Real-World Treatment Adherence and Persistence with C5 Inhibitor Therapy Versus Satralizumab in Patients with Neuromyelitis Optica Spectrum Disorder in Japan

INTRODUCTION: Eculizumab and ravulizumab [complement component 5 inhibitor therapies (C5ITs)] and satralizumab (interleukin-6 receptor inhibitor) are approved for treatment of anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (NMOSD) in Japan. Here, we evaluate real-world treatment adherence and persistence with C5IT and satralizumab in patients with NMOSD in Japan. METHODS: In this retrospective observational study, data (January 2016 to May 2024) from the Japan Medical Data Vision database were used to assess treatment adherence [number of treated days, proportion of days covered (PDC), continuous multiple-interval measure of gaps (CMG), observed versus expected doses ratio (OvEDR)] and persistence (proportion of patients without treatment discontinuation) during the 1-year follow-up after treatment initiation. RESULTS: Of 206 patients, 49 (23.8%) received C5IT and 157 (76.2%) received satralizumab. Patients receiving C5IT were younger than those receiving satralizumab [mean (SD) 51.0 years (11.3) vs. 56.2 years (13.8)], P = 0.009]. Comedication rates were similar at baseline and through follow-up. Median (Q1, Q3) treatment duration was 351.0 (336.0, 356.0) days for C5IT and 337.0 (316.0, 347.0) days for satralizumab. Significantly greater adherence was observed in the C5IT cohort than the satralizumab cohort [median (Q1, Q3) 96.2% (92.1%, 97.5%) vs. 92.3% (86.6%, 95.1%), P < 0.001 for PDC; 3.8% (2.5%, 7.9%) vs. 7.7% (4.9%, 13.4%), P < 0.001 for CMG; 94.7% (82.8%, 98.2%) vs. 86.7% (80.0%, 93.3%), P = 0.001 for OvEDR]. C5IT was associated with greater treatment persistence than satralizumab when evaluated using gaps ≥ 3 times (main analysis; 98.0% vs. 87.9%, P = 0.043) and ≥ 2.5 times (sensitivity analysis; 93.9% vs. 87.3%, P = 0.21) the normal dosing interval to define discontinuation. CONCLUSION: In this real-world study, treatment adherence and persistence were higher in patients with NMOSD receiving C5IT than satralizumab in Japan. Further prospective and larger studies of adherence and persistence in NMOSD are needed.