Phase III open-label randomized study of eribulin mesylate versus capecitabine in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline and a taxane

Pooled analyses of eribulin in metastatic breast cancer patients with at least one prior chemotherapy

Eribulin is indicated in the EU for advanced/metastatic breast cancer patients following ≥1 prior chemotherapy for advanced disease, and anthracycline and taxane in adjuvant/metastatic setting. We pooled 1644 patients from two phase III trials and found that eribulin significantly increased survival versus control, particularly in some subgroups of interest like HER2- and triple-negative disease.

Background

Based on data from two multicenter, phase III clinical trials (Studies 301 and 305), eribulin (a microtubule dynamics inhibitor) is indicated in the European Union (EU) for patients with locally advanced or metastatic breast cancer (MBC) after ≥1 prior chemotherapy for advanced disease, including an anthracycline and a taxane in either the adjuvant or metastatic setting. Data from Studies 305 and 301 were pooled to investigate the efficacy of eribulin in various subgroups of patients who matched the EU label, including those with human epidermal growth factor receptor 2 (HER2)-negative and triple-negative disease.

Patients and methods

In Study 305 (NCT00388726), patients were randomized 2:1 to eribulin mesylate 1.4 mg/m² (equivalent to eribulin 1.23 mg/m² [expressed as free base]) intravenously on days 1 and 8 every 21 days] or treatment of physician's choice after 2–5 prior chemotherapies (≥2 for advanced disease), including an anthracycline and a taxane (in early/advanced setting). In Study 301 (NCT00337103), patients were randomized 1:1 to eribulin (as above) or capecitabine (1.25 g/m² orally twice daily on days 1–14 every 21 days) following ≤3 prior chemotherapies (≤2 for advanced disease), including an anthracycline and a taxane. Efficacy end points were investigated in the intent-to-treat population and subgroups, pooled as discussed above.

Results

Overall, 1644 patients were included (eribulin: 946; control: 698); baseline characteristics were well matched. Overall survival was significantly longer with eribulin versus control (P < 0.01), as were progression-free survival and clinical benefit rate (both P < 0.05). Significant survival benefits with eribulin versus control were observed in a wide range of patient subgroups, including HER2-negative or triple-negative disease (all P < 0.05).

Conclusion

Our findings underline the survival benefit achieved by eribulin used according to EU label in the overall MBC population and in various subgroups of interest, including patients with HER2-negative and triple-negative disease.

Review of the Reporting of Survival Analyses within Randomised Controlled Trials and the Implications for Meta-Analysis

BACKGROUND

Meta-analysis is a growing approach to evidence synthesis and network meta-analysis in particular represents an important and developing method within Health Technology Assessment (HTA). Meta-analysis of survival data is usually performed using the individual summary statistic-the hazard ratio (HR) from each randomised controlled trial (RCT).

OBJECTIVES

The objectives of this study are to: (i) review the methods and reporting of survival analyses in oncology RCTs; and (ii) assess the suitability and relevance of survival data reported in RCTs for inclusion into meta-analysis.

METHODS

Five oncology journals were searched to identify Phase III RCTs published between April and July 2015. Eligible studies included those that analysed a survival outcome.

RESULTS

Thirty-two RCTs reporting survival outcomes in cancer populations were identified. None of the publications reported details relating to a strategy for statistical model building, the goodness of fit of the final model, or final model validation for the analysis of survival outcomes. The majority of studies (88%) reported the use of Cox proportional hazards (PH) regression to analyse survival endpoints. However, most publications failed to report the validation of the statistical models in terms of the PH assumption.

CONCLUSIONS

This review highlights deficiencies in terms of reporting the methods and validity of survival analyses within oncology RCTs. We support previous recommendations to encourage authors to improve the reporting of survival analyses in journal publications. We also recommend that the final choice of a statistical model for survival should be informed by goodness of model fit to a given dataset, and that model assumptions are validated. The failure of trial investigators and statisticians to investigate the PH for RCT survival data is likely to result in clinical decisions based on inappropriate methods. The development of alternative approaches for the meta-analysis of survival outcomes when the PH assumption is implausible is required if valid clinical decisions are to be made.

Safety of eribulin mesylate and concomitant radiotherapy for metastatic breast cancer: a single-center experience

Aim: This study evaluates, for the first time, the safety of eribulin in metastatic breast cancer patients concomitantly treated with palliative radiotherapy (RT). Patients & materials: A total of 17 patients were pretreated for metastatic breast cancer. Patients received eribulin mesylate and bone RT. Results: The most frequent grade 3 hematologic adverse events were neutropenia (56%) and anemia (20%). Mean pain score decreased from 2 (baseline) to 0.7 (end of observation). Analgesic score remained stable (1.8 vs 1.6). Bone pain scores dropped within a few weeks and remained below baseline values throughout the analysis. The overall response rate was 29%, and the clinical benefit rate was 59%. Conclusion: Eribulin is characterized by a manageable safety profile also when combined with palliative RT.

Phase II clinical study of eribulin monotherapy in Japanese patients with metastatic breast cancer who had well-defined taxane resistance

No clinical evidence on the efficacy and safety of eribulin monotherapy has been obtained by a prospective clinical study in patients with metastatic breast cancer (MBC) who had well-defined taxane resistance. The present Phase II, multicenter, single-arm, open-label study aimed to obtain the evidence. Japanese female patients, aged 33-74 years who had the metastasis of taxane-resistant and histopathologically confirmed breast cancer, received eribulin mesylate 1.4 mg/m(2) (equivalent to eribulin 1.23 mg/m(2) [expressed as free base]) as a 2- to 5-min intravenous infusion on days 1 and 8 of each 21-day cycle. The primary endpoint was the clinical benefit rate (CBR) [complete response (CR), partial response (PR), and long-term stable disease (LSD) ≥24 weeks]. A total of 51 patients underwent chemotherapy cycles (median 4; range 1-42 cycles). The CBR was 39.2 % (CR 2.0 %; PR 23.5 %; and LSD 13.7 %), and the rate of progressive disease was 49.0 %. The median progression-free survival and the median overall survival were 3.6 months [95 % confidence interval (CI) 2.6-4.6 months] and 11.7 months (95 % CI 9.2-14.2 months), respectively. Grade 3 or greater adverse events were leukopenia (23.5 %), neutropenia (35.3 %), anemia (5.9 %), and febrile neutropenia (7.8 %). The incidences of grade 3 and 4 peripheral sensory neuropathy were 2.0 and 0 %, respectively. Eribulin showed a clinically manageable tolerability profile by dose adjustments or symptomatic treatment. Eribulin was effective and well tolerated in heavily pretreated patients with MBC who had well-defined taxane resistance, thus providing a potential therapeutic option in the clinical settings.

Results of the Belgian expanded access program of eribulin in the treatment of metastatic breast cancer closely mirror those of the pivotal phase III trial

BACKGROUND

Eribulin is a non-taxane microtubule dynamics inhibitor that showed a survival benefit versus treatment of physician's choice in a phase III trial enrolling patients with metastatic breast cancer (MBC).

METHODS

The E7389-G000-398 trial was designed to provide eribulin to MBC patients pre-treated with anthracylines, taxanes and capecitabine. Patient characteristics, efficacy and safety data were collected prospectively. Efficacy and survival analyses were performed using retrospectively collected data of patients treated at a single institution.

RESULTS

One hundred fifty-four patients were enrolled and the median number of previous lines of chemotherapy was 4. The most frequent adverse events were fatigue/asthenia (74%), alopecia (55%), peripheral neuropathy (46%) and neutropenia (43%). Objective response rate (ORR) was 24% in the evaluable population and 14% in patients pre-treated with both taxanes and vinorelbine. In patients with oestrogen receptor (ER)+/human epidermal growth factor receptor 2 (HER2)- MBC, response rate was 29% and 21% with triple-negative disease. Activity was minimal in HER2+ MBC treated with eribulin monotherapy (14% ORR). Median progression-free survival was 3.2 months. Median overall survival was 11.3 months; 77% of patients were alive at 6 months and 43% at 12 months.

CONCLUSION

Eribulin was active in MBC patients with a high tumour burden and predominant visceral disease. Safety profile was similar to what was reported in the phase III trials. Prophylactic granulocyte colony-stimulating factor administration allowed optimal dose intensity and could have contributed to the recorded response rate. Activity is sustained after treatment with taxanes and vinorelbine. The recently investigated combination of eribulin and trastuzumab should lead to higher activity in HER2-positive MBC.

Eribulin versus dacarbazine in previously treated patients with advanced liposarcoma or leiomyosarcoma: a randomised, open-label, multicentre, phase 3 trial

BACKGROUND

A non-randomised, phase 2 study showed activity and tolerability of eribulin in advanced or metastatic soft-tissue sarcoma. In this phase 3 study, we aimed to compare overall survival in patients with advanced or metastatic soft-tissue sarcoma who received eribulin with that in patients who received dacarbazine (an active control).

METHODS

We did this randomised, open-label, phase 3 study across 110 study sites in 22 countries. We enrolled patients aged 18 years or older with intermediate-grade or high-grade advanced liposarcoma or leiomyosarcoma who had received at least two previous systemic regimens for advanced disease (including an anthracycline). Using an interactive voice and web response system, an independent statistician randomly assigned (1:1) patients to receive eribulin mesilate (1·4 mg/m(2) intravenously on days 1 and 8) or dacarbazine (850 mg/m(2), 1000 mg/m(2), or 1200 mg/m(2) [dose dependent on centre and clinician] intravenously on day 1) every 21 days until disease progression. Randomisation was stratified by disease type, geographical region, and number of previous regimens for advanced soft-tissue sarcoma and in blocks of six. Patients and investigators were not masked to treatment assignment. The primary endpoint was overall survival in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT01327885, and is closed to recruitment, but treatment and follow-up continue.

FINDINGS

Between March 10, 2011 and May 22, 2013, we randomly assigned patients to eribulin (n=228) or dacarbazine (n=224). Overall survival was significantly improved in patients assigned to eribulin compared with those assigned to dacarbazine (median 13·5 months [95% CI 10·9-15·6] vs 11·5 months [9·6-13·0]; hazard ratio 0·77 [95% CI 0·62-0·95]; p=0·0169). Treatment-emergent adverse events occurred in 224 (99%) of 226 patients who received eribulin and 218 (97%) of 224 who received dacarbazine. Grade 3 or higher adverse events were more common in patients who received eribulin (152 [67%]) than in those who received dacarbazine (126 [56%]), as were deaths (10 [4%] vs 3 [1%]); one death (in the eribulin group) was considered treatment-related by the investigators.

INTERPRETATION

Overall survival was improved in patients assigned to eribulin compared with those assigned to an active control, suggesting that eribulin could be a treatment option for advanced soft-tissue sarcoma.

FUNDING

Eisai.

In Search of Alternative Antibiotic Drugs: Quorum-Quenching Activity in Sponges and their Bacterial Isolates

Owing to the extensive development of drug resistance in pathogens against the available antibiotic arsenal, antimicrobial resistance is now an emerging major threat to public healthcare. Anti-virulence drugs are a new type of therapeutic agent aiming at virulence factors rather than killing the pathogen, thus providing less selective pressure for evolution of resistance. One promising example of this therapeutic concept targets bacterial quorum sensing (QS), because QS controls many virulence factors responsible for bacterial infections. Marine sponges and their associated bacteria are considered a still untapped source for unique chemical leads with a wide range of biological activities. In the present study, we screened extracts of 14 sponge species collected from the Red and Mediterranean Sea for their quorum-quenching (QQ) potential. Half of the species showed QQ activity in at least 2 out of 3 replicates. Six out of the 14 species were selected for bacteria isolation, to test for QQ activity also in isolates, which, once cultured, represent an unlimited source of compounds. We show that ≈20% of the isolates showed QQ activity based on a Chromobacterium violaceum CV026 screen, and that the presence or absence of QQ activity in a sponge extract did not correlate with the abundance of isolates with the same activity from the same sponge species. This can be explained by the unknown source of QQ compounds in sponge-holobionts (host or symbionts), and further by the possible non-symbiotic nature of bacteria isolated from sponges. The potential symbiotic nature of the isolates showing QQ activity was tested according to the distribution and abundance of taxonomically close bacterial Operational Taxonomic Units (OTUs) in a dataset including 97 sponge species and 178 environmental samples (i.e., seawater, freshwater, and marine sediments). Most isolates were found not to be enriched in sponges and may simply have been trapped in the filtration channels of the sponge at the time of collection. Our results highlight potential for QQ-bioactive lead molecules for anti-virulence therapy both from sponges and the bacteria isolated thereof, independently on the symbiotic nature of the latter.

A Review of Systemic Treatment in Metastatic Triple-Negative Breast Cancer

Patients with breast cancer along with metastatic estrogen and progesterone receptor (ER/PR)- and human epidermal growth factor receptor 2 (HER2)-negative tumors are referred to as having metastatic triple-negative breast cancer (mTNBC) disease. Although there have been many new treatment options approved by the Food and Drug Administration for ER/PR-positive and Her2/neu-amplified metastatic breast cancer, relatively few new agents have been approved for patients with mTNBC. There have been several head-to-head chemotherapy trials performed within the metastatic setting, and much of what is applied in clinical practice is extrapolated from chemotherapy trials in the adjuvant setting, with taxanes and anthracyclines incorporated early on in the patient's treatment course. Select synergistic combinations can produce faster and more significant response rates compared with monotherapy and are typically used in the setting of visceral threat or symptomatic disease. Preclinical studies have implicated other possible targets and mechanisms in mTNBC. Ongoing clinical trials are underway assessing new chemotherapeutic strategies and agents, including targeted therapy and immunotherapy. In this review, we evaluate the standard systemic and future treatment options in mTNBC.

Chemotherapy options for patients suffering from heavily pretreated metastatic breast cancer

The identification of additional chemotherapy agents for anthracycline- and taxane-pretreated advanced breast cancer (ABC) is an urgent medical need. Single agent chemotherapy is most times administered because combined therapy is only associated with modest, if any, improvement in median progression-free survival. Randomized trials failed to show overall survival benefit compared with single agent chemotherapy. We hope to modify the natural history of ABC by the consecutive use of treatments with documented activity in heavily pretreated patients. Quality of life remains an important end point as cure is in general not possible. We first review the activity of the approved and the most frequently used agents in heavily pretreated ABC. Thereafter, the potential role and safety profile of etirinotecan pegol is discussed given the results recently released of a Phase III trial comparing this agent to Treatment of Physician's Choice.

A comparison of toxicity profiles between the lower and standard dose capecitabine in breast cancer: a systematic review and meta-analysis

Capecitabine 1000 mg/m(2) bid × 14 days every 21 days (14/21) has been reported to have similar efficacy but more favorable toxicity profile than the approved dosage of 1250 mg/m(2). However, a dose-toxicity relationship of capecitabine in breast cancer patients has not been fully elucidated. We performed a systematic review and meta-analysis to compare a safety profile between capecitabine starting dose of 1000 and 1250 mg/m(2) bid. Studies were identified using PubMed, ASCO, and San Antonio Breast Cancer Symposium abstract databases through December 2015. Eligible trials included phase II/III trials of capecitabine monotherapy at 1000 or 1250 mg/m(2) bid (14/21) for breast cancer patients that reported adequate safety data for all (grade 1-4) or high (grade 3-4) grade hand foot syndrome (HFS), diarrhea, fatigue, nausea, vomiting, stomatitis, neutropenia, thrombocytopenia, or anemia, as well as dose reductions, treatment discontinuation or treatment-related deaths. The summary incidence was calculated using random-effects models. A total of 4833 patients from 34 trials were included. 1218 and 3615 patients were treated with capecitabine 1000 and 1250 mg/m(2) bid, respectively. A significantly lower incidence of dose reduction (15.9 vs. 39.0 %; P = 0.007), high-grade HFS (12.0 vs. 19.0 %; P = 0.01), diarrhea (5.3 vs. 9.1 %; P = 0.01), and neutropenia (1.8 vs. 7.3 %; P < 0.01), and all-grade neutropenia (5.8 vs. 25.4 %; P = 0.01) was seen in capecitabine 1000 mg/m(2) compared to 1250 mg/m(2). Capecitabine monotherapy at 1000 mg/m(2) bid (14/21) has a clinically meaningful and significantly better toxicity profile compared to 1250 mg/m(2) bid (14/21).

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.

A phase II, multicenter, single-arm trial of eribulin as first-line chemotherapy for HER2-negative locally advanced or metastatic breast cancer

The treatment goals for metastatic breast cancer (MBC) are prolonging survival and improving the quality of life. Eribulin, a non-taxane tubulin inhibitor, demonstrated improved survival in previous studies and also showed mild toxicity when used in late-line therapy for MBC. We conducted a phase II study to investigate the efficacy of eribulin mesylate as the first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)-negative MBC. This was a phase II, open-label, single-arm, multicenter trial conducted in Japan. Patients with HER2-negative MBC received intravenous eribulin (1.4 mg/m² on days 1 and 8 of each 21-day cycle). The primary efficacy outcome was overall response rate (ORR). Secondary outcomes included time to treatment failure, progression-free survival (PFS), overall survival (OS), and safety. A total of 35 patients were enrolled and received a median of 8 (range 1–21) cycles of eribulin therapy. ORR and clinical benefit rate were 54.3 and 62.9 %, respectively. Median PFS was 5.8 months and median OS was 35.9 months. Grade 3 or 4 neutropenia was observed in 63 % of patients. The majority of non-hematological adverse events were mild in severity. The present trial demonstrated that eribulin has antitumor activity comparable with other key established cytotoxic agents with acceptable safety and tolerability. Thus, eribulin as first-line chemotherapy might be beneficial for patients with HER2-negative MBC.

Eribulin in the Management of Advanced Breast Cancer: Implications of Current Research Findings

The search for cytotoxic agents from marine natural products ultimately led to the production of eribulin, which is a synthetic macrocyclic ketone analog of halichondrin B. Eribulin binds to tubulin to induce mitotic arrest and gained approval in Japan in May 2010; it was approved by the US Food and Drug Administration in November 2010 and the European Medicines Agency in March 2011 and was reimbursed by the Taiwan National Health Insurance in December 2014 for patients with metastatic breast cancer who had received at least one anthracycline and one taxane. The recommended regimen for eribulin mesylate comprises intravenous administration of 1.4 mg/m(2) (equivalent to 1.23 mg/m(2) eribulin) over two to five minutes on days 1 and 8 of a three-week cycle. Since 2011, various clinical investigations of eribulin monotherapy with dose or schedule modifications, combined use with other antineoplastic therapeutics, or head-to-head comparisons with specific agents have been performed in the management of advanced breast cancer. Ethnic-specific data from Japan and Korea indicate higher rates (>85%) of grade 3 or 4 neutropenia. Some anecdotal evidence suggests that eribulin can shrink brain and retinal metastases, which warrants further detailed studies. In this review, current observations of the effects of eribulin monotherapy are summarized and eribulin-backbone combination (bio-) chemotherapy is investigated.

"New" metastases are associated with a poorer prognosis than growth of pre-existing metastases in patients with metastatic breast cancer treated with chemotherapy

INTRODUCTION

Progression-free survival (PFS) and overall survival (OS) endpoints often only weakly correlate. This analysis investigates how different progression events impact on OS, using data from two phase 3 studies with eribulin in women with advanced/metastatic breast cancer (MBC).

METHODS

In Study 301, 1102 women with ≤2 prior chemotherapies for advanced/MBC were randomized to eribulin mesylate (1.4 mg/m(2) on days 1 and 8 every 21 days) or capecitabine (1.25 g/m(2) twice daily on days 1-14 every 21 days). Study 305/EMBRACE enrolled 762 patients following two to five prior chemotherapies for advanced/MBC, randomized to eribulin (as above) or treatment of physician's choice. We analyzed OS and PFS post hoc for patients whose disease progressed due to development of "new" metastases, growth of pre-existing lesions, and patients with no reported disease progression.

RESULTS

In both clinical studies, development of new metastases was associated with an increased risk of death (p < 0.0001). The time to development of new metastasis or death was significantly longer with eribulin than the comparator in Study 305 (p = 0.0017), but not in Study 301 (p = 0.46). Significantly longer OS was observed in the eribulin compared with the comparator arm for the new metastases subgroup in Study 301 (p = 0.008), but not in Study 305 (p = 0.16), compared with other progression subgroups.

CONCLUSIONS

Patients with MBC progressing with new metastases have a worse prognosis than those whose disease progresses due to growth of existing lesions or patients with no reported disease progression. These findings have potentially important implications for the interpretation of clinical study data and clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov registration IDs: Study 301: NCT00337103 ; Study 305: NCT00388726 .

SEOM clinical guidelines in metastatic breast cancer 2015

Metastatic breast cancer is essentially an incurable disease. However, recent advances have resulted in a significant improvement of overall survival. The SEOM guidelines are intended to make evidence-based recommendations on how to manage patients with metastatic breast cancer to achieve the best patient outcomes based on a rational use of the currently available therapies. To assign a level of certainty and a grade of recommendation the United States Preventive Services Task Force guidelines methodology was selected as reference.

Body Mass Index and Treatment Outcomes in Metastatic Breast Cancer Patients Treated With Eribulin

Eribulin has shown survival advantage and manageable toxicity in heavily pre-treated metastatic breast cancer (mBC). We assessed whether body mass index (BMI) impacts treatment outcomes in 101 patients treated with eribulin at six Italian Oncologic Centers. BMI was addressed as a categorical variable (18.5-24.9 vs. at least 25). Clinical benefit rate (CBR) was assessed overall and in subgroups defined by BMI, line of therapy (LOT), and hormone receptor (HR) status. Analysis of CBR by LOT and HR status were further stratified by BMI. Survival curves were compared using the Kaplan-Meier method and log-rank test. Predictors of survival were tested in Cox models. Patients treated with eribulin as third line showed greater CBR when their BMI was in the lowest category (77.8 vs. 58.1%, P = 0.03). Median progression free survival (PFS) and overall survival (OS) in normal and overweight patients were 4 (95% CI, 3-5) versus 3 (2.1-4) months, P = 0.02 and 13 (11-15) versus 12 (6-18) months, P = 0.96, respectively. Median PFS and OS in estrogen receptor (ER) positive and negative tumours were 4 (3-5) versus 3 (2-4) months, P = 0.005 and 14 (10-18) versus 7 (4-10), P = 0.02, respectively. In multivariate analyses, BMI impacted PFS at a nearly significant extent (P = 0.05), while ER expression significantly affected PFS and OS (P = 0.01 and 0.02, respectively). No relevant findings emerged concerning toxicity. We found evidence of greater efficacy of eribulin in leaner mBC patients, particularly if given as third line and in ER positive tumors. Further studies are warranted to confirm our findings.

Health-related quality of life in patients with locally advanced or metastatic breast cancer treated with eribulin mesylate or capecitabine in an open-label randomized phase 3 trial

The clinical benefit of eribulin versus capecitabine was evaluated using health-related quality of life (HRQoL) data from a phase 3 randomized trial in patients with pretreated advanced/metastatic breast cancer (ClinicalTrials.gov identifier: NCT00337103). The study population has been described previously (Kaufman et al. in J Clin Oncol 33:594–601, 2015). Eligible patients received eribulin (1.4 mg/m² intravenously on days 1 and 8) or capecitabine (1.25 g/m² orally twice daily on days 1–14) per 21-day cycles. HRQoL was assessed using the European Organisation for Research and Treatment of Cancer (EORTC) Quality-of-life Questionnaire-Core 30 questions (QLQ-C30) and breast module-23 questions (QLQ-BR23), administered at baseline through 24 months, until disease progression or other antitumor treatment initiation. Minimally important difference (MID) and time to symptom worsening (TSW) were investigated. 1062 (96.4 %) Patients completed the EORTC questionnaire at baseline; overall, compliance was ≥80 %. Patients receiving capecitabine versus eribulin had significantly worse symptoms (higher scores) for nausea/vomiting (MID 8; P < 0.05) and diarrhea (MID 7; P < 0.05). Treatment with eribulin versus capecitabine, led to worse systemic therapy side-effects (dry mouth, different tastes, irritated eyes, feeling ill, hot flushes, headaches, and hair loss; MID 10; P < 0.01). Clinically meaningful worsening was observed for future perspective (MID 10; P < 0.05) with capecitabine and for systemic therapy side-effects scale (MID 10; P < 0.01) with eribulin. Patients receiving capecitabine experienced more-rapid deterioration in body image (by 2.9 months) and future perspective (by 1.4 months; P < 0.05) compared with those on eribulin; the opposite was observed for systemic side-effects where patients receiving eribulin experienced more-rapid deterioration than those receiving capecitabine (by 2 months; P < 0.05). Eribulin and capecitabine were found to have similar impact on patient functioning with no overall difference in HRQoL. Patients receiving eribulin reported worse systemic side-effects of chemotherapy but reduced gastrointestinal toxicity compared with capecitabine.

Case Studies in the Management of Metastatic Breast Cancer with Eribulin

Outcomes for triple-negative or hormone-refractory metastatic breast cancer (MBC) are poor and treatment options are limited. Described herein are cases of two women who developed MBC following adjuvant chemotherapy and endocrine therapy for human epidermal growth factor receptor 2 (HER2)-negative ductal carcinoma. Both underwent treatment with fulvestrant, followed by paclitaxel and letrozole or nab-paclitaxel. Following disease progression, both patients started single-agent eribulin mesylate (1.4 mg/m² on Days 1 and 8 of a 21-day cycle). The first patient is currently continuing on eribulin at full dose, despite interruption for hip surgery and the presence of grade 1 neuropathy in the hands and feet. The second patient had a partial response with eribulin, which was sustained for 4 months. She was able to tolerate the full dose of eribulin despite slight worsening of the neuropathy that was present at baseline. Eribulin may be a beneficial option for hormone-refractory MBC with extensive treatment experience.

Etirinotecan pegol (NKTR-102) versus treatment of physician's choice in women with advanced breast cancer previously treated with an anthracycline, a taxane, and capecitabine (BEACON): a randomised, open-label, multicentre, phase 3 trial

BACKGROUND

New options are needed for patients with heavily pretreated breast cancer. Etirinotecan pegol is a long-acting topoisomerase-I inhibitor that prolongs exposure to, but reduces the toxicity of, SN38 (the active metabolite of irinotecan). We assessed whether etirinotecan pegol is superior to currently available treatments for patients with previously treated, locally recurrent or metastatic breast cancer.

METHODS

In this open-label, multicentre, randomised phase 3 study (BEACON; BrEAst Cancer Outcomes with NKTR-102), conducted at 135 sites in 11 countries, patients with locally recurrent or metastatic breast cancer previously treated with an anthracycline, a taxane, and capecitabine (and two to five previous regimens for advanced disease) were randomly assigned (1:1) centrally via an interactive response system to etirinotecan pegol (145 mg/m(2) as a 90-min intravenous infusion every 3 weeks) or single-drug treatment of physician's choice. Patients with stable brain metastases and an Eastern Cooperative Oncology Group performance status of 0-1 were eligible. Randomisation was stratified with a permuted block scheme by region, previous eribulin, and receptor status. After randomisation, patients and investigators were aware of treatment assignments. The primary endpoint was overall survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01492101.

FINDINGS

Between Dec 19, 2011, and Aug 20, 2013, 852 patients were randomly assigned; 429 to etirinotecan pegol and 423 to treatment of physician's choice. There was no significant difference in overall survival between groups (median 12·4 months [95% CI 11·0-13·6] for the etirinotecan pegol group vs 10·3 months [9·0-11·3] for the treatment of physician's choice group; hazard ratio 0·87 [95% CI 0·75-1·02]; p=0·084). The safety population includes the 831 patients who received at least one dose of assigned treatment (425 assigned to etirinotecan pegol and 406 to treatment of physician's choice). Serious adverse events were recorded for 128 (30%) patients treated with etirinotecan pegol and 129 (32%) treated with treatment of physician's choice. Fewer patients in the etirinotecan pegol group had grade 3 or worse toxicity than those in the treatment of physician's choice group (204 [48%] vs 256 [63%]; p<0·0001). The most common grade 3 or worse adverse events were diarrhoea (41 [10%] in the experimental group vs five [1%] in the control group), neutropenia (41 [10%] vs 125 [31%]), and peripheral neuropathy (two [<1%] vs 15 [4%]). Three patients in the etirinotecan pegol group died of treatment-related adverse events (pneumonia, myelodysplastic syndrome, and acute renal failure) and two in the treatment of physician's choice group (neutropenic sepsis and septic shock).

INTERPRETATION

This trial did not demonstrate an improvement in overall survival for etirinotecan pegol compared to treatment of physician's choice in patients with heavily pre-treated advanced breast cancer. The toxicity profile noted in the etirinotecan pegol group differed from that in the control group. In view of the frequency of cross-resistance and overlapping toxicities noted with many available drugs and the need for effective drugs in highly refractory disease, etirinotecan pegol may warrant further research in some subgroups of patients.

FUNDING

Nektar Therapeutics.

Cost Effectiveness Analysis of Eribulin Mesylate as a Treatment for Metastatic Breast Cancer in Spain: Management in the Later Line of Therapy

Background: Two thirds (62%) of metastatic breast cancer (MBC) patients in Western Europe have human epidermal growth factor receptor 2 (HER2)-negative disease, for which anthracyclines and taxanes are recommended as first-line treatments, followed by microtubule-targeting agents such as capecitabine, vinorelbine and/or eribulin. The study objective was to compare the cost-effectiveness of eribulin in Spain as a second-line treatment for HER2-negative MBC with its current status as a third-line treatment for patients who have received capecitabine. Methods: A Markov model was developed from the perspective of the Spanish healthcare system. The model had three health states: Stable; Progression and Death. In Stable, patients received eribulin or: capecitabine and vinorelbine for HER2-negative patients; primary treatment of physician's choice (TPC) for post-capecitabine patients. In Progression, all patients received secondary TPC. Model inputs were overall survival, progression-free survival and costs relating to chemotherapies, grade 3/4 adverse events and healthcare utilization. Sensitivity analyses were conducted to identify uncertainty. Results: As second-line treatment, Eribulin was associated with a greater incremental benefit in life years (LYs) and quality-adjusted life years (QALYs) than capecitabine and vinorelbine. Erubilin as third-line treatment was associated with greater benefit in life years (LYs) and QALYs than TPC. The incremental cost-effectiveness ratios (ICERs) for eribulin were higher in the second-line than the third-line setting in terms of LYs (€35,149 versus €24,884) and QALYs (€37,152 versus €35,484). In both settings, deterministic sensitivity analyses demonstrated that the ICER is most sensitive to the eribulin price. Conclusion: Eribulin is cost-effective as second-line treatment for HER2-negative MBC patients in Spain; albeit, slightly less so than as third-line treatment for MBC patients who have received capecitabine (an ICER per QALY difference of €1,668). This difference may fall within the margin of error for the model and could potentially be addressed by a minor reduction in the eribulin price.

Eribulin monotherapy improved survivals in patients with ER-positive HER2-negative metastatic breast cancer in the real world: a single institutional review

Despite being routinely prescribed worldwide for several years, data regarding the safety, efficacy, and survival benefit of eribulin in clinical settings for the treatment of metastatic breast cancer (MBC) are limited. This retrospective observational study investigated the survival benefit of eribulin compared with conventional chemotherapy regimens in Japanese women with MBC. Women with estrogen receptor (ER)-positive human epidermal growth factor receptor 2 (HER2)-negative (ER+/HER2-) MBC, including unresectable locally advanced breast cancer, treated at a single institution were included in this study. The primary efficacy measure assessed overall survival (OS), and safety was evaluated as the number of grade 3 and 4 adverse events. Of the 293 patients analyzed, 66 received eribulin (eribulin arm) and 227 received conventional chemotherapeutic agents excluding eribulin (noneribulin arm). The median OS from MBC diagnosis in the eribulin arm was 72.1 months (95 % CI 13.3-168.3) compared with 43.3 months (95 % CI 9.1-202.0) in the noneribulin arm [hazard ratio (HR): 0.67, 95 % CI 0.47-0.96; P = 0.025]. No significant differences were noted in OS between eribulin used as a first-/second-line or third-/>third-line treatment for MBC. No patient discontinued eribulin therapy due to AEs. In the eribulin arm, grade 4 neutropenia and grade 3 febrile neutropenia were observed in 8 (12.1 %) and 4 (6.1 %) patients, respectively. Eribulin therapy has a survival benefit in Japanese women with ER+/HER2- MBC in routine clinical practice, with no unexpected grade 3/4 AEs. Interestingly, eribulin might be beneficial as any line therapy for ER+/HER2- MBC.

Tumour biology, metastatic sites and taxanes sensitivity as determinants of eribulin mesylate efficacy in breast cancer: results from the ERIBEX retrospective, international, multicenter study

BACKGROUND

Our retrospective, international study aimed at evaluating the activity and safety of eribulin mesylate (EM) in pretreated metastatic breast cancer (MBC) in a routine clinical setting.

METHODS

Patients treated with EM for a locally advanced or MBC between March 2011 and January 2014 were included in the study. Clinical and biological assessment of toxicity was performed at each visit. Tumour response was assessed every 3 cycles of treatment. A database was created to collect clinical, pathological and treatment data.

RESULTS

Two hundred and fifty-eight patients were included in the study. Median age was 59 years old. Tumours were Hormone Receptor (HR)-positive (73.3 %) HER2-positive (10.2 %), and triple negative (TN, 22.5 %). 86.4 % of the patients presented with visceral metastases, mainly in the liver (67.4 %). Median previous metastatic chemotherapies number was 4 [1-9]. Previous treatments included anthracyclines and/or taxanes (100 %) and capecitabine (90.7 %). Median number of EM cycles was 5 [1-19]. The relative dose intensity was 0.917. At the time of analysis (median follow-up of 13.9 months), 42.3 % of the patients were still alive. The objective response rate was 25.2 % (95 %CI: 20-31) with a 36.1 % clinical benefit rate (CBR). Median time to progression (TTP) and overall survival were 3.97 (95 %CI: 3.25-4.3) and 11.2 (95 %CI: 9.3-12.1) months, respectively. One- and 2-year survival rates were 45.5 and 8.5 %, respectively. In multivariate analysis, HER2 positivity (HR = 0.29), the presence of lung metastases (HR = 2.49) and primary taxanes resistance (HR = 2.36) were the only three independent CBR predictive factors, while HR positivity (HR = 0.67), the presence of lung metastases (HR = 1.52) and primary taxanes resistance (HR = 1.50) were the only three TTP independent prognostic factors. Treatment was globally well tolerated. Most common grade 3-4 toxicities were neutropenia (20.9 %), peripheral neuropathy (3.9 %), anaemia (1.6 %), liver dysfunction (0.8 %) and thrombocytopenia (0.4 %). Thirteen patients (5 %) developed febrile neutropenia.

CONCLUSION

EM is an effective new option in heavily pretreated MBC, with a favourable efficacy/safety ratio in a clinical practice setting. Our results comfort the use of this new molecule and pledge for the evaluation of EM-trastuzumab combination in this setting. Tumour biology, primary taxanes sensitivity and metastatic sites could represent useful predictive and prognostic factors.

Impact of prior anthracycline or taxane use on eribulin effectiveness as first-line treatment for metastatic breast cancer: results from two phase 2, multicenter, single-arm studies

Eribulin mesylate has efficacy in patients who have received ≥2 prior chemotherapies for metastatic breast cancer (MBC) including an anthracycline and taxane. Phase 2 trials showed clinical activity and acceptable tolerability of first-line eribulin (HER2− MBC; Study 206) and eribulin plus trastuzumab (HER2+ MBC; Study 208). Prespecified analyses evaluated efficacy by prior anthracycline and/or taxane use. Patients received eribulin mesylate (1.4 mg/m² IV; Days 1 and 8) and, in Study 208, trastuzumab (8 mg/kg IV/Cycle 1, then 6 mg/kg; Day 1) in 21-day cycles. Endpoints included objective response rate (ORR), progression-free survival (PFS), and tolerability. In Study 206 (N = 56), 48 % of patients had received prior anthracycline, 46 % prior taxane, 36 % prior anthracycline and taxane, and 41 % were chemotherapy-naïve. In Study 208 (N = 52), these percentages were 21, 44, 17, and 52 %, respectively. In Study 206, ORR and median PFS were similar for anthracycline-pretreated (25.9 %, 5.8 months), taxane-pretreated (26.9 %, 5.8 months), anthracycline- and taxane-pretreated (25.0 %, 6.7 months), and anthracycline/taxane-naïve patients (30.4 %, 7.6 months). In Study 208, ORR/median PFS were 63.6 %/6.7 months among anthracycline-pretreated patients, 56.5 %/6.8 months among taxane-pretreated patients, 55.6 %/5.9 months among anthracycline- and taxane-pretreated patients, and 81.5 %/13.1 months among anthracycline/taxane-naïve patients. Tolerability was generally similar among subgroups. In these studies, first-line eribulin in HER2− MBC and eribulin/trastuzumab in HER2+ MBC was effective with acceptable tolerability, regardless of prior anthracycline/taxane treatment. Prior chemotherapy was associated with lower ORR and shorter PFS with eribulin/trastuzumab in HER2+ MBC but not with eribulin in HER2− MBC.

Eribulin for heavily pre-treated metastatic breast cancer patients

AIM: To discuss treatment with eribulin in clinical practice outside a clinical trial.

METHODS: Archives of patients treated for metastatic breast cancer were reviewed and 21 patients treated with the new chemotherapeutic eribulin mesylate, a synthetic analog of a natural marine product, were identified. Information on patients’ characteristics and treatment outcomes was extracted. Treatment with eribulin mesylate was initiated at the recommended dose of 1.4 mg/m² on days 1 and 8 of a 21-day cycle in 17 patients and at a decreased dose of 1.1 mg/m² on days 1 and 8 of a 21-day cycle in 4 patients due to comorbidities and frailty. Efficacy of the drug was evaluated using the revised Response Evaluation Criteria in Solid Tumors criteria. Progression-Free Survival and overall survival (OS) were calculated using the Kaplan-Meier method starting from the date of eribulin therapy initiation to the date of disease progression documentation or death, respectively.

RESULTS: The median age of patients at the time of eribulin mesylate treatment was 53 years (range 34-75). Sixteen patients had estrogen receptor (ER) and/or partial response (PR) positive disease and 5 had ER/PR negative disease (all triple negative). Eight patients had received 2 or 3 previous lines of chemotherapy for metastatic disease and 13 patients had received 4 or more lines of treatment. The median number of cycles of eribulin received was 3 (range 1-16 years). All patients, except one, discontinued treatment due to progressive disease and one patient due to adverse effects. Six patients had a dose reduction due to side effects. All patients had progressed at the time of the report with a median time to progression of 3 mo (range 1 to 14 mo). Fifteen patients had died with a median OS of 7 mo (range 1-18 mo). Six patients were alive with a median follow-up of 13.5 mo (range 7 to 19 mo).

CONCLUSION: This series of patients confirms the activity of eribulin in a heavily pre-treated metastatic breast cancer population consistent with phase II and III trials.

Eribulin in Cancer Treatment

Halichondrin B is a complex, natural, polyether macrolide derived from marine sponges. Eribulin is a structurally-simplified, synthetic, macrocyclic ketone analogue of Halichondrin B. Eribulin was approved by United States Food and Drug Administration in 2010 as a third-line therapy for metastatic breast cancer patients who have previously been treated with an anthracycline and a taxane. It has a unique microtubule dynamics inhibitory action. Phase III studies have either been completed or are currently ongoing in breast cancer, soft tissue sarcoma, and non-small cell lung cancer. Phase I and II studies in multiple cancers and various combinations are currently ongoing. This article reviews the available information on eribulin with respect to its clinical pharmacology, pharmacokinetics, pharmacodynamics, mechanism of action, metabolism, preclinical studies, and with special focus on clinical trials.

Chemotherapy for Metastatic Breast Cancer - An Anachronism in the Era of Personalised and Targeted Oncological Therapy?

Based on the findings of modern molecular biology, breast cancer is nowadays considered to be a heterogeneous disease. This leads to the objective of an individualised, more patient-oriented therapy. A series of target molecules for this purpose has already been identified. The principle of targeted oncological therapy was realised decades ago with the introduction of endocrine therapy for patients with hormone receptor-positive tumours. The modern therapy for HER2-positive tumours is a further example for the translation of targeted therapy into clinical routine. For patients with HER2-negative metastatic breast cancer, to date two targeted drugs, bevacizumab and everolimus, are available for routine clinical use. Many other substances are still undergoing clinical development. However, validated predictive markers to aid in therapeutic decision-making and therapy control are still lacking. Chemotherapy constitutes an effective palliative therapy with proven efficacy for the patients. In this process strategies have also been realised for a targeted therapy against tumour cells with the help of chemotherapeutic agents such as, for example, the intracellular activation of the prodrug capecitabine or the active albumin-mediated transport of nab-paclitaxel which leads to higher peri- and intratumoural enrichments. The continuing unchanged relevance of chemotherapy is often underestimated in the current discussions and will be comprehensively evaluated in this review.

Brain Metastases from Breast Cancer and Response to Treatment with Eribulin: A Case Series

Brain metastases are common in patients with advanced breast cancer (BC), causing considerable morbidity and mortality. Eribulin is a microtubule dynamics inhibitor approved for treating certain patients with metastatic BC, previously treated with an anthracycline and a taxane. In the 301 phase 3 study in 1102 women with advanced BC, eribulin and capecitabine treatments did not differ for co-primary endpoints (overall survival [OS]: 15.9 vs 14.5 months, P = 0.056; progression-free survival [PFS]: 4.1 vs 4.2 months, P = 0.30). Here, we report outcomes for six patients (eribulin, n = 3; capecitabine, n = 3) who had received treatment for brain metastases from BC (BCBM) at baseline. All eribulin-treated patients experienced brain lesion shrinkage at some point during treatment, compared with one capecitabine-treated patient. Fewer patients in study 301 developed new BCBM with eribulin (13/544, 2.4%) compared with capecitabine (25/546, 4.6%). Eribulin does not cross the healthy blood-brain barrier (BBB), but could have the potential to do so after cranial radiation therapy. Capecitabine may cross the BBB and has demonstrated activity in BCBM. Data from these patients and previous cases suggest that further investigation of eribulin for BCBM may be warranted.

Stereoselective synthesis of the Halaven C14-C26 fragment from D-quinic acid: crystallization-induced diastereoselective transformation of an α-methyl nitrile

Crystallization-induced diastereoselective transformation (CIDT) of an α-methyl nitrile completes an entirely non-chromatographic synthesis of the halichondrin B C14-C26 stereochemical array. The requisite α-methyl nitrile substrate is derived from D-quinic acid through a series of substrate-controlled stereoselective reactions via a number of crystalline intermediates that benefit from a rigid polycyclic template. Therefore, all four stereogenic centers in the Halaven C14-C26 fragment were derived from the single chiral source D-quinic acid.

Systemic treatment approaches in her2-negative advanced breast cancer-guidance on the guidelines

Despite advancements in the treatment of early-stage breast cancer, many patients still develop disease recurrence; others present with de novo metastatic disease. For most patients with advanced breast cancer, the primary treatment intent is noncurative-that is, palliative-in nature. The goals of treatment should therefore focus on maximizing symptom control and extending survival. Treatments should be evaluated on an individualized basis in terms of evidence, but also with full respect for the wishes of the patient in terms of acceptable toxicity. Given the availability of extensive reviews on the roles of endocrine therapy and her2 (human epidermal growth factor receptor 2)-targeted therapies for advanced disease, we focus here mainly on treatment guidelines for the non-endocrine management of her2-negative advanced breast cancer in a Canadian health care context.

A phase I dose-escalation study of eribulin and S-1 for metastatic breast cancer

Background:

We evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, recommended dose for phase II (P2RD), and preliminary anticancer activity of a combination eribulin and S-1 therapeutic in metastatic breast cancer patients pretreated with anthracycline and taxane.

Method:

Patients aged 20–74 years were recruited. In level 1, patients received S-1 (65 mg m⁻²) from day 1 to 14, and eribulin (1.1 mg m⁻²) on day 1 and 8 in a 21-day cycle. In level 2, eribulin was increased to 1.4 mg m⁻². In level 3, S-1 was increased to 80 mg m⁻².

Results:

Twelve patients were enrolled into three cohorts. Planned dose escalation was completed, with one case exhibiting dose-limiting toxicity (grade 3 hypokalaemia) at level 3, without reaching the MTD. The P2RD was determined to be level 2 (eribulin 1.4 mg m⁻² and S-1 65 mg m⁻²). The most common grade 3 or 4 toxicity was neutropenia (83.3%), followed by febrile neutropenia (25.0%). Five of eleven patients (41.7%) with measurable disease had a partial response. Pharmacokinetics were characterised by dose-dependent elimination and nonlinear exposure.

Conclusion:

Dose level 3 was not tolerated owing to febrile neutropenia development. Thus, intermediate dose level 2 was recommended for further evaluation. Preliminary antitumour activity warrants further investigation in this setting.

Eribulin for the treatment of metastatic breast cancer: an update on its safety and efficacy

Breast cancer remains a leading cause of cancer-related death internationally. Treatment approaches for metastatic breast cancer have evolved in recent years; however chemotherapy remains a core component for the majority of patients. Agents such as anthracyclines and taxanes have been extensively studied and form standard treatment. Eribulin mesylate is a novel synthetic microtubule-directed chemotherapy, based on a naturally-occurring compound. Through phase I studies, eribulin was found to be tolerable and activity was seen in patients with metastatic breast cancer. Phase II studies in metastatic breast cancer further demonstrated its efficacy, with responses and survival which compare favorably with other studied chemotherapy agents. The phase III EMBRACE study showed superior survival for patients treated with eribulin compared with those who received a physician's choice control. This led to its approval for use in many countries in this setting. Its toxicity profile is well established and manageable for the most part, with the commonest reported toxicities being alopecia, fatigue, neutropenia and peripheral neuropathy. A second reported phase III study comparing eribulin to capecitabine failed to show an improvement in survival in pretreated patients. This article reviews the clinical pharmacology and mechanism of action of eribulin, and summarizes the results of the major preclinical and clinical studies of eribulin in metastatic breast cancer.

Efficacy of eribulin in women with metastatic breast cancer: a pooled analysis of two phase 3 studies

Data from two phase 3 studies of eribulin were pooled in analyses initially requested by the European Medicines Agency to assess whether specific patient subgroups, previously treated with an anthracycline and a taxane, benefited from eribulin. Study 305/EMBRACE included women after two-to-five lines of chemotherapy for advanced breast cancer who were randomized to eribulin mesylate (1.4 mg/m(2) on days 1 and 8 every 21 days) or treatment of physician's choice. In Study 301, patients who had received up to two prior chemotherapy regimens for advanced disease were randomized to eribulin (as above) or capecitabine (1.25 g/m(2) b.i.d. on days 1-14 every 21 days). In the pooled population, overall survival (OS), progression-free survival and response rates were analysed in the intent-to-treat population and selected subgroups. Overall, 1,062 patients were randomized to eribulin and 802 patients to control. Median OS was 15.2 months with eribulin versus 12.8 months with control (hazard ratio [HR] 0.85; 95% CI 0.77, 0.95; P = 0.003). In all subgroups assessed, OS data favoured eribulin; significant improvements occurred in some subgroups, notably in women with human epidermal growth factor receptor 2 (HER2)-negative disease (HR 0.82; P = 0.002), although the effect in those with HER2-negative but hormone-receptor-positive disease did not reach statistical significance; benefits were also seen, among others, in those with estrogen-receptor-negative and triple-negative disease. Eribulin improves OS in various patient subgroups with advanced/metastatic breast cancer who had previously received an anthracycline and a taxane. Women with HER2-negative disease are among those who may obtain benefit from eribulin.