OBJECTIVE: This post hoc analysis of the CHAMPION-NMOSD trial evaluated the safety and efficacy of ravulizumab in patients with aquaporin-4 antibody-positive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) previously exposed or naïve to rituximab (RTX). METHODS: Patients received weight-based intravenous ravulizumab with a loading dose followed by maintenance dosing every 8 weeks. Patients were stratified by prior RTX exposure: no RTX exposure (RTX-naïve) vs RTX exposure > 3 months bef...