In three phase III trials, ixekizumab—a monoclonal antibody against interleukin-17A—was superior to placebo in the treatment of moderate-to-severe psoriasis.
The results of the large, long-term clinical trials, UNCOVER-1, UNCOVER-2, and UNCOVER-3, were compiled in a paper published in The New England Journal of Medicine (June 6, 2016).
To test the treatment’s efficacy over time, the investigators enrolled a total of 3,736 adult patients at more than 100 study sites in 21 countries. All participants had moderate-to-severe psoriasis and patients were randomly assigned to receive injections of ixekizumab at various doses or placebo over a period of more than a year.
By week 12, 76.4% to 81.8% of patients on ixekizumab had achieved a static Physician’s Global Assessment (sPGA) score of 0 (clear) or 1 (minimal psoriasis) compared to 3.2% to 3.9% of patients on the placebo. By week 60, 68.7% to 78.3% of patients on ixekizumab had maintained their improvement. Also, almost 80% of patients reached a Psoriasis Area and Severity Index (PASI) 75 response.
“This group of studies not only shows very high and consistent levels of safety and efficacy, but also that the great majority of the responses persist at least 60 weeks,” said Dr. Kenneth Gordon, a professor of dermatology at Feinberg School of Medicine, Northwestern University, in Chicago, and the first author of the paper, in a press release.
“Based on these findings, we expect that 80 per cent of patients will have an extremely high response rate to ixekizumab, and about 40 per cent will be completely cleared of psoriasis,” Dr. Gordon said. “Ten years ago, we thought complete clearance of this disease was impossible. It was not something we would even try to do. Now with this drug, we’re obtaining response levels higher than ever seen before.”
Adverse events associated with ixekizumab included slightly higher rates of neutropenia, yeast infection, and inflammatory bowel disease compared to the placebo. The safety of therapy longer than 60 weeks will need to be monitored in the future, noted the researchers.