a72 VH Framework for Rabbit CDR Grafting

Solution Overview

Problem

Current methods for humanizing rabbit antibodies face challenges due to structural differences between rabbit and human antibodies, leading to reduced antigen binding affinity and stability, and there is a need for reliable and rapid methods to generate humanized rabbit antibodies with improved biophysical properties.

Innovation Solution

A highly soluble and stable human antibody framework, specifically the 'a72' VH framework sequence, is identified for grafting rabbit CDRs, allowing for consistent retention of spatial orientation and high-throughput humanization of rabbit antibodies with superior solubility and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If classical grafting approaches are used to humanize rabbit antibodies, then human framework similarity is improved, but antigen binding affinity and stability deteriorate

Engineering Contradiction:

Improvehuman framework similarityVSAvoidantigen binding affinity and stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by making different parts of the antibody framework have different degrees of humanization. Specifically, framework positions are selectively humanized based on their impact on CDR conformation and antigen binding. Positions critical for maintaining CDR spatial orientation and binding affinity are preserved from the rabbit sequence, while non-critical positions are humanized to reduce immunogenicity. This selective approach ensures that local structural requirements are met while achieving overall humanization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by systematically varying the degree and pattern of humanization at different framework positions. Multiple humanization variants are generated with different combinations of human and rabbit framework residues, allowing optimization of the balance between immunogenicity reduction and functional preservation. The specific humanization pattern is tuned to maintain CDR conformation while achieving human-like framework characteristics.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If rabbit antibodies are humanized for therapeutic use, then immunogenicity is reduced, but binding properties and functional stability deteriorate

Engineering Contradiction:

ImproveimmunogenicityVSAvoidbinding properties and functional stability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by making different parts of the antibody framework have different degrees of humanization. Specifically, framework positions are selectively humanized based on their impact on CDR conformation and antigen binding. Positions critical for maintaining CDR spatial orientation and binding affinity are preserved from the rabbit sequence, while non-critical positions are humanized to reduce immunogenicity. This selective approach ensures that local structural requirements are met while achieving overall humanization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs preliminary action by using computational modeling and structural analysis to predict which framework positions can be humanized without affecting CDR conformation or binding affinity. In silico simulations are performed before actual humanization to identify safe positions for modification, allowing the most critical functional positions to be protected while achieving humanization elsewhere. This preliminary assessment prevents loss of binding properties during the humanization process.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If rapid humanization methods are developed, then productivity is improved, but manufacturing precision and optimization deteriorate

Engineering Contradiction:

Improvehumanization speedVSAvoidbinding affinity optimization

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs preliminary action by using computational modeling and structural analysis to predict which framework positions can be humanized without affecting CDR conformation or binding affinity. In silico simulations are performed before actual humanization to identify safe positions for modification, allowing the most critical functional positions to be protected while achieving humanization elsewhere. This preliminary assessment prevents loss of binding properties during the humanization process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by systematically varying the degree and pattern of humanization at different framework positions. Multiple humanization variants are generated with different combinations of human and rabbit framework residues, allowing optimization of the balance between immunogenicity reduction and functional preservation. The specific humanization pattern is tuned to maintain CDR conformation while achieving human-like framework characteristics.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9994645B2Acceptor framework for CDR grafting

Publication Date: 2018.06.12 CELL MEDICA INC

AI summary

The present invention relates to an antibody acceptor framework and to methods for grafting non-human antibodies, e.g., rabbit antibodies, using a particularly well suited antibody acceptor framework. Antibodies generated by the methods of the invention are useful in a variety of diagnostic and therapeutic applications.