Analysis of FcRn-antibody interactions on the Octet Platform

The Fc region of human IgG contributes to a number of beneficial biological and pharmacological characteristics of therapeutic antibodies. One of the most important is prolonging plasma halflife, due to its unique, pH-dependent interaction with the neonatal Fc-receptor (FcRn). Because altered FcRn binding can increase or decrease serum half-life of Fc-containing therapeutics, thereby impacting drug efficacy, FcRn binding interactions are increasingly being assessed at multiple stages of biologic drug development. In this application note, assay design and best practices for FcRn-IgG kinetic analysis on the Octet system will be discussed, as well as considerations for assay optimization, data acquisition, curve fitting, and analysis of results.