MSLN/PD-L1 Nanobodies for Controlled T-Cell Activation

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Solution Overview

Problem

Current nanobodies targeting MSLN or PD-L1 are inadequate, and T cell activating drugs for solid tumors face safety issues like cytokine release syndrome (CRS) and T cell dysfunction due to over-activation.

Innovation Solution

Development of nanobodies with specific sequences targeting CD3, MSLN, and PD-L1, combined with immunoglobulin Fc domains and peptide linkers, to modulate T cell activation and enhance anti-tumor effects while reducing cytokine release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If traditional IgG heavy-light chain antibodies are used to target MSLN or PD-L1, then they have standard antibody structure and function, but they lack the advantages of small molecular weight, good stability, and strong permeability

Engineering Contradiction:
Improvemolecular weightVSAvoidstability and permeability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent extracts only the essential antigen-binding function from the complete antibody structure by using single-domain antibodies (nanobodies) composed of a single variable domain (VHH) instead of the full IgG structure with both heavy and light chains. This extraction achieves reduced molecular weight while maintaining binding functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the structural parameters of the antibody by adopting camelid-derived VHH domains with unique properties (disulfide bond configuration, framework regions) that provide enhanced stability and permeability despite the reduced size, thus optimizing the weight-stability-permeability parameter set.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If CD3 bispecific antibody drugs are used to activate T cells for treating solid tumors, then T cell activation is achieved, but cytokine release syndrome (CRS) and T cell dysfunction occur due to over-activation

Engineering Contradiction:
Improveanti-tumor effectVSAvoidcytokine release syndrome and T cell dysfunction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating a multispecific antibody where different domains have specialized functions: one domain targets CD3 for T cell engagement, another targets MSLN or PD-L1 for tumor specificity, and the structure is designed to provide moderate rather than maximal activation. This localized functional differentiation enables controlled T cell activation that reduces CRS and T cell dysfunction while maintaining anti-tumor efficacy.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs partial action by designing the CD3-binding domain to provide moderate T cell activation rather than full activation. The multispecific antibody structure enables sufficient anti-tumor response through partial activation, thereby avoiding the harmful effects of excessive T cell activation such as CRS and T cell dysfunction.

Inventive Principle:
Principle #16Partial or excessive action

3Weight of moving object

If nanobodies are designed to target MSLN or PD-L1, then small molecular weight and good stability are achieved, but satisfactory nanobodies with effective anti-tumor activity are still lacking

Engineering Contradiction:
Improvemolecular weightVSAvoidanti-tumor efficacy
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent merges multiple functional domains into a single multispecific antibody molecule: VHH domains targeting MSLN and/or PD-L1 are combined with a CD3-binding domain (comprising VH and VL regions). This merging enables the nanobody to simultaneously achieve tumor antigen binding, T cell recruitment, and moderate activation, thereby providing effective anti-tumor activity despite the small molecular weight.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements multi-functionality by designing the multispecific antibody to perform multiple functions: (1) binding to tumor-associated antigens (MSLN, PD-L1) for tumor targeting, (2) binding to CD3 for T cell engagement, and (3) providing moderate T cell activation. This universal design enables a single molecule to address multiple requirements for effective cancer therapy.

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

Data Source

PatentEP4617290A1Antibody and use thereof
Publication Date: 2025.09.17 SICHUAN HUIYU PHARMA
  • EP4617290A1 patent drawingFigure 1A~1C
  • EP4617290A1 patent drawingFigure 2~4
  • EP4617290A1 patent drawingFigure 5~6b

AI summary

The present invention relates to a humanized single-domain antibody or an antigen-binding fragment thereof targeting MSLN or PD-L1. The present invention also relates to a multispecific antibody, and particularly provides a multispecific antibody targeting CD3, a tumor-associated antigen and an immune checkpoint, wherein the multispecific antibody has good medication safety and anti-tumor efficacy. The present invention further relates to use of the single-domain antibody or the multispecific antibody in disease treatment.