Acologix Presents Preclinical Data on Bone Formation and Maturation Stimulated by AC-100 at the European Orthopedic Research Society Meeting

HAYWARD, Calif., June 8, 2006 – Acologix, Inc., a privately-held biopharmaceutical company, announced today that two preclinical studies demonstrated that AC-100, its novel synthetic peptide derived from an endogenous human protein produced by bone and dental cells, promoted bone formation and maturation in animal models. The data was presented as an oral presentation at the 16th Annual Meeting of the European Orthopedic Research Society in Bologna, Italy.

In a canine tooth extraction model for bone regeneration, extraction sockets were filled with either collagen sponge containing AC-100 at two different doses, or collagen sponge soaked in saline (control group).

In a rodent calvarial critical defect model, bone defect sites were filled with collagen sponge containing AC-100 or collagen sponge soaked in saline (control group). The rats then received daily injections of AC-100 at different doses or saline over the surgery site for six days. In both studies, 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 the newly formed bone as assessed histologically. In the canine study, the groups treated with both doses of AC-100 had bone quality scores approximately two and three times higher than controls, respectively. In the rodent study, AC-100 was evaluated over a broad dose range and exhibited a biphasic dose response curve, with optimal daily doses in the range of 0.1 – 0.5 mg/day. Furthermore, 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. 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. These data further expand our understanding of AC-100’s activities,” said David M. Rosen, Ph.D., Vice President, Research and Development at Acologix. “This ability to promote mature bone formation has now been confirmed in several models”.

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 TRK-820 for the treatment of uremic pruritus in dialysis patients. TRK-820 is being studied in a European Phase III pivotal clinical trial, with a Phase III trial planned to launch in the United States. 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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Abstract # 06: “AC-100, A Synthetic Fragment of MEPE, Promotes Bone Formation and Maturation in Rodent and Canine Bone Regeneration Model,” by David M. Rosen, Ph.D. Catherine Middleton-Hardie, Ph.D., , Mirella Lazarov, D.D.S., Ph.D., Shakun Aswani of Acologix. Presented by Dr. Rosen at 10:20AM on Thursday, June 8, 2006, at the 16th Annual Meeting of the European Orthopedic Research Society in Bologna, Italy.

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