VBY329

VBY329 is a monoclonal antibody being developed by Invivyd for the prevention of Respiratory Syncytial Virus (RSV) infections in newborns, infants, and children. It targets the RSV F (fusion) protein and was discovered using Invivyd's proprietary antibody discovery technology platform. The antibody is engineered with half-life extension technology to provide prolonged protection, potentially matching or exceeding the in vivo half-life of current standards of care. Preclinical data indicates that VBY329 possesses significantly higher antiviral potency compared to nirsevimab and clesrovimab, and it maintains high neutralization activity against nirsevimab-resistant RSV F protein variants. Invivyd expects to advance the candidate toward IND readiness in the second half of 2026.