ArQule Enrolls First Patient in Phase 1 Trial with ARQ 087, an FGFR Inhibitor

  ArQule Enrolls First Patient in Phase 1 Trial with ARQ 087, an FGFR
  Inhibitor

Business Wire

WOBURN, Mass. -- December 13, 2012

ArQule, Inc. (Nasdaq: ARQL) today announced the commencement of patient dosing
in a Phase 1 clinical trial with ARQ 087, an orally bioavailable, potent
multi-kinase inhibitor with pan-FGFR (fibroblast growth factor receptor)
activity.

“FGFR has been a difficult target to drug historically, and we are pleased
that we have been able to do so through the application of the Company’s
proprietary ArQule Kinase Inhibitor Platform (AKIP™),” said Brian Schwartz,
M.D., chief medical officer of ArQule. “We look forward to characterizing the
activity of ARQ 087 in the clinical setting.”

The primary objective of the Phase 1 trial with ARQ 087 is determine its
safety, tolerability and recommended Phase 2 dose. Patients with metastatic
solid tumors who are refractory to available therapies or for whom no standard
systemic therapy exists will be enrolled. The number of patients expected to
be enrolled will depend on the number of patient cohorts investigated until
dose-limiting toxicity is reached.

Fibroblast growth factors (FGF) and their receptors (FGFR) play important
roles in cell proliferation, cell differentiation, cell migration, cell
survival, protein synthesis, and angiogenesis. Dysregulation of FGFR signaling
has been implicated in a number of cancers, including squamous non-small cell
lung cancer (NSCLC), small cell lung cancer (SCLC), gastric, liver, breast,
ovarian, endometrial, and bladder carcinomas, fueling significant interest in
FGFRs as targets for therapeutic intervention.

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 Phase 3 clinical development, is tivantinib (ARQ 197), 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, ARQ
736, designed to inhibit the RAF kinases, and ARQ 087, designed to inhibit
fibroblast growth factor receptor (FGFR). 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.

This press release contains forward-looking statements regarding the progress
of ArQule’s clinical trial with ARQ 087, an inhibitor of fibroblast growth
factor receptor (FGFR). These statements are based on the Companies’ current
beliefs and expectations, 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, ARQ 087
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 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 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. 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 undertakes any obligation to
publicly update any forward-looking statements.

Contact:

ArQule, Inc.
William B. Boni, 781-994-0300
VP, Investor Relations / Corp. Communications
www.ArQule.com