Anacor Announces Positive Results from Phase 2 Psoriasis Trial.

PALO ALTO, Calif. -- Anacor Pharmaceuticals today announced that its second Phase 2 clinical trial of AN2728, an investigational topical anti-inflammatory product candidate, achieved its objective of defining the optimal duration of therapy in patients with psoriasis. Statistically significant reductions were observed in the overall target plaque severity score (OTPSS), as well as in the individual signs of psoriasis, such as erythema, scale and plaque thickness. Compared to those treated with vehicle, psoriasis plaques treated with AN2728 achieved a lower OTPSS in a significantly greater proportion of patients after as few as 2 weeks of treatment, with optimal responses seen at 6 and 8 weeks (P<0.001 and <0.01, respectively). Of note, 13 percent of the treated plaques cleared completely and 43 percent of the plaques achieved clear or almost clear with a two-grade improvement from baseline.

"In addition to successfully defining the optimal duration of therapy, these Phase 2 data confirm results from our previous three microplaque studies and one Phase 2 study in which AN2728 demonstrated highly significant activity against psoriasis," said Karl R. Beutner, M.D., Ph.D., Senior Vice President and Chief Medical Officer of Anacor. "We are encouraged by these results as we believe there is a significant role for an efficacious topical psoriasis product with a good safety profile. AN2728 has the advantage that it is not a corticosteroid and works by inhibiting the production of a number of pro-inflammatory cytokines including TNF-alpha, IL-12 and IL-23."

The randomized, double-blind, vehicle-controlled trial evaluated the safety and efficacy of AN2728 5% ointment applied twice daily for 12 weeks for the treatment of plaque-type psoriasis. Taking advantage of the characteristically symmetric location of psoriasis plaques on the body, the trial was designed to have each of the 30 patients apply AN2728 5% ointment to one target plaque and the vehicle ointment alone to a similar matching plaque on the other side. Investigators scored the plaques every 2 weeks. Treatments were generally well tolerated with the most common side effect being irritation at the application site. Based on these results, Anacor expects to initiate a Phase 2b dose-ranging trial for AN2728 in the second half of 2009.

About Psoriasis

Affecting approximately 10 million people worldwide, psoriasis is an inflammation of the skin caused by a reaction of the immune system. It is characterized by thickened plaques of inflamed, red skin covered with thick, silvery scales typically found at the elbows, knees, scalp and genital areas.

About Anacor Pharmaceuticals

Anacor is a biopharmaceutical company developing novel small molecule therapeutics derived from its boron chemistry platform. Anacor has focused initially on developing topical applications of its compounds to treat fungal, bacterial and inflammatory diseases. In addition, the Company is developing systemic antiviral and antibacterial therapeutics under a research and development agreement with GlaxoSmithKline. Anacor's most advanced product candidate is AN2690, a novel topical antifungal in development for the treatment of toenail onychomycosis, which is a fungal infection of the nail and nail bed. AN2690 is licensed to Schering-Plough Corporation under a worldwide development and commercialization agreement for all indications including the treatment of onychomycosis. For more information visit www.anacor.com.

Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding the progress and timing of our clinical trials, the safety and efficacy of our product candidates, and the role that AN2728 may play in the future treatment of psoriasis. These statements relate to future events and involve known and unknown risks, uncertainties and other factors that could cause actual levels of activity, performance or achievement to differ materially from those expressed or implied by these forward-looking statements. Some factors that may affect these forward-looking statements include, but are not limited to, undesirable effects, lack of efficacy or other developments resulting in clinical failure at later stages of development of our product candidates. These statements reflect the views of Anacor as of the date of this press release with respect to future events and, except as required by law, it undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise after the date of this press release.