Global Phase III Trial With Selective c-MET Inhibitor Tivantinib (ARQ 197) Starts Enrolling Patients in Europe

MARQUEE Trial to Study Tivantinib in Advanced, Non-squamous, Non-small Cell Lung Cancer

MUNICH, April 18, 2011 - Daiichi Sankyo announced today that it has begun
enrolling patients in Europe into a large, multinational phase III trial of
tivantinib (ARQ 197). Tivantinib is an investigational small molecule
inhibitor of the c-MET receptor tyrosine kinase in final phase of clinical
development for the treatment of advanced, non-squamous, non-small cell
lung cancer (NSCLC).

Lung cancer is a devastating disease. In Europe, it is one of the most
common cancers and the leading cause of cancer-related death among men and
women(1). NSCLC is the most common form, accounting for approximately 85% of
all lung cancer cases(2).

"Lung cancer is such an aggressive disease with a great unmet need for
more effective treatments. Survival rates are still very poor when compared
to other common cancer types. We are very pleased to be involved in this
trial and we hope that tivantinib will prove to be an effective treatment
option for people diagnosed with this disease", said Prof. Giorgio
Scagliotti, Head of the Department of Clinical and Biological Sciences at S.
Luigi Hospital, Orbassano (Torino), Italy and Principal European
Investigator in the trial.

The trial - known as MARQUEE (Met inhibitor ARQ 197 plus Erlotinib vs
Erlotinib plus placebo in NSCLC) - is a randomised, double-blinded,
controlled study of tivantinib plus erlotinib, versus
placebo plus erlotinib in patients who have received prior treatment for
advanced, non-squamous NSCLC. The primary objective of the study is to
evaluate overall survival (OS) in the intent-to-treat (ITT) population*.
Secondary endpoints include OS in the subpopulation of patients with
epidermal growth factor receptor (EGFR) wild type, the time patients in the
ITT population live without their disease getting worse (progression-free
survival or PFS), and further assessment of the safety of
tivantinib in combination with erlotinib.

"We are very pleased to have started enrollment in Europe and we hope
that this late-stage study will confirm the results observed with tivantinib
in phase II. Cancer is a major concern across Europe and the world and
Daiichi Sankyo is committed to the discovery and development of oncology
compounds that might help to advance cancer treatment," said Glenn Gormley,
Chief Science Officer and President, Daiichi Sankyo Pharma Development.

The MARQUEE study will enroll 988 patients in 150 sites in the U.S.,
Canada, Eastern and Western Europe, Australia and Latin America.

About tivantinib (ARQ 197) and c-MET

ARQ 197 now has a generic name approved by the World Health Organisation
(WHO) - tivantinib. Tivantinib is an orally administered, selective inhibitor
of c-MET, a receptor tyrosine kinase. In healthy adult cells, c-MET is
present in normal levels to support natural cellular function, but in cancer
cells c-MET is inappropriately and continuously activated for unknown
reasons. When abnormally activated, c-MET plays multiple roles in aspects of
human cancer, including cancer cell growth,
survival, angiogenesis, invasion and metastasis.

Tivantinib has the potential to be a first-in-class c-MET inhibitor for
the treatment of NSCLC and is currently being studied for other indications
including liver and colorectal cancers. In clinical trials to date, treatment
with tivantinib has been well-tolerated and has resulted in tumor responses
and prolonged stable disease across a broad range of tumors.

In December 2008, ArQule, Inc. and Daiichi Sankyo signed a license,
co-development and co-commercialization agreement to co-develop tivantinib in
the U.S., Europe, South America and the rest of the world, excluding Japan,
China (including Hong Kong), South Korea and Taiwan, where Kyowa Hakko Kirin
Co., Ltd. has exclusive rights for development and commercialization.

* Intent-to-treat (ITT) analysis: A method of analysis for randomized
trials in which all patients randomly assigned to one of the treatments are
analysed together, regardless of whether or not they completed or received
that treatment.

References

1 Ferlay J, Shin HR, Bray F, et al (GLOBOCAN 2008). Cancer Incidence and
Mortality Worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France:
International Agency for Research on Cancer; 2010. Available from:
globocan.iarc.fr. Last accessed 11 April 2011.

2 Huq S, Maghfoor I, Perry M (Feb 2010) Lung cancer, non-small cell.
E-medicine from WebMD. Available from
emedicine.medscape.com/article/279960-overview. Last accessed 11 April
2011.

About Daiichi Sankyo

The Daiichi Sankyo Group is dedicated to the creation and supply of
innovative pharmaceutical pro­ducts to address the diversified, unmet
medical needs of patients in both mature and emerging
markets. The company was created in 2005 through the merger of two
traditional Japanese enterprises, Daiichi and Sankyo. With net sales of
nearly EUR7.3 billion, Daiichi Sankyo is one of the world's 20 leading
pharmaceutical companies. While maintaining its portfolio of marketed
pharmaceuticals for hypertension, hyperlipidemia, and bacterial infections,
the Group is engaged in the development of treatments for thrombotic
disorders and focused on the discovery of novel oncology and
cardiovas­cular-metabolic therapies. Furthermore, the Daiichi Sankyo Group
has created a "Hybrid Business Model", which will respond to market and
customer diversity and optimize growth opportunities across the value chain.

The company's world headquarters is in Tokyo. Its European base is
located in Munich. Daiichi Sankyo Europe has affiliates in 12 European
countries in addition to a global manufacturing site
located in Pfaffenhofen, Germany.

For more information, please visit: www.daiichisankyo.com or
www.daiichi-sankyo.eu

Forward-looking statements

This press release contains forward-looking statements and information
about future developments in the sector, and the legal and business
conditions of Daiichi Sankyo Europe GmbH. Such forward-looking statements are
uncertain and are subject at all times to the risks of change, particularly
to the usual risks faced by a global pharmaceutical company, inclu­ding the
impact of the prices for products and raw materials, medication safety,
changes in exchange rates, government regulations, employee relations, taxes,
political instability and terrorism as well as the results of independent
demands and governmental inquiries that affect the affairs of the company.
All forward-looking statements contained in this release hold true as of the
date of publication. They do not represent any guarantee of future
performance. Actual events and developments could differ materially from the
forward-looking statements that are explicitly expressed or implied in these
statements. Daiichi Sankyo Europe GmbH assumes no responsibility for the
updating of such forward-looking statements about future developments of the
sector, legal and business conditions and the company.

    Contact

    Federico Maiardi                   Dr Elke Adamietz
    European Product PR Manager        Director Medical Affairs Oncology
    Phone +49-172-8386112              Phone +49-89-7808210
    Federico.maiardi@daiichi-sankyo.eu Elke.adamietz@daiichi-sankyo.eu

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