A Study of Orelabrutinib in Patients With AQP4-IgG Positive Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic inflammatory demyelinating autoimmune disease of the central nervous system. NMOSD is a highly relapsing, severely disabling disease. AQP4-IgG positive NMOSD is related to a specific aquaporin 4 antibody (AQP4 IgG) produced by mature B cells. BTK is a key kinase in B cell receptor signal transduction pathway. Abnormal activation of BTK related signaling pathway can lead to autoantibody production and autoimmune diseases. Therefore, BTK can be developed as a new target for autoimmune diseases.