Elpi-Extend Fc
Elpi-Extend Fc
Enhancing Antibody Half-Life with Elpi-Extend Fc Technology
Engineering the human IgG Fc domain to improve pharmacokinetic (PK) properties is of great interest for therapeutic purposes. Extended antibody half-life enables less frequent dosing and lower drug administration requirements, leading to improved patient compliance and reduced treatment costs.
FcRn is responsible for the transfer of maternal IgG to the fetus and for protecting serum IgG from lysosomal degradation. Both processes depend on the ability of FcRn to bind with high affinity to IgG at acidic pH (<6.5) in the recycling endosome and to dissociate at neutral pH, releasing the IgG back into the serum. Fc mutations that preferentially enhance FcRn affinity at pH 6.0 conferincreased antibody half-life in circulation, making them an attractive strategy for therapeutic antibody optimization.
What is Elpi-Extend Fc?
Elpi-Extend Fc is an engineered IgG1 Fc domain with that significantly enhance FcRn binding at acidic pH, leading to a prolonged circulating half-life up to a 100-fold increase.
In addition to improving antibody half-life, Elpi-Extend Fc mutations also eliminate interaction with protein A while maintaining strong FcRn binding. This unique property enables efficient purification of bispecific antibodies: when combined with a wild-type IgG1 Fc, the Elpi-Extend Fc-containing bispecific antibody can be effectively separated from parental monoclonal antibodies through differential protein A elution.