CollaGenex Pharmaceuticals Reports Highly Significant Outcomes of Phase 3 Clinical Trials Evaluating Oracea as a Treatment for Rosacea; For the Primary Endpoint, Oracea Demonstrated up to a 61% Reduction in Inflammatory Lesions.

NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (Nasdaq: CGPI) today announced the highly significant positive outcomes of two Phase 3, double-blinded, placebo-controlled clinical trials designed to evaluate the safety and efficacy of Oracea(TM) for the treatment of rosacea.

The trials enrolled a total of 537 patients in 28 centers across the U.S. Patients in the study were administered either Oracea or placebo once a day for 16 weeks.

Dr. James del Rosso, Clinical Assistant Professor, Department of Dermatology, University of Nevada School of Medicine, Las Vegas, Nevada said: "With millions of patients seeking treatment for rosacea, it is exciting that the studies with Oracea are so impressive. The availability of a systemic treatment for rosacea that is effective, safe and devoid of antibiotic effects, will be a major advance in treatment over existing systemic therapies. In addition, once daily dosage allows for much better compliance, which translates into better results."

Both studies achieved their primary endpoint by demonstrating a greater reduction in inflammatory lesion count over base-line for the Oracea-treated patients compared to the placebo controls. The differences were clinically and statistically highly significant (p less than 0.001 in each study). In the studies, patients receiving Oracea experienced a 61% and 46% mean reduction in inflammatory lesions compared to 29% and 20%, respectively, in patients receiving placebo.

With respect to secondary endpoints, the change in the Investigator's Global Assessment (IGA) scores and the change in the "dichotomized" IGA also showed a clinically and statistically significant improvement over placebo in both studies. The third secondary endpoint of improvement in erythema showed a trend towards improvement in one study and achieved statistical significance in the other.

IGA is a subjective measure of overall disease severity, and dichotomized IGA measures the percentage of patients considered clear or near clear of symptoms at week 16.

Colin Stewart, president and chief executive officer of CollaGenex, stated, "We are delighted with the results from these clinical studies which support our belief that Oracea offers real therapeutic benefits for rosacea patients. If approved by the FDA, we anticipate that Oracea would be the first systemic treatment to be approved for this disease. We also believe that the availability of a convenient, safe and effective product could significantly expand the current $500 million market for prescription drugs to treat this potentially disfiguring condition."

Klaus Theobald, M.D., Ph.D., chief medical officer of CollaGenex said, "We believe that these results demonstrate an excellent efficacy and safety profile for Oracea, and we expect to file our NDA in the third quarter of 2005."

The data from these trials will be presented by Dr. James del Rosso at the American Academy of Dermatology in Chicago, IL in July.

Rosacea is a condition that affects approximately 13.6 million adults in the U.S. It affects primarily the face and is characterized by the appearance of inflammatory lesions (papules, pustules and nodules), erythema (skin redness) and telangiectasia (spider veins). If allowed to progress to a moderate to severe condition, rosacea can cause itching, pain and thickening of the skin.

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company that has built its reputation on providing innovative medical therapies to the dental and dermatology markets. CollaGenex currently sells Periostat(R) as the first and only pharmaceutical to treat periodontal disease by inhibiting the enzymes that destroy periodontal support tissues and by enhancing bone protein synthesis. The company also markets Atridox(R), Atrisorb FreeFlow(R) and Atrisorb-D FreeFlow(R), which are products of QTL USA, Inc., the successor to Atrix Laboratories, Inc., for the treatment of adult periodontitis. Its professional dermatology sales force markets Pandel(R), a prescription topical corticosteroid licensed from Altana, Inc.

Research has shown that certain tetracyclines can be chemically modified to retain non-antibiotic properties that may make them effective in treating diseases involving inflammation and/or destruction of the body's connective tissues. CollaGenex is evaluating various chemically modified tetracyclines (so called "IMPACS(TM)" compounds because they are Inhibitors of Multiple Proteases And CytokineS") to assess whether they are safe and effective in these applications. The Company has a pipeline of innovative product candidates with possible applications in dermatology and other disease states. In addition, CollaGenex has acquired the Restoraderm(TM) technology, a unique, proprietary dermal drug delivery system, and plans to develop a range of topical dermatological products with enhanced pharmacologic and cosmetic properties.

To receive additional information on the Company, please visit our Web site at www.collagenex.com, which does not form part of this press release.

Forward-Looking Statements

Statements in this press release regarding management's future expectations, beliefs, goals, plans or prospects, including statements relating to the Company's research, technology, future products and the market for them, its clinical trials and its future product development and introduction efforts, may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. CollaGenex' actual results could differ materially from those stated or implied in forward-looking statements due to a number of factors, including those factors contained in CollaGenex' most recent Quarterly Report on Form 10-Q for the quarter ended March 31, 2005 under the section "Additional Risks That May Affect Results" as well as other documents that may be filed by CollaGenex from time to time with the Securities and Exchange Commission. Forward-looking statements include statements regarding CollaGenex' expectations, beliefs, intentions or strategies regarding the future and can be identified by forward-looking words such as "anticipate", "believe", "could", "estimate", "expect", "intend", "may", "should", "will", and "would" or similar words. CollaGenex assumes no obligations to update the information included in this press release.

Periostat(R) is a registered trademark and Restoraderm(TM), IMPACS(TM) and Oracea(TM) are trademarks of CollaGenex Pharmaceuticals, Inc.

Pandel(R) is a trademark of Taisho Pharmaceuticals.

Atridox(R), Atrisorb(R) and Atrisorb-D(R) are registered trademarks of QLT USA, Inc.