Pharmacodynamics (PD) and pharmacokinetics (PK) of E7389 (eribulin, halichondrin B analog) during a phase I trial in patients with advanced solid tumors: a California Cancer Consortium trial

An intracerebral microdialysis study to determine the neuropharmacokinetics of eribulin in patients with metastatic or primary brain tumors

PURPOSE

Eribulin is an inhibitor of microtubule dynamics. It is not as highly protein bound as the taxanes and is less vulnerable to extrusion by P-glycoprotein in the blood-brain barrier (BBB). These features predict that eribulin could play an active role in managing brain tumors. Indeed, the small amount of published clinical data indicates eribulin may have some efficacy against breast cancer brain metastases. To better understand the potential of eribulin for treating brain tumors, we performed an intracerebral microdialysis study to determine the neuropharmacokinetics of eribulin in cancer patients undergoing tumor resection.

METHODS

After tumor removal, two microdialysis catheters were inserted into peritumoral brain tissue. Approximately 24 h after surgery, a single dose of eribulin 1.4 mg/m2 was administered intravenously. Dialysate samples were collected continuously for 72 h, with plasma samples collected in parallel. Eribulin concentrations were analyzed by tandem mass spectrometry.

RESULTS

Dialysate samples from 12 intracerebral microdialysis catheters placed in 7 study participants were included in the analysis. A statistically significant difference was observed between eribulin concentrations in brain tissue where BBB was disrupted versus intact, with a difference in mean maximum concentrations on log2 scale of 3.37 (std err = 0.59, p-value = 0.005). Nonetheless, overall brain to plasma ratios of eribulin only ranged from 0.13 to 1.99%.

CONCLUSION

Although we could detect higher concentrations of eribulin in brain tissue where BBB was disrupted, intracerebral eribulin levels were not sufficient to predict eribulin would have consistent clinically meaningful activity against tumors in the brain.

CLINICALTRIALS

GOV IDENTIFIER

NCT02338037 (January 9, 2015).

Immunomodulatory Effects of Halichondrin Isolated from Marine Sponges and Its Synthetic Analogs in Oncological Applications

Marine natural products comprise unique chemical structures and vast varieties of biological activities. This review aims to summarize halichondrin, a marine natural product, and its synthetic analogs along with its therapeutic properties and mechanisms. Halichondrin and its analogs, derived from marine sponges, exhibit potent antineoplastic properties, making them promising candidates for cancer therapeutics. These compounds, characterized by their complex molecular structures, have demonstrated significant efficacy in inhibiting microtubule dynamics, leading to cell cycle arrest and apoptosis in various cancer cell lines. Several types of halichondrins such as halichondrins B, C, norhalichondrin B, and homohalichondrin B have been discovered with similar anticancer and antitumor characteristics. Since naturally available halichondrins show hurdles in synthesis, recent advancements in synthetic methodologies have enabled the development of several halichondrin analogs, such as E7389 (eribulin), which have shown improved therapeutic indices. Eribulin has shown excellent immunomodulatory properties by several mechanisms such as reprogramming tumor microenvironments, facilitating the infiltration and activation of immune cells, and inhibiting microtubule dynamics. Despite promising results, challenges remain in the synthesis and clinical application of these compounds. This review explores the mechanisms underlying the immunomodulatory activity of halichondrin and its analogs in cancer therapy, along with their clinical applications and potential for future drug development.

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) methods for the therapeutic drug monitoring of cytotoxic anticancer drugs: An update

In the era of precision medicine, there is increasing evidence that conventional cytotoxic agents may be suitable candidates for therapeutic drug monitoring (TDM)- guided drug dosage adjustments and patient's tailored personalization of non-selective chemotherapies. To that end, many liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) assays have been developed for the quantification of conventional cytotoxic anticancer chemotherapies, that have been comprehensively and critically reviewed. The use of stable isotopically labelled internal standards (IS) of cytotoxic drugs was strikingly uncommon, accounting for only 48 % of the methods found, although their use could possible to suitably circumvent patients' samples matrix effects variability. Furthermore, this approach would increase the reliability of cytotoxic drug quantification in highly multi-mediated cancer patients with complex fluctuating pathophysiological and clinical conditions. LC-MS/MS assays can accommodate multiplexed analyses of cytotoxic drugs with optimal selectivity and specificity as well as short analytical times and, when using stable-isotopically labelled IS for quantification, provide concentrations measurements with a high degree of certainty. However, there are still organisational, pharmacological, and medical constraints to tackle before TDM of cytotoxic drugs can be more largely adopted in the clinics for contributing to our ever-lasting quest to improve cancer treatment outcomes.

Real-world effect of bevacizumab and eribulin on metastatic breast cancer using a propensity score matching analysis

Bevacizumab and eribulin are novel agents for the treatment of HER2-negative metastatic breast cancer (MBC); however, the choice between bevacizumab and eribulin for MBC can be difficult. The present study aimed to compare two treatment strategies, eribulin followed by bevacizumab and paclitaxel (BEV + PTX) versus BEV + PTX followed by eribulin, to determine whether the order of administration affects the outcome of MBC in the real world. A total of 180 patients who started BEV + PTX and eribulin treatment for HER2-negative MBC from August 2011 to June 2018 were selected. Of these, 84 patients were treated with both BEV + PTX and eribulin sequentially. To evaluate the influence of the sequential order, the efficacy of BEV + PTX followed by eribulin (B-E arm) was compared to treatment with the reverse sequence (E-B arm). The propensity score matching method (PSMA) was used to improve the robustness of the findings from the present study. A total of 60 cases analyzed received BEV + PTX or eribulin as either first- or second-line treatment. In the entire cohort, the median time to failure of strategy (TFS) was 16.8 and 9.9 months in the B-E and E-B arms, respectively [hazard ratio (HR)=0.515, 95% CI 0.298-0.889, P=0.017). A similar HR was derived from PSMA for TFS. Using PSMA, TFS was 16.9 and 9.9 months in the B-E and E-B arms, respectively (HR=0.491, 95% CI 0.253-0.952, P=0.031). These results suggested that when both bevacizumab and eribulin are administered, bevacizumab should be administered first and eribulin should be administered later to ensure the most effective use of each drug.

Efficacy of Eribulin in Soft Tissue Sarcomas

Soft tissue sarcomas are a highly heterogenous group of tumors with limited systemic therapy options. Eribulin, a synthetic analogue of halichondrin B, is a potent mitotic inhibitor. A phase 3 trial of previously treated advanced Liposarcoma and Leiomyosarcoma demonstrated superiority of eribulin to dacarbazine. Eribulin appears to be particularly effective for liposarcomas. It has also been shown to be a safe and effective treatment alternative to doxorubicin in patients where doxorubicin is contraindicated. From retrospective studies, eribulin has demonstrated efficacy in patients with angiosarcoma, pleomorphic sarcomas, synovial sarcomas, rhabdomyosarcomas, angiosarcomas, and myxofibrosarcomas. Future areas of development include liposomal eribulin, which may provide increased efficacy and lower toxicity, and delineation of biomarkers of response and resistance, allowing better selection of patients for treatment.

Development and validation of an LC-MS/MS generic assay platform for small molecule drug bioanalysis

AIM

We developed a generic high-performance liquid chromatography mass spectrometry approach for quantitation of small molecule compounds without availability of isotopically labelled standard.

METHODS

The assay utilized 50 μL of plasma and offers 8 potential internal standards (IS): acetaminophen, veliparib, busulfan, neratinib, erlotinib, abiraterone, bicalutamide, and paclitaxel. Preparation consisted of acetonitrile protein precipitation and aqueous dilution in a 96 well-plate format. Chromatographic separation was achieved with a Kinetex C18 reverse phase (2.6 μm, 2 mm x 50 mm) column and a gradient of 0.1 % formic acid in acetonitrile and water over an 8 min run time. Mass spectrometric detection was performed on an AB SCIEX4000QTRAP with electrospray, positive-mode ionization. Performance of the generic approach was evaluated with seven drugs (LMP744, olaparib, cabozantinib, triapine, ixabepilone, berzosertib, eribulin) for which validated assays were available.

RESULTS

The 8 IS covered a range of polarity, size, and ionization; eluted over the range of chromatographic retention times; were quantitatively extracted; and suffered limited matrix effects. The generic approach proved to be linear for test drugs evaluated over at least 3 orders of magnitude starting at 1-10 ng/mL, with extension of assay ranges with analyte isotopologue MRM channels. At a bias of less than 16 % and precision within 15 %, the assay performance was acceptable.

CONCLUSION

The generic approach has become a useful tool to further define the pharmacology of drugs studied in our laboratory and may be utilized as described, or as starting point to develop drug-specific assays with more extensive performance characterization.

Antibody-drug conjugate MORAb-202 exhibits long-lasting antitumor efficacy in TNBC PDx models

The antibody‐drug conjugate (ADC) MORAb‐202, consisting of farletuzumab paired with a cathepsin B–cleavable linker and eribulin, targets folate receptor alpha (FRA), which is frequently overexpressed in various tumor types. MORAb‐202 was highly cytotoxic to FRA‐positive cells in vitro, with limited off‐target killing of FRA‐negative cells. Furthermore, MORAb‐202 showed a clear in vitro bystander cytotoxic effect in coculture with FRA‐positive/negative cells. In vivo antitumor efficacy studies of MORAb‐202 were conducted with a single administration of MORAb‐202 in triple‐negative breast cancer (TNBC) patient–derived xenograft (PDx) models expressing low and high levels of FRA. MORAb‐202 exhibited durable efficacy proportional to tumor FRA expression. Toxicology studies (Q3Wx2) in nonhuman primates suggested that the major observed toxicity of MORAb‐202 is hematologic toxicity. Overall, these findings support the concept that MORAb‐202 represents a promising investigational ADC for the treatment of TNBC patients.

Evaluation of Eribulin Combined with Irinotecan for Treatment of Pediatric Cancer Xenografts

PURPOSE

Vincristine combined with camptothecin derivatives showed synergy in preclinical pediatric cancer models, and the combinations are effective in treatment of childhood solid tumors. We determined whether the synergy between vincristine and irinotecan extends to eribulin, another microtubule inhibitor.

EXPERIMENTAL DESIGN

Vincristine or eribulin, alone or combined with irinotecan, was studied in 12 xenograft models. Tumor regression and time to event were used to assess antitumor activity. Pharmacodynamic studies and RNA sequencing (RNA-seq) were conducted 24 and 144 hours after single-agent or combination treatment. Effects on vascular development were studied in Matrigel plugs implanted in mice. The interaction between binary combinations was examined in vitro.

RESULTS

Eribulin combined with irinotecan was more effective than vincristine-irinotecan in 6 of 12 models. Pharmacodynamic markers induced by eribulin (phospho-histone H3) and irinotecan (γ-H2A.X) were abrogated in combination-treated tumors. The predominant RNA-seq signature in combination-treated tumors was activation of the TP53 pathway with increased nuclear TP53. Massive apoptosis was observed 24 hours only after treatment with the eribulin combination. In vitro, neither combination showed interaction using combination index analysis. Eribulin alone and the combination caused alterations in developing vasculature.

CONCLUSIONS

The eribulin combination is very active in these xenograft models, but not synergistic in vitro. The combination reduced pharmacodynamic markers indicative of single-agent mechanisms but in tumors, dramatically activated the TP53 pathway. Although a mechanism for in vivo synergy requires further study, it is possible that eribulin-induced inhibition of microtubule dynamics enhances irinotecan-induced nuclear accumulation of TP53, leading to rapid cell death.

Electrolyte Disorders Induced by Antineoplastic Drugs

The use of antineoplastic drugs has a central role in treatment of patients affected by cancer but is often associated with numerous electrolyte derangements which, in many cases, could represent life-threatening conditions. In fact, while several anti-cancer agents can interfere with kidney function leading to acute kidney injury, proteinuria, and hypertension, in many cases alterations of electrolyte tubular handling and water balance occur. This review summarizes the mechanisms underlying the disturbances of sodium, potassium, magnesium, calcium, and phosphate metabolism during anti-cancer treatment. Platinum compounds are associated with sodium, potassium, and magnesium derangements while alkylating agents and Vinca alkaloids with hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Novel anti-neoplastic agents, such as targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, immunomodulators, mammalian target of rapamycin), can induce SIADH-related hyponatremia and, less frequently, urinary sodium loss. The blockade of epidermal growth factor receptor (EGFR) by anti-EGFR antibodies can result in clinically significant magnesium and potassium losses. Finally, the tumor lysis syndrome is associated with hyperphosphatemia, hypocalcemia and hyperkalemia, all of which represent serious complications of chemotherapy. Thus, clinicians should be aware of these side effects of antineoplastic drugs, in order to set out preventive measures and start appropriate treatments.

The safety of eribulin for the treatment of metastatic breast cancer

Introduction: Eribulin mesylate is a highly potent anticancer agent approved for use in pretreated metastatic breast cancer (MBC). Clinical trials of eribulin in MBC have demonstrated activity against this tumor type, and a phase 3 study in patients with MBC previously treated with an anthracycline and a taxane showed a significant increase in overall survival (OS) with eribulin versus control regimens. Areas covered: This review presents overviews of the development of eribulin, its pharmacology, and its efficacy in MBC. A detailed review of its safety profile is presented, and the safety of eribulin is compared with other agents commonly used to treat MBC. Expert opinion: As eribulin is the only drug shown to improve OS in patients with pretreated MBC, it is an important treatment option for many patients. Eribulin is currently considered a second-line (Europe) or third-line (United States) therapy, and studies have been examining use in the first-line setting. The use of eribulin in combination with other therapies is beginning to be explored because its manageable safety profile makes it an ideal combination-treatment partner. Emerging eribulin combination-treatment data suggest a manageable toxicity profile, and eribulin is set to be a key drug for the treatment of MBC in the future.

Phase 1 dose-finding and pharmacokinetic study of eribulin-liposomal formulation in patients with solid tumours

BACKGROUND

This phase 1 study examined the safety, tolerability, pharmacokinetics and preliminary efficacy of eribulin-liposomal formulation (eribulin-LF) in patients with advanced solid tumours.

METHODS

Eligible patients with ECOG PS 0-1 were treated with eribulin-LF either on day 1 every 21 days (Schedule 1), or on days 1 and 15 every 28 days (Schedule 2). Doses ranged from 1.0 to 3.5 mg/m2, with dose escalation in a 3 + 3 design. The dose-expansion phase evaluated eribulin-LF in select tumour types.

PRIMARY OBJECTIVES

maximum tolerated dose (MTD) and the recommended dose/schedule of eribulin-LF.

RESULTS

Totally, 58 patients were enroled (median age = 62 years). The MTD was 1.4 mg/m2 (Schedule 1) or 1.5 mg/m2 (Schedule 2), the latter dose selected for the dose-expansion phase. Dose-limiting toxicity (DLTs) in Schedule 1: hypophosphatemia and increased transaminase levels. DLTs in Schedule 2: stomatitis, increased alanine aminotransferase, neutropenia and febrile neutropenia. The pharmacokinetic profile of eribulin-LF showed a similar half-life to that of eribulin (~30 h), but with a 5-fold greater maximum serum concentration and a 40-fold greater area-under-the-curve. Eribulin-LF demonstrated clinical activity with approximately 10% of patients in both schedules achieving partial responses.

CONCLUSIONS

Eribulin-LF was well tolerated with a favourable pharmacokinetic profile. Preliminary evidence of clinical activity in solid tumours was observed.

Systemic treatments for metastatic urothelial carcinoma

INTRODUCTION

Urothelial carcinoma is one of the most common cancers in the western world and, until recently, had limited therapeutic options. The contemporary advancement of immune checkpoint inhibitors (ICI) has heralded a new era for these patients and represents a major shift in the evolving treatment landscape.

AREAS COVERED

This article provides a comprehensive summary of the currently available treatments for metastatic urothelial carcinoma (mUC). The authors also review ongoing, phase-III studies with novel therapeutic targets and highlight recent insights into tumor biology that may help better understand the disease.

EXPERT OPINION

The treatment landscape for first-line therapy of mUC continues to include platinum-based chemotherapy for patients who are eligible. While the approval of ICI has changed the management in those who are post-platinum or platinum-ineligible, the wider use of ICI in the first-line setting requires further clarity given recent FDA announcements. Maintaining the remarkable progress in mUC may depend upon ongoing phase-III studies evaluating treatment options beyond ICI. Better prognostication and identification of those unlikely to respond to ICI remain important unanswered questions, particularly as this class of agents moves further along the disease spectrum of non-metastatic UC.

Pharmacodynamic analysis of eribulin safety in breast cancer patients using real-world postmarketing surveillance data

Postmarketing surveillance is useful to collect safety data in real-world clinical settings. In this study, we applied postmarketing real-world data on a mechanistic model analysis for neutropenic profiles of eribulin in patients with recurrent or metastatic breast cancer. Demographic and safety data were collected using an active surveillance method from eribulin-treated recurrent or metastatic breast cancer patients. Changes in neutrophil counts over time were analyzed using a mechanistic pharmacodynamic model. Pathophysiological factors that might affect the severity of neutropenia were investigated, and neutropenic patterns were simulated for different treatment schedules. Clinical and laboratory data were collected from 401 patients (5199 neutrophil count measurements) who had not received granulocyte colony-stimulating factor and were eligible for pharmacodynamic analysis. The estimated mean parameters were as follows: mean transit time = 104.5 h, neutrophil proliferation rate constant = 0.0377 h-1 , neutrophil elimination rate constant = 0.0295 h-1 , and linear coefficient of drug effect = 0.0413 mL/ng. Low serum albumin levels and low baseline neutrophil counts were associated with severe neutropenia. The probability of grade ≥3 neutropenia was predicted to be 69%, 27%, and 27% for patients on standard, biweekly, and triweekly treatment scenarios, respectively, based on virtual simulations using the developed pharmacodynamic model. In conclusion, this is the first application of postmarketing surveillance data to a model-based safety analysis. This analysis of safety data reflecting authentic clinical settings will provide useful information on the safe use and potential risk factors of eribulin.

A phase 1 study of eribulin mesylate (E7389), a novel microtubule-targeting chemotherapeutic agent, in children with refractory or recurrent solid tumors: A Children's Oncology Group Phase 1 Consortium study (ADVL1314)

BACKGROUND

Eribulin mesylate is a novel anticancer agent that inhibits microtubule growth, without effects on shortening, and promotes nonproductive tubulin aggregate formation. We performed a phase 1 trial to determine the dose-limiting toxicities (DLTs), maximum tolerated or recommended phase 2 dose (MTD/RP2D), and pharmacokinetics (PK) of eribulin in children with refractory or recurrent solid (excluding central nervous system) tumors.

METHODS

Eribulin was administered intravenously on days 1 and 8 in 21-day cycles. Three dose levels (1.1, 1.4, and 1.8 mg/m2 /dose) were evaluated using the rolling six design with additional patients enrolled into a PK expansion cohort at the MTD. PK samples were obtained following the day 1, cycle 1 dose.

RESULTS

Twenty-three patients, ages 3-17 (median 14) years were enrolled; 20 were evaluable for toxicity. DLTs occurred in 0/6 and 1/6 subjects at the 1.1 and 1.4 mg/m2 /dose, respectively. One subject at the 1.4 mg/m2 /dose had grade 4 neutropenia and grade 3 fatigue. At the 1.8 mg/m2 /dose, 2/5 subjects experienced dose-limiting (grade 4) neutropenia. Grade 3/4 non-DLTs included lymphopenia and hypokalemia, while low-grade toxicities included anorexia and nausea. No episodes of grade > 2 corrected QT interval prolongation or peripheral neuropathy were reported. Eribulin pharmacokinetic parameters were highly variable; the median elimination half-life was 39.6 (range 24.2-96.4) hr. A partial response was observed in one patient (Ewing sarcoma).

CONCLUSIONS

Eribulin was well tolerated in children with refractory or recurrent solid tumors with neutropenia identified as the primary DLT. The RP2D of eribulin is 1.4 mg/m2 /dose on days 1 and 8 of a 21-day cycle.

Eribulin inhibits the growth of small cell lung cancer cell lines alone and with radiotherapy

OBJECTIVES

Small cell lung cancer (SCLC) patients of all stages are treated with etoposide and cisplatin or carboplatin with or without surgery or chest radiotherapy. Initial response rates are ≥70% however the majority of patients relapse and are resistant to additional therapies due to pan-resistance to these salvage therapies. Therefore, new treatments are urgently needed. The non-taxane microtubule inhibitor eribulin has produced responses in heavily pretreated breast cancer patients. We evaluated the efficacy of eribulin alone and in combination with radiation in a panel of SCLC cell lines established from patients prior to or after receiving chemotherapy and or radiation.

MATERIAL AND METHODS

Growth inhibition by eribulin alone, radiation alone and the combination was assessed by MTS assay and clonogenic survival. Eribulin induced cell cycle arrest was evaluated by FACS. Apoptosis was evaluated by using the Caspase-GLO 3/7 luminescent plate assay and by the Vybrant apoptosis assay with analysis by FACS.

RESULTS

Eribulin mesylate inhibited the growth of all 17-SCLC lines at concentrations of ≤10 nM which is a clinically achievable dose. Growth inhibition was not significantly different between cell lines established prior to or after chemotherapy (p = .5). Concurrent eribulin + radiation induced a greater G2-M arrest, an increase in apoptotic cells and increased growth inhibition over radiation alone.

CONCLUSIONS

Eribulin was highly active alone and in combination with radiation in treatment naïve SCLC lines and lines established from previously treated patients. In vivo pre-clinical studies of eribulin alone and in combination with radiation should be considered in SCLC cell lines.

Advances in the treatment of soft tissue sarcoma: focus on eribulin

Eribulin mesylate is a synthetic derivative of halichondrin B isolated from a marine sponge. Its mechanism of action is through microtubule inhibition, which is different from that of taxanes. Eribulin has been approved for the treatment of metastatic breast cancer and more recently for non-operable or metastatic liposarcoma in patients who have received prior anthracycline chemotherapy. The major side effects of eribulin are bone marrow suppression including neutropenia, leukopenia, anemia, and fatigue/weakness, which can be well managed. In this article, we reviewed evidence from the latest published data on eribulin and its use in the treatment of soft tissue sarcomas. We explored the drug’s mechanism of action, pharmacodynamics, pharmacokinetics, and metabolism. Lastly, we reviewed all preclinical studies as well as clinical trials that investigated 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.

Proceedings of the 3rd Annual Albert Institute for Bladder Cancer Research Symposium

The Third Annual Albert Institute Bladder Symposium was held on September 8–10th, 2016, in Denver Colorado. Participants discussed several critical topics in the field of bladder cancer: 1) Best practices for tissue analysis and use to optimize correlative studies, 2) Modeling bladder cancer to facilitate understanding and innovation, 3) Targeted therapies for bladder cancer, 4) Tumor phylogeny in bladder cancer, 5) New Innovations in bladder cancer diagnostics. Our understanding of and approach to treating urothelial carcinoma is undergoing rapid advancement. Preclinical models of bladder cancer have been leveraged to increase our basic and mechanistic understanding of the disease. With the approval of immune checkpoint inhibitors for the treatment of advanced urothelial carcinoma, the treatment approach for these patients has quickly changed. In this light, molecularly-defined subtypes of bladder cancer and appropriate pre-clinical models are now essential to the further advancement and appropriate application of these therapeutic improvements. The optimal collection and processing of clinical urothelial carcinoma tissues samples will also be critical in the development of predictive biomarkers for therapeutic selection. Technological advances in other areas including optimal imaging technologies and micro/nanotechnologies are being applied to bladder cancer, especially in the localized setting, and hold the potential for translational impact in the treatment of bladder cancer patients. Taken together, advances in several basic science and clinical areas are now converging in bladder cancer. These developments hold the promise of shaping and improving the clinical care of those with the disease.

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.

Electrolyte disorders associated with the use of anticancer drugs

The use of anticancer drugs is beneficial for patients with malignancies but is frequently associated with the occurrence of electrolyte disorders, which can be hazardous and in many cases fatal. The review presents the electrolyte abnormalities that can occur with the use of anticancer drugs and provides the related mechanisms. Platinum-containing anticancer drugs induce hypomagnesemia, hypokalemia and hypocalcemia. Moreover, platinum-containing drugs are associated with hyponatremia, especially when combined with large volumes of hypotonic fluids aiming to prevent nephrotoxicity. Alkylating agents have been linked with the occurrence of hyponatremia [due to syndrome of inappropriate antidiuretic hormone secretion (SIADH)] and Fanconi's syndrome (hypophosphatemia, aminoaciduria, hypouricemia and/or glucosuria). Vinca alkaloids are associated with hyponatremia due to SIADH. Epidermal growth factor receptor monoclonal antibody inhibitors induce hypomagnesemia, hypokalemia and hypocalcemia. Other, monoclonal antibodies, such as cixutumumab, cause hyponatremia due to SIADH. Tyrosine kinase inhibitors are linked to hyponatremia and hypophosphatemia. Mammalian target of rapamycin inhibitors induce hyponatremia (due to aldosterone resistance), hypokalemia and hypophosphatemia. Other drugs such as immunomodulators or methotrexate have been also associated with hyponatremia. The administration of estrogens at high doses, streptozocin, azacitidine and suramin may induce hypophosphatemia. Finally, the drug-related tumor lysis syndrome is associated with hyperphosphatemia, hyperkalemia and hypocalcemia. The prevention of electrolyte derangements may lead to reduction of adverse events during the administration of anticancer drugs.

Patient Management with Eribulin in Metastatic Breast Cancer: A Clinical Practice Guide

Eribulin, an antimicrotubule chemotherapeutic agent, is approved for the treatment of pretreated metastatic breast cancer (mBC) based on the positive outcomes of phase II and phase III clinical trials, which enrolled mainly Western patients. Eribulin has recently been approved in an increasing number of Asian countries; however, there is limited clinical experience in using the drug in certain countries. Therefore, we established an Asian working group to provide practical guidance for eribulin use based on our clinical experience. This paper summarizes the key clinical trials, and the management recommendations for the reported adverse events (AEs) of eribulin in mBC treatment, with an emphasis on those that are relevant to Asian patients, followed by further elaboration of our eribulin clinical experience. It is anticipated that this clinical practice guide will improve the management of AEs resulting from eribulin treatment, which will ensure that patients receive the maximum treatment benefit.