the University Hospital Medical Information Network (UMIN) Clinical Trial Registry (ID number: UMIN000010334).

Date of trial registration: April 1st, 2013.

Concomitant administration of radiation with eribulin improves the survival of mice harboring intracerebral glioblastoma

Glioblastoma is the most common and devastating type of malignant brain tumor. We recently found that eribulin suppresses glioma growth in vitro and in vivo and that eribulin is efficiently transferred into mouse brain tumors at a high concentration. Eribulin is a non‐taxane microtubule inhibitor approved for breast cancer and liposarcoma. Cells arrested in M‐phase by chemotherapeutic agents such as microtubule inhibitors are highly sensitive to radiation‐induced DNA damage. Several recent case reports have demonstrated the clinical benefits of eribulin combined with radiation therapy for metastatic brain tumors. In this study, we investigated the efficacy of a combined eribulin and radiation treatment on human glioblastoma cells. The glioblastoma cell lines U87MG, U251MG and U118MG, and SJ28 cells, a patient‐derived sphere culture cell line, were used to determine the radiosensitizing effect of eribulin using western blotting, flow cytometry and clonogenic assay. Subcutaneous and intracerebral glioma xenografts were generated in mice to assess the efficacy of the combined treatment. The combination of eribulin and radiation enhanced DNA damage in vitro. The clonogenic assay of U87MG demonstrated the radiosensitizing effect of eribulin. The concomitant eribulin and radiation treatment significantly prolonged the survival of mice harboring intracerebral glioma xenografts compared with eribulin or radiation alone (P < .0001). In addition, maintenance administration of eribulin after the concomitant treatment further controlled brain tumor growth. Aberrant microvasculature was decreased in these tumors. Concomitant treatment with eribulin and radiation followed by maintenance administration of eribulin may serve as a novel therapeutic strategy for glioblastomas.

Experience with eribulin in patients with metastatic breast cancer and associated hepatic impairment: case studies

Hepatic impairment in breast cancer arises from metastatic spread of tumor cells to the liver and signals a poor prognosis. Systemic therapy is the mainstay of treatment. Three women with hepatic dysfunction secondary to breast cancer who were treated with eribulin are presented herein. In the first case, third-line eribulin at the time of acute liver failure due to metastases maintained response for up to 9 months with good tolerability. In the second case, a woman with secondary bone and liver disease had progression-free survival of 5 months to third-line eribulin and, upon rechallenge after a drug holiday, had almost four more months of stable disease. Last, a heavily pretreated patient with secondary bone and hepatic involvement showed a response to fourth-line eribulin.

Study on the progression types of cancer in patients with breast cancer undergoing eribulin chemotherapy and tumor microenvironment

Background

Recently, the concepts of progression due to pre-existing lesions (PPL) and progression due to new metastasis (PNM) have been proposed to differentiate the progression types of treatment-resistant cancers. Previously, the differences between these two progression types did not affect the determination of treatment strategies since both PPL and PNM are classified as progressive disease based on the response evaluation criteria in solid tumors (RECIST) diagnostic criteria. On the other hand, tumor infiltrating lymphocytes (TILs) are effective when used as indicators for monitoring the immune tumor microenvironment (iTME) in the cancer host, and TILs play an important role as biomarkers in predicting prognosis and therapeutic effects. This study focused on the progression types of cancer in patients undergoing eribulin chemotherapy. In addition, the iTME in individuals with PPL and PNM was evaluated using TILs as a marker.

Methods

Of the 52 patients with locally advanced or metastatic breast cancer who underwent chemotherapy with eribulin, 40 remained in the study, and 12 patients were dropout cases. The antitumor effect was evaluated based on the RECIST criteria using version 1.1. TILs were defined as the infiltrating lymphocytes within tumor stroma and were expressed in proportion to the field investigated. In PPL cases, the high-TIL group was considered as type I and the low-TIL group was classified as type II. In PNM cases, the high-TIL group was considered as type III and the low-TIL group was classified as type IV.

Results

In 19 cases, individuals with type I progression had significantly longer progression free survival and overall survival (OS) compared to those with type III progression (p = 0.040, p < 0.001, log-rank). Individuals with type I progression had significantly prolonged survival post progression compared to those with type II progression (p = 0.048, log-rank). A multivariate analysis that validate the effect of OS showed that these were independent factors of good prognosis (p = 0.003; hazard ratio [HR] = 0.065) (p = 0.006; HR = 0.105).

Conclusions

The effects of eribulin chemotherapy suggested that patients with progressive-type breast cancer that proliferates in a good iTME may have a good prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1443-5) contains supplementary material, which is available to authorized users.

Experience with eribulin in triple-negative metastatic breast cancer: case studies

Triple-negative breast cancers are defined as tumors negative for estrogen receptors, progesterone receptors and human EGFR2. These tumors exhibit diverse biological behavior and have a poor prognosis; chemotherapy is the mainstay of treatment. The first case involves a young woman with cerebral and cerebellar metastases who achieved a persistent objective response to fourth-line eribulin. In the second case, a woman who became metastatic during adjuvant therapy with anthracyclines and taxanes, and was refractory to capecitabine + bevacizumab, achieved a partial response and local symptom improvement with eribulin + bevacizumab. Last, a poly-treated patient demonstrated reasonable response and longer progression-free interval on third-line eribulin relative to previous lines of chemotherapy which is unusual in this clinical setting.

Pertuzumab, trastuzumab and eribulin mesylate therapy for previously treated advanced HER2-positive breast cancer: a feasibility study with analysis of biomarkers

The standard treatment for advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer is the triple combination of pertuzumab, trastuzumab and docetaxel, but some patients cannot tolerate taxane. To explore a non-taxane triple therapy, we conducted a feasibility study of pertuzumab, trastuzumab and eribulin mesylate (PTE) therapy for previously treated advanced HER2-positive breast cancer with analyses of quality of life and biomarkers. Ten patients were enrolled, two of whom had a history of docetaxel allergy. The median number of prior regimens was 3. The most common Grade 3 toxicities were leukopenia (70%) and neutropenia (70%). Grade 4 or 5 adverse events were not observed. An improving trend for the Functional Assessment of Cancer Therapy-Breast (FACT-B) score at 3 months was observed. Eight cases were included in the biomarker analysis. The peripheral CD8+ T cell/ CD4+Foxp3+ regulatory T cells (Tregs) ratio was significantly increased (p = 0.039). The frequency of peripheral Tregs was associated with the trastuzumab trough concentration (p = 0.019). In a non-clinical analysis, Eribulin mesylate significantly inhibited Ser473 Akt phosphorylation in PIK3CA wild-type cells and mutated cells. These results suggest that PTE therapy is a feasible and promising option for advanced HER2-positive breast cancer. Further investigation is warranted.

Antitumor effects of eribulin depend on modulation of the tumor microenvironment by vascular remodeling in mouse models

We previously reported that eribulin mesylate (eribulin), a tubulin‐binding drug (TBD), could remodel tumor vasculature (i.e. increase tumor vessels and perfusion) in human breast cancer xenograft models. However, the role of this vascular remodeling in antitumor effects is not fully understood. Here, we investigated the effects of eribulin‐induced vascular remodeling on antitumor activities in multiple human cancer xenograft models. Microvessel densities (MVD) were evaluated by immunohistochemistry (CD31 staining), and antitumor effects were examined in 10 human cancer xenograft models. Eribulin significantly increased MVD compared to the controls in six out of 10 models with a correlation between enhanced MVD levels and antitumor effects (R² = 0.54). Because of increased MVD, we next used radiolabeled liposomes to examine whether eribulin treatment would result in increased tumoral accumulation levels of these macromolecules and, indeed, we found that eribulin, unlike vinorelbine (another TBD) enhanced them. As eribulin increased accumulation of radiolabeled liposomes, we postulated that this treatment might enhance the antitumor effect of Doxil (a liposomal anticancer agent) and facilitate recruitment of immune cells into the tumor. As expected, eribulin enhanced antitumor activity of Doxil in a post‐erlotinib treatment H1650 (PE‐H1650) xenograft model. Furthermore, infiltrating CD11b‐positive immune cells were significantly increased in multiple eribulin‐treated xenografted tumors, and natural killer (NK) cell depletion reduced the antitumor effects of eribulin. These findings suggest a contribution of the immune cells for antitumor activities of eribulin. Taken together, our results suggest that vascular remodeling induced by eribulin acts as a microenvironment modulator and, consequently, this alteration enhanced the antitumor effects of eribulin.

Eribulin in advanced breast cancer: safety, efficacy and new perspectives

Eribulin is a synthetic analog of halichondrin B belonging to microtubule-targeted agents with a distinct mechanism of inhibition of microtubule dynamics. This molecule has multiple nonmitotic effects on tumor biology, exhibiting effects on epithelial-mesenchimal transition and tumor vasculature. We review here preclinical and clinical studies on eribulin. The mitotic and nonmitotic effects together with its favorable safety profile make eribulin a unique drug with high potential in the treatment of metastatic breast cancer. The new emphasis of eribulin mechanism of action on vascular remodeling, microenvironment modifications and reversal of epithelial-mesenchimal transition paves the way to rethinking the use of the drug in an immunological perspective.

Eribulin shows high concentration and long retention in xenograft tumor tissues

Purpose

Eribulin, a synthetic analog of the natural product halichondrin B, is a microtubule dynamics inhibitor. In this study, we report the pharmacokinetic profiles of eribulin in mice, rats, and dogs following intravenous administrations with optimized and validated bio-analytical methods.

Methods

Eribulin was administered at 0.5 and 2 mg/kg in mice, 0.5 and 1 mg/kg in rats, and 0.08 mg/kg in dogs. Tumor and brain penetration of eribulin was also evaluated in LOX human melanoma xenograft models. Concentrations in plasma, tumor, and brain were measured by the LC–MS/MS method.

Results

The profiles of eribulin were characterized by extensive distribution, moderate clearance, and slow elimination in the three species. The pharmacokinetics are linear in mice and rats. In xenograft mice, the penetration into the brain was low, as expected, since eribulin is a P-glycoprotein substrate. In contrast to disposition in brain, the exposure of eribulin was approximately 20–30 times higher in tumor than that in plasma and half-lives were 17.8–35.9 h after both single and multiple dose regimens.

Conclusions

Eribulin was distributed rapidly and eliminated slowly in mice, rats, and dogs. The exposure of eribulin was approximately 20–30 times higher in tumor than in plasma in xenograft mice. These results might be caused by eribulin’s mechanism of action including increased perfusion in tumor by vascular remodeling effect.

Eribulin in advanced liposarcoma and leiomyosarcoma

INTRODUCTION

The heterogeneity of soft tissue sarcomas (STS) presents a formidable management challenge. Consequently, one of the main research goals is to define specific tailored therapy for each histological subtype and to develop a more personalised approach to treatment. The standard first line chemotherapy for advanced STS is doxorubicin, with or without ifosfamide, however, a number of different drugs are emerging as active therapies beyond first-line. Areas covered: Eribulin has recently been approved for advanced liposarcoma, after an anthracycline-containing regimen, demonstrating an overall survival (OS) advantage in liposarcoma and leiomyosarcoma in a randomised Phase III clinical trial. In this manuscript, an overview of the efficacy and safety of eribulin in STS is presented, highlighting different clinical outcomes between histological subtypes and comparing data with other effective drugs used in the treatment of sarcomas. The potential mechanisms of action of eribulin are also described, including its activity as potent microtubule-destabilizing anticancer agent, which has other antitumor biological effects. Expert commentary: Eribulin is highly effective in some STS populations and also has an acceptable toxicity profile. Further studies are required to better understand the precise mechanism of action of this agent and potential role in combination schedules.

Efficacy of eribulin in breast cancer: a short report on the emerging new data

Eribulin is a novel microtubule-targeting agent that is approved for the treatment of patients with locally advanced or metastatic breast cancer who have previously received treatment with an anthracycline and a taxane in either the adjuvant or metastatic setting. Eribulin induces mitotic catastrophe leading to cell death but has other important antitumor effects, including reversal of epithelial–mesenchymal transition and remodeling of the tumor vasculature. Eribulin was licensed for the treatment of advanced breast cancer based on results from two large randomized Phase III clinical trials. Current clinical trials of eribulin for breast cancer are evaluating response to treatment earlier in the patient pathway and in combination with other therapeutic agents. This review provides a short overview of emerging new data on the mode of action of eribulin in breast cancer.