Acologix's AC-100 Stimulates Mature Bone Formation in Preclinical Study

HAYWARD, Calif., March 22, 2006 – Acologix, Inc., a privately-held biopharmaceutical company, announced today that a preclinical study demonstrated that AC-100, its novel synthetic peptide derived from an endogenous human protein produced by bone and dental cells, significantly stimulated new mature bone formation versus control. The data were presented at the 52nd Annual Meeting of the Orthopaedic Research Society in Chicago during a poster session entitled “Fracture Healing and Repair.”

In this study, a tooth extraction model in animals was used to evaluate the effects of AC-100 on bone formation, tissue healing and bone quality. Following extraction, sockets were filled with a collagen sponge containing AC-100 at two different doses or a collagen sponge soaked in saline (control group). New bone formation and bone quality were evaluated 28 days later.

Application of AC-100 resulted in a significant and dose-dependent improvement in the quality of new bone formed. The groups treated with AC-100 at the two different doses had bone quality scores approximately two and three times higher than controls, respectively. Giving an indication of a favorable safety profile, the degree of inflammation was lower in the AC-100-treated groups than in the control group, although not statistically significant.

These results follow a recently reported Phase II clinical trial that demonstrated AC-100 stimulates the formation of new dentin (the hard tissue of teeth that protects the tooth pulp and supports the outer enamel) when applied directly to tooth defects (prepared cavities). AC-100 also demonstrated a favorable safety profile in that study.

“Clinical and preclinical trial results to date have shown that AC-100 stimulates hard tissue formation – specifically the formation of new bone in bony defects and at fracture healing sites, and new dentin in teeth. As a result, we believe AC-100 represents a potential treatment for bone repair in periodontal and orthopedic applications and a novel biological approach to dentistry,” said David M. Rosen, Ph.D., Vice President, Research and Development at Acologix. “Because of its ability to promote mature bone formation, AC-100 could prove useful in orthopedics and other sites of bone repair where the formation of mature bone would be expected to correlate with improved mechanical strength. This might reduce the time needed for an orthopedic patient to resume weight-bearing activities or return to full functioning.”

Acologix is studying AC-100 for periodontal, oral bone, dental implant and orthopedic applications. Phase II study results of AC-100 used in periodontal surgery are expected later this year.

About Acologix, Inc.

Acologix, a privately held biopharmaceutical company, is developing and commercializing innovative biopharmaceuticals targeting osteo-renal diseases, including chronic kidney disease, renal osteodystrophy, bone repair and regeneration, periodontal disease, general dentistry and oral care. Acologix is partnering with Toray Industries, Inc. of Japan on the development and commercialization of AC-820 (or TRK-820) for the treatment of uremic pruritus in dialysis patients. AC-820 is being studied in a European Phase III pivotal clinical trial, with a Phase III trial scheduled to launch in the United States in the second half of 2006. AC-100 (Dentonin®), a novel small peptide with dental, periodontal and orthopedic applications, is currently being studied in two Phase II clinical studies, one in dental restoration procedures and another for the repair of periodontal defects. Acologix is also developing AC-200 (Phosphatonin) to treat hyperphosphatemia and subsequent clinical problems associated with chronic kidney disease. For more information go to www.acologix.com

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Poster #1674: “AC-100, A Synthetic Fragment of MEPE, Promotes Alveolar Bone Maturation in a Tooth Extraction Model in Dogs,” by Mirella Lazarov, D.D.S., Ph.D., David M. Rosen, Ph.D., and Catherine Middleton-Hardie, Ph.D., of Acologix; Mei-Shu Shih, Ph.D., of SkeleTech; and Veronica Kiklevich, D.V.M., Michael Powers, D.V.M., and Sonya Martinez, Ph.D., of the Department of Veterinary Clinical Sciences, Washington State University. Presented by Dr. Rosen on Tuesday, March 21, 2006, at the 52nd Annual Meeting of the Orthopaedic Research Society Annual Meeting in Chicago.

This press release contains 'forward-looking' statements. These statements involve risks and uncertainties, which may cause results to differ materially from those set forth in the statements. The forward-looking statements include statements regarding product development and cannot be guaranteed. Acologix undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, or otherwise. Forward-looking statements in this press release should be evaluated together with the many uncertainties that affect Acologix’s business.

Acologix Contact

Yoshi Kumagai
President and CEO
Phone: 510-512-7200
Fax: 510-786-1116
ir-usa@acologix.com