MADRID – Guselkumab, an IL-23 blocker that has proved its mettle in psoriasis, also posted excellent results in an early-phase psoriatic arthritis trial.
The fully human monoclonal antibody, which is being developed by Janssen, targets the p19 subunit of interleukin-23, Atul Deodhar, MD, said at the European Congress of Rheumatology. The 52-week phase 2a study randomized 149 patients to 100 mg guselkumab or placebo given subcutaneously at baseline and week 4, then every 8 weeks, for 24 weeks. Patients who didn’t respond adequately in either arm could begin using ustekinumab. After 24 weeks, everyone remaining in the placebo group switched to guselkumab, and patients in both arms continued open-label treatment until 52 weeks.
Dr. Deodhar of the Oregon Health and Science University, Portland, reported 24-week outcomes. A full year of data will be presented at the American College of Rheumatology meeting in San Diego in November.
Guselkumab aced the study’s primary endpoint – ACR 20 response by week 24 (58% vs. 18% with the placebo, P less than .001). Improvement developed rapidly, with a significant separation between the groups by week 4 (21% vs. 0%; P less than .001). It also succeeded on the secondary endpoints of ACR 50 response (34% vs. 10%) and ACR 70 (14% vs. 2%). The antibody also significantly outperformed placebo on the Health Assessment Questionnaire Disability Index (HAQ-DI), 36-Item Short Form Health Survey (SF-36), and Minimal Disease Activity score. Skin clearance was strikingly good, Dr. Deodhar said: 39% achieved complete clearance, with a Psoriasis Area and Severity Index (PASI) score of 100; 66% achieved a PASI of 90; and 79% acheived a PASI of 75.
Guselkumab also significantly improved enthesitis – a symptom that can be terribly troubling for patients with psoriatic arthritis. Enthesitis was present in 106 at baseline. By 24 weeks, it had resolved in 56.6% of those taking the antibody and 29% of those taking the placebo (P = .012.).
A phase III trial in psoriatic arthritis will be forthcoming, Dr. Deodhar said.
Dr. Deodhar has received research funding and is a consultant for Janssen and other pharmaceutical companies.
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