NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (NASDAQ:CGPI) today announced that it has initiated enrollment in a 40 mg cohort in its Phase II double-blinded, placebo-controlled, dose-finding clinical trial to determine the appropriate dose for Phase III testing of incyclinide in the treatment of acne. The 40 mg cohort will enroll 100 patients with moderate-to-severe acne at 13 investigational centers across the United States. The placebo-controlled study will evaluate a daily 40 mg dose of incyclinide over a 12 week period.

Klaus Theobald, M.D., Ph.D., chief medical officer of CollaGenex, said, "We are extremely encouraged that the analysis of the 5, 10, and 20 mg cohorts demonstrated a dose-response relationship for incyclinide in the treatment of acne. We established a minimum effective dose at 10 mg per day and saw greater efficacy at the 20 mg daily dose. Incyclinide appears to be safe and effective at a 20 mg daily dose with a side effect profile similar to placebo. Since we do not believe that we have yet seen peak efficacy, we are continuing the study with a 40 mg cohort."

Colin Stewart, president and chief executive officer of CollaGenex, stated, "Our ability to initiate the 40 mg cohort quickly should allow us to complete our Phase II dose-ranging study later this year and initiate Phase III clinical trials of incyclinide in acne patients in the first quarter of 2008. We continue to be very excited about the potential of incyclinide to be the first new compound approved to treat acne in over 20 years."

About CollaGenex

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company currently focused on developing and marketing innovative proprietary medical therapies to the dermatology market. In July 2006, CollaGenex launched Oracea(TM), the first FDA-approved systemic product for the treatment of rosacea. CollaGenex is also conducting Phase I clinical trials to evaluate COL-118, a topical compound based on the SansRosa(TM) technology, for the treatment of redness associated with rosacea and other skin disorders. CollaGenex's professional dermatology sales force also markets Pandel(R), a prescription topical corticosteroid licensed from Altana, Inc., Alcortin(TM) (1% iodoquinol and 2% hydrocortisone), a prescription topical antifungal steroid combination, and Novacort(TM) (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.

Research has shown that new 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 several of these compounds (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(R) 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, intentions, goals, strategies, plans or prospects, including statements relating to the clinical results and commercial potential of Oracea, may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. CollaGenex's 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 the most recent Form 10-K for the quarter ended December 31, 2006 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. Forward-looking statements include statements regarding CollaGenex's expectations, beliefs, intentions, goals, strategies, plans or prospects 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 or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

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

MetroGel(R) is a registered trademark of Galderma Laboratories, Inc.

Novacort(TM) and Alcortin(TM) are trademarks of Primus Pharmaceuticals, Inc.

Pandel(R) is a registered trademark of Taisho Pharmaceuticals.

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.