Activatable Anti-CD3 Antibodies for Tumor-Localized T-Cell Engagement

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Solution Overview

Problem

Bispecific T-cell engager antibodies (BiTEs) face severe dose-limiting toxicities due to cytokine release syndrome, limiting their therapeutic window, and there is a need for activatable antibodies with enhanced specificity and reduced side effects.

Innovation Solution

Development of multispecific and activatable antibodies that include a masking moiety to prevent binding in healthy tissues and activate in the tumor microenvironment, utilizing a cleavable linker to enhance antigen-binding affinity and specificity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bispecific T-cell engager antibodies are used to recruit cytolytic T-cells to kill tumor cells, then tumor killing efficacy is improved, but severe dose-limiting toxicities manifest as cytokine release syndrome

Engineering Contradiction:

Improvetumor killing efficacyVSAvoidcytokine release syndrome

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The antibody is pre-designed with a masking motif that blocks the antigen-binding interface before administration. This preliminary masking action prevents premature binding and cytokine release in healthy tissues, while allowing activation only when needed in the tumor microenvironment through proteolytic cleavage or antigen competition

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A masking motif is introduced as an intermediary element between the antigen-binding fragment and the target antigen. This intermediary blocks binding in circulation and healthy tissues, but can be removed or displaced in the tumor microenvironment, thereby mediating controlled activation and reducing off-target toxicities

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the antibody is activated in healthy tissues, then antigen binding occurs, but severe side effects result from non-specific binding

Engineering Contradiction:

Improveantigen bindingVSAvoidside effects

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The antibody system exhibits different functional qualities in different locations: in circulation and healthy tissues, the masking motif maintains an inactive state with blocked binding; in the tumor microenvironment, local conditions (proteases, antigen concentration) trigger activation. This spatial differentiation of functional state ensures binding occurs only where needed, minimizing side effects

Inventive Principle:

Principle #3Local quality

3Measurement precision

If a masking motif is added to mask the antigen-binding interface, then specificity in the tumor microenvironment is improved, but the device complexity increases

Engineering Contradiction:

ImprovespecificityVSAvoidantibody structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The masking motif is merged with the antigen-binding fragment through fusion, creating a single integrated molecule rather than requiring separate components. This fusion approach simplifies the overall system architecture while maintaining the dual functionality of masking and binding, reducing complexity compared to using separate masking and antibody molecules

Inventive Principle:

Principle #5Merging (Combining)

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 antibodies achieve targeted tumor killing with reduced side effects by activating only in the tumor microenvironment, enhancing therapeutic efficacy while minimizing toxicity in healthy tissues.

Implementation Method 1

the masking motif is designed to activate, or unmask, the antibody to allow binding in the tumor microenvironment where certain activation conditions such as a protease is upregulated or favorable competition via highly localized antigen concentration

Methodology Applied

Scientific EffectCompetition binding:

Implementation Method 2

The masking motif is designed to activate, or unmask, the antibody to allow binding in the tumor microenvironment where certain activation conditions such as a protease is upregulated

Methodology Applied

Scientific EffectProteolytic cleavage: Hydrolysis

Data Source

PatentUS20250326860A1Anti-CD3 antibodies and methods of use thereof

Publication Date: 2025.10.23 ADAGENE PTE LTD

AI summary

The present application provides antibodies comprising an antigen-binding fragment of an anti-CD3 antibody having tailor-made affinity to CD3 in low to medium range. In some embodiments, the antibody further comprises an antigen-binding fragment that specifically binds to a target antigen, such as HER2, CD20, TROP2, BCMA, or CD19. Also provided are anti-CD3 antibodies, masked anti-CD3 antibodies (including activatable anti-CD3 antibodies), anti-CD20 antibodies, and masked anti-HER2 antibodies (including activatable anti-HER2 antibodies). The antibodies described herein are useful for treatment of cancer.