Eisai Oncology to Present New Research on Product Portfolio and Pipeline at ASCO Annual Meeting

HATFIELD, England, May 20, 2011 - Eisai announced today that 10 abstracts highlighting new study results in
thyroid cancer, metastatic breast cancer, ovarian cancer and other cancers
will be presented during the 47th Annual Meeting of the American Society of
Clinical Oncology (ASCO), taking place in Chicago from June 3 to June 7,
2011.

These studies highlight Eisai's current product portfolio and oncology
pipeline, reinforcing the company's commitment to help address the diverse
needs of patients and their families affected by cancer.

"We have a strong and growing commitment to oncology and in particular
cancers affecting women," said Takashi Owa, Ph.D., President, Oncology
Product Creation Unit, Eisai Product Creation Systems, Eisai Inc. "Eisai has
a significant portfolio of oncology compounds and therapies that are
representative of our human health care mission — to help address unmet
medical needs and increase benefits to patients and their families."

The following Eisai abstracts are accepted for presentation at this
year's ASCO meeting:

    Product         Abstract Name

    Lenvatinib      A Phase II Trial of the Multi-Targeted Kinase Inhibitor
    (E7080)         E7080 in Advanced Radioiodine (RAI)-Refractory
    Abstract No:    Differentiated Thyroid Cancer (DTC)
    5503            Oral Session

    Lenvatinib      Assessment of Clinical Activity of E7080, a Multi-
    (E7080)         Targeted Kinase Inhibitor, in Patients with Advanced
    Abstract No:    Melanoma Treated in Two Phase I trials
    8527            Poster discussion session

    Lenvatinib      The Effect of E7080, a VEGFR and FGFR Tyrosine Kinase
    (E7080)         Inhibitor (TKI), on BRAF Wild-Type Melanoma
    Abstract No:    Poster Presentation
    8566

    Lenvatinib      Mechanism of Antitumor Activity of E7080, a Selective
    (E7080)         VEGFR and FGFR Tyrosine Kinase Inhibitor (TKI) in
    Abstract No:    Combination with Selective Mutant BRAF Inhibition
    8567            Poster Session

    Lenvatinib      Molecular Profiling of Melanoma tumor biopsies to
    E7080           identify a response signature to the multi-RTK inhibitor
    Abstract No.    E7080
    8595

    Farletuzumab    Phase I Safety Study of Farletuzumab, Carboplatin and
    Abstract No:    Peglyated Liposomal Doxorubicin (PLD) in Subjects with
    5056            Platinum-Sensitive Epithelial Ovarian Cancer (EOC)
                    Poster Session

    MORAb-004       A First-in-Human Phase I Study of MORAb-004 (MOR4), a
    Abstract No:    humanized monoclonal antibody recognizing TEM-1
    3086            (endosialin), in patients with solid tumors
                    Poster Session

    Eribulin        The Relationship Between Age and Survival Outcomes for
    Mesylate        Eribulin in Metastatic Breast Cancer
    Abstract No:    Poster Session
    1060

    Eribulin        Eribulin Dosing in Patients with Advanced Solid Tumors
    Mesylate        and Hepatic Impairment
    Abstract No:    Poster Session
    2544

    Polifeprosan 20 Effects of Surgery with BCNU Wafer Placement on
    with carmustine Neurocognitive Function in Patients with One to Three
    implant         Brain Metastases
    Abstract No:    Poster Discussion
    2015

Notes to Editors

Eisai Oncology

Eisai Oncology is dedicated to discovering, developing and producing
innovative oncology therapies that can help make a difference and impact the
lives of patients 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. 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, biologic and supportive care agents for cancer across multiple
indications.

About Eisai

Eisai is one of the world's leading R&D-based pharmaceutical companies
that has defined its corporate mission as "giving first thought to patients
and their families and to increasing the benefits health care provides,"
which we call human health care (hhc).

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

- Integrative Neuroscience: Alzheimer's disease, multiple sclerosis,
neuropathic pain, epilepsy, depression, etc

- Integrative Oncology: Anticancer therapies; tumour regression, tumour
suppression, antibodies, etc and Supportive cancer therapies; pain relief,
nausea, etc

- Vascular/Immunological Reaction: Acute coronary syndrome,
atherothrombotic disease, sepsis, rheumatoid arthritis, psoriasis, Crohn's
disease, etc

With operations in the U.S., Asia, Europe and its domestic home market of
Japan, we employ more than 10,000 people worldwide, and reported consolidated
sales of over GBP3.53 billion in FY2007, an increase of 8.9% year on year. In
Europe, Eisai undertakes sales and marketing operations in over 20 markets,
including the United Kingdom, France, Germany, Italy, Spain, Switzerland,
Sweden, Ireland, Austria, Denmark, Finland, Norway, Portugal, Iceland, Czech
Republic, Hungary, Slovakia and the Netherlands.

For further information please visit our web site www.eisai.com

Media Enquiries, Eisai Europe Ltd, Cressida Robson, +44(0)7908-314-155, Cressida_Robson at eisai.net; Tonic Life Communications, Benjamyn Tan / Helen Swift, +44(0)207-798-9262 / +44(0)7792-034-191, benjamyn.tan at toniclc.com / helen.swift at toniclc.com