Inebilizumab for Treatment of Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease characterized by recurrent optic neuritis and transverse myelitis often resulting in severe disability. Anti-AQP4-immunoglobulin G (IgG) is a pathogenic product of CD19-positive plasma cells found in most, but not all, individuals with NMOSD and is associated with immune-mediated neurologic injury. Inebilizumab, an afucosylated humanized IgG1κ, anti-CD19 monoclonal antibody, may target pathogenic CD19-expressing B cells. In a Phase II/III trial, inebilizumab significantly reduced the proportion of participants experiencing an NMOSD attack and was well tolerated versus placebo. Fewer treated participants had worsening disability than those receiving placebo. Inebilizumab was approved in 2020 by the US FDA for treatment of anti-AQP4 antibody positive NMOSD.Lay abstract Neuromyelitis optica spectrum disorder (NMOSD) is a rare nervous system disease. People with NMOSD experience ‘attacks’ of the brain, spinal cord and an important nerve that sends visual signals to the brain, and they may experience severe disability. NMOSD is thought to be caused by an imbalanced immune system response. In a portion of patients with NMOSD, immune cells produce antibodies which may lead to inflammation in the nervous system and cause brain injury leading to attacks. Inebilizumab is a medication that directly targets these immune cells, reducing the likelihood of a person having an NMOSD attack.