Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) are severe demyelinating inflammatory autoimmune neurological disorders. The estimated global pooled prevalence of NMOSD is 1.82 per 100 000 people (Etemadifar et al. 2015). The disorder is characterized by inflammatory lesions in the optic nerve, spinal cord, brainstem, and cerebrum; and clinically by optic neuritis (ON) and/or transverse myelitis causing potentially severe motor and sensory impairment, bladder dysfunction, vision loss, pain, and other debilitating symptoms (Wingerchuk et al. 2015). Recovery is variable, and inflammatory attacks often result in permanent disability. Untreated, the risks of severe disability or death are substantial (Jarius et al. 2014).~NMOSD is radiologically and prognostically distinct from multiple sclerosis (MS), and has a pathophysiology unresponsive to typical MS treatment (Weinshenker 2007; Oh, and Levy et al. 2012).
Objective of the trial is to describe the efficacy and safety of satralizumab in patients with aquaporin-4 (AQP4) antibody seropositive NMOSD, either treatment naive or inadequate responders to previous treatment with rituximab (RTX) (or its biosimilar)