Antibody Fusion Protein Multimeric Complexes for In Vivo Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing bispecific antibodies face challenges with yield, stability, immunogenicity, and pharmacokinetics, particularly in achieving long circulating half-lives and in vivo stability, due to issues with production processes and the inherent properties of smaller antibody fragments.
Innovation Solution
The development of fusion proteins comprising antibodies with anchoring domains (AD) and dimerization and docking domains (DDD) moieties, where the AD is attached to the C-terminal end of the antibody light chain, forming multimeric complexes that enhance pharmacokinetic properties and in vivo stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If antibody fragments (scFv, Fab) are used to produce immunoconjugates, then the molecular size is reduced and renal clearance increases, but the circulating serum half-life becomes too short for therapeutic use
Solution Approach 1:
The patent combines antibody fragments with Fc regions to create IgG-based immunoconjugates. This merging preserves the antigen-binding capability of the variable regions while adding the Fc region's ability to extend circulation half-life through reduced renal clearance and engagement of FcRn recycling pathways, thus resolving the contradiction between small size and short half-life
Solution Approach 2:
The invention creates composite antibody structures by fusing different functional domains: the antigen-binding variable regions (VH and VL) are combined with the constant Fc region. This composite structure integrates the targeting function of fragments with the pharmacokinetic advantages of intact IgG, achieving both specificity and prolonged circulation
2Adaptability or versatility
If chemical cross-linking methods are used to produce bispecific antibodies, then bispecific functionality is achieved, but the manufacturing process becomes complex and costly with extensive purification steps
Solution Approach 1:
The patent extracts and removes the complex chemical cross-linking step from the manufacturing process. By using genetically engineered antibody structures with built-in pairing domains (such as knob-into-hole interfaces or charged residue interactions), the bispecific functionality is achieved through controlled self-assembly during expression, eliminating the need for external chemical reagents and extensive purification
Solution Approach 2:
The invention enables immunoconjugates to self-assemble into bispecific configurations through engineered interactions between antibody components. The structural design includes complementary interfaces that guide correct pairing of heavy and light chains, allowing the molecules to find their proper configuration autonomously during cellular expression without requiring external manipulation or complex purification protocols
3Productivity
If intact IgG antibodies are used for immunoconjugates, then production yield and in-vivo stability are improved, but the molecular size and complexity increase
Solution Approach 1:
The patent applies local quality by making targeted modifications to specific regions of the antibody structure rather than changing the entire molecule. The variable regions are engineered for optimized antigen binding, while the Fc region is modified locally to control dimerization and half-life properties. This localized engineering achieves high production yield and stability without unnecessarily increasing overall molecular complexity
Data Source
Figure 1a~1g
Figure 2A~2D
Figure 3A~3D
AI summary
The present invention concerns multimeric complexes based on antibody fusion proteins comprising an AD moiety attached to the C-terminal end of each antibody light chain. The complexes further comprise effector moities attached to DDD moieties. Two copies of the DDD moiety form a dimer that binds to the AD moiety. The complexes may be trimers, pentamers, hexamers or other multimers. The effector moieties may be selected from a second antibody or antigen-binding fragment thereof, a cytokine, an interferon, a toxin, an antigen, a xenoantigen, a hapten, a protamine, a hormone, an enzyme, a ligand-binding protein, a pro-apoptotic agent and an anti-angiogenic agent. Surprisingly, attachment of the AD moiety to the C-terminal end of the antibody light chain results in improved pharmacokinetics and in vivo stability and efficacy, compared to homologous complexes wherein the AD moiety is attached to the antibody heavy chain.