Arqule, Inc. to Present at the UBS Global Life Sciences Conference on September 29, 2005; Live Webcast Scheduled for 9:30 a.m. Eastern Time.

WOBURN, Mass. -- ArQule, Inc. (Nasdaq: ARQL) today announced that it will participate in the UBS 2005 Global Life Sciences Conference on Thursday, September 29, 2005 at 9:30 a.m. (eastern time). ArQule's presentation will be webcast live and can be accessed through the investor relations section of the Company's website, www.ArQule.com. The conference will be held at The Grand Hyatt Hotel, New York City, NY.

About ArQule

ArQule, Inc. is a biotechnology company engaged in research and development of next-generation small-molecule cancer therapeutics based on its innovative Activated Checkpoint Therapy(SM) (ACT) platform. ACT compounds are intended to improve the way cancer patients are treated because they selectively kill cancer cells and spare normal cells by restoring and activating cellular checkpoints that are defective in cancer. ArQule's lead program based on E2F elevation is partnered with Roche. In addition to advancing its own programs, ArQule continues to advance the drug discovery efforts of pharmaceutical collaborators by providing high-quality library design and compound production, including collaborations with Pfizer. For more information, please visit www.ArQule.com.

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, which provides a safe harbor for forward-looking statements made by or on behalf of ArQule. ArQule and its representatives may from time to time make written or oral forward-looking statements, including statements contained in this press release. Generally, the words "believe," "expect," "intend," "estimate," "anticipate," "will" and similar expressions identify forward-looking statements. All statements which address operating performance, events or developments that ArQule expects or anticipates will occur in the future, such as projections about its future results of operations or its financial condition, research, development and commercialization of its products and anticipated trends in its business are forward-looking statements within the meaning of the Reform Act. Actual results may differ materially from those projected in the forward-looking statements or historical performance due to numerous risks and uncertainties that exist in ArQule's operations, development efforts and the business environment, including without limitation: the ACT platform may not improve efficacy or reduce toxicity and compounds resulting from the platform may not operate as intended; the current and future clinical studies may encounter enrollment difficulties and unexpected toxicity; the commencement of the anticipated clinical trials may be delayed or the trials may never commence; the preclinical efforts associated with the ACT pipeline may fail or prove disappointing; the animal xenograft preclinical studies may be unpredictive of human response; collaborators may terminate their agreements with ArQule because ArQule may fail to satisfy the collaborators' needs or for other reasons; and, the risks and uncertainties described in ArQule's Form 10-Q filed with the Securities and Exchange Commission on August 5, 2005, its Form 10-Q filed with the Commission on April 29, 2005, its Form 10-K filed with the Commission on March 16, 2005, its Form 10-Q filed with the Commission on November 9, 2004, and its Form 10-Q filed with the Commission on August 4, 2004. The forward-looking statements contained herein represent the judgment of ArQule as of the date of this report. ArQule disclaims any intent or obligation to update any forward-looking statement except to the extent required by law.