IgG4 Antibody Hinge Mutations to Prevent Half-mAb Formation
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Solution Overview
Problem
Therapeutic IgG4 antibodies are prone to half-mAb formation due to interchain disulfide bond reduction during manufacturing and in vivo recombination with endogenous IgG4s, leading to a heterogeneous mixture of bispecific antibodies, and existing mutations like S228P do not adequately prevent this issue in reducing environments.
Innovation Solution
Incorporating mutations at residues 219, 220, and/or 228 in the human IgG4 constant region of the heavy chains, such as cysteines and prolines, to stabilize the antibody against reduction and prevent half-mAb formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the S228P mutation is introduced to prevent half-mAb formation, then half-mAb formation is reduced, but the antibody remains susceptible to half-mAb formation in reducing environments
Solution Approach 1:
The patent introduces multiple mutations at specific positions (219, 220, and 228) in the hinge region to alter the chemical and structural parameters of the antibody. These mutations collectively change the redox sensitivity and stability characteristics, making the antibody resistant to reduction while maintaining prevention of half-mAb formation.
Solution Approach 2:
The patent combines multiple mutations (e.g., 219C, 220C, 228P) into a composite modified hinge region. This composite structure integrates the benefits of each individual mutation to achieve both prevention of half-mAb formation and protection against reduction in reducing environments, creating a synergistic effect that neither mutation alone could achieve.
2Stability of the object's composition
If mutations are introduced to stabilize the antibody against reduction, then stability is improved, but the complexity of the antibody structure increases
Solution Approach 1:
The patent applies mutations specifically to the hinge region (positions 219, 220, and 228) rather than throughout the entire antibody structure. This localized modification approach maintains the overall simplicity of the antibody while concentrating the stabilizing effects in the critical hinge region where reduction most commonly occurs.
3Manufacturing precision
If multiple mutations are introduced to prevent half-mAb formation and reduce heterogeneity, then purity is improved, but the difficulty of manufacturing increases
Solution Approach 1:
The patent incorporates the stability-conferring mutations directly into the antibody sequence design before manufacturing. This preliminary incorporation of stabilizing mutations ensures that the antibody is inherently resistant to half-mAb formation and reduction throughout the manufacturing process and storage, eliminating the need for additional purification steps to remove heterogeneous products.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The mutated IgG4 antibodies exhibit enhanced stability against reduction, with up to 80% less half-antibody formation compared to unmodified IgG4s, maintaining functional integrity and reducing heterogeneity.
Implementation Method 1
Interchain disulfide bond reduction results in two half antibodies that reform intact antibodies
Data Source
AI summary
The disclosure relates to an antibody of the class IgG4 comprising two heavy chains, wherein each of the heavy chains comprises a human IgG4 constant region comprising a mutation. The disclosure further relates to methods of treating a disorder or condition using the IgG4 antibody comprising two heavy chains, wherein each of the heavy chains comprises a human IgG4 constant region comprising a mutation.