Anacor Pharmaceuticals Announces Positive Preliminary Results from Phase 2b Trial of AN2728 for Psoriasis

Anacor Pharmaceuticals ANAC -1.60% announced today preliminary results from its Phase 2b trial of AN2728 for the treatment of mild-to-moderate plaque-type psoriasis. The trial enrolled 68 subjects randomized in a 2:1 ratio, AN2728 to vehicle. Subjects treated with AN2728 showed improvement over vehicle at each of the recorded timepoints during the 12-week study period with peak efficacy of 26% occurring after six weeks of treatment with AN2728.This Phase 2b trial, while not powered to demonstrate statistical significance, was conducted under anticipated Phase 3 conditions to inform the design and conduct of fully-powered Phase 3 trials. The trial was designed to provide preliminary indications of efficacy and local tolerability and systemic safety when treating all or nearly all of the plaques on each subject. The previous four Phase 1 and three Phase 2 trials assessing the safety and efficacy of AN2728 had been designed to treat psoriasis on smaller body surface areas."AN2728 continues to show promise as a topical treatment for mild-to-moderate plaque-type psoriasis with the efficacy of a mid-potency steroid but without the side effects of a steroid or the tolerability issues of Vitamin D analogs," said David Perry, Chief Executive Officer of Anacor Pharmaceuticals. "We saw improvement over vehicle throughout this Phase 2b study and observed no serious adverse events in the subjects treated with AN2728. The seven previous AN2728 trials demonstrated statistically significant efficacy and, combined with the results from this trial, provide us with the data to prepare us for our end of Phase 2 meeting with the FDA and to plan the Phase 3 trials of AN2728 for psoriasis."The trial was conducted at 10 sites in the United States on 68 subjects with a diagnosis of mild-to-moderate plaque-type psoriasis (defined as a Physicians' Global Assessment (PGA) score of 2 or 3 out of 5), involving 2% to 35% of total body surface area. The trial design and endpoints were meant to simulate anticipated Phase 3 trial designs. Subjects were randomized to 2% AN2728 topical ointment or vehicle in a 2:1 ratio. Subjects applied the study medication to plaques twice a day for 12 weeks. Primary efficacy was defined as "Clear" (score of 0) or "Almost Clear" (score of 1) with at least a 2-grade improvement from baseline ("PGA Success").The highest proportion of subjects achieving PGA Success in the Intent to Treat analysis occurred at Day 42 with 26% of subjects in the AN2728 arm (n=46) achieving PGA Success compared to 18% in the vehicle arm (n=22). At the end of treatment (Day 84), 17% of the subjects in the AN2728 arm met PGA Success, while 14% of the vehicle group met that standard. The most common adverse events were "upper respiratory tract infection" (9.1% in the vehicle group), "contact dermatitis" (8.7% in the AN2728 group) and "nasopharyngitis" (8.7% in the AN2728 group and 4.5% in the vehicle group)."These trial results demonstrate that AN2728 has the potential to make an important contribution to the treatment of psoriasis," said Karl Beutner, M.D., Ph.D., and Chair of Anacor's Clinical Advisory Board.Psoriasis affects approximately 100 million people worldwide, with about 80% of cases being classified as "mild-to-moderate." The majority of mild-to-moderate psoriasis patients are treated topically. Topical treatments for mild-to-moderate psoriasis consist primarily of corticosteroids, which have safety issues, and Vitamin D analogs, which can cause stinging and burning upon application. In 2009, sales of topical therapies for psoriasis were $1.1 billion in the seven major pharmaceutical markets. In 2010, 3.9 million prescriptions were written for topical therapies for psoriasis in the United States.