Fc Variants With Altered FcRn Binding
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Solution Overview
Problem
Current IgG antibodies have limitations in terms of serum half-life and effector functions due to suboptimal binding to the FcRn receptor and Fcγ receptors, which affects their therapeutic efficacy and dosing frequency.
Innovation Solution
Development of novel Fc domain variants with increased binding to FcRn at lower pH to enhance serum retention and altered binding to Fcγ receptors, optimizing both in vivo half-life and effector functions such as ADCC and CDC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If Fc domain variants are engineered to increase binding to FcRn at lower pH, then serum retention and half-life are improved, but binding to Fcγ receptors may be altered affecting effector functions
Solution Approach 1:
The patent applies local quality by making specific localized mutations at defined positions (246-438) within the Fc domain to selectively enhance FcRn binding at acidic pH while preserving FcγR binding at physiological pH. This localized modification approach allows differential binding characteristics at different pH conditions without globally altering the Fc domain structure.
Solution Approach 2:
The patent employs parameter changes by engineering Fc variants with altered pH-dependent binding characteristics. The mutations are designed to specifically enhance binding affinity to FcRn at lower pH (simulating endosomal conditions) while maintaining appropriate binding to Fcγ receptors at physiological pH, thereby optimizing both serum half-life and effector functions through pH-differential parameter tuning.
2Reliability
If Fc variants are designed with altered binding properties, then therapeutic efficacy is enhanced, but structural complexity of the Fc domain increases
Solution Approach 1:
The patent reduces structural complexity by implementing local quality changes through targeted mutations at specific positions (246-438) rather than global Fc domain redesign. This localized approach achieves enhanced therapeutic efficacy through precise modification of binding interfaces while preserving the overall Fc domain architecture and simplifying structural analysis.
Solution Approach 2:
The patent manages structural complexity by applying parameter changes to specific binding characteristics rather than redesigning the entire Fc domain. The engineered variants modify pH-dependent binding parameters at defined positions, achieving enhanced therapeutic efficacy through controlled parameter optimization while maintaining structural tractability.
Data Source
AI summary
The present application relates to optimized IgG immunoglobulin variants, engineering methods for their generation, and their application, particularly for therapeutic purposes.