AQP4 and neuromyelitis optica: The recommendation of ravulizumab is supported by the open-label trial with an external comparator called “A Phase 3, External Placebo-Controlled, Open-Label, Multicenter Study to Evaluate the Efficacy and Safety of Ravulizumab in Adult Patients With Neuromyelitis Optica Spectrum Disorder (NMOSD)” (CHAMPION-NMOSD).13A total of 58 AQP4-IgG-positive NMOSD adults received IV loading doses of ravulizumab ranging from 2,400 to 3,000 mg, followed by 3,000 to 3,600 mg every 8 weeks.