Safety and Effectiveness of Satralizumab in Japanese Patients with Neuromyelitis Optica Spectrum Disorder: A 6-month Interim Analysis of Post-marketing Surveillance.

ABSTRACT

INTRODUCTION: Satralizumab, an anti-interleukin-6 receptor antibody, is approved in Japan for relapse prevention in neuromyelitis optica spectrum disorder (NMOSD) and is undergoing post-marketing surveillance (PMS) of clinical use. We aimed to describe the real-world safety and effectiveness of satralizumab in Japanese patients with NMOSD. METHODS: This is an ongoing PMS (planned completion February 2027). This 6-month interim analysis assessed the safety and effectiveness of satralizumab in Japanese patients with NMOSD using data collected from August 2020 to July 2021. RESULTS: Among 570 patients who participated, 523 (91.75%) were female and the mean ± standard deviation (SD) age was 52.4 ± 14.1 years. At baseline, NMOSD expanded disability status scale mean ± SD was 4.19 ± 2.19; 490 (85.96%) patients used glucocorticoids and 277 (48.59%) patients used immunosuppressants concomitantly. Of 570 satralizumab-treated patients, 85 (14.91%) had discontinued satralizumab treatment at 6 months. For the overall adverse drug reactions (ADRs), 76.22 (66.07-87.48) events/100 person-years occurred in 118 (20.70%) patients, and infections occurred in 28 (4.91%) patients. Serious infections occurred in 18 (3.15%) patients, with an event rate of 9.05 (5.80-13.47) events/100 person-years. Of the 24 events of serious infections, respiratory tract infections (29.17%; 7) and urinary tract infections (25.00%; 6) were the most common serious infection events. One fatal ADR (septic shock) suspected to be related to satralizumab was reported. The mean ± SD glucocorticoid dose reduced from 12.28 ± 10.17 mg/day at the index date to 8.11 ± 7.30 mg/day at 6 months. The Kaplan-Meier cumulative relapse-free rate (95% confidence interval) was 94.59% (92.25-96.23) at 6 months. CONCLUSION: In this study, satralizumab was found to be safe, well tolerated, and effective in patients with NMOSD in routine clinical practice. The results are consistent with those of previous clinical trials. The safety and effectiveness of satralizumab in Japanese patients with NMOSD will be analyzed over the 6-year surveillance period. TRIAL REGISTRATION UMIN Clinical Trials Registry, UMIN000041047.