Eculizumab monotherapy for NMOSD: Data from PREVENT and its open-label extension.

During PREVENT (a phase 3, randomized, double-blind, placebo-controlled, time-to-event study) and its open-label extension (interim analysis), 33 adults with aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-IgG + NMOSD) received eculizumab monotherapy for a median of 2.8 years (range, 14 weeks-5.2 years). At 192 weeks (~4 years), 96% of these patients were free from adjudicated relapses (Kaplan-Meier analysis; 95% confidence interval, 75.7-99.4). During PREVENT, 95% (20/21) of patients receiving eculizumab monotherapy had no disability worsening. Eculizumab monotherapy provides effective long-term relapse prevention, relieving the chronic immunosuppression burden in patients with AQP4-IgG + NMOSD. ClinicalTrials.gov; PREVENT: NCT01892345; open-label extension: NCT02003144.