Nirsevimab

Specification

• Cat#: THA-0145
• Product Name: Nirsevimab
• Description: Nirsevimab is a long-acting monoclonal antibody indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants.
• Sequences: Heavy_chain: QVQLVQSGAEVKKPGSSVMVSCQASGGLLEDYIINWVRQAPGQGPEWMGGIIPVLGTVHYGPKFQGRVTITADESTDTAYMELSSLRSEDTAMYYCATETALVVSETYLPHYFDNWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLYITREPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLEGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK Light_chain: DIQMTQSPSSLSAAVGDRVTITCQASQDIVNYLNWYQQKPGKAPKLLIYVASNLETGVPSRFSGSGSGTDFSLTISSLQPEDVATYYCQQYDNLPLTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC
• Molecular Weight: 146300.0 Da (approximate)
• Introduction: Nirsevimab (MEDI8897) is a recombinant human immunoglobulin G1 kappa (IgG1ĸ) monoclonal antibody used to prevent respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants. It binds to the prefusion conformation of the RSV F protein, a glycoprotein involved in the membrane fusion step of the viral entry process, and neutralizes several RSV A and B strains. Compared to palivizumab, another anti-RSV antibody, nirsevimab shows greater potency at reducing pulmonary viral loads in animal models. In addition, nirsevimab was developed as a single-dose treatment for all infants experiencing their first RSV season, whereas palivizumab requires five monthly doses to cover an RSV season. This is due to a modification in the Fc region of nirsevimab that grants it a longer half-time compared to typical monoclonal antibodies. On November 2022, nirsevimab was approved by the EMA for the prevention of RSV lower respiratory tract disease in newborns and infants. Nirsevimab was also approved by Health Canada on April 19, 2023 and by the FDA in July 17, 2023 for the same indication.
• Purity: >99% by SDS-Page and HPLC analysis
• Formula: C6494H10060N1708O2050S46
• Appearance: Solid
• Endotoxin Level: < 0.001 EU/μg of the protein by the LAL method

Pharmaceutical Information

• Pharmacodynamics: A phase 1b/2a dose-escalation study that included healthy preterm infants with a gestational age of 32–35 weeks observed that, at day 8 after dosing, more than 95% of infants treated with nirsevimab had RSV-neutralizing antibody levels higher than 4-fold rise from baseline, and that the RSV-neutralizing antibody levels persisted in infants treated with 50 mg of nirsevimab at day 151. Furthermore, RSV-neutralizing antibody levels correlated with nirsevimab serum concentrations. A study that evaluated the efficacy of nirsevimab in healthy preterm infants reported that a single injection led to less medically attended RSV-associated lower respiratory tract infections.3 Similar results were reported in another study that included healthy late-preterm and term infants. The use of nirsevimab may lead to serious hypersensitivity reactions, including anaphylaxis. Similar to other intramuscular injections, nirsevimab should be given with caution to infants with thrombocytopenia or other coagulation disorders.
• Targets: Fusion glycoprotein F0