Variant CH3 Domains for Preferential Bispecific Pairing
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Solution Overview
Problem
Current methods for producing bispecific antibodies face challenges such as inefficient production processes, stability issues, and short half-lives, primarily due to mispairing of heavy and light chains, which hinder the broad commercial application of these therapeutic agents.
Innovation Solution
Engineered variant CH3 domains that preferentially form CH3-CH3 heterodimers over homodimers, incorporated into polypeptides or multi-specific antibodies, to enhance pairing specificity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If co-expression of two different heavy chains and two different light chains is used to produce bisspecific antibodies, then multiple antigen binding specificities are achieved, but mispairing of chains occurs leading to mixture of sixteen possible combinations
Solution Approach 1:
The patent applies local quality by introducing specific amino acid substitutions at defined positions in the CH3 domain (e.g., T366W in one heavy chain and T366S plus Y407G in the other heavy chain). These localized changes create complementary surfaces that enable preferential heterodimerization while maintaining the overall antibody structure and function.
Solution Approach 2:
The invention employs asymmetry by creating non-identical CH3 domains through specific amino acid substitutions. The first and second heavy chains have different amino acid sequences at positions 366, 407, and/or 409, resulting in asymmetric interfaces that favor heterodimer formation over homodimer formation, thereby resolving the mispairing issue.
2Ease of manufacture
If heavy chains bind light chains in a relatively promiscuous manner to form bispecific antibodies, then production flexibility is maintained, but mispairing leads to maximal yield of only 12.5% for the desired antibody
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence parameters of the CH3 domain. Specific substitutions at positions 366, 407, and 409 alter the binding parameters (affinity and specificity) of the heavy chain interface, enabling preferential heterodimerization and dramatically improving the yield of the desired bispecific antibody while maintaining production flexibility.
3Manufacturing precision
If separate production of first and second heavy-light chain pairs followed by mixing is used, then some control over chain pairing is achieved, but three possible combinations are still possible with maximal yield of 50%
Solution Approach 1:
The patent applies local quality by introducing specific amino acid substitutions at defined positions in the CH3 domain (e.g., T366W in one heavy chain and T366S plus Y407G in the other heavy chain). These localized changes create complementary surfaces that enable preferential heterodimerization while maintaining the overall antibody structure and function.
Solution Approach 2:
The patent applies parameter changes by modifying the amino acid sequence parameters of the CH3 domain. Specific substitutions at positions 366, 407, and 409 alter the binding parameters (affinity and specificity) of the heavy chain interface, enabling preferential heterodimerization and dramatically improving the yield of the desired bisspecific antibody while maintaining production flexibility.
Data Source
AI summary
Variant CH3 domain polypeptides are provided that preferentially form CH3-CH3 heterodimers over CH3-CH3 homodimers. Such variant CH3 domains can be used to promote desired Fc pairing, thus providing for efficient development of bispecific and multispecific antibodies as well as Fc fusions of different formats. Methods of producing bispecific antibodies using such variant CH3 domains and for producing libraries containing such variant CH3 domains are also provided.