C5 and neuromyelitis optica: For example, systemic eculizumab (Alexion Pharmaceuticals [Cheshire, CT]), an anti-C5 antibody, did not significantly decrease the growth rate of GA secondary to AMD, but significantly lowered the risk of relapse in aquaporin-4 antibody (AQP4-IgG) positive neuromyelitis optica spectrum disorder (NMOSD) [28,29].