Phase II Study Results Showed Eisai's E7080 (Lenvatinib [USAN]) Demonstrated an Objective Response Rate of 59% in Radioiodine (RAI)-Refractory Differentiated Thyroid Cancer[1]

HATFIELD, England, June 1, 2011 -

Preliminary results of a Phase II study to be presented at the
American Society of Clinical Oncology (ASCO) Annual Meeting showed that
Eisai's E7080 (lenvatinib [USAN]) demonstrated an Objective Response Rate
(ORR) of 59% (34/58, 95% CI:45 - 71),[2] based on an updated investigator
assessment, in patients with advanced radioiodine (RAI)-refractory
differentiated thyroid cancer (DTC).[1] These results will be presented
during an ASCO oral session on June 6, 2011.

"These findings are significant because there are very limited
treatment options for this difficult-to-treat, life-threatening form of
thyroid cancer," said Steven Sherman, M.D, study investigator and
Distinguished Professor of Endocrinology, Department of Endocrine Neoplasia
and Hormonal Disorders at the University of Texas MD Anderson Cancer Center
in Houston. "These results indicate that E7080 should be further evaluated in
a definitive Phase III trial."

Although the prognosis for thyroid cancer is generally quite
good, for those patients with RAI-refractory, recurrent, or metastatic
disease the outcome is poor, and death from thyroid cancer within three years
under these circumstances is common.[3],[4]

Notes to Editors

About the Study

The open-label, global, single-arm study, "A Phase II Trial of
the Multi-Targeted Kinase Inhibitor E7080 in Advanced Radioiodine
(RAI)-refractory differentiated thyroid cancer (DTC)," involved 58 patients
with advanced RAI refractory DTC (papillary, follicular or Hurthle Cell)
whose disease had progressed during the prior 12 months.[1] (Disease
progression was measured using Response Evaluation in Solid Tumors (RECIST)
criteria.) The starting dose of E7080 was 24 mg once daily in 28 day cycles
until disease progression or development of unmanageable toxicities.[1]

All enrolled patients reported at least one treatment related
adverse event. The most frequently reported treatment related adverse events
were: hypertension 74% (Gr: 3: 10%), proteinuria 60% (Gr: 3: 10%), decreased
weight 57% (Gr: 3: 7%), diarrhoea 55% (Gr: 3: 10%) and fatigue 53%
(Gr: 3: 7%).[2] Toxicities were managed with dose reduction in 35% of
patients and 23% were ultimately withdrawn from therapy due to toxicity.[1]

About E7080

E7080 is an investigational small molecule vascular endothelial
growth factor receptor (VEGFR) multi target tyrosine kinase inhibitor being
studied by Eisai as an oral agent in a wide array of tumour types. E7080
works by targeting a number of receptors including VEGFR 1-3, fibroblast
growth factor receptors 1-4 (FGFR 1-4), RET, KIT and platelet-derived growth
factor receptor-beta (PDGFRbeta).

About Thyroid Cancer

Thyroid cancer refers to cancer that forms in the tissues of the
thyroid gland, located at the base of the throat near the trachea.[5] It
usually occurs between the ages of 25 and 65[6] and affects more women than
men. In 2008, 24,695 women and 8,254 men were diagnosed with thyroid cancer
in Europe.[7]

The most common types of thyroid cancer, papillary and follicular
(including Hurthle cell), are classified as differentiated thyroid cancer
(DTC) and account for 95 percent of all cases.[8] Although the prognosis for
thyroid cancer is generally quite good, for those patients with
RAI-refractory, recurrent, or metastatic disease the outcome is poor, and
death from thyroid cancer within three years under these circumstances is
common.[3],[4]

About Eisai and Women's Oncology

Eisai is dedicated to discovering, developing and producing
innovative oncology therapies that can help make a difference and impact the
lives of women with cancer. Our unique oncology pipeline focuses heavily on
breast cancer, ovarian cancer, thyroid cancer and endometrial carcinoma
demonstrating our commitment to this area. 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.

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

References

———————————

[1] Sherman, S I. A phase II trial of the multitargeted kinase
inhibitor E7080 in advanced radioiodine (RAI)-refractory differentiated
thyroid cancer (DTC). Oral presentation at ASCO 2011. Monday 6 June. Abstract
#5503.

[2] Eisai Data on File. Sherman, S.I et al ASCO presentation. Abstract
#5503

[3] Pittas AG, Adler M, Fazzari M, et al: Bone metastases from thyroid
carcinoma: Clinical characteristics and prognostic variables in one hundred
forty-six patients. Thyroid 10:261-268, 2000

[4] Wang W, Larson SM, Fazzari M, et al: Prognostic value of
[18F] fluorodeoxyglucose positron emission tomographic scanning in patients
with thyroid cancer.J Clin Endocrinol Metab 85:1107-1113, 2000

[5] www.cancer.gov/cancertopics/pdq/treatment/thyroid/Patient,
paragraph 1. Accessed 5/9/11

[6]
www.cancer.gov/cancertopics/pdq/treatment/thyroid/Patient, paragraph
7. Accessed 5/9/11

[7] European Cancer Observatory. Country: European Union (27).
Cancer Factsheet (2008):

Last accessed May 2011:
eu-cancer.iarc.fr/country-930–european-union-27.html,en

[8] www.cancer.gov/cancertopics/wyntk/thyroid/page4/print.
paragraph 1,2. Accessed 5/9/11

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