Newtown, PA – (June 15, 2004) – CollaGenex Pharmaceuticals, Inc. (Nasdaq:CGPI) today announced that the FDA has cleared the way for the immediate enrollment of patients in two Phase 3 clinical trials of Col-101, the Company's once daily, modified-release formulation of doxycycline, 40 mg, for the treatment of rosacea. Col-101 is also known as Periostat MR, which is already in Phase 3 clinical testing for the adjunctive treatment of adult periodontitis. CollaGenex is currently developing a brand name specifically for the use of Col-101 in dermatology.

   The two double-blinded, placebo-controlled Phase 3 clinical studies will each enroll up to 264 patients at a total of 22 investigational centers. The studies will evaluate the clinical indices of rosacea, including reductions in inflammatory lesions and erythema, during a 16-week period of administration.

   In a recent Phase 3 study involving Periostat, a twice daily, 20 mg dosage of doxycycline with a similar pharmacokinetic profile as Col-101, patients showed clinically and statistically highly significant improvements in their rosacea conditions compared with patients on placebo. These improvements included significantly greater reductions in the number of inflammatory lesions (p = 0.009) and in overall disease severity based on the Clinician's Global Severity Assessment Scale, with a greater number of patients on Periostat(R) showing a complete clearing of the disease at 16 weeks compared to those patients on placebo (p = 0.014). Erythema scores in patients in the Periostat group showed greater improvement compared with patients in the placebo group (p = 0.08).

   "The highly positive results of the Periostat study in rosacea convinced us to develop our once daily, modified-release formula, Col-101, for the treatment of rosacea," said Colin Stewart, president and chief executive officer of CollaGenex. "Col-101 has been developed using patented, extended-release drug delivery technology from Shire Laboratories. If we are successful, Col-101 will be the first systemic treatment approved by the FDA for rosacea and will offer patients the convenience of once-daily dosing. The launch of these Phase 3 clinical trials marks a very important milestone as we build our dermatology franchise."

   Rosacea is an increasingly common diagnosis affecting more than 14 million people in the United States. The disease is characterized by inflammatory lesions and the appearance of erythema, a persistent redness of the skin, that usually affect the nose, cheeks and forehead. As rosacea becomes more severe, itching and pain can occur. The prescription rosacea category is one of the fastest growing segments of the dermatology market and is estimated to be $500 million annually.

   CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on providing innovative medical therapies to the dental and dermatology markets. Currently, the Company's professional dental pharmaceutical sales force markets Periostat, which is indicated as an adjunct to scaling and root planing for the treatment of adult periodontitis. Periostat is 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 dental sales force also promotes Atridox(R), Atrisorb FreeFlow(R) and Atrisorb-D FreeFlow(R), Atrix Laboratories, Inc.'s products for the treatment of adult periodontitis, to the dental market. The Company's professional dermatology sales force markets Pandel(R), a prescription topical corticosteriod licensed from Altana, Inc.

   Research has shown that certain unique properties of the tetracyclines discovered during the development of Periostat(R) may be applicable to other diseases involving inflammation and/or destruction of the body's connective tissues, including acne, rosacea, meibomianitis and cancer metastases, among others. CollaGenex is further evaluating Periostat(R), as well as the new IMPACS(R) compounds, to assess whether they are safe and effective in these applications. In addition, CollaGenex has licensed the Restoraderm(R) 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 Web site at www.collagenex.com, which does not form part of this press release.

   This press release contains forward-looking statements that involve risks and uncertainties. Our business of selling, marketing and developing pharmaceutical products is subject to a number of significant risks, including risks relating to the implementation of CollaGenex's sales and marketing plans for Periostat and other products that we market, risks associated with our arrangement with Mutual, risks inherent in research and development activities, risks associated with enforcement of our intellectual property rights, risks that the FDA will approve products that will compete with and limit the market for Periostat, risks relating to our litigation with the FDA, risks associated with conducting business in a highly regulated environment and uncertainty relating to clinical trials of products under development. CollaGenex's success depends to a large degree upon the market acceptance of Periostat by periodontists, dental practitioners, other health care providers, patients and insurance companies and the success of our dermatology product candidates. There can be no assurance that CollaGenex's product candidates (other than the FDA's approval of Periostat for marketing in the United States, the United Kingdom Medicines Control Agency's approval of Periostat for marketing in the United Kingdom and Periostat's marketing approval in Austria, Finland, Switzerland, Ireland, Israel, Italy, Luxembourg, the Netherlands, Portugal and Canada) will be approved by any regulatory authority for marketing in any jurisdiction or, if approved, that any such products will be successfully commercialized by CollaGenex. In addition, there can be no assurance that CollaGenex will successfully promote Pandel, Atridox, Atrisorb-FreeFlow or Atrisorb-D. As a result of such risks and those risks set forth in CollaGenex's filings with the Securities and Exchange Commission, CollaGenex's actual results may differ materially from the results discussed in or implied by the forward-looking statements contained herein. We undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

   Periostat(R), IMPACS(R), Metastat(R) and Restoraderm(R) are registered trademarks of CollaGenex Pharmaceuticals, Inc.

   All other trade names, trademarks or service marks are the property of their respective owners and are not the property of CollaGenex Pharmaceuticals, Inc. or any of our subsidiaries.

   Pandel(R) is a trademark of Taisho Pharmaceuticals.

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

   SOURCE: CollaGenex Pharmaceuticals, Inc.

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