April 17, 2008 -- A novel immune-suppressing drug appears to effectively treat moderate to severe plaque psoriasis, according to a new report published in The Lancet.
Psoriasis is a chronic inflammatory skin condition that affects about 7.5 million Americans, according to the National Institutes of Health. Plaque psoriasis is the most common type of psoriasis.
Cyclosporin, a type of drug called a calcineurin inhibitor, is among the most effective short-term treatments for plaque psoriasis. However, concerns that the drug can lead to kidney damage has limited its long-term use. Newer drugs offer alternatives, but they are often cost prohibitive, and few data exist on their long-term safety and effectiveness.
ISA247 is a new type of calcineurin inhibitor taken by mouth that is designed to treat autoimmune conditions, including psoriasis. Canada-based researcher Kim Papp and colleagues evaluated the drug's effectiveness in a phase III clinical trial involving 451 patients 18 to 65 years old. To be eligible for the study, the patient had to have plaque psoriasis on at least 10% of their body.
Papp's team divided the patients into four groups and randomly assigned them to different doses of the medication or a placebo. The study participants took the medicine twice a day.
Researchers considered the drug effective if it caused a 75% reduction in the psoriasis area and severity index score (PASI 75) at week 12.
At 12 weeks, researchers found that the higher the dose of ISA247, the better it performed. The drug was effective in 47% of those who received the highest dose, compared with only 16% of those on the lowest dose and 4% in the placebo group. After following participants for another 12 weeks, the researchers demonstrated continued efficacy.
The researchers noted temporary mild to moderate reduction in kidney function in some patients in the study. The most common adverse events were headache, upper respiratory tract infection, and inflammation of the nose and throat.