Incidence of Relapses After Meningococcal Vaccination in Clinical Trials of Eculizumab and Ravulizumab in Anti-Aquaporin-4 Antibody-Positive (AQP4-Ab+) Neuromyelitis Optica Spectrum Disorder (NMOSD)

occurring within 4 weeks of last meningococcal vaccination and before study drug initiation. ResultsIn CHAMPION-NMOSD (N=71), 1 enrolled patient was excluded from this analysis because of vaccination before AQP4-Ab+ confirmation.Among the remaining patients (57 enrolled; 13 screen failures), 2/ 70 (2.9%)patients experienced a relapse; both were screen failures.In PREVENT, 3.1% (3/96) of eculizumab and 10.6% (5/47) of placebo patients had a relapse. ConclusionsThis retrospective analysis indicates a low relapse incidence (2.9%-3.1%)within 4 weeks of meningococcal vaccinations before C5IT initiation and up to 10.6% for those randomized to placebo.Available information precludes determination as to whether relapses observed are attributable to meningococcal vaccination or inherent relapse risk among patients with AQP4-Ab+ NMOSD.