T Cell-Recruiting Polypeptide Complexes With Long Blood Half-Life

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Solution Overview

Problem

Existing cancer treatments using T cell-recruiting antibodies face challenges such as cytokine storms and short blood half-life, limiting their effectiveness and convenience.

Innovation Solution

Development of novel polypeptide complexes with reduced Fc receptor-binding activity and regulated CH1/CL interface association, incorporating Knobs-into-Holes (KiH) modifications, to enhance anti-tumor activity and prolong blood half-life while avoiding cytokine storms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If T cell-recruiting antibodies are administered to enhance anti-tumor activity, then cytotoxic activity against cancer cells is improved, but blood half-life becomes short and cytokine storms occur

Engineering Contradiction:
Improvecytotoxic activityVSAvoidblood half-life
Core Design Contradiction:
PowerVSDuration of action of moving object

Solution Approach 1:

The patent modifies the molecular structure of the T cell-recruiting antibody by altering the Fc region to reduce Fcγ receptor binding activity. This parameter change in the antibody structure extends blood half-life from hours to days while preserving T cell recruitment capability, thereby resolving the contradiction between high cytotoxic activity and short duration of action

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality modification by specifically targeting the Fc region of the antibody for structural modification while leaving the antigen-binding and CD3-binding regions intact. This localized change reduces FcγR binding in specific areas of the molecule, extending circulation time without compromising the overall anti-tumor mechanism

Inventive Principle:
Principle #3Local quality

2Power

If T cell-recruiting antibodies are administered to achieve strong anti-tumor effect, then cytotoxic activity is improved, but harmful side effects such as cytokine storms occur

Engineering Contradiction:
Improveanti-tumor effectVSAvoidcytokine storm
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

By changing the Fc region structure to reduce Fcγ receptor binding affinity, the patent modifies the immunological parameters of the antibody. This parameter change prevents excessive immune activation and cytokine release while maintaining effective T cell recruitment, thereby achieving strong anti-tumor effect without harmful cytokine storms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the potentially harmful FcγR binding activity into a beneficial feature by selectively reducing it. The modified Fc region prevents harmful cytokine storm while the antibody retains its ability to recruit T cells through the CD3 complex, effectively converting a harmful interaction into a controlled, beneficial one

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP3434767B1Cytotoxicity-inducing therapeutic agent
Publication Date: 2026.01.07 CHUGAI PHARMA CO LTD
  • EP3434767B1 patent drawingFigure 1
  • EP3434767B1 patent drawingFigure 2
  • EP3434767B1 patent drawingFigure 3

AI summary

By replacing the antigen-binding domain, the present inventors discovered novel polypeptide complexes that retain BiTE's strong anti-tumor activity and excellent safety properties, as well as have long half-life in blood and can damage various different target cells.