Site-Selective Antibody Labeling for Homogeneous ADC Synthesis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for synthesizing antibody-drug conjugates lack site-selectivity and homogeneity, leading to reduced antibody binding affinity and difficulties in quality control, and often require genetic modification of antibodies.

Innovation Solution

A method using a conjugation-mediating protein with incorporated non-canonical amino acids and a pyridinium oxime derivative for site-specific synthesis of antibody-drug conjugates, applicable to native antibodies without additional modifications to existing production systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chemical incorporation method utilizing lysine or cysteine is used, then the conjugation process is simple and existing antibodies can be used without modification, but the site selectivity is poor and homogeneity is low

Engineering Contradiction:
Improveconjugation process simplicityVSAvoidsite selectivity and homogeneity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention changes the chemical parameters of the antibody by introducing non-canonical amino acids with specific functional groups (azide, alkyne, tetrazine) at defined positions, transforming the conjugation process from non-specific chemical reactions to highly selective bioorthogonal reactions with controlled kinetics and specificity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality by incorporating non-canonical amino acids at specific local positions on the antibody molecule (e.g., Fc region, Fab region, or N-/C-terminus), creating sites with unique chemical properties that enable selective conjugation while maintaining the rest of the antibody structure unchanged

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If site-specific incorporation methods utilizing enzyme are used, then site selectivity and homogeneity are improved, but genetic modification is required to incorporate amino acid sequences recognizable by the enzyme

Engineering Contradiction:
Improvesite selectivity and homogeneityVSAvoidgenetic modification requirement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention uses non-canonical amino acids as intermediaries that bridge the gap between existing antibody production systems and site-specific conjugation capabilities. These ncAAs can be incorporated through genetic code expansion in existing systems without requiring additional enzyme recognition sequences, serving as universal handles for bioorthogonal chemistry

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a universal platform where non-canonical amino acids with different reactive groups (azide, alkyne, tetrazine) can be incorporated at various positions on different antibody types, enabling a single conjugation chemistry approach to work across multiple antibody platforms without system-specific modifications

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If non-canonical amino acids are incorporated into binding protein and pyridinium oxime derivative is conjugated, then site-selective and homogeneous ADC synthesis is achieved without genetic modification of antibody production systems

Engineering Contradiction:
Improvesite selectivity and homogeneityVSAvoidconjugation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the complexity of site-specific conjugation from the antibody production system itself and separates it into a post-production step. The antibody is produced using standard systems, then purified and subjected to the ncAA incorporation and pyridinium oxime conjugation process, isolating the complex chemistry from the biological production

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables high-yield, homogeneous synthesis of antibody-drug conjugates with site-selective drug incorporation, maintaining antibody efficacy and facilitating quality control.

Implementation Method 1

proximity effect-based site-selective antibody labeling

Methodology Applied
Scientific EffectProximity effect:

Data Source

PatentEP4678648A1Synthesis method of antibody-drug conjugates using proximity effect-based site-selective antibody labeling
Publication Date: 2026.01.14 SOGANG UNIV RES & BUSINESS DEV FOUND
  • EP4678648A1 patent drawingFigure 1
  • EP4678648A1 patent drawingFigure 2a
  • EP4678648A1 patent drawingFigure 2b

AI summary

The present invention relates to a method for the synthesis of an antibody-drug conjugate using proximity effect-based site-selective antibody labeling. Provided according to the present invention may be a method for the synthesis of an antibody-drug conjugate by site-selectively introducing a drug into an antibody using a pyridinium oxime derivative (labeling mediator protein) introduced into a binding protein containing a non-standard amino acid.