CollaGenex Pharmaceuticals Initiates Multicenter Phase 3 Clinical Study to Evaluate Periostat as a Treatment for Rosacea.

Business Editors

NEWTOWN, Pa.--(BUSINESS WIRE)--Aug. 13, 2002

210-Patient Study Designed to Confirm Anecdotal Reports of Efficacy

CollaGenex Pharmaceuticals, Inc. (Nasdaq:CGPI) today announced that it has initiated a multi-center, double-blinded, placebo-controlled Phase 3 clinical study to evaluate the efficacy of its product, Periostat(R) (doxycycline hyclate tablets) 20 mg, for the treatment of rosacea. There is currently no FDA-approved systemic treatment for rosacea.

This study, which will enroll up to 210 patients, is being conducted by James Leyden, MD, Professor of Dermatology at the University of Pennsylvania, Robert Skidmore, MD, Associate Professor of Dermatology at Shands Medical Center of the University of Florida, Diane Thiboutot, MD, Professor of Dermatology at the Milton S. Hershey Medical Center of the Pennsylvania State University, Joseph Fowler, MD, Clinical Dermatologist, Louisville, KY and Brian Berman, MD, PhD, Professor of Dermatology and Internal Medicine at the University of Miami School of Medicine. The study design calls for four months of dosing with either Periostat or placebo, with primary end points including the number of facial lesions apparent at the end of the study compared with baseline, and an assessment by the investigator of the patient's facial redness.

"Rosacea is a chronic inflammatory disease, with no cure," said Dr. James Leyden. "The primary mode of treatment is to administer topical and systemic antibiotics for long periods of time. This treatment regimen often leads to significant side effects, primarily nausea, diarrhea and dry skin. Another potential risk of current therapeutic regimens is the development of microbial resistance associated with long-term administration of antibiotics. Anecdotal evidence suggests that Periostat, a subantimicrobial formulation of doxycycline, may be effective in treating rosacea without the side effects or the risk of developing microbial resistance."

"The potential to treat rosacea with Periostat is based on our understanding of its biological properties, as well as anecdotal reports from current patients that their rosacea improved while being treated with the drug for periodontitis," said Brian M. Gallagher, PhD, chairman, president and chief executive officer of CollaGenex. "A recent study demonstrated that Periostat, the first FDA-approved and commercialized product from our IMPACS technology, has the potential to treat moderate acne vulgaris, a disease with similar inflammatory symptoms to rosacea. We look forward to developing a novel treatment for patients suffering from this potentially disfiguring disease."

Rosacea is an increasingly common diagnosis affecting more than 12 million people in the United States. It is estimated that patients suffering from rosacea spend in excess of $500MM on prescription medications every year in the United States. The disease is characterized by the appearance of erythema (a characteristic pattern of persistent redness of the skin that is frequently exacerbated by spicy foods and alcohol) which usually affects the nose, cheeks and forehead, and is often combined with small spider veins called telangiectasia near the surface of the skin of the cheeks and nose. As the disease progresses, inflammatory lesions appear and accompany the erythema. As rosacea becomes more severe, itching and pain can occur.

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company currently focused on providing innovative medical therapies to the dental and dermatology markets. Currently, the Company's 120-person professional dental pharmaceutical sales force markets Periostat, the first and only pharmaceutical to treat periodontal disease by inhibiting the enzymes that destroy periodontal support tissues, Vioxx(R), a Merck & Co. drug that CollaGenex co-promotes for the treatment of acute dental pain, and Atridox(R), Atrisorb(R) and Atrisorb-D(R), Atrix Laboratories Inc.'s products for the treatment of adult periodontitis. Research has shown that the enzyme suppression technology underlying Periostat may also be applicable to other diseases involving inflammation and/or destruction of the body's connective tissues, including acne, rosacea, meibomianitis and cancer metastasis, among others. CollaGenex is further developing Periostat, as well as a series of novel, proprietary compounds known as IMPACS (Inhibitors of Multiple Proteases and Cytokines), to address these applications. In addition CollaGenex has licensed the Restoraderm(TM) technology, a unique, proprietary dermal drug delivery system, in order to develop a range of topical dermatological products with enhanced pharmacologic and cosmetic properties.

To receive additional information on the Company, please visit our website at www.collagenex.com, which is not a part of this press release.

This press release contains forward-looking statements within the meaning of Section 21E of the Securities and Exchange Act of 1934, as amended. Investors are cautioned that forward-looking statements involve risks and uncertainties that may affect the company's business and prospects. The company's business of selling, marketing and developing pharmaceutical products is subject to a number of significant risks, including marketing plans; risks inherent in research and development activities; risks associated with conducting business in a highly regulated environment and uncertainty relating to clinical trials of products under development, all as discussed in the company's periodic filings with the U.S. Securities and Exchange Commission.

Periostat(R), Metastat(R), IMPACS(TM) and Restoraderm(TM) are United States trademarks of CollaGenex Pharmaceuticals, Inc. Periostat(R) is a European Community trademark of CollaGenex Pharmaceuticals, Inc.

Periostat(R), IMPACS(R) and Restoraderm(R) are United Kingdom trademarks of the Company's wholly owned subsidiary, CollaGenex International Limited. CollaGenex(R) is a European Community and United Kingdom trademark of CollaGenex International Limited.

Pandel(R) is a trademark of Taisho Pharmaceuticals.

VIOXX(R)is a trademark of Merck & Co., Inc.

Atridox(R), Atrisorb(R) and Atrisorb-D(R) are trademarks of Atrix Laboratories, Inc.