Unknown Manufacturer • Nirsevimab is indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants during their first RSV season in Canada, the US, and Europe. Additionally, Nirsevimab is also approved in Canada and the US for use in infants up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. These infants include, but are not limited to, those with chronic lung disease of prematurity, hemodynamically significant congenital heart disease, immunocompromised states, Down syndrome, cystic fibrosis, neuromuscular disease, and congenital airway anomalies.
Nirsevimab is a long-acting monoclonal antibody indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants.
Nirsevimab is a recombinant human immunoglobulin G1 kappa (IgG1ĸ) long-acting monoclonal antibody that binds to the prefusion conformation of the respiratory syncytial virus (RSV) F protein. RSV is coated with two types of glycoproteins, the attachment glycoprotein (G protein) and the fusion glycoprotein (F protein). Of these two, only the F protein is essential for the entry of the virus into cells lining the respiratory tract, making it a desirable drug target. The RSV F protein is initially in a metastable prefusion conformation and undergoes conformational changes after being triggered by an unknown event. These conformational changes lead to a postfusion conformation, where both viral and host-cell membranes are together. Nirsevimab binds to a highly conserved epitope of the RSV prefusion F protein, inhibiting the membrane fusion step in the viral entry process. This allows nirsevimab to neutralize various RSV A and B strains and block cell-to-cell fusion. Nirsevimab has also been modified with a triple amino acid substitution (M257Y/S259T/T261E [YTE]) in the Fc region to extend serum half-life from the typical 21–28 days to approximately 69 days.
