ABX-IL-8 is a humanized monoclonal antibody generated in transgenic mice. The antibody has a high affinity for IL-8, and can neutralize IL-8, as demonstrated in several assay systems. The antibody inhibits binding to neutrophils, inhibits IL-8-induced calcium flux, and inhibits MAC-1 expression, elastase release, and chemotaxis. Dr. Krueger did the developmental work for this protocol by demonstrating in an experimental system that unaffected skin from patients with psoriasis, grafted onto nude mice, generated psoriasis-like lesions when IL-8 was injected. This effect was totally blocked by administering ABX-IL-8. These animal data suggest that an antibody against IL-8 might be an effective method of treating plaque-phase psoriasis. From the study done on the GCRC, safety of the drug was determined, and then appropriate dosing ranges established. The drug proved remarkably effective in the treatment of plaque-phase psoriasis, and a manuscript describing the beneficial effects of this therapy is now in preparation.