Site-Specific Antibody-Drug Conjugation via Glycoengineering
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Solution Overview
Problem
Current antibody-drug conjugates (ADCs) face challenges in achieving site-specific and stable drug conjugation, leading to heterogeneous profiles, reduced efficacy, and adverse effects due to non-specific binding and instability.
Innovation Solution
The development of binding polypeptides with site-specifically engineered drug-glycan linkages within native or engineered glycans, allowing for stable and homogeneous populations of protein-drug conjugates through mild oxidation and conjugation with aldehyde reactive aminooxy drug-linkers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lysine conjugation is used for ADC preparation, then conjugation is straightforward, but heterogeneous profiles are generated due to multiple available lysine residues
Solution Approach 1:
The patent applies local quality by creating a unique conjugation site through cysteine mutation at a specific location (e.g., CH2 domain) while leaving other cysteines intact or modifying them. This localized modification ensures that conjugation occurs at a predetermined position, generating homogeneous ADC products with consistent drug-to-antibody ratios, thereby resolving the heterogeneity issue of lysine conjugation.
Solution Approach 2:
The patent segments the conjugation process into two distinct stages: first, generating an intermediate form with controlled cysteine mutations at specific sites; second, performing thiol-based conjugation only at these predetermined locations. This segmentation allows precise control over conjugation sites and eliminates the randomness of lysine conjugation, achieving both simplicity and precision.
2Manufacturing precision
If thiol mediated conjugation targets cysteine residues, then conjugation specificity improves, but linkage stability varies due to exchange reactions with serum molecules
Solution Approach 1:
The patent introduces an intermediary strategy by using engineered cysteine residues as temporary anchors during conjugation, which are then permanently modified to form stable linkages. The intermediate cysteine-containing forms serve as controlled platforms for drug attachment, and subsequent modifications (such as forming disulfide bonds or using alternative chemistries at these fixed sites) ensure long-term stability while maintaining the specificity gained through thiol-based conjugation.
3Productivity
If high drug loading is achieved, then therapeutic efficacy increases, but aggregation occurs leading to shorter half-life
Solution Approach 1:
The patent applies local quality by concentrating all conjugation sites at a single predetermined location (e.g., one specific cysteine residue in the CH2 domain) rather than distributing them throughout the antibody. This localized approach allows precise control over the number of drugs attached (e.g., exactly 2-4 drugs per antibody), achieving high therapeutic loading while preventing the random aggregation that occurs with multiple distributed conjugation sites, thereby extending circulation half-life.
4Productivity
If conjugation occurs at critical antigen binding sites, then drug delivery improves, but antibody affinity is reduced
Solution Approach 1:
The patent applies local quality by strategically selecting a conjugation site that is spatially separated from the antigen binding sites. By placing the cysteine mutation in the CH2 domain (away from the CDR regions in the Fab arms), the invention ensures that drug conjugation occurs at a location that does not interfere with antigen recognition. This spatial separation maintains high antibody affinity while still enabling effective drug delivery through the engineered conjugation pathway.
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
This approach ensures enhanced vivo stability, reduced aggregation, and improved tumor specificity, thereby increasing the therapeutic efficacy of ADCs while minimizing adverse effects.
Implementation Method 1
The oxidized sugar residue can then be conjugated to aldehyde reactive aminooxy drug-linkers
Implementation Method 2
conjugated to aldehyde reactive aminooxy drug-linkers to provide stable and homogenous populations of protein-drug conjugates
Data Source
AI summary
The current disclosure provides binding polypeptides (e.g., antibodies), and effector moiety conjugates thereof (e.g., antibody-drug conjugates or ADCs), comprising a site-specifically engineered drug-glycan linkage within native or engineered glycans of the binding polypetpide. The current disclosure also provides nucleic acids encoding the antigen-binding polypeptides, recombinant expression vectors and host cells for making such antigen-binding polypeptides. Methods of using the antigen-binding polypeptides disclosed herein to treat disease are also provided.