Antibody-Drug Conjugate Linker Design for Tumor Selectivity

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Solution Overview

Problem

Current antibody-drug conjugates (ADCs) face challenges in achieving optimal therapeutic efficacy while minimizing toxic side effects due to issues with target selectivity and limited effectiveness on solid tumors.

Innovation Solution

Development of a novel antibody-drug conjugate that includes a bioactive molecule, a linker, and a targeting moiety, where the targeting moiety is attached to the linker via an active group, such as a sulfhydryl group, to enhance specificity and efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If highly lethal cytotoxic molecules are used for chemotherapy, then anti-tumor activity is improved, but toxic side effects increase due to killing of normal cells

Engineering Contradiction:
Improveanti-tumor activityVSAvoidtoxic side effects
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The ADC system segments the therapeutic function into two distinct components: the antibody moiety that provides targeting specificity to tumor cells, and the cytotoxic drug moiety that provides anti-tumor activity. This segmentation allows the toxic drug to be delivered selectively to tumor cells while sparing normal cells, thereby maintaining anti-tumor activity while reducing toxic side effects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The antibody acts as an intermediary that bridges the cytotoxic drug and the target tumor cells. The antibody binds specifically to antigens on tumor cell surfaces, forming an antibody-drug conjugate that serves as a mediator to deliver the cytotoxic payload selectively to tumor cells, thus reducing off-target toxicity while preserving anti-tumor efficacy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If targeted anti-tumor drugs are used to improve specificity, then target selectivity is improved, but toxic side effects still occur due to limited target selectivity

Engineering Contradiction:
Improvetarget selectivityVSAvoidtoxic side effects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The ADC exhibits local quality by concentrating the cytotoxic effect specifically at the target site (tumor cells) through antibody-mediated targeting. The drug is activated or released locally within or near the tumor cells via enzymatic hydrolysis by specific enzymes, ensuring that the harmful effect is localized to the tumor tissue while normal tissues remain protected.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes in the form of enzyme-specific hydrolysis to activate the cytotoxic drug. The drug is designed to be cleaved by specific enzymes (such as cathepsin B) that are present in higher concentrations within tumor cells or the tumor microenvironment, thereby changing the drug's state from inactive to active only at the target site, improving target selectivity and reducing systemic toxicity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If antibodies are used as biomacromolecule drugs to achieve high targeting, then targeting effect is improved, but therapeutic effect on solid tumors is limited

Engineering Contradiction:
Improvetargeting effectVSAvoidtherapeutic effect
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The ADC merges the targeting capability of the antibody with the potent anti-tumor activity of the cytotoxic small molecule drug into a single conjugate molecule. This combination allows the ADC to inherit the high targeting effect of the antibody while simultaneously acquiring the strong therapeutic effect of the cytotoxic agent, thereby overcoming the limitation of antibodies having limited therapeutic effect on solid tumors.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ADC is a composite material consisting of two distinct functional components: the antibody portion that provides targeting and the small molecule drug portion that provides therapeutic effect. This composite structure integrates the advantages of both biologic and small molecule therapies, enabling the ADC to achieve both high targeting effect and potent anti-tumor activity against solid tumors.

Inventive Principle:
Principle #40Composite materials

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 novel ADC design improves therapeutic efficacy, reduces toxic side effects, and expands the therapeutic window by ensuring precise targeting and controlled release of the bioactive molecule within tumor cells.

Implementation Method 1

the disulfide bond may be opened by reducing the disulfide bond using the reducing agent TCEP to generate the sulfhydryl group -SH

Methodology Applied
Scientific EffectReduction: Reduction

Implementation Method 2

The small molecule drug is then released inside the cell through enzymatic hydrolysis by a specific enzyme to treat a disease

Methodology Applied
Scientific EffectEnzymatic hydrolysis: Hydrolysis

Data Source

PatentEP4556026A1Antibody-drug conjugate, and preparation method therefor and use thereof
Publication Date: 2025.05.21 MEDILINK THERAPEUTICS (SUZHOU) CO LTD
  • EP4556026A1 patent drawingFigure 1~2
  • EP4556026A1 patent drawingFigure 3A~3B
  • EP4556026A1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a bioactive conjugate, and a preparation method therefor and the use thereof. Specifically, disclosed are an antibody-drug conjugate as represented by formula XV, and a preparation method therefor and the use thereof in the prevention and/or treatment of diseases related to an abnormal cell activity, including but not limited to tumor diseases.