Healthy skin. Credit: SPL / Photo Researchers, Inc.

While basic researchers tease out the critical cytokines behind psoriasis, clinicians have not been idle. A monoclonal antibody that recognizes both IL-12 and IL-23 has been making its way through clinical trials; the most recent results were reported February 8 in the New England Journal of Medicine (356, 580–592).

Gerald Krueger et al. treated 320 individuals with psoriasis with either a placebo or a monoclonal antibody that binds the p40 subunit shared by both IL-12 and IL-23. The researchers report a 75 percent improvement in psoriasis symptoms in about half of subjects at the lowest doses and about 80 percent of subjects receiving the highest doses. A higher percentage of treated individuals suffered severe effects such as cancer or a heart attack—but the effects were not significant and larger trials are needed.

The study does nothing to resolve whether IL-12 or IL-23 is the most effective target for psoriasis. But the researchers point out that the efficacy is similar to that of other biologic therapeutics on the market, such as etanercept, which blocks TNF-α signaling.