Treatment Discontinuation in Patients With Myelin Oligodendrocyte Glycoprotein Antibody–Associated Disease

Importance: Therapeutic deescalation strategies are increasingly considered in demyelinating diseases to mitigate the risks associated with prolonged immunosuppression. The impact of treatment discontinuation in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is not established. Objective: To assess the relapse risk following treatment discontinuation in adult patients with MOGAD and to evaluate factors associated with disease reactivation. Design, Setting, and Participants: This retrospective cohort study including 41 centers was conducted using the French NOMADMUS database. Adult patients with MOGAD diagnosed between January 2013 and April 2024 were included. Data were extracted on July 1, 2024. A total of 1047 patients with MOGAD were screened, and 705 patients fulfilled the inclusion criteria. Among them, 319 (45.2%) received at least 1 maintenance therapy. Exposure: All instances of treatment discontinuation were collected and categorized according to their underlying reasons. Only discontinuations that were scheduled or related to adverse events were analyzed. Main Outcomes and Measures: Time to first relapse was estimated using Kaplan-Meier survival curves, and differences between groups were assessed using the log-rank test. Results: A total of 83 patients (median [IQR] age, 42.7 [28.9-53.3] years; 52 [63.7%] female) discontinued either oral immunosuppressants (azathioprine or mycophenolate mofetil) or rituximab in 60 (72.1%) and 23 (27.7%) individuals, respectively. Discontinuations were scheduled (n = 54 [65.1%]) or related to adverse events (n = 29 [34.9%]). After discontinuation, 7 patients relapsed, with a median (IQR) time to relapse of 0.5 (0.1-1.4) years. The Kaplan-Meier estimated cumulative incidence of relapse at 1 year after discontinuation was 8.7% (95% CI, 1.0-15.9). Severity of relapses was mild, with a median (IQR) change in the Expanded Disability Status Scale score of 0 (0-1) points. Factors associated with an increased relapse risk were a treatment duration of less than 1 year (7 relapses [19.4%] vs 0 relapses; log-rank P = .002) and a time since last relapse of less than 2 years (7 relapses [15.9%] vs 0 relapses; log-rank P = .01). Conclusions and Relevance: The low risk of disease reactivation found in this study suggests that discontinuing treatment may be considered in selected adult patients with MOGAD. Future clinical trials are necessary to confirm these results and establish guidelines in this situation.