Binding of therapeutic Fc-fused factor VIII to the neonatal Fc receptor at neutral pH associates with poor half-life extension
Alejandra Reyes-Ruiz,
Sandrine Delignat,
Aishwarya Sudam Bhale,
Victoria Daventure,
Robin V. Lacombe,
Leslie Dourthe,
Olivier Christophe,
Sune Justesen,
Krishnan Venkataraman,
Jordan D. Dimitrov,
Sebastien Lacroix-Desmazes
Affiliations
Alejandra Reyes-Ruiz
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Sandrine Delignat
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Aishwarya Sudam Bhale
Centre for Bio-Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu
Victoria Daventure
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Robin V. Lacombe
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Leslie Dourthe
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Olivier Christophe
Laboratory for Hemostasis, Inflammation and Thrombosis, Unité Mixed de Recherche 1176, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Le Kremlin-Bicêtre
Sune Justesen
Immunitrack Aps, Lersoe Park Alle 42, 2100, Copenhagen East, Denmark
Krishnan Venkataraman
Centre for Bio-Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu
Jordan D. Dimitrov
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Sebastien Lacroix-Desmazes
Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, CNRS, Sorbonne Université, Université Paris Cité, Paris
Fusion of therapeutic proteins to the Fc fragment of human IgG1 promotes their FcRn-mediated recycling and subsequent extension in circulating half-life. However, different Fc-fused proteins, as well as antibodies with different variable domains but identical Fc, may differ in terms of extension in half-life. Here we compared the binding behaviour to FcRn of Fc-fused FVIII, Fc-fused FIX and two human monoclonal HIV-1 broadly-neutralizing IgG1, m66.6 and VRC01 with identical Fc. While all molecules bound FcRn at acidic pH, only rFVIIIFc and m66.6 interacted with FcRn at neutral pH. In silico modelling predicted a role for charged residues in the C1 and C2 domains of FVIII, and in the variable domains of m66.6, in the neutral binding to FcRn. Accordingly, mutations of key positively charged amino-acids in the FVIII C1C2 domains decreased the binding of the protein to FcRn at pH 7.4 in vitro and increased the half-life of rFVIIIFc in VWFKO mice. Our findings suggest that the removal of positively charged patches on Fc-fused proteins to ameliorate FcRn recycling without affecting therapeutic efficacy, may improve their pharmacokinetic properties.
