Secukinumab is a fully-human IgG1k monoclonal antibody that selectively targets IL-17A. The drug, manufactured by Novartis, was unanimously recommended for approval by an advisory committee to the Food and Drug Administration. It was administered weekly as a subcutaneous injection for the first 4 weeks of the study, then given again at week 8 and once every 4 weeks thereafter in patients assigned to one of the secukinumab arms of the double-blind, randomized study. Patient assigned to the placebo group were either responders and assigned to receive secukinumab at week 24 and every 4 weeks thereafter or were nonresponders assigned to receive secukinumab at week 16 and every 4 weeks thereafter. Only patients with at least 20% reductions in the number of tender joints or swollen joints continue to receive the drug beyond 1 year.
To be eligible for the study, patients needed to have a diagnosis of active psoriatic arthritis classified by CASPAR criteria and tenderness in at least 3 of 78 joints and swelling of at least 3 of 76 joints. They additionally needed to have an inadequate response to nonsteroidal anti-inflammatory drugs, methotrexate, or anti-TNF therapy
The primary endpoint of the study was ACR20 response at 24 weeks. Secondary endpoints included PASI 75 and PASI 90 responses, change in DAS28-CRP (28-joint Disease Activity Score using C-reactive protein) from baseline, change in SF-36 PCS and HAQ-DI (Health Assessment Questionnaire-Disability Index) from baseline, ACR50 response, the proportion of subjects with dactylitis and enthesitis, and overall safety and tolerability.
As of press time, the FDA was expected to take additional action in January 2015, according to Novartis.
The study was sponsored by Novartis, the maker of secukinumab. Dr. McInnes receives consulting fees from Novartis as well as multiple other pharmaceutical companies.