Tocilizumab vs Azathioprine in Neuromyelitis Optica Spectrum Disorders

Safety and Efficacy of Tocilizumab Versus Azathioprine in Neuromyelitis Optica Spectrum Disorders: a Randomized, Controlled, Open-label, Phase 2 Trial

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.

The investigators primarily aim to observe the time to first relapse from initiation of tocilizumab or azathioprine treatment. The proportion of participants who experience relapse-free in one year follow-up will be compared.

The secondary outcomes are to determine: The safety profile of tocilizumab and azathioprine in participants with NMO and whether tocilizumab improves visual function, Expanded Disability Status Scale (EDSS), et al.

Inclusion Criteria:

1. Male or female patients ≥ 18 years old
2. Diagnosis of NMO or NMO spectrum disorder
3. Clinical evidence of at least 2 relapses in last 12 months or 3 relapses in the last 24 months
4. Able and willing to give written informed consent and comply with the requirements of the study protocol.
5. EDSS <= 7.5 (8 in special circumstances)
6. Men and women of reproductive potential must agree to use a highly effective method of birth control from screening to 6 months after final dose of the investigational product.

Exclusion Criteria:

1. Current evidence or known history of clinically significant infection (Herpes simplex virus, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus,human immunodeficiency virus, Hepatitis viruses, Syphilis, etc)
2. Pregnant, breastfeeding, or child-bearing potential during the course of the study
3. Patients will not participate in any other clinical therapeutic study or will not have participated in any other experimental treatment study within 30 days of screening
4. Participation in another interventional trial within the last 3 months
5. Heart or kidney insufficiency
6. Tumor disease currently or within last 5 years
7. Clinically relevant liver, kidney or bone marrow function disorder
8. Intolerance of azathioprine or previous relapses on azathioprine treatment
9. Receipt of rituximab or any experimental B-cell depleting agent within 6 months prior screening and B-cells below the lower limit of normal.