Modified Antigen-Binding Constructs for Homogeneous Bispecific Pairing
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Solution Overview
Problem
Existing methods struggle to produce bi-specific antibodies with homogeneous pairing of antibody heavy and light chains, leading to mispairing and challenges in manufacturing and biological efficacy.
Innovation Solution
The development of antigen binding polypeptide constructs with specific amino acid modifications in the CH1 and VL domains to promote preferential pairing of heavy and light chains, ensuring stable and specific binding to antigens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional methods are used to produce bi-specific antibodies by concomitant expression of two heavy chains and two light chains, then the therapeutic benefit of targeting multiple molecules is achieved, but mispairing of heavy and light chains occurs leading to heterogeneous products
Solution Approach 1:
The patent introduces asymmetrical mutations specifically at the CH3 domain interface of antibody heavy chains. These localized modifications create distinct interaction surfaces that enable selective pairing: the first heavy chain pairs preferentially with the first light chain, and the second heavy chain pairs preferentially with the second light chain. This local quality differentiation resolves the mispairing issue while maintaining bi-specific functionality.
Solution Approach 2:
The invention employs asymmetrical amino acid substitutions in the CH3 regions of the two different heavy chains. By creating asymmetric interaction interfaces, the patent ensures directional and selective heavy-light chain pairing. The asymmetric modifications prevent promiscuous pairing while preserving the ability of each heavy chain to bind its cognate light chain, thereby achieving homogeneous bi-specific antibody production.
2Manufacturing precision
If asymmetrical mutations are introduced into CH3 regions to drive directional Fab-arm exchange, then specific heavy-light chain pairing is achieved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent enables the antibody chains to self-assemble into correct heterodimeric pairs through engineered complementary interfaces. The asymmetrical mutations create inherent affinity differences that guide spontaneous correct pairing without requiring external intervention, complex purification steps, or additional assembly reagents. This self-service mechanism simplifies the overall manufacturing process despite the molecular-level complexity of the mutations.
3Manufacturing precision
If multiple amino acid modifications are introduced to promote preferential pairing, then pairing purity is enhanced, but thermal stability may be affected
Solution Approach 1:
The patent carefully selects amino acid substitutions that modify pairing affinity without disrupting the overall structural integrity and thermal stability of the antibody. The asymmetrical mutations are positioned at the CH3 interface where they influence pairing specificity while maintaining the folded structure and stability of the heavy chains. This parameter optimization ensures both high pairing purity and adequate thermal stability.
Data Source
AI summary
The present invention provides heterodimer pairs that can comprise a first heterodimer and a second heterodimer wherein each heterodimer comprises an immunoglobulin heavy chain or fragment thereof and an immunoglobulin light chain or fragment thereof. At least one of the heterodimers can comprise one or more amino acid modifications in the CH1 and/or CL domains, one or more amino acid modifications in the VH and/or VL domains, or a combination thereof. The modified amino acid(s) can be part of the interface between the light chain and heavy chain and are typically modified to create preferential pairing between each heavy chain and a desired light chain such that when the two heavy chains and two light chains of the heterodimer pair are co-expressed in a cell, the heavy chain of the first heterodimer preferentially pairs with one of the light chains rather than the other. Likewise, the heavy chain of the second heterodimer typically preferentially pairs with the second light chain rather than first.