Ravulizumab (ALXN1210) is a humanized monoclonal antibody targeting complement factor 5 that specifically binds to human complement protein C5 with high affinity to block complement activation. Ravulizumab can be used for the prevention and treatment of paroxysmal sleep hemoglobinuria, atypical hemolytic uremic syndrome and myasthenia gravis.

Crovalimab (SKY59; RO7112689) is a novel humanized antibody designed to target C5 in a pH-dependent manner, demonstrating binding affinities (KD) of 15.2 nM and 16.8 μM at pH levels of 7.4 and 5.8, respectively. Additionally, it shows high affinity for human FcRn at pH 6.0, with a KD of 17 μM. By blocking C5 cleavage by C5 convertase and inhibiting the activity of a C5 variant (p.Arg885His), Crovalimab effectively prevents the formation of C5b-9 across the classical (CP), lectin (LP), and alternative (AP) complement pathways. This characteristic highlights its potential utility in research concerning paroxysmal nocturnal hemoglobinuria (PNH) and other complement-mediated diseases.