Rituximab Use for Relapse Prevention in Anti-NMDAR Antibody-Mediated Encephalitis
Nabil Seery, Robb Wesselingh, Paul Beech, Laurie McLaughlin, Tiffany Rushen, Amy J. Halliday, Liora ter Horst, Sarah Griffith, Mirasol Forcadela, Tracie Tan, Christina Kazzi, Cassie Nesbitt, James Broadley, Katherine Buzzard, Andrew Duncan, Wendyl D’Souza, Yang Tran, Anneke van der Walt, Genevieve Skinner, Bruce Taylor, Andrew Swayne, Amy Brodtmann, David Gillis, Ernest Butler, Tomáš Kalinčík, Udaya Seneviratne, Richard Macdonell, Stefan Blum, Sudarshini Ramanathan, Charles B. Malpas, Stephen Reddel, Todd A. Hardy, Terence J. O’Brien, Paul G. Sanfilippo, Helmut Butzkueven, Mastura Monif
Abstract
BACKGROUND AND OBJECTIVES: Rituximab is an anti-CD20 monoclonal antibody used in patients with anti-NMDAR antibody (Ab)-mediated encephalitis as both an acute escalation therapy and a longer term relapse risk-reduction treatment. The potential long-term benefit of a single course administered during the acute disease phase on future relapse risk is uncertain. Moreover, the optimal dosing duration to reduce relapse risk is unknown. The aim of this study was to evaluate the effect of a single course of rituximab on relapse incidence. We also studied the duration of effect of a course of rituximab in adult patients with anti-NMDAR Ab-mediated encephalitis. METHODS: We recruited 67 patients with anti-NMDAR Ab-mediated encephalitis from 10 Australian hospitals. Rituximab exposure was quantified as a time-varying covariate in Cox proportional hazard models. RESULTS: = 0.47). DISCUSSION: A single course of rituximab reduces the risk of relapse of anti-NMDAR antibody-mediated encephalitis. In select patients for whom redosing of rituximab is considered, administration at 6 months delays relapses. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that rituximab delays relapses in patients with anti-NMDAR antibody-mediated encephalitis.