title: A Novel Platform for the Potentiation of Therapeutic Antibodies Based on Antigen-Dependent Formation of IgG Hexamers at the Cell Surface.
abstract: IgG antibodies can organize into ordered hexamers on cell surfaces after binding their antigen. These hexamers bind the first component of complement C1 inducing complement-dependent target cell killing. Here, we translated this natural concept into a novel technology platform (HexaBody technology) for therapeutic antibody potentiation. We identified mutations that enhanced hexamer formation and complement activation by IgG1 antibodies against a range of targets on cells from hematological and solid tumor indications. IgG1 backbones with preferred mutations E345K or E430G conveyed a strong ability to induce conditional complement-dependent cytotoxicity (CDC) of cell lines and chronic lymphocytic leukemia (CLL) patient tumor cells, while retaining regular pharmacokinetics and biopharmaceutical developability. Both mutations potently enhanced CDC- and antibody-dependent cellular cytotoxicity (ADCC) of a type II CD20 antibody that was ineffective in complement activation, while retaining its ability to induce apoptosis. The identified IgG1 Fc backbones provide a novel platform for the generation of therapeutics with enhanced effector functions that only become activated upon binding to target cell-expressed antigen.
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Rob N
authors.initials: RN
authors.lastname: de Jong
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Beurskens
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Verploegen
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Kristin
authors.initials: K
authors.lastname: Strumane
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Muriel D
authors.initials: MD
authors.lastname: van Kampen
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: Voorhorst
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Wendy
authors.initials: W
authors.lastname: Horstman
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Engelberts
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Simone C
authors.initials: SC
authors.lastname: Oostindie
authors.affiliation: Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: Guanbo
authors.initials: G
authors.lastname: Wang
authors.affiliation: Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: Albert J R
authors.initials: AJ
authors.lastname: Heck
authors.affiliation: Genmab, Utrecht, The Netherlands.
authors.forename: Janine
authors.initials: J
authors.lastname: Schuurman
authors.affiliation: Genmab, Utrecht, The Netherlands.|Department of Cancer and Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.|Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Paul W H I
authors.initials: PW
authors.lastname: Parren
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D045744:Cell Line, Tumor; D003167:Complement Activation; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics / Q000378:metabolism*; D007167:Immunotherapy / Q000379:methods*; D016513:Mice, SCID; D009154:Mutation; D009368:Neoplasm Transplantation; D058105:Polymerization
chemical_list: D007074:Immunoglobulin G