Tocilizumab vs Azathioprine in Neuromyelitis Optica Spectrum Disorders

In neuromyelitis optica spectrum disorder (NMOSD),interleukin-6 (IL-6) may play an important role in facilitating plasma cells to produce pathological aquaporin 4 (AQP4) autoantibody. Inhibition of IL-6 signaling pathway by Tocilizumab (ACTEMRA®), a humanized monoclonal antibody may have shown beneficial clinical effects in a few patients with NMOSD. Larger scale clincial trials may be needed to observe its efficacy and safety. Here, by choosing azathioprine, one of the most frequently used medication in case of relapses, the investigators compare the safety and efficacy of tocilizumab in preventing NMOSD attacks.