Xoma Ltd. announced successful results with a research formulation of Xoma 629 (formerly XMP.629). Xoma has initiated a development programme with the goal of reentering clinical trials of the topically-applied reformulated drug in mild to moderate acne in 2007.

"After evaluating the results of our earlier phase II clinical trial in 253 patients and after conducting additional laboratory work, we concluded that a reformulation of our original gel was needed to increase its skin penetration and improve other characteristics," said John L. Castello, chairman of the board, president and chief executive officer. "We have conducted additional testing on research formulations of Xoma 629 and are happy to report that we have developed a reformulation that meets our criteria for skin penetration and anti-microbial activity."

Xoma is currently conducting preclinical studies to optimize the reformulated product, with the goal of amending its Investigational New Drug application and initiating phase I clinical trials in 2007. "While we will have to start at Phase I with our reformulated product, the path to approval of topical preparations in acne is well established and our experience in this indication should allow us to expedite development significantly," remarked Castello.

Xoma 629 is a novel synthetic peptide compound derived from bactericidal/permeability-increasing protein (BPI) -- a human host-defense protein that is part of the body's early lines of defense against invading microorganisms. In preclinical studies, Xoma 629 has shown potent anti-bacterial activity against P. acnes, believed to be the major causative agent in acne. Xoma 629 also has shown similar activity against antibiotic-resistant strains of P. acnes, including strains resistant to other antibiotics such as erythromycin or clindamycin.

According to the American Academy of Dermatology, acne affects nearly 100% of adolescents and nearly half of adults over 25 in the US. Various sources estimate that 15-40% of Americans seek medical treatment for acne by their mid teens. It is estimated that every year, five million prescriptions for oral antibiotics are dispensed for acne treatment in the U.S.