ArQule and Daiichi Sankyo Expand Drug Discovery Collaboration in Oncology

Woburn, Massachusetts (ots/PRNewswire) - ArQule, Inc.
and Daiichi Sankyo Co., Ltd. (TSE 4568) today announced the expansion
of their research, development and license agreement for the
discovery of novel kinase inhibitors in the field of oncology. This
expanded agreement establishes a third therapeutic target, with an
option for a fourth, in the field of oncology, and it includes a
two-year extension based on the application of the proprietary ArQule
Kinase Inhibitor Platform (AKIP(TM)) technology.

"This technology has provided us with a unique and innovative
approach for discovery in the treatment of cancer," said Dr. Hideyuki
Haruyama, the Global Head of Research, Daiichi Sankyo. "We expect
that the expansion of this collaboration will produce other drug
candidates and lay the foundation for future growth in this field."

Consistent with the existing AKIP collaboration, the economic
terms provided for in the expanded agreement include payments for
research support, licensing fees for compounds discovered as a result
of this research, milestone payments related to clinical development,
regulatory review and sales, and tiered royalty payments on net sales
of each product. Daiichi Sankyo will have an option to license
compounds directed to the targets defined under the agreement
following the completion of certain pre-clinical studies. ArQule
retains the option to co-commercialize any resulting licensed
products in the U.S.

"Our initial drug discovery collaboration has identified a
development candidate for one target, and we are optimizing advanced
lead compounds for the other target," said Dr. Thomas C.K. Chan,
chief scientific officer of ArQule. "The expansion of this
collaboration will continue to deploy AKIP technology to discover
inhibitors with novel modes of action for additional oncology targets
over the next two years."

About the ArQule Kinase Inhibitor Platform (AKIP(TM))

Kinases play pivotal roles in modulating diverse cellular
activities and have been implicated as important mediators of certain
forms of cancer and other diseases. The AKIP(TM) technology is based
on a novel binding mode that leads to inhibition of target kinases by
small molecules that do not compete with adenosine triphosphate
(ATP). ArQule has identified binding sites in more than 200 kinases
involved in multiple therapeutic areas that are amenable to such
non-ATP competitive inhibition.

ArQule's ability to rationally design novel kinase inhibitors
that encompass new chemical spaces allows for an expanding
intellectual property estate. The Company believes that non-ATP
competitive small molecule inhibitors may have fewer off-target side
effects and utility in a broad range of human diseases.

About ArQule

ArQule is a biotechnology company engaged in the research and
development of next-generation, small-molecule cancer therapeutics.
The Company's targeted, broad-spectrum products and research programs
are focused on key biological processes that are central to human
cancers. ArQule's lead product, in Phase 2 and upcoming Phase 3
clinical development, is ARQ 197, an inhibitor of the c-Met receptor
tyrosine kinase. The Company has also initiated Phase 1 clinical
testing with ARQ 621, designed to inhibit the Eg5 kinesin motor
protein. The Company's pre-clinical pipeline includes a compound
designed to inhibit the BRAF kinase. ArQule's current discovery
efforts, which are based on the ArQule Kinase Inhibitor Platform
(AKIP(TM)), are focused on the identification of novel kinase
inhibitors that are potent, selective and do not compete with ATP
(adenosine triphosphate) for binding to the kinase.

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.
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. For more information, please visit
http://www.daiichisankyo.com.

Daiichi Sankyo, Inc., headquartered in Parsippany, New Jersey, is
a member of the Daiichi Sankyo Group. For more information on Daiichi
Sankyo, Inc., please visit http://www.dsi.com.

This press release contains forward-looking statements regarding
the Company's ArQule Kinase Inhibitor Platform (AKIP(TM)) and its
related agreement with Daiichi Sankyo. These statements are based on
the Company's current beliefs and expectations, and are subject to
risks and uncertainties that could cause actual results to differ
materially. Positive information about pre-clinical results does not
ensure that later stage pre-clinical or clinical development will be
successful. For example, targets for the kinase research may not
prove to be therapeutically relevant. Compounds developed through
application of the AKIP(TM) platform may not demonstrate positive
activity in pre-clinical in vivo or in vitro testing or in subsequent
clinical trials; in addition, they may not demonstrate an appropriate
safety profile later development as a result of known or as yet
unanticipated side effects. The results achieved in later stage
trials may not be sufficient to meet applicable regulatory standards.
Problems or delays may arise during clinical trials or in the course
of developing, testing or manufacturing these compounds that could
lead the Company or Daiichi Sankyo to discontinue development. Even
if later stage clinical trials are successful, the risk exists that
unexpected concerns may arise from analysis of data or from
additional data or that obstacles may arise or issues be identified
in connection with review of clinical data with regulatory
authorities. Regulatory authorities may disagree with the Company's
or Daiichi Sankyo's view of the data or require additional data or
information or additional studies. Drug development involves a high
degree of risk. Only a small number of research and development
programs result in the commercialization of a product. Positive
pre-clinical data may not be supported in later stages of
development. Furthermore, ArQule may not have the financial or human
resources to successfully pursue drug discovery in the future.
Daiichi Sankyo may not exercise its option to license compounds even
if the compounds show initial promise. For more detailed information
on the risks and uncertainties associated with the Company's drug
development and other activities, see the Company's periodic reports
filed with the Securities and Exchange Commission. The Company does
not undertake any obligation to publicly update any forward-looking
statements.

Contacts:
William B. Boni Toshiaki Sai
VP, Investor Relations/Corp. Corporate Officer, Corporate
Communications Communications
ArQule, Inc. Daiichi Sankyo, Co., Ltd. (Japan)
+1-781-994-0300 +81-3-6225-1126

ots Originaltext: Daiichi Sankyo
Im Internet recherchierbar: http://www.presseportal.de

Contact:
CONTACT: William B. Boni, VP, Investor Relations/Corp.,
Communications,ArQule, Inc., +1-781-994-0300; Toshiaki Sai, Corporate
Officer, Corporate,Communications, Daiichi Sankyo, Co., Ltd. (Japan),
+81-3-6225-1126