An Exploratory, Non-Interventional, Prospective, Multicenter, Nationwide, Clinical Study to Evaluate the Effects of the Complement C5 Inhibitor Ravulizumab on Serum Neurofilament Light Chain (sNfL) and Glial Fibrillary Acidic Protein (sGFAP) Levels in Patients With Aquaporin-4-Positive (AQP4-Ab+) Neuromyelitis Optica Spectrum Disorder (NMOSD)

This is an exploratory, non-interventional, prospective, multicenter, clinical study. The maximum total number of 40 patients with a diagnosis of seropositive AQP4-IgG NMOSD is expected to be enrolled. The goal is to include at least one-third of these patients in the complement inhibitor ravulizumab group, with the remaining patients in the off-label ISTs group based on current therapeutic clinical practice in Greece. Multiple Neurological Departments with experience in NMOSD diagnosis and treatment will participate. Eligible patients will be recruited in both groups and each participant will be followed up approximately every 60 days for 24 months.

Data Source(s):

Study-related data will be collected and recorded at specific and predetermined data collection timepoints, during routine clinical and laboratory assessments. Information related to the patients' medical history will be collected for the NMOSD patients from each neurological department's database (records/files/electronic database) and patient self-reports. Baseline characteristics (age, sex, height, body weight, and BMI) will also be recorded for all participants.

Study Population:

The target population in the study will include diagnosed patients with AQP4-IgG seropositive NMOSD. Age ≥ 18 years with a history of ≥ 1 NMOSD clinical attack according to 2015 NMOSD criteria. The participants should be undergoing treatment either with off-label ISTs (corticosteroids, azathioprine, mycophenolate mofetil, rituximab) or complement inhibitor therapy with ravulizumab. Corticosteroids can be used as add-on therapy to ravulizumab or the off-label ISTs