Press Release

LONDON, October 30 /PRNewswire/ -- Eisai Co., Ltd. (Headquarters: Tokyo, President and CEO: Haruo Naito)today announced preliminary results from a recently completed Phase III studywith E7389 (generic name: eribulin mesylate, "eribulin"), discovered anddeveloped by the Company, in patients with locally advanced or metastaticbreast cancer.

This global Phase III study, known as "EMBRACE," (Eisai Metastatic BreastCancer Study Assessing Physician's Choice Versus E7389), was an open-label,randomized, parallel two-arm, multi-center study of 762 women(1) with locallyrecurrent or metastatic breast cancer previously treated with at least twoand a maximum of five prior chemotherapy regimens, including an anthracyclineand a taxane.(2)

The patients were treated either with eribulin (administeredintravenously over two to five minutes on days 1 and 8 every 21 days) or withtreatment of physician's choice.(3) Treatment of physician's choice isdefined as any single agent chemotherapy, hormonal treatment or biologicaltherapy approved for the treatment of cancer; or palliative treatment orradiotherapy administered according to local practice.(4)

Preliminary results from the study demonstrated a statisticallysignificant improvement in overall survival, the primary endpoint, ineribulin-treated patients compared with the physician's choice of therapy.The safety profile of eribulin in this Phase III study was consistent withthe adverse events seen in previous Phase II clinical studies and the mostcommon adverse event reported was myelosuppression.

Eribulin is a new chemical compound discovered and developed by Eisai. Itis a synthetic analogue of halichondrin B, a naturally-derived compound thatwas first isolated from a marine sponge. While taxanes inhibit cell divisionby stabilising microtubules, eribulin is a microtubule dynamics inhibitorthat arrests the cell cycle through inhibition of the growth of microtubuleswithout interfering with microtubule shortening.

While early detection by breast cancer screening and the development ofinnovative anti-cancer drugs have contributed to the decline in breast cancermortality around the world, breast cancer remains one of the leading causesof cancer death in women. Although advances are being made every year in thetreatment of breast cancer, women with locally advanced or metastatic breastcancer have limited treatment options and the development of more effectivetreatment or anti-cancer drugs is critically important.

Eisai will complete a more detailed analysis of the data prior tosubmitting marketing authorization applications for eribulin to healthauthorities in Japan, the United States, and Europe for locally advanced andmetastatic breast cancer by the end of the fiscal year 2009.

Eisai is currently conducting clinical trials of this compound in-houseto evaluate the efficacy and safety not only in breast cancer, but also innon-small cell lung cancer (NSCLC), hormone refractory prostate cancer, andsarcoma. Eisai also includes eribulin as one of the compounds in theco-development projects based on the strategic collaboration agreement withQuintiles and will proceed with joint clinical development of this compoundfor NSCLC as well as bladder cancer.

Eisai defines oncology as a therapeutic area of focus and is committed todeveloping novel anti-cancer agents and treatments for supportive care. Withthese efforts, Eisai will make further contributions to addressing thediversified needs of and improving benefits to patients and families affectedby cancer as well as healthcare professionals.

For more information about eribulin, health care professionals andpatients in Europe may call +44 (0) 845-676-5200 or send enquiries toeumedinfo@eisai.net.

Eisai Europe Ltd

Eisai Europe Limited (EEL) is a wholly-owned subsidiary of Eisai Co.,Ltd. and supports the activities of its operations across Europe, where Eisaihas sales and marketing operations in over 20 markets, including: the UnitedKingdom, France, Germany, Italy, Spain, Switzerland, Sweden, Ireland,Austria, Denmark, Finland, Norway, Portugal, Iceland, Czech Republic,Hungary, and Slovakia. In addition, other Eisai operating companies in Europecarry out basic discovery research; distribution & logistics; clinicalresearch; and manufacturing.

Eisai Co., Ltd.

Eisai Co., Ltd. is a research-based human health care (hhc) company thatdiscovers, develops and markets products throughout the world. Through aglobal network of research facilities, manufacturing sites and marketingsubsidiaries, Eisai actively participates in all aspects of the worldwidehealth care system. Eisai employs approximately 11,000 employees worldwide.

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

  - Integrative Neuroscience, including Alzheimer's disease,neuropathic pain and epilepsy. - Integrative Oncology, including anticancer therapies, tumorregression, tumor suppression and antibodies; supportive cancertherapies include nausea and vomiting. - Vascular/Immunological Reaction including acute coronarysyndrome, atherothrombotic disease and sepsis.

[Please refer to the following notes for a glossary of terms]

Note to editors:

About locally advanced and metastatic breast cancer

Breast cancer is staged from Stage 0 to Stage IV, based on the size ofthe breast lump, whether lymph nodes are involved, and whether the distantmetastases have developed. Locally advanced breast cancer, also known asStage III, is invasive breast cancer that has spread to axillary lymph nodes,the chest wall, skin of the breast, or above or below the collarbone.Metastatic breast cancer, considered Stage IV, is diagnosed when cells fromthe original breast tumour have spread beyond the breast to other parts ofthe body, usually the liver, bone, brain, or lungs.

It is believed that more than one million women are newly diagnosed withbreast cancer each year around the world.(5)

About overall survival

Overall survival is defined as the time from the date of randomisationuntil the date of death from any cause.

References:

(1) Data on file

(2) Eisai Clinical Study Protocol, The "EMBRACE" Trial: Eisai MetastaticBreast Cancer Study Assessing Physician's Choice Versus E7389, FinalIncorporating Amendment 1, Version Date: 08 August 2006. Page 1, par. 3

(3) Ibid page 8, par.1

(4) Ibid, page 8, par.2

(5) Freddie Bray, Peter McCarron, D Maxwell Parkin, "The changing globalpatterns of female breast cancer incidence and mortality." Breast Cancer Res2004; 6(6);229-239

Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1064079/

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