satralizumab + azathioprine

Satralizumab + azathioprine is a combination therapy used in the management of neuromyelitis optica spectrum disorder (NMOSD), especially in patients at high risk of relapse. **Satralizumab** is a recombinant humanized monoclonal antibody that targets and blocks both soluble and membrane-bound interleukin-6 (IL-6) receptor subunit alpha, thereby inhibiting IL-6-mediated pro-inflammatory signaling and suppressing differentiation of Th17 cells, B cell maturation, and production of autoantibodies[1][2][4]. **Azathioprine** is an oral small molecule immunosuppressant that acts as a purine analog, inhibiting DNA and RNA synthesis, predominantly influencing T and B lymphocyte proliferation. The combination is primarily used off-label or within structured protocols for NMOSD, often for patients with elevated disease risk, such as during pregnancy, and may provide additive immunosuppressive effects[3].