Comparative Effectiveness of Disease-Modifying Treatments in Double Seronegative Neuromyelitis Optica Spectrum Disorder

Abstract

BACKGROUND AND OBJECTIVES: Double seronegative NMOSD (DS-NMOSD) lacks approved disease-modifying treatments, and limited data exist on optimal relapse-prevention strategies. In this multicenter, international, retrospective cohort study, we sought to compare the real-world effectiveness of anti-CD20 agents vs nonspecific immunosuppressants as disease-modifying strategies for relapse prevention in DS-NMOSD. METHODS: A retrospective cohort database was constructed using standardized data collection from medical records across collaborating centers in the United States, Brazil, the United Kingdom, Thailand, Turkiye, and China. Patients meeting IPND-2015 NMOSD criteria with negative serum aquaporin-4 and myelin oligodendrocyte glycoprotein antibody testing via cell-based assays and at least 12 months of follow-up were reviewed. The primary outcome was the incidence rate ratio (IRR) of relapses; secondary outcomes included the annualized relapse rate (ARR) and time to relapse. RESULTS: A total of 103 patients with DS-NMOSD met study criteria, with a median follow-up of 6 years. Anti-CD20 therapy was associated with a significantly lower IRR (0.02, 95% CI 0.01-0.04) and ARR (0.17, 95% CI 0.07-0.40) compared with nonspecific immunosuppressants (0.76, 95% CI 0.40-1.43) after adjusting for covariates. Survival analysis demonstrated a prolonged relapse-free interval with anti-CD20 agents. DISCUSSION: Our findings support the use of B-cell depletion as a potentially superior relapse-prevention strategy in DS-NMOSD, highlighting its potential as a first-line therapy. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that, in patients with DS-NMOSD, treatment with a DMT reduces relapse incidence rate ratio compared with no treatment and anti-CD20 DMTs are associated with a lower relapse incidence rate ratio compared with nonspecific immunosuppressants.