Research on Ixekizumab in Psoriatic Arthritis and More Presented at EULAR 2016

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LONDON—Results from the extension phase of a Phase 3 trial for the IL-17A inhibitor ixekizumab in psoriatic arthritis (PsA) show that patients started on placebo, adalimumab and ixekizumab continued to show improvements in arthritis, dactylitis and ethesitis, said Philip Mease, MD, a rheumatologist at Swedish Medical Center University of Washington in Seattle.¹

Dr. Mease presented the data in an abstract session at the Annual Congress of the European League Against Rheumatism (EULAR 2016)—a session that also featured the effects of conventional disease-modifying anti-rheumatic drugs (DMARDs) on TNF-inhibitor use and a debate over the value of indirect comparisons of adalimumab and secukinumab.

52 Weeks of Ixekizumab

Previous results through 24 weeks of follow-up found that ixekizumab was superior to placebo in ACR20 response for patients with active PsA who had not yet tried biologics.

The new results are through 52 weeks, with 381 of the 417 patients entering this extension period. Those with an inadequate response were switched from placebo or adalimumab at Week 16 to 80 mg of ixekizumab every two weeks or every four weeks. The others were switched at Week 24.

A total of 55.6% of patients on the every-two-week regimen and 48.9% of those in the every-four-week group achieved a Psoriatic Area and Severity Index (PASI) 100 response by the end of the 52 weeks. Improvements also continued to be seen in Leeds Ethesis Index scores and Leeds Dactylitis Index scores.

Although 102 patients, about half, in each group experienced some type of treatment-emergent adverse event—12 considered serious—only a total of three people in the extension phase discontinued their treatment because of adverse events.

Dr. Mease

“We are pleased to show this persistence of effect,” Dr. Mease said.

Synthetic DMARDs

In another study, researchers set out to clarify the effects of concomitant conventional synthetic DMARDs on continuation of TNF-inhibitor therapy.² Other trials have tended not to fully adjust for confounding on this question, making their results less informative to clinical practice, or even “spurious,” said presenter Alexandre Sepriano, MD, a PhD student at Leiden University Medical Center.

Researchers studied patients with axial spondyloarthritis from the Rheumatic Diseases Portuguese Register who had started on a TNF inhibitor between 2001 and 2014. This totaled 954 patients.

Their analyses adjusted for confounders, including level of disease activity, use of other therapies and propensity scores to account for differences in patients taking DMARDs compared with those not taking DMARDs. The primary endpoint was discontinuation of the first TNF inhibitor. In the end, lack of efficacy was the main reason for these discontinuations—the top reason 55% of the time—followed by adverse events—31%. They didn’t find that conventional synthetic DMARD use had any measurable effect.