This is a humanized IgG1 antibody using the same sequences as the therapeutic antibody inebilizumab. It is cytolytic, directed against the broadly epressed B-cell surface antigen CD19, resulting in B-cell depletion in autoimmune conditions. Inebilizumab is indicated for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. NMOSD is a rare autoimmune disorder in which immune system cells and autoantibodies attack and damage the optic nerves and spinal cord. In most people with NMOSD, B cells produce antibodies that attack AQP4, a protein involved in nverve cell function, causing inflammation and damage to the central nervous system. By reducing the numbers of B cells, the medicine is expected to prevent damage to nerve cells and reduce the symptoms of the condition.