ArQule Announces Acceptance of Clinical Data on ARQ 197, c-Met Inhibitor, for Oral Presentation at ASCO.

Additional abstracts related to ArQule products and scientific platforms accepted at ASCO and AACR 

WOBURN, Mass. -- ArQule, Inc. (NASDAQ: ARQL) today announced that the American Society of Clinical Oncology (ASCO) has accepted for oral presentation the Company's abstract for ARQ 197 (A Phase 1 Dose Escalation Study of ARQ 197, a Selective Inhibitor of the c-Met Receptor in Patients with Metastatic Solid Tumors) at the 43rd ASCO Annual Meeting, June 1-5, 2007, in Chicago. This presentation will describe findings from a Phase 1 trial with ARQ 197, a selective, small molecule inhibitor of the c-Met receptor tyrosine kinase, in cancer patients with a broad range of metastatic solid tumor types who had failed prior treatment regimens.

In addition, abstracts describing protocol design and patient recruitment as of January, 2007 in the Company's ongoing Phase 2 trials with ARQ 501 in leiomyosarcoma and pancreatic cancer have been accepted for publication in the ASCO Proceedings. The Company expects to announce further results from these trials, as well as from a Phase 2 trial in head and neck cancer, in mid-2007. ARQ 501 is an activator of the DNA damage response/checkpoint pathway regulated by the E2F-1 regulatory protein and is the lead product from the Company's Activated Checkpoint Therapy (ACT) platform.

The American Association for Cancer Research (AACR) has accepted eleven abstracts submitted by the Company in connection with AACR's 2007 Annual Meeting, April 14-18, 2007, in Los Angeles. The AACR abstracts are based on pre-clinical studies that cumulatively provide a rationale for the company's approaches to cancer therapy as embodied in its c-Met inhibition and DNA damage response/checkpoint activation platforms. They represent a broad scope of findings from in vitro (cell line) and in vivo (animal) experiments.

Consistent with the disclosure policies mandated by ASCO and AACR, ArQule will summarize the contents of these studies at the time the complete abstracts are presented or published. Following is a list of the abstracts related to ARQ 197 and ARQ 501 that have been accepted at the ASCO and AACR meetings.

ASCO Abstracts

For oral presentation

* A Phase 1 dose escalation study of ARQ 197, a selective inhibitor of the c-Met receptor in patients with metastatic solid tumors

For publication in ASCO proceedings

* A Phase 2 study of ARQ 501 in combination with gemcitabine in adult patients with treatment naove, unresectable pancreatic adenocarcinoma 

* A Phase 2 dose multi-center, open-label study of ARQ 501, a checkpoint activator, in adult patients with persistent, recurrent or metastatic leiomyosarcoma (LMS)

AACR Abstracts

* Pharmacokinetics of a novel PGA-ARQ 501 conjugate in mouse xenografts

* Mass balance and characterization of the Metabolites of ARQ 501 ([eth]-lapachone), a checkpoint pathway activator in clinical development

* Pharmacodynamic biomarkers for checkpoint pathway activator ARQ501 in a human colon xenograft model

* Selective induction of necrotic cell death in cancer cells by [eth]-lapachone through activation of DNA damage response pathway

* Evaluation of biomarkers for HGFR/c-Met inhibitor ARQ 197 in a human xenograft model

* Functional chemogenomics approach to identify checkpoint pathway activators against cancer

* Selective killing of cancer cells by activation of human checkpoint kinase 2

* ARQ 197, a highly selective small molecule inhibitor of c-Met, inhibits invasive and metastatic growth of cancer cells

* ARQ 197, a highly selective small molecule inhibitor of c-Met, with selective antitumor properties in a broad spectrum of human cancer cells

* Broad spectrum anti-cancer activity of ARQ 197, a highly selective oral c-Met Inhibitor, in multiple xenograft models

* Anti-metastatic activity of ARQ 197, a highly selective oral small molecule inhibitor of c-Met, in experimental metastatic models of colon cancer

About ArQule

ArQule, Inc. 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 designed to affect key biological processes that are central to cancer. ArQule's lead clinical-stage products have been generated from two scientific platforms: Cancer Survival Protein modulation and Activated Checkpoint Therapy([R]) (ACT). The Cancer Survival Protein modulation platform has generated a clinical-stage product designed to inhibit a molecule known as c-Met, which plays multiple roles in cancer cell growth, survival, invasion, angiogenesis and metastasis. The ACT platform is designed to kill cancer cells selectively while sparing normal cells through direct activation of DNA damage response/checkpoint pathways. The Company's lead ACT program, based on the E2F-1 pathway, is partnered with Roche. For more information, please visit www.arqule.com.

This press release contains forward-looking statements regarding the Company's Phase 1 trial with ARQ 197 and Phase 2 trials with ARQ 501. 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 early stage clinical trial results does not ensure that later stage or larger scale clinical trials will be successful. For example, ARQ 197 and ARQ 501 may not demonstrate promising therapeutic effect; in addition, they 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 ongoing or 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 its partner 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 or that regulatory authorities may disagree with the Company'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 ARQ 197 and ARQ 501 are subject to the ability of the Company to enroll patients, enter into agreements with clinical trial sites and investigators, and other technical hurdles and issues that may not be 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. 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.