Xeligekimab, an Interleukin-17A Antagonist for Active Radiographic Axial Spondyloarthritis in Chinese Patients: 16- and 48-Week Results from a Phase III, Randomized, Double-Blind, Placebo-Controlled Study.

BACKGROUND

Xeligekimab is a novel immunoglobulin G4 (IgG4) monoclonal antibody targeting interleukin-17A (IL-17A). In a phase III trial in patients with plaque psoriasis, xeligekimab showed efficacy and safety consistent with other IL-17A inhibitors, supporting its potential application in the treatment of spondyloarthritis.

OBJECTIVE

This phase III trial aimed to investigate the efficacy and safety of xeligekimab in patients with radiographic axial spondyloarthritis (r-axSpA).

METHODS

This was a phase III study conducted at multiple centers in China. Eligible patients were randomly assigned (1:1:1) to receive xeligekimab 100 mg, xeligekimab 200 mg, or placebo. Randomization was stratified by medication history (biologic-experienced vs. biologic-naïve) and weight (≥ 70 kg vs. < 70 kg). The primary endpoint was the proportion of patients achieving an Assessment of SpondyloArthritis International Society 20 (ASAS20) response at week 16. A key secondary endpoint was the ASAS40 response rate at the same time point.

RESULTS

A total of 465 patients were recruited. A significantly higher proportion of patients receiving xeligekimab 200 mg (n = 114 (74.0%); p < 0.001, 95% confidence interval (CI) 28.5-48.4) and xeligekimab 100 mg (n = 102 (65.8%); p < 0.001, 95% CI 19.4-41.0) achieved an ASAS20 response compared to the placebo group (n = 56 (35.9%)) at week 16. Similarly, a significantly higher ASAS40 response rate was observed in the xeligekimab 100 mg group (n = 62 (40.0%); p < 0.001) and the xeligekimab 200 mg group (n = 64 (41.6%); p < 0.001) compared to placebo. Adverse events were similar across all groups, with serious adverse events occurring in 1.6% of the treatment group during the core treatment period. No unexpected safety signals were reported through week 48.

CONCLUSION

Xeligekimab demonstrated significant efficacy in improving the signs and symptoms of active r-axSpA in Chinese patients at week 16, with sustained effects observed through week 48 and no new safety signals identified.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05881785 (Date: 21 May 2023).