Silevimig Clinical Bispecific

GR1801 is a human bispecific antibody, which simultaneously recognizes antigenic sites I and III of the RABV G protein. Antigen-binding fragments targeting epitope I and III of the RABV G protein were designed as a scFv and a Fab form, respectively, to construct human IgG1 heterodimers based on the Knob-Into-Hole (KIH) technology. Specifically, the A2 antigen-binding fragment in Fab form was fused to the N-terminus of an Fc segment containing the Knob mutation, while the B353 antigen-binding fragment in scFv form was fused to the N-terminus of an Fc segment containing the Hole mutation. This process resulted in the construction of the bispecific antibody GR1801, targeting the RABV G protein. Three constructed vectors expressing B353-scFv-FcH, A2VH-IgG1K, and A2VK-VK were cotransfected into HEK293F cells using liposomes. The bispecific antibodies GR1801 present in the culture supernatant were purified using a Protein A/G affinity chromatography. https://doi.org/10.1002/jmv.29016