In Vitro: Cilgavimab and Tixagevimab simultaneously bind to distinct, nonoverlapping epitopes of the SARS-CoV-2 spike-protein (S) receptor-binding domain to potently neutralize the virus. Cilgavimab exhibits potent monoclonal antibody neutralization activity, and human ACE2-blocking activity, with IC50s of 10-150 ng/mL, and shows binding ability to either trimeric S2Pecto protein or monomeric SRBD with IC50s of 0.1-10 ng/mL.
In Vivo: Cilgavimab (200 μg/mouse; i.p.; before SARS-CoV-2 injection) protects mice from weight loss and reduces the viral burden and levels of inflammation in the lungs.