Tocilizumab vs. Azathioprine for Neuromyelitis Optica Spectrum Disorder

Azathioprine is an off-label immunosuppressant used to treat patients with neuromyelitis optica spectrum disorder (NMOSD; NEJM JW Neurol Jun 2020). However, a substantial number of NMOSD patients relapse while taking the agent and experience adverse effects with prolonged use. Tocilizumab — a humanized antibody targeting the interleukin-6 receptor — is mainly used for inflammatory arthritis, but it has been shown in several studies to reduce NMOSD relapses and disability (e.g., JAMA Neurol 2015; 72:756).

Now, Chinese investigators have conducted a multicenter, open-label, randomized phase II study (TANGO) to compare the efficacy and safety of intravenous tocilizumab with that of oral azathioprine in 118 patients with active NMOSD. Most patie…