Results Announced for Phase III Head-to-head Study of Halaven® (eribulin) Versus Capecitabine (Xeloda®) in Patients With Locally Advanced or Metastatic Breast Cancer

HATFIELD, UK, December 7, 2012 /PRNewswire/ --

For EU Medical Media Only

Second large Phase III study for eribulin presented at San Antonio Breast Cancer Symposium

Results from a global Phase III study (Study 301) of Halaven^® (eribulin) in women with metastatic breast cancer (MBC) were presented today during a plenary session at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium. For the first time this study compares eribulin and capecitabine (Xeloda^®) in women with earlier stage locally advanced or MBC. This study, one of the largest evaluating monotherapy chemotherapy, confirms eribulin as an active drug in patients with MBC, and exploratory analyses suggest possible benefits of eribulin in specific subset of patients, sufficient to warrant further studies.^[1]

Eribulin is currently approved for use in later line patient populations, where the pivotal Phase III trial (EMBRACE) demonstrated a statistically significant overall survival (OS) versus current single agent treatments and showed eribulin had a predictable and manageable safety profile.^[2]

Study 301 had a co-primary endpoint of overall survival (OS) and progression-free survival (PFS). The study demonstrated a trend favouring improved OS with eribulin compared to capecitabine in the intention-to-treat (ITT) population, although the improvement was not statistically significant. Women treated with eribulin had a median OS of 15.9 months (HR 0.879; 95% CI: 0.770-1.003; p=0.056) versus 14.5 months with capecitabine. The trial did not meet the pre-specified endpoint for progression-free survival, with 4.1 and 4.2 months for eribulin and capecitabine respectively (HR 1.079; 95% CI: 0.932-1.250; p=0.305).^[1]

1-,2- and 3- year overall survival rates for eribulin versus capecitabine showed an early improvement which was maintained throughout the study (1 year, 64.4% eribulin vs 58.0% capecitabine (P=0.0351), 2 year 32.8% eribulin vs 29.8% capecitabine (P=0.3235), 3 year, 17.8% eribulin vs 14.5% capecitabine (P=0.1751).^[1]

Unlike studies conducted today, Study 301 included all women regardless of their human epidermal growth factor receptor 2 (HER2), oestrogen receptor (ER) or progesterone receptor (PR) status. Patients are usually tested for their HER2 status as there are now effective treatments specifically for patients with the HER2 mutation.^[3] HER2 positive patients would generally not be treated with non-HER2 positive directed therapy. In an exploratory analysis for the planned subset of HER2 negative women (n=755), OS was 15.9 months for eribulin vs 13.5 months for capecitabine (HR 0.838; 95% CI: 0.715-0.983; nominal p=0.030). In the HER2 positive population (n=169) OS was 14.3 months for eribulin vs 17.1 months for capecitabine (HR; 95% 0.965; CI: 0.688-1.355).

Professor Christopher Twelves, Professor of Clinical Cancer Pharmacology and Oncology, University of Leeds and St James' University Hospital and Co-Primary Investigator for the trial commented, "It is important to note that eribulin is the first and only single-agent chemotherapy being assessed against capecitabine in this setting. The results suggest that there is a possible clinical advantage over capecitabine in certain patient populations that warrants further analysis to fully understand the implications of this study in clinical practice."

"Eisai remains committed to evaluating the safety and efficacy of eribulin in women living with locally advanced or MBC and are using these results to consider further evaluations," said Kenichi Nomoto, Ph.D., President, Oncology Product Creation Unit at Eisai.

Furthermore, adverse events in Study 301 were consistent with the known profile of both drugs. The most common AEs for eribulin and capecitabine (≥20% all grades) were neutropaenia (54.2% vs 15.9%), hand-foot syndrome (0.2% vs 45.1%) alopecia (34.6% vs 4.0%), leukopaenia (31.4% vs 10.4%), diarrhoea (14.3 vs 28.8%) and nausea (22.2% vs 24.4%), respectively.^[1]

Eribulin is the first and only single-agent therapy proven to significantly extend overall survival after two prior lines of MBC therapy when compared to other single-agent therapies. Results from a pivotal Phase III study (EMBRACE) demonstrated a statistically significant overall survival benefit for women treated with eribulin compared with a single-agent treatment of physician's choice (TPC). Women entering the EMBRACE trial had more advanced disease than those entering Study 301.^[2]

Eribulin is currently indicated in Europe for the treatment of women with locally advanced or MBC who have previously received at least two chemotherapeutic regimens. Prior therapy should have included an anthracycline and a taxane unless women were not suitable for these treatments.^[4]

Eisai is dedicated to discovering, developing and producing innovative oncology therapies that can make a difference and impact the lives of women and their families. This passion for people is part of Eisai's human health care (hhc) mission, which strives for better understanding of the needs of patients and their families to increase the benefits health care provides.

Notes to Editors

Halaven^® (eribulin)

Eribulin is a non-taxane, microtubule dynamics inhibitor indicated for the treatment of patients with breast cancer who have previously received at least two chemotherapeutic regimens for metastatic disease and whose prior therapy should have included an anthracycline and a taxane.^[4] Eribulin belongs to a class of antineoplastic agents, the halichondrins, which are natural products, isolated from the marine sponge Halichondria okadai. It is believed to work by inhibiting the growth phase of microtubule dynamics without affecting the shortening phase and sequesters tubulin into non-productive aggregates.

Halaven is approved in the European Union, USA, Russia, Switzerland, South Korea, Japan, and Singapore. Halaven has received pricing authorisation and has launched in Canada, Denmark, Finland, France, Iceland, Italy, Norway, Sweden, Switzerland, Slovenia, and the UK.  In addition, Halaven is available in Austria and Germany.

Global Phase III Study 301^[1]

Study 301 was an open-labelled, randomised, two-parallel-arm, multicentre study of Halaven (eribulin) versus capecitabine in 1,102 women with locally advanced or metastatic breast cancer previously treated with anthracyclines and taxanes, either in the (neo) adjuvant setting or for locally advanced or metastatic disease. Patients in the study received zero to two previous chemotherapies for advanced disease.

The study opened in 2006 and the last patient was randomised in 2010. Patients were randomised to treatment with either eribulin 1.23mg/m^[2] (administered intravenously over two to five minutes on days 1 and 8, every 21 days) or capecitabine 2.5g/m^[2] (administered orally twice daily in two equal doses on days 1 to 14, every 21 days).

Global Phase III Clinical Study 305 (EMBRACE)^[2]

EMBRACE (Eisai Metastatic Breast Cancer Study Assessing Treatment of Physician's Choice (TPC) Versus Eribulin E7389) was an open-label, randomised, global, multi-centre, parallel two-arm study designed to compare overall survival in patients treated with eribulin versus a Treatment of Physician's Choice (TPC) arm. TPC was defined as any single-agent chemotherapy, hormonal treatment or biologic therapy approved for the treatment of cancer; or palliative treatment or radiotherapy administered according to local practice. The study included 762 patients with metastatic breast cancer who previously had been treated with at least two and a maximum of five prior chemotherapies, including an anthracycline and a taxane. The vast majority (96%) of patients in the TPC arm received chemotherapy.

In the total Phase III EMBRACE study population, eribulin was shown to prolong overall survival in heavily pre-treated patients with metastatic breast cancer compared to patients receiving TPC by 2.7 months (13.2 vs 10.5 HR 0.81 (95% CI 0.067, 0.96) nominal p=0.014). A pre-planned analysis of patients from Region 1 of the study (North America/Western Europe/Australia) showed a significant overall survival benefit of eribulin over TPC of 3.0 months (nominal p=0.031).

The most commonly reported adverse reactions among patients treated with eribulin in the EMBRACE study were fatigue (asthenia), a decrease in infection-fighting white blood cells (neutropaenia), hair loss (alopecia), numbness and tingling in arms and legs (peripheral neuropathy), nausea and constipation. Peripheral neuropathy was the most common adverse event leading to discontinuation from eribulin, occurring in less than 5% of the patients involved in the EMBRACE trial. Neutropaenia only led to eribulin discontinuation for 0.6% patients. Death due to serious side effects, discontinuation and dose interruptions to treatment were lower in the eribulin arm of the trial compared with the TPC arm.

Metastatic Breast Cancer

Metastatic breast cancer is an advanced stage of the disease that occurs when cancer spreads beyond the breast to other parts of the body. In Europe, approximately 6% of breast cancers are metastatic at diagnosis with a five-year survival rate of 21%.^[5]

Eisai in Oncology

Our commitment to meaningful progress in oncology research, built on scientific expertise, is supported by a global capability to conduct discovery and preclinical research, and develop small molecules, therapeutic vaccines, and biologic and supportive care agents for cancer across multiple indications.

About Eisai

Eisai recently expanded their UK Hatfield commercial, research and manufacturing facility which now supports the company's growing EMEA business.

Eisai concentrates its R&D activities in three key areas:

• Neuroscience, including: Alzheimer's disease, epilepsy, pain and weight loss
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References

1. Kaufman P, Awada A, Twelves C et al. A Phase III, open-label, randomised, multicenter study of eribulin mesylate versus capecitabine in patients with locally advanced or metastatic breast cancer previously treated with anthracyclines and taxanes. Presented at 2012 CTRC-AACR San Antonio Breast Cancer Symposium

2. Cortes J, O'Shaughnessy J, Loesch D, et al. Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study. The Lancet. 2011; 377: 914 -923

3. HER2-positive breast cancer: What is it? http://www.mayoclinic.com/health/breast-cancer/AN00495 (last accessed November 2012)

4. Summary of Product Characteristics Halaven (updated March 2011). Available at:

  http://www.medicines.org.uk/EMC/medicine/24382/SPC/Halaven+0.44+mg+ml+solution+for+injection/  

5. Cardoso, M. and Castiglione F. Locally recurrent or metastatic breast cancer: ESMO Clinical Recommendations for diagnosis, treatment and follow-up. On behalf of the ESMO Guidelines Working Group. Ann Oncol (2009) 20 (suppl 4): iv15-iv18

Date of preparation: December 2012

Job code: Halaven-UK0065