Improvement of Functioning and Health With Ixekizumab in the Treatment of Active Nonradiographic Axial Spondyloarthritis in a 52-Week, Randomized, Controlled Trial

Objective: To evaluate the effect of ixekizumab on self-reported functioning and health in patients with active nonradiographic axial spondyloarthritis (SpA). Methods: COAST-X was a randomized, controlled trial conducted in patients with nonradiographic axial SpA over 52 weeks. Participants were randomized at a ratio of 1:1:1 to receive 80 mg of ixekizumab subcutaneously every 4 weeks or 2 weeks or placebo for 52 weeks. Self-reported functioning and health end points included the Medical Outcomes Study Short Form 36 (SF-36) health survey, Assessment of Spondyloarthritis International Society (ASAS) health index, and European Quality of Life-5 Dimensions-5 Level (EQ-5D-5L) health-utility descriptive system. Results: Compared to placebo, ixekizumab treatment resulted in improvement of SF-36 physical component summary scores from baseline, with a score of 4.7 improving to 8.9 with ixekizumab therapy every 4 weeks (P < 0.05) and a score of 9.3 with ixekizumab therapy every 2 weeks (P < 0.01); the greatest improvements were observed in the domains of physical functioning, role-physical, and bodily pain at weeks 16 and 52. A higher proportion of patients receiving ixekizumab therapy every 2 weeks reported ≥3 improvements based on the ASAS health index from baseline to weeks 16 and 52 (P < 0.05). Significantly more patients receiving ixekizumab every 4 weeks reported improvements in “good health status” on the ASAS health index (ASAS score of ≤5) at weeks 16 and 52 (P < 0.05). Patients receiving ixekizumab reported improvements on the EQ-5D-5L compared to those who received placebo at week 16 (0.11 versus 0.17 for patients receiving treatment every 4 weeks and 0.19 for patients receiving treatment every 2 weeks; P < 0.05), which remained consistent at week 52. There were no clinical meaningful differences in responses based on the ixekizumab dosing regimen for patients who received ixekizumab therapy every 2 weeks or every 4 weeks. Conclusion: In patients with nonradiographic axial SpA, therapy with ixekizumab was superior to placebo in the improvement of self-reported functioning and health at weeks 16 and 52.