CollaGenex Pharmaceuticals Announces Results of Phase 4 Clinical Study Showing Oracea Equally Effective as 100 mg Doxycycline in Treatment of Rosacea

CollaGenex Pharmaceuticals, Inc. (NASDAQ:CGPI) today announced results of a Phase 4 dose-comparison study designed to evaluate the safety and efficacy of Oracea(R) once daily versus doxycycline 100 mg once daily for the treatment of rosacea. A presentation of the results was made yesterday by James Q. Del Rosso, D.O., Clinical Assistant Professor, Department of Dermatology at the University of Nevada, School of Medicine, at the 7th Annual Caribbean Dermatology Symposium. Oracea is a patented, delayed release formulation of doxycycline, 40 mg, that is the only FDA-approved treatment for the papules and pustules associated with rosacea. Doxycycline at much higher doses is often prescribed off-label by dermatologists for the treatment of rosacea. The study demonstrated that the higher, antimicrobial dose does not provide a greater clinical benefit than the anti-inflammatory dose of 40 mg, controlled release. However, the higher dose was associated with a significantly higher incidence of adverse events. This prospectively randomized, double-blinded, placebo-controlled clinical study enrolled 91 patients at 7 investigational centers across the United States. The study had two arms, and patients were treated once daily with either 100 mg of doxycycline or Oracea (40 mg doxycycline, controlled release). Both treatments were administered as an adjunct to topical MetroGel(R) 1%. The treatment duration was 16 weeks, and patients were evaluated for efficacy and adverse events at baseline and at weeks 4, 8, 12 and 16. The primary endpoint was mean change in total inflammatory lesion count from baseline to the week 16 visit. Patients in the Oracea group had an average of 19.8 inflammatory lesions at baseline and experienced a decrease in lesion count of 12.5 lesions, compared with 17.7 lesions at baseline and a decrease of 12.2 lesions in the doxycycline, 100 mg group. The difference between the treatment groups is neither clinically nor statistically significant (p-value = 0.83). In addition, there were no differences observed between the treatment groups regarding the secondary endpoints of Investigators Global Assessment and Clinician’s Erythema Assessment with (p-values of 0.86 and 0.50, respectively). In contrast, a clear difference was observed between the two treatment groups in the incidence of adverse events, primarily gastrointestinal reactions. Gastrointestinal adverse events, including nausea, vomiting, diarrhea and stomach discomfort, were observed in 26% of patients administered 100 mg of doxycycline versus only 5% in the Oracea group. Klaus Theobald, M.D., Ph.D., chief medical officer of CollaGenex, said, "We are extremely pleased with the outcome of our Phase 4 study. The study clearly demonstrates that increasing the dose of doxycycline above the anti-inflammatory levels provided by Oracea does not provide any additional benefit but significantly adds to the adverse event profile.” "These data are clinically important as clinicians strive to provide the most effective treatment while reducing the potential for side effects,” said James Q. Del Rosso, D.O., the lead principal investigator of the study. "This study has demonstrated that, in patients with rosacea, increasing the daily dose of doxycycline to 100 mg does not lead to greater efficacy than Oracea, but has a much greater incidence of gastrointestinal side effects. In addition, Oracea’s onset of action was not different from the 100 mg doxycycline dose.” Colin Stewart, president and chief executive officer of CollaGenex, stated, "The results of this trial provide sound clinical evidence that Oracea provides maximum benefit with minimal adverse events. These data will help clarify the inflammatory nature of rosacea and the need for the anti-inflammatory dose of doxycycline that Oracea provides.” About CollaGenex CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company currently focused on developing and marketing proprietary, innovative medical therapies to the dermatology market. In July 2006, CollaGenex launched Oracea(R), the first FDA-approved systemic product for the treatment of rosacea. CollaGenex's professional dermatology sales force also markets Alcortin(R) (1% iodoquinol and 2% hydrocortisone), a prescription topical antifungal steroid combination, and Novacort(R) (2% hydrocortisone acetate and 1% pramoxine HCl), a prescription topical steroid and anesthetic. Alcortin and Novacort are marketed by the Company under a Promotion and Cooperation agreement with Primus Pharmaceuticals, Inc. CollaGenex recently completed a Phase II clinical trial to evaluate COL-118, a topical compound based on the SansRosa(R) technology, for the treatment of redness associated with rosacea and other skin disorders. CollaGenex recently acquired the rights to develop and commercialize becocalcidiol, a patented Vitamin D analogue developed by QuatRx Pharmaceuticals Company that is currently in Phase II clinical trials for the topical treatment of mild to moderate psoriasis. Research has shown that compounds can be created by chemically modifying certain tetracyclines and that these new compounds have 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 SansRosa(R) technology, which consists of a class of compounds that have shown promise in reducing the redness associated with rosacea, and the Restoraderm(R) technology, a unique, proprietary dermal drug delivery system. CollaGenex plans to leverage these platforms 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 does not form part of this press release. Forward Looking Statements Statements in this press release regarding management's future expectations, beliefs, intentions, goals, strategies, plans or prospects, including statements relating to the Company's revenue, cost of goods sold, net loss and expenses and future cash position, including the remainder of fiscal year 2007, and its future research and development efforts, including the Company's clinical and development programs relating to becocalcidiol, incyclinide and COL-118 and its dermatology franchise, product pipeline and intellectual, property, may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by terminology such as "anticipate," "believe," "could," "could increase the likelihood," "estimate," "expect," "intend," "is planned," "may," "should," "will," "will enable," "would be expected," "look forward," "may provide," "would" or similar terms, variations of such terms or the negative of those terms. Such forward-looking statements involve known and unknown risks, uncertainties and other factors including those risks, uncertainties and factors referred to in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2007 filed with the Securities and Exchange Commission under the section "Risk Factors," as well as other documents that may be filed by CollaGenex from time to time with the Securities and Exchange Commission. As a result of such risks, uncertainties and factors, the Company's actual results may differ materially from any future results, performance or achievements discussed in or implied by the forward-looking statements contained herein. CollaGenex is providing the information in this press release as of this date and assumes no obligations to update the information included in this press release or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Restoraderm(R), SansRosa(R) and Oracea(R) are registered trademarks and IMPACS(TM) is a trademark of CollaGenex Pharmaceuticals, Inc. Novacort(R) and Alcortin(R) are trademarks of Primus Pharmaceuticals, Inc. Pandel(R) is a trademark of Taisho Pharmaceuticals. Atridox(R), Atrisorb(R) and Atrisorb-D(R) are registered trademarks of Tolmar, 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.