Eculizumab in AQP4-IgG-positive relapsing neuromyelitis optica spectrum disorders: an open-label pilot study

TLDR: Eculizumab seems to be well tolerated, significantly reduce attack frequency, and stabilise or improve neurological disability measures in patients with aggressive neuromyelitis optica spectrum disorders.

Abstract: Summary Background Complement activation after binding of an IgG autoantibody to aquaporin 4 (AQP4) is thought to be a major determinant of CNS inflammation and astrocytic injury in neuromyelitis optica. The aim of this study was to investigate the use of eculizumab—a therapeutic monoclonal IgG that neutralises the complement protein C5—in neuromyelitis optica spectrum disorders. Methods Between Oct 20, 2009, and Nov 3, 2010, we recruited patients from two US centres into an open-label trial. Patients were AQP4-IgG-seropositive, aged at least 18 years, had a neuromyelitis optica spectrum disorder, and had at least two attacks in the preceding 6 months or three in the previous 12 months. Patients received meningococcal vaccine at a screening visit and 2 weeks later began eculizumab treatment. They received 600 mg intravenous eculizumab weekly for 4 weeks, 900 mg in the fifth week, and then 900 mg every 2 weeks for 48 weeks. The coprimary endpoints were efficacy (measured by number of attacks [new worsening of neurological function lasting for more than 24 h and not attributable to an identifiable cause]) and safety. Secondary endpoints were disability (measured by expanded disability status scale), ambulation (Hauser score), and visual acuity. At follow-up visits (after 6 weeks and 3, 6, 9, and 12 months of treatment; and 3 and 12 months after discontinuation), complete neurological examination was undertaken and an adverse event questionnaire completed. This trial is registered with ClinicalTrials.gov, number NCT00904826. Findings We enrolled 14 patients, all of whom were women. After 12 months of eculizumab treatment, 12 patients were relapse free; two had had possible attacks. The median number of attacks per year fell from three before treatment (range two to four) to zero (zero to one) during treatment (p Interpretation Eculizumab seems to be well tolerated, significantly reduce attack frequency, and stabilise or improve neurological disability measures in patients with aggressive neuromyelitis optica spectrum disorders. The apparent effects of eculizumab deserve further investigation in larger, randomised controlled studies. Funding Alexion Pharmaceuticals.