Core Viewpoint - AstraZeneca's long-acting C5 complement inhibitor, Relatuzumab, has been approved in China for the treatment of adult patients with anti-AQP4 antibody-positive neuromyelitis optica spectrum disorder (NMOSD) [1][2] Group 1: Product Approval and Impact - Relatuzumab is now officially approved in China for NMOSD, a condition characterized by unpredictable relapses leading to irreversible disability and significantly affecting patients' quality of life [1] - The drug aims to provide a convenient treatment experience with an administration frequency of once every eight weeks, potentially helping patients achieve a "zero relapse" lifestyle [1] Group 2: Disease Overview - NMOSD is a rare central nervous system disease caused by the immune system attacking healthy tissues and cells, with approximately 75% of patients testing positive for anti-AQP4 antibodies [2] - Symptoms of NMOSD can include vision problems, severe pain, loss of bladder or bowel function, sensory abnormalities, and coordination or motor skill impairments [2] Group 3: Mechanism of Action - As a long-acting C5 complement inhibitor, Relatuzumab provides immediate, complete, and sustained complement suppression by inhibiting C5 activation in the immune system's terminal complement cascade [3] - The drug has received approvals in multiple regions, including the US, EU, and Japan, for various indications, including NMOSD [3]