Rituximab efficacy at different initial and maintenance doses in neuromyelitis optica spectrum disorder: Experience from a national health institute in México

Abstract Background NMOSD is an inflammatory disorder of the central nervous system that primarily affects the optic nerves and spinal cord. Rituximab (RTX) is a monoclonal antibody directed against CD20, an epitope expressed on pre-B and mature B cells. It has of wide use in several antibody-mediated autoimmune diseases. Objectives To demonstrate RTX clinical efficacy at different initial and maintenance doses administered in patients with NMOSD. Methods In this retrospective/observational study we recruited subjects with NMOSD with at least one RTX infusion. Annual relapse rates (ARR) were compared in several induction and maintenance regimens with RTX in 66 patients with NMOSD. Results Fifty-four (81.8%) were female and two thirds (66.7%) had positive anti-AQP4 antibodies. The most prevalent induction and maintenance regimens were 1000 mg on days 1 and 15 (51.5%) and 1000 mg every 6 months (40.9%), respectively. Overall, the annual relapse rate (ARR) decreased from 1.15 to 0.46 with RTX (p  Conclusion RTX treatment in patients with NMOSD demonstrated a marked and sustained reduction in the ARR, regardless of induction and maintenance regimens. EDSS stability was observed, even in patients with active and severe NMOSD.