Complement C5 inhibitor as a rescue therapy for acute NMOSD attacks: a multicenter retrospective cohort study in China

Abstract

Background Complement activation plays a key role in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD). While eculizumab effectively prevents relapses, its role in acute attacks remains uncertain. Methods We retrospectively analyzed 38 patients with acute NMOSD treated with eculizumab across seven tertiary hospitals in China. Neurological assessments included EDSS, visual, motor, and sensory deficits, evaluated at baseline and weekly through 8 weeks. Clinical improvement was defined using prespecified criteria. Safety and adverse events were recorded. Results Patients were predominantly female (92.1%) with a mean age of 47.5 ± 14 years. Median EDSS decreased from 4 (IQR 3–6.88) to 3 (IQR 2–6) at the 4–8-week follow-up assessment (p = 5.45 × 10-6), with improvement observed in at least one neurological domain in 35/38 patients (92.1%). Improvement was more frequent in visual (83.3%) and motor function (88.8%) than in sensory function (31.6%). The median time to first improvement was 2 weeks, with cumulative probabilities of 47.4%, 55.3%, and 71.1% at weeks 1, 2, and 4, respectively. In exploratory analyses, the ON+TM phenotype was associated with a lower likelihood of improvement after adjustment for age and baseline EDSS. Four patients experienced mild adverse events, and one patient with a baseline EDSS of 9 died from septic shock. Conclusion This exploratory study observed neurological improvement following eculizumab initiation in patients with NMOSD attacks, but serious infections can occur in severely disabled patients, highlighting the need for careful monitoring and patient selection.