CollaGenex Pharmaceuticals Provides Update on Examination of Incyclinide Patent Application.

NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (NASDAQ:CGPI) today announced that the U.S. Patent and Trademark Office (USPTO) has posted on its Website a final rejection of CGPI's patent application No. 10/757,656 covering a method of treating acne using chemically modified tetracyclines, including incyclinide. The notice does not state the reason for the rejection.

Colin W. Stewart, president and chief executive officer of CollaGenex, stated, "We are confident that our '656 patent application includes patentable claims and that a patent will ultimately issue to cover incyclinide. A final rejection by the patent office is not unusual, and as soon as we have analyzed the reasons for this rejection, we will continue examination of this application. While we remain confident that a patent will issue, the continuing examination process may add a few months to our estimates of when examination may be favorably concluded."

CollaGenex recently announced the results of a Phase 2 dose-finding study of incyclinide for the treatment of acne. The study examined 5 mg, 10 mg and 20 mg doses and achieved its objectives by demonstrating a clear dose-response relationship with an excellent side effect profile similar to placebo. CollaGenex is continuing with a placebo-controlled study of a 40 mg dose over a 12 week period, and expects to conclude this study in the fourth quarter of 2007.

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 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. CollaGenex is conducting a 300-patient, Phase II dose-finding study to evaluate its second dermatology candidate, incyclinide, for the treatment of acne. CollaGenex is also conducting Phase I clinical trials to evaluate COL-118, a topical compound based on the SansRosa technology, for the treatment of redness associated with rosacea and other skin disorders.

Research has shown that certain tetracyclines can be chemically modified to remove their antibiotic effects while retaining the 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" 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.

Statements in this press release regarding management's future expectations, beliefs, intentions, goals, strategies, plans or prospects, including statements relating to the Company's plans, timing and success related to its patent applications and the launch of Oracea for the treatment of inflammatory lesions of rosacea, 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 the most recent Form 10-Q for the quarter ended September 30, 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' 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 or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Periostat(R) and Restoraderm(R) are registered trademarks and IMPACS(TM), and Oracea(R) are 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.

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 QLT USA, Inc.