Methylene Amide ADC Linker for Controlled Intracellular Drug Release

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Solution Overview

Problem

Existing antibody-drug conjugates lack effective linkers that control the release mode and rate of drugs within cells, limiting their therapeutic efficacy, particularly for targeting malignant cells.

Innovation Solution

Development of a methylene amide linker-based antibody-drug conjugate with a specific structure (Formula I) that allows for controlled drug release, featuring a cytotoxic drug linked to an antibody via a non-cleavable peptide residue, with a drug-to-antibody ratio (DAR) of 2-8, enhancing targeted delivery to malignant cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing linker release technologies (PAB-carbonyl fragment, hemiaminal, cleavable peptide chains) are used, then the conjugation function is achieved, but the controlled release mode and rate of drugs within cells is insufficient

Engineering Contradiction:
Improvecontrolled release mode and rate of drugsVSAvoidlinker release technologies
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent modifies the linker structure by introducing a methylene amide bond with specific n values (n=6-8 or n=6.2-7.8) to optimize the drug release characteristics. This structural parameter change enables controlled release while maintaining stability during circulation, resolving the contradiction between reliable controlled release and limited adaptability of existing linkers.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a linker structure is designed for controlled drug release, then the therapeutic efficacy is improved, but the complexity of the conjugate structure increases

Engineering Contradiction:
Improvetherapeutic efficacyVSAvoidconjugate structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The linker is divided into distinct functional segments: a stabilizing portion that maintains circulation stability, a methylene amide bond that enables controlled release, and a drug payload. This segmentation allows each portion to perform its specific function optimally, achieving high therapeutic efficacy while managing structural complexity through functional modularity.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the drug-to-antibody ratio (DAR) is increased to enhance anti-tumor effect, then the therapeutic efficacy improves, but the stability and delivery control become more challenging

Engineering Contradiction:
Improveanti-tumor effectVSAvoiddrug-to-antibody ratio control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The methylene amide linker design provides universal applicability across different antibody-drug conjugates with varying DAR values (2-8). The linker structure maintains its controlled release functionality and stability characteristics regardless of the specific DAR, enabling scalable production and consistent therapeutic performance across different conjugate formulations.

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

Data Source

PatentEP4643883A2Antibody-drug conjugate containing n-methylene amide linker
Publication Date: 2025.11.05 HANGZHOU ADCORIS BIOPHARMA CO LTD
  • EP4643883A2 patent drawingFigure 1~2
  • EP4643883A2 patent drawingFigure 3~4
  • EP4643883A2 patent drawingFigure 5~6

AI summary

The present invention relates to a linking structure capable of being used for linking an antibody and a drug that is toxic to malignant cells, and an antibody-drug conjugate as represented by formula (I) formed by means of linking an antibody and a cytotoxic drug via the linking structure, wherein each group in the formula is as defined in the description. The antibody-drug conjugate has a significant anti-tumor effect.