Conference Coverage

PASI-75 with ixekizumab approaches 90% in pediatric psoriasis study


 

REPORTING FROM THE EADV CONGRESS

– The interleukin-17A inhibitor ixekizumab met all primary and secondary endpoints in a phase 3 trial in 6- to 18-year-olds with moderate to severe plaque psoriasis, Kim A. Papp, MD, PhD, reported at the annual congress of the European Academy of Dermatology and Venereology.

Dr. Kim A. Papp, a dermatologist and president of Probity Medical Research in Waterloo, Ont. Bruce Jancin/MDedge News

Dr. Kim A. Papp

The results bode well for an underserved population.

“I think all of us know that there is still a vulnerable population that remains a high-risk population because of the limited number of therapies available for them, and that is children,” said Dr. Papp, a dermatologist and president of Probity Medical Research, Inc., of Waterloo, Ont.

At present, etanercept, one of the earliest biologics to become available, and a relatively less effective one, is the only biologic approved for treatment of pediatric psoriasis. However, Lilly, which sponsored the phase 3 ixekizumab study, has announced that based upon the highly positive findings the company plans to seek Food and Drug Administration approval for an expanded indication for the medication in pediatric psoriasis. The company now markets ixekizumab for the approved indications of treatment of adults with moderate to severe plaque psoriasis, active psoriatic arthritis, or active ankylosing spondylitis.

The 12-week, double-blind, multicenter phase 3 trial known as IXORA-PEDS included 115 pediatric psoriasis patients randomized to weight-based ixekizumab, 30 on weight-based etanercept, and 58 on placebo. At the 12-week mark, everyone was switched to open-label ixekizumab in a long-term extension study. Children weighing less than 25 kg received a 40-mg loading dose of ixekizumab, followed by a maintenance dose of 20 mg by subcutaneous injection every 4 weeks. Patients weighing 25-50 kg got a starting dose of 80 mg, then 40 mg for maintenance therapy. Those who weighed more than 50 kg got the usual adult dosing: a 160-mg loading dose followed by 80 mg every 4 weeks. Etanercept was dosed at 0.8 mg/kg once weekly.

The coprimary endpoints were the proportion of subjects achieving a static Physician’s Global Assessment (sPGA) of 0 or 1 – that is, clear or almost clear skin – at week 12, and the PASI 75 response rate.

An sPGA of 0 or 1 at week 12 was documented in 81% of the ixekizumab group, 11% on placebo, and 40% of etanercept-treated patients, who on average had more severe baseline disease than did the other two groups.

The PASI 75 rate was 89% with ixekizumab, 25% for placebo, and 63% on etanercept. But Dr. Papp indicated that’s too low a bar. “I don’t think PASI 75s are the standard any longer,” he said.

More revealing was the PASI 90 rate: 78% with the IL-17A inhibitor, 5% in placebo-treated controls, and 40% with etanercept.

And then there’s the PASI 100 response rate: 50% with ixekizumab, 2% for placebo, and 17% for etanercept.

“I think this is very telling. I’ll leave it as a tantalizing comment that if one looks at the slope of the curve, it doesn’t yet seem to have reached its plateau at week 12 – and this is very similar to the pattern that we see in the adult population. I don’t have the long-term extension efficacy data, but I am, like you, very interested in seeing where this PASI 100 response rate finally plateaus,” Dr. Papp said.

He did, however, have the combined safety data for the 12-week double-blind phase plus the open-label extension, which he described as essentially the same as the adult experience. Injection-site reactions occurred in 19% of pediatric patients on ixekizumab, but they were generally mild and there were few if any treatment discontinuations for that reason. There was a 2% incidence of Crohn’s disease. Candidiasis and other infections were rare.

Seventy-one percent of the ixekizumab group had at least a 4-point improvement in itch on a 10-point self-rated scale by week 12, as did 20% of placebo-treated controls. A Dermatologic Life Quality Index score of 0 or 1 at week 12, indicative of no or minimal impact of psoriasis on quality of life, was documented in 64% of the ixekizumab group and 23% of controls.

Dr. Papp reported serving as a consultant, investigator, and/or speaker for Lilly and more than three dozen other pharmaceutical companies.

SOURCE: Papp KA. EADV Late breaker.

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