Invivyd, Inc. announced that VYD222 (pemivibart), a half-life extended investigational monoclonal antibody (mAb), shows continued in vitro
neutralization activity in pseudovirus assays designed to represent the predominant emerging variants of SARS-CoV-2, including the KP.1.1 FLiRT and KP.3 variants. FLiRT variants account for over half of circulating SARS-CoV-2 variant sequences for the two-week period ending June 8, 2024, with KP.3 prevalence increasing and the Centers for Disease Control and Prevention (CDC) predicting it will become the most dominant SARS-CoV-2
lineage nationally in the near term. Of note, VYD222 has previously demonstrated antiviral in vitro neutralization activity against ancestral XBB lineage viruses that also encoded mutations described in the FLip and FLiRT nomenclature. Of note, there have been no observed changes to residues within this defined VYD222:RBD binding interface for the spike proteins encoded by the KP.1.1 FLiRT and KP.3 variants. Invivyd continually monitors the SARS-CoV-2 variant landscape using VivydTools, its in-house proprietary software that tracks virus variation across SARS-CoV-2, towards enabling early detection and characterization of neutralization activity of emergent variants, including FLiRT variants.