AXYS Pharmaceuticals Announces the First X-Ray Crystal Structure of a Key Protease Associated With Inflammatory Disease.

SOUTH SAN FRANCISCO, Calif.--(BW HealthWire)--July 23, 1998--Axys Pharmaceuticals, Inc. (Nasdaq: AXPH) today announced that it has elucidated the first three-dimensional structure of cathepsin S, a protease associated with normal cellular protein degradation with links to several inflammatory diseases, including arthritis, asthma and other autoimmune diseases. As reported in the June 1998, issue of the peer-reviewed journal, Protein Science, the researchers delineated the binding site and characteristics distinct to cathepsin S and believe that its structure provides a sound basis for the development of potent and selective inhibitors against this therapeutically-relevant enzyme.

"This study provides valuable insight into the structure and attributes particular to cathepsin S," stated Mary McGrath, Ph.D., lead author of the study and group leader of structural biology at Axys Pharmaceuticals. "Using this information, we will now be able to dissect out structural features which distinguish this protease target from other related proteases that play central roles in normal cellular metabolism."

"The outstanding research leading to the crystallization and solution of the X-ray crystal structure of cathepsin S is a prime component of Axys' gene-to-drug capabilities," stated Michael C. Venuti, Ph.D., Axys' senior vice president of research, South San Francisco. "We believe the information we have gathered on both the structure and function of cathepsin S has significantly advanced our program of structure-based design, synthesis and optimization of inhibitors of this enzyme, and provides Axys with an attractive partnering opportunity. Currently, our medicinal chemistry efforts have identified sub-nanomolar, reversible, selective inhibitors of cathepsin S, which are now undergoing pharmacological evaluation. This research is part of our ongoing program in the development of the inhibitors of several members of the papain family of cysteine proteases, including our current program based on the role of cathepsins K & L in osteoporosis, which is partnered with Merck."

The authors of the paper, entitled "Crystal Structure of Human Cathepsin S," include Mary E. McGrath, James T. Palmer, Dieter Bromme and John R. Somoza (Protein Science, (1998) 7:1294-1302).

A paper in the June 1, 1998 issue of the Journal of Clinical Investigation, which was authored by Professor Hal Chapman of The Brigham & Women's Hospital, Boston, MA, and co-authored by James T. Palmer, a group leader at Axys, has confirmed the role of cathepsin S in the class II MHC (major histocompatibility complex) mediated pathway of antigen presentation in animal models of inflammation and the immune response to foreign antigen.

Axys Pharmaceuticals is a leader in the integration of life science technologies with a focus on transforming gene discoveries into drugs. The company has research collaborations with world-class pharmaceutical companies, covering a broad range of therapeutic areas, including respiratory, cardiovascular, and infectious disease, as well as oncology and central nervous system disorders.

Except for the historical information contained herein, this press release contains forward-looking statements that involve risks and uncertainties which could cause Axys' actual results to differ materially from those discussed here, including the risk that Axys' collaborations will not be successful, the risk that Axys will not be successful in entering into new collaborations, the risk of Axys' early stage of development, Axys' reliance on the efforts of its collaborative partners, competition, and general economic conditions that may affect Axys' actual results and developments. Additional factors that could cause or contribute to such differences include, but are not limited to, those discussed in the sections entitled "Business" and "Additional Risk Factors" in the company's SEC Reports, including the company's report on Form 10-K for the fiscal year ended December 31, 1997.

For more information on Axys Pharmaceuticals, Inc., please visit the company's website at http://www.axyspharm.com.

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