casirivimab

Casirivimab is a recombinant human IgG1 monoclonal antibody developed for the treatment and prevention of COVID-19. It specifically targets the receptor binding domain (RBD) of the spike protein of SARS-CoV-2, blocking its interaction with the human ACE2 receptor and thereby inhibiting viral attachment, fusion, and entry into host cells. Casirivimab is used in combination with imdevimab as part of an antibody cocktail (marketed as REGEN-COV or Ronapreve) to reduce viral load and prevent mutational escape by targeting non-overlapping epitopes on the spike protein. The drug was developed using Regeneron's VelocImmune technology, which utilizes genetically modified mice and convalescent plasma from recovered COVID-19 patients[5][6][8]. Casirivimab has been authorized for emergency use in several countries but its use has been limited due to reduced efficacy against certain SARS-CoV-2 variants such as Omicron[3][7].