– Crovalimab (SKY59; RO7112689) is a novel humanized antibody designed to target C5 in a pH-dependent manner, exhibiting binding affinities (KD) of 15.2 nM and 16.8 μM at pH levels of 7.4 and 5.8, respectively. It also 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, highlighting its potential utility in research on paroxysmal nocturnal hemoglobinuria (PNH) and other complement-mediated diseases.