Arqule and Daiichi Sankyo Announce Completion of Patient Recruitment in Phase 3 Clinical Trial of Tivantinib in Non-small Cell

Arqule and Daiichi Sankyo Announce Completion of Patient Recruitment in Phase
         3 Clinical Trial of Tivantinib in Non-small Cell Lung Cancer

  PR Newswire

  WOBURN, Massachusetts and TOKYO, May 18, 2012

WOBURN, Massachusetts and TOKYO, May 18, 2012 /PRNewswire/ --

ArQule, Inc. (Nasdaq: ARQL) and Daiichi Sankyo, Co., Ltd. (TSE 4568) today
announced that recruitment of patients has been completed in the randomized,
double-blind, controlled Phase 3 MARQUEE pivotal trial of their
investigational selective c-MET inhibitor, tivantinib, in combination with
erlotinib in previously treated patients with locally advanced or metastatic,
non-squamous, non-small cell lung cancer (NSCLC).

The MARQUEE ( M et inhibitor ARQ 197 plus E rlotinib vs E rlotinib plus
placebo in NSCLC) trial began enrollment in January 2011 and is being
conducted under a Special Protocol Assessment (SPA), which was established
following agreement with the U.S. Food and Drug Administration (FDA).
Tivantinib is currently in Phase 3 development and has not yet been approved
for any indication.

"At the time of diagnosis with lung cancer, more than half of all patients
have progressed to advanced stages of the disease, with a poor prognosis for
long-term survival. There is a high unmet need for additional effective
treatment options for patients and their families," said Glenn Gormley, MD,
PhD, Global Head, Research & Development and Senior Executive Officer, Daiichi
Sankyo and President, Daiichi Sankyo Pharma Development.

Lung cancer is one of the most commonly diagnosed cancers around the globe,
^[1] with an estimated 1.6 million new cases diagnosed worldwide each year.
^[2] NSCLC is the most common form of lung cancer, accounting for
approximately 85 percent of all cases. ^[3] The majority of all lung cancers
are non-squamous. ^[4]

"We would like to thank the patients, investigators and clinical sites who are
participating in the MARQUEE trial," said Brian Schwartz, chief medical
officer of ArQule. "Their commitment, diligence and care have been essential
in the timely achievement of this important milestone in the development of

Approximately 1,000 patients have been recruited in MARQUEE from more than 200
clinical sites worldwide. The primary endpoint in the trial is overall
survival in the overall intent-to-treat population. Giorgio Scagliotti, MD,
PhD, Head of the Department of Clinical and Biological Sciences at S. Luigi
Hospital, Orbassano (Torino), Italy is the principal European investigator for
MARQUEE, and the principal U.S. investigator is Alan Sandler, MD, Professor of
Medicine in the Division of Hematology and Medical Oncology, Department of
Medicine, at Oregon Health and Science University in Portland.

In December 2008, ArQule and Daiichi Sankyo signed a license, co-development
and co-commercialization agreement to co-develop tivantinib (ARQ 197) in the
U.S., Europe, South America and the rest of the world, excluding Japan, China
(including Hong Kong), South Korea and Taiwan.

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 candidate,
in Phase 2 and Phase 3 clinical development together with development and
commercialization partner, Daiichi Sankyo, Co. Ltd., is tivantinib, an oral,
selective inhibitor of the c-MET receptor tyrosine kinase. The Company's
pipeline consists of ARQ 621, designed to inhibit the Eg5 kinesin motor
protein, and ARQ 736, designed to inhibit the RAF kinases. ArQule's current
discovery efforts, which are based on the ArQule Kinase Inhibitor Platform
(AKIP™), 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 .

This press release contains statements regarding the clinical trials with
tivantinib (ARQ 197) by ArQule and its business partner, Daiichi Sankyo.
These statements are based on the current beliefs and expectations of both
companies, and are subject to risks and uncertainties that could cause actual
results to differ materially. Positive information about pre-clinical and
early stage clinical trial results does not ensure that later stage or larger
scale clinical trials will be successful. For example, tivantinib may not
demonstrate a promising therapeutic effect; in addition, it may not
demonstrate an appropriate safety profile in current or later stage or larger
scale clinical trials 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 or to justify further development.
Problems or delays may arise during clinical trials or in the course of
developing, testing or manufacturing these compounds that could lead ArQule or
its partners to discontinue development. Even if later stage clinical trials
are successful, unexpected concerns may arise from analysis of data or from
additional data. Obstacles may arise or issues may be identified in
connection with review of clinical data with regulatory authorities.
Regulatory authorities may disagree with ArQule's view of the data or require
additional data or information or additional studies. In addition, the
planned timing of initiation and completion of clinical trials for tivantinib
are subject to the ability of ArQule, Daiichi Sankyo, and Kyowa Hakko Kirin, a
licensee of tivantinib, to enroll patients, enter into agreements with
clinical trial sites and investigators, and overcome technical hurdles and
other issues related to the conduct of the trials for which each of them is
responsible. There is a risk that these issues may not be successfully
resolved. 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. Moreover, with
respect to partnered programs, even if certain compounds show initial promise,
Daiichi Sankyo or Kyowa Hakko Kirin may decide not to license or continue to
develop them, as the case may be. In addition, Daiichi Sankyo and Kyowa Hakko
Kirin have certain rights to unilaterally terminate their agreements with
ArQule. If either company were to do so, ArQule might not be able to complete
development and commercialization of the applicable licensed products on its
own. For more detailed information on the risks and uncertainties associated
with ArQule's drug development and other activities, see ArQule's periodic
reports filed with the Securities and Exchange Commission. Neither ArQule nor
Daiichi Sankyo undertake any obligation to publicly update any forward-looking

1. American Cancer Society. Global Cancer Facts & Figures 2nd Edition.
. Accessed April 11, 2012.

2. American Cancer Society. Global Cancer Facts & Figures 2nd Edition.
. Accessed April 11, 2012.

3. American Cancer Society. Non-Small Cell Lung Cancer. .
Accessed April 11, 2012.

4. American Cancer Society. Non-Small Cell Lung Cancer. .
Accessed April 11, 2012.

Contact: Contact: William B. Boni, VP, Investor Relations/Corp.
Communications, ArQule, Inc., +1(781)994-0300,; Michaela
Paudler-Debus, PhD, Daiichi Sankyo, Co., Ltd., +81-3-6225-1338 (office)
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