March 28, 2012 -- Two experimental biologic treatments may help treat psoriasis, researchers report in The New England Journal of Medicine.
The biologics are called brodalumab and ixekizumab. They're both given by injection and target the same inflammation-promoting protein, interleukin-17.
In trials of each biologic, patients with moderate-to-severe psoriasis were followed for more than 12 weeks. People in both trials showed dramatic improvements in their psoriasis, with many experiencing total clearance of the lesions that characterize the skin condition.
“The response that we saw was utterly profound,” dermatologist Kim A. Papp, MD, PhD, who headed the brodalumab study, tells WebMD.
Psoriasis Treatments Target IL-17
One of the most common skin conditions worldwide, psoriasis most often involves red, inflamed, scaly skin lesions or plaques that are often extremely itchy or painful.
About 7.5 million people in the U.S. have psoriasis, which tends to run in families, but many people don't seek treatment.
“You don’t see these patients out there in the world because they hide,” says dermatologist Craig Leonardi, MD, who led the ixekizumab study. “They hide their psoriasis, they hide themselves, they wear long sleeves, and take night jobs. This is a life-altering condition, both physically and psychologically.”
Interleukin-17 is part of a family of inflammatory proteins that appear to play a major role in psoriasis.
The two new experimental therapies both target IL-17, but they do so in different ways.
Brodalumab is a monoclonal antibody that binds to the IL-17 receptor. Ixekizumab directly targets and neutralizes IL-17.
In the brodalumab study, 198 patients with moderate-to-severe plaque psoriasis got different doses of the injected biologic treatment, or a placebo. In patients who got the highest doses, 75% had a 90% improvement in their psoriasis severity, and 62% had their psoriasis lesions clear up completely.
In the ixekizumab study, 142 patients with moderate-to-severe plaque psoriasis were also randomized to different dosages of the injected treatment. Just as in the brodalumab study, patients who got the highest overall doses of ixekizumab had the most improvement in psoriasis severity, with psoriasis totally clearing up in many patients.
No serious adverse events were reported. Two patients in each trial experienced a decline in infection-fighting white blood cells, but the problem did not persist when the treatments were discontinued. Common side effects included inflammation of the nose and throat, upper respiratory infection, and skin reaction at the injection site.
“These are high-performance [treatments] that appear to be very safe,” says Leonardi, who is a professor of dermatology at the St. Louis University School of Medicine.
He agrees that the IL-17-targeting therapies could prove to be highly effective game-changers for treating plaque psoriasis.
Both studies were funded by the treatments' makers: Amgen for brodalumab and Eli Lilly for ixekizumab. Both treatments are headed for larger studies.