Engineering of the Fc Region for Improved PK (FcRn Interaction)

Interaction of antibodies with the neonatal FcRn receptor controls largely the length of their life cycle. Altering the serum persistence of antibodies through modulation of their interaction with the FcRn may be advantageous for achieving high contrast images shortly after application of the radiolabeled antibody tracer or more efficient therapy with fewer administrations. This protocol describes the steps required for producing antibodies, antibody fragments or antibody Fc fusion proteins with altered in vivo pharmacokinetics through introduction of specific mutations in the antibody Fc region. Included are also protocols for evaluation of binding to the FcRn in vitro and determination of serum half-life through radioiodinating the antibody Fc variants and performing biodistribution studies in mice.