Antibody-Drug Conjugate Linker for Uniform Thiol Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing antibody-drug conjugates (ADCs) suffer from poor product uniformity and stability due to non-selective coupling reactions and the use of reducing agents that affect the disulfide bonds of antibodies.
Innovation Solution
A new linker is developed that can simultaneously couple with thiol or amino groups on antibodies, allowing for uniform coupling with 2, 3, or 4 thiol groups, thereby enhancing product uniformity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lysine residue is used as the coupling site, then the coupling reaction is simple, but the coupling number and site have great uncertainty and product uniformity is very poor
Solution Approach 1:
The patent introduces site-specific engineered cysteine residues at predetermined locations on the antibody molecule, creating localized coupling sites with specific chemical properties. This allows the coupling reaction to occur at defined positions rather than randomly across all lysine residues, thereby achieving both ease of manufacture and high product uniformity.
Solution Approach 2:
The patent changes the chemical parameters of the antibody by introducing engineered cysteine residues with specific sequences (e.g., EC1, EC2, EC3 configurations) at defined positions. This parameter change enables selective thiol-maleimide coupling at predetermined sites, transforming the coupling process from non-selective to highly selective while maintaining simplicity.
2Manufacturing precision
If cysteine residue produced by reduction of interchain disulfide bond is used as the coupling site, then the DAR value is relatively uniform, but the disulfide bond is destroyed affecting antibody stability
Solution Approach 1:
The patent segments the antibody structure by introducing specific engineered cysteine residues at defined positions (e.g., at the N-terminus of light chain or heavy chain) rather than relying on the interchain disulfide bonds. This segmentation allows coupling to occur at isolated, predetermined sites without affecting the structural integrity of the disulfide bond network.
Solution Approach 2:
The patent uses engineered cysteine residues as intermediary coupling sites that mediate the attachment of drug-linker conjugates without requiring reduction of disulfide bonds. These intermediary cysteines provide thiol groups for maleimide coupling while leaving the native disulfide bonds intact, thus maintaining antibody stability.
3Ease of manufacture
If existing reducing agents (DTT, TCEP) are used for coupling, then the coupling reaction can proceed, but the selectivity for interchain disulfide bonds is poor and final product uniformity is poor
Solution Approach 1:
The patent extracts the need for reducing agents by using naturally occurring or engineered cysteine thiol groups that are already available for coupling. By taking out the reduction step entirely and using direct thiol-maleimide coupling, the method eliminates the selectivity issues associated with reducing agents while maintaining coupling feasibility.
Solution Approach 2:
Instead of using reducing agents to generate thiols from disulfide bonds (the conventional approach), the patent inverts the approach by using engineered cysteine residues that provide thiols directly without requiring reduction. This inversion eliminates the selectivity problem of reducing agents while achieving the desired coupling.
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 new linker achieves uniform and structurally stable antibody-drug conjugates, improving product uniformity and maintaining the stability of the antibody, which is crucial for therapeutic efficacy and drug supervision.
Implementation Method 1
The linker is capable of coupling simultaneously with the thiol group(s) or amino group(s) on the antibody or functional fragment of the antibody
Data Source
AI summary
The present invention provides a linker for preparing antibody-drug conjugates and antibody-drug conjugates prepared by the linker, as well as use of the antibody-drug conjugates in a medicament for treating tumor. The linker is capable of coupling simultaneously with the thiol group or amino group on the antibody or functional fragment of the antibody, especially it is capable of coupling with 2, 3 or 4 thiol groups on the antibody or functional fragment of the antibody. A coupled product is uniform and structurally stable.