Global Phase III Study Results Show Eribulin Meets Primary Endpoint of Overall Survival

Global Phase III Study Results Show Eribulin Meets Primary Endpoint of Overall
Survival
Eisai Plans to Submit Marketing Authorization Applications for Eribulin
Mesylate in Locally Advanced or Metastatic Breast Cancer

WOODCLIFF LAKE, N.J., Oct. 30 /PRNewswire/ -- Eisai Inc. today announced
preliminary results from a recently completed Phase III study with eribulin
mesylate (E7389), discovered and developed by the company, in patients with
locally advanced or metastatic breast cancer.

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

The patients were treated either with eribulin (administered intravenously
over two to five minutes on days 1 and 8 every 21 days) or with treatment of
physician's choice. Treatment of physician's choice is defined as any single
agent chemotherapy, hormonal treatment or biological therapy approved for the
treatment of cancer; or palliative treatment or radiotherapy administered
according to local practice.

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

Eribulin is a new chemical compound discovered and developed by Eisai. It is a
synthetic analogue of halichondrin B, a naturally-derived compound that was
first isolated from a marine sponge. While taxanes inhibit cell division by
stabilizing microtubules, eribulin is a microtubule dynamics inhibitor that
arrests the cell cycle through inhibition of the growth of microtubules
without interfering with microtubule shortening.

While early detection by breast cancer screening and the development of
innovative anti-cancer drugs have contributed to the decline in breast cancer
mortality around the world, breast cancer remains one of the leading causes of
cancer death in women. Although advances are being made every year in the
treatment of breast cancer, women with locally advanced or metastatic breast
cancer have limited treatment options and the development of more effective
treatment or anti-cancer drugs is critically important. It is believed that
more than one million women are newly diagnosed with breast cancer each year
around the world.

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

Eisai is currently conducting clinical trials of this compound in-house to
evaluate the efficacy and safety not only in breast cancer, but also in
non-small cell lung cancer (NSCLC), hormone refractory prostate cancer, and
sarcoma. Eisai also includes eribulin as one of the compounds in the
co-development projects based on the strategic collaboration agreement with
Quintiles and will proceed with joint clinical development of this compound
for NSCLC as well as bladder cancer.

Eisai defines oncology as a therapeutic area of focus and is committed to
developing novel anti-cancer agents and treatments for supportive care. With
these efforts, Eisai will make further contributions to addressing the
diversified needs of and improving benefits to patients and families affected
by cancer as well as healthcare professionals.

For more information about eribulin, U.S. health care professionals and
patients may call 1-877-220-3921.

Eisai Inc.

Eisai Inc. is a wholly-owned subsidiary of Eisai Corporation of North America.
Established in 1995 and ranked among the top-20 U.S. pharmaceutical companies
(based on retail sales), the company began marketing its first product in the
United States in 1997 and has rapidly grown to become a fully integrated
pharmaceutical business with fiscal year 2008 (year ended March 31, 2009)
sales of approximately $3.7 billion. Eisai Inc.'s areas of commercial focus
include neurology, gastrointestinal disorders and oncology/critical care. The
company serves as the U.S. pharmaceutical operation of Eisai Co., Ltd., a
research-based human health care (hhc) company that discovers, develops and
markets products throughout the world. Headquartered in Woodcliff Lake, New
Jersey, Eisai Inc. has several R&D facilities in Massachusetts, New Jersey and
North Carolina, as well as manufacturing facilities in Maryland and North
Carolina. For more information about Eisai, please visit www.eisai.com.

*On October 1, 2009, Eisai Research Institute of Boston, Inc. (established in
1987) and Eisai Medical Research Inc. (established in 2002) were merged into
Eisai Inc.

Eisai Co., Ltd.

Eisai Co., Ltd. is a research-based human health care (hhc) company that
discovers, develops and markets products throughout the world. Through a
global network of research facilities, manufacturing sites and marketing
subsidiaries, Eisai actively participates in all aspects of the worldwide
health 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, tumor
regression,
tumor suppression and antibodies; supportive cancer therapies include
nausea and vomiting.

-- Vascular/Immunological Reaction including acute coronary syndrome,
atherothrombotic disease and sepsis.

SOURCE Eisai Inc.

CONTACT: Judee Shuler, +1-201-746-2241 (office), +1-908-337-2540 (cell), or
Robert Laverty, +1-201-746-2265 (office), +1-201-937-2591 (cell), both of
Eisai Inc.