Safety and effectiveness of ixekizumab in Japanese patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis in real-world use: a post-marketing safety study

Objectives To evaluate the long-term safety and effectiveness of ixekizumab for axial spondyloarthritis in the real-world setting in Japan. Methods This single-arm, multicentre, observational study was conducted from 26 May 2020 to 10 March 2023 on adult patients with axial spondyloarthritis who were administered ixekizumab under daily clinical practice in Japan. Baseline patient characteristics were summarized. Adverse events, adverse drug reactions, physician-rated overall improvement, and patient-reported Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were assessed for 96 weeks after ixekizumab initiation. Results Of the 39 enrolled patients, 29 consented to publication and were included in these analyses (n=21 ankylosing spondylitis; n=8 non-radiographic axial spondyloarthritis). Sixteen patients (55.2%) were male, with a median (range) age of 52.0 (32.0–76.0) years. Fourteen (48.3%) and 4 (13.8%) patients experienced adverse events and adverse drug reactions, respectively, most commonly infections and administration site reactions. No serious adverse events or adverse drug reactions were reported. Across 96 weeks, physicians rated ≥75.0% patients as showing improvement. BASDAI scores showed trends consistent with improvement. Conclusions These findings are consistent with ixekizumab clinical trial data from other countries, showing the long-term safety and effectiveness of ixekizumab in patients with axial spondyloarthritis under routine clinical care in Japan.