Ixekizumab Superior to Placebo in Improving Symptoms, Inflammation in Nonradiographic Axial Spondyloarthritis

The following article is a part of conference coverage from the 2019 American College of Rheumatology/Association of Rheumatology Professionals (ACR/ARP) Annual Meeting, being held in Atlanta, Georgia. The team at Rheumatology Advisor will be reporting on the latest news and research conducted by leading experts in rheumatology. Check back for more from the 2019 ACR/ARP Annual Meeting.

ATLANTA ­– Compared with conventional background medication and placebo, ixekizumab shows improved signs, symptoms, and inflammation in patients with nonradiographic axial spondyloarthritis (axSpA), according to research results presented at the 2019 American College of Rheumatology/Association of Rheumatology Professionals (ACR/ARP) Annual Meeting, held November 8 to 13, 2019, in Atlanta, Georgia.

Researchers assessed the efficacy and safety of ixekizumab in patients with active nonradiographic axSpA in a 52-week randomized double-blind placebo-controlled trial, COAST-X (ClinicalTrials.gov Identifier: NCT02757352).

The study included adults with an established diagnosis of axSpA who met the Assessment of SpondyloArthritis International Society (ASAS) classification, but not the modified New York criteria, had a Bath Ankylosing Spondylitis Disease Activity Index score ≥4, back pain ≥4, inflammation, and an inadequate response or intolerance to nonsteroidal anti-inflammatory drugs (NSAIDs).

At week 16, patients were allowed to switch to conventional background medication, including NSAIDs, and/or open-label ixekizumab every 2 weeks. At ≥8 weeks of ixekizumab every 2 weeks, patients were allowed to switch to tumor necrosis factor inhibitors. Primary end points included a >40% improvement in ASAS criteria at week 16 and week 52. A logistic regression model with nonresponder (patients with missing data or those who switched to the regimen of ixekizumab every 2 weeks) imputation and a mixed effects model of repeated measures for continuous variables were used for analysis. Researchers also analyzed covariance for sacroiliac joint Spondyloarthritis Research Consortium of Canada (SIJ SPARCC) scores.

After stratification, 303 patients were randomly assigned to receive 1:1:1 of 80 mg of ixekizumab (n=96) every 4 weeks, 80 mg ixekizumab every 2 weeks (n=102), or placebo (n=105). Compared with placebo, a significantly greater number of patients with nonradiographic axSpA who received either dose of ixekizumab demonstrated a >40% improvement in ASAS criteria at week 16 (placebo, 19% vs ixekizumab every 4 weeks, 35%; ixekizumab every 2 weeks, 40%; P <.01) and at week 52 (placebo, 13% vs ixekizumab every 4 weeks, 30%; ixekizumab every 2 weeks, 31%; P <.01). Compared with placebo, patients who received either dose of ixekizumab showed significantly greater changes from baseline to week 16 and week 52 in terms of disease activity, functional status, and SIJ SPARCC scores. A significant percentage of patients who escaped to the regimen of ixekizumab every 2 weeks had a >40% improvement in ASAS criteria response at the time of escape.

Frequency of adverse events that resulted in treatment discontinuation was low across all treatment groups, and no new safety signals were identified.

Overall, all patients who received ixekizumab met the primary end point, as well as all major secondary end points.

“[Ixekizumab] added to conventional background medication was superior to conventional background medication and [placebo] for improving signs, symptoms, and inflammation on [magnetic resonance imaging] in [patients] with [nonradiographic axSpA],” the researchers concluded.

Visit Rheumatology Advisor for live coverage and more news from the 2019 ACR/ARP Annual Meeting.

Reference

Deodhar A, van der Heijde D, Gensler L, et al. Ixekizumab in non-radiographic axial spondyloarthritis: primary results from a phase 3 trial. Presented at: 2019 ACR/ARP Annual Meeting; November 8-13, 2019; Atlanta, GA. Abstract 2729.