Fc Variant Polypeptides Reducing Effector Function

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Solution Overview

Problem

Current monoclonal antibodies with Fc regions exhibit unwanted effector functions such as ADCC, ADCP, and CDC, which can lead to toxicity and tissue targeting issues, necessitating a reduction in these functions for therapeutic antibodies.

Innovation Solution

Development of Fc region variants with specific amino acid substitutions, particularly at position Pro329, combined with other mutations like L234A and L235A, to reduce affinity to FcγRIIIA and C1q, thereby decreasing ADCC and CDC activities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wild-type Fc region is used, then effector functions (ADCC, ADCP, CDC) are maintained, but toxicity and tissue targeting issues occur

Engineering Contradiction:
Improvetherapeutic efficacyVSAvoidtoxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying specific amino acid residues in the Fc region (positions 234, 235, and 329) to alter the biological activity parameters. The L234A, L235A, and P329G mutations change the chemical structure to reduce affinity for Fcγ receptors and C1q, thereby decreasing effector functions and associated toxicity while preserving antigen binding capability.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If Fc region variants with reduced effector function are created, then toxicity is minimized, but affinity to FcγRIIIA and C1q is reduced

Engineering Contradiction:
ImprovetoxicityVSAvoidreceptor binding affinity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by making targeted amino acid substitutions at specific positions (234, 235, 329) within the Fc region while leaving the rest of the antibody structure unchanged. This localized modification approach reduces effector function through decreased receptor affinity at these specific sites while preserving the overall antibody structure and antigen binding capabilities.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If multiple amino acid substitutions are introduced, then ADCC activity is reduced to 20% of wild-type levels, but structural complexity increases

Engineering Contradiction:
ImproveADCC activityVSAvoidprotein structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent systematically changes multiple parameters (amino acid identities at positions 234, 235, and 329) to achieve the desired reduction in ADCC activity to 20% of wild-type levels. Despite introducing three mutations, the overall structural complexity remains manageable because the mutations are confined to a specific region and use conservative amino acid substitutions that maintain protein folding and stability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2691417B2Antibody fc variants
Publication Date: 2024.10.30 ROCHE GLYCART AG
  • EP2691417B2 patent drawingFigure 1a
  • EP2691417B2 patent drawingFigure 1b
  • EP2691417B2 patent drawingFigure 1c

AI summary

The invention relates to engineered polypeptides comprising Fc variants and their uses. More specifically, Fc variants are described exhibiting reduced effector function. These variants cause a benefit for a patient suffering from a disease which could be treated with an antibody for which it is desirable to reduce the effector function elicited by antibodies.