Ixekizumab Superior to Placebo in Self-Reported Functioning and Health in Patients With Axial Spondyloarthritis

Treatment with ixekizumab vs placebo may improve overall functioning and health in patients with active nonradiographic axial spondyloarthritis (nr-axSpA), according to study results published in Arthritis Care & Research.

The diagnosis of nr-axSpA is based on the absence of definite sacroiliitis on x-ray. The objective of the COAST-X study (ClinicalTrials.gov Identifier: NCT02757352) was to determine the effect of ixekizumab on self-reported functioning and health in patients with nr-axSpA.

Overall functioning and health status were determined through 52 weeks of treatment using self-reported questionnaires, including the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), the 118 Assessment of SpondyloArthritis international Society Health Index (ASAS HI), and the European Quality 119 of Life-5 Dimensions-5 Level (EQ-5D-5L).

The phase 3, multicenter, randomized-controlled trial included 303 adults (53% women; mean age, 40.3±13.0 years) with nr-axSpA who did not receive biologic disease-modifying antirheumatic drugs and had an inadequate response or intolerance to nonsteroidal anti-inflammatory drugs. Participants were randomly assigned to receive 80 mg ixekizumab every 4 or 2 weeks, or placebo every 2 weeks.

A total of 96 participants received ixekizumab every 4 weeks, 102 received ixekizumab every 2 weeks, and 105 received placebo.

Physical function and health status improved significantly more in both the ixekizumab treatment groups compared with the placebo group. At 52 weeks, ixekizumab significantly improved SF-36 Physical Component Summary scores with least squares mean change from baseline of 4.7 with placebo, 8.9 with ixekizumab every 4 weeks, and 9.3 with ixekizumab every 2 weeks (P <.01). Largest improvements were reported in physical functioning, role-physical, and bodily pain domains at weeks 16 and 52.

At week 16, improvements in ASAS HI were significantly greater in patients who received ixekizumab every 2 weeks compared with those who received placebo (-2.74 vs -1.76, respectively; P =.023). At week 52, changes in ASAS HI from baseline were numerically greater in both the ixekizumab groups compared with the placebo group.

Improvements in ASAS HI of 3 or more from baseline to 16 weeks were reported in 40.4% patients who received ixekizumab every 4 weeks (P =.198) and 49.0% of those who received ixekizumab every 2 weeks (P =.017) compared with 31.7% of those who received placebo. At 52 weeks, the rates were 33.0% and 34.3% in patients who received ixekizumab every 4 and 2 weeks, respectively, compared with 18.8% of those who received placebo.

At 52 weeks, the percentage of patients achieving ASAS HI of 5 or less, indicating a good health status, was 26.9% with ixekizumab every 4 weeks (P =.02) and 34.8% with ixekizumab every 2 weeks (P <.001), compared with 12.8% with placebo. 

At week 16, significant improvements in EQ-5D-5L were reported in patients who received ixekizumab every 4 or 2 weeks, compared with placebo (0.17 and 0.19 vs 0.11, respectively; P <.05). Changes remained consistent at week 52 (0.18 for both ixekizumab groups vs 0.12 for placebo; P =.041 and P =.036, respectively). There were no clinical meaningful differences in responses based on the ixekizumab dosing regimen.

The study had several limitations, including lack of data in patients previously treated with tumor necrosis factor inhibitors and allowing patients to switch to open-label therapy with no prespecified switching criteria.

“These findings demonstrate that ixekizumab is effective in improving the overall functioning and health of patients affected with active nr-axSpA,” the researchers concluded.

Disclosure: This clinical trial was supported by Eli Lilly. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Walsh JA, Magrey MN, Baraliakos X, et al. Ixekizumab improves functioning and health in the treatment of active non-radiographic axial spondyloarthritis: 52-week results, COAST-X Trial. Arthritis Care Res (Hoboken). Published online October 12, 2020. doi:10.1002/acr.24482