GPC3 CAR T Cell Targeting Specificity and Safety

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Solution Overview

Problem

Current CAR T lymphocyte therapies for tumor treatment face challenges such as the need for continuous administration, high treatment costs, allergic reactions, and off-target effects due to the expression of specific antigens in normal tissues, leading to unsatisfactory efficacy and safety concerns.

Innovation Solution

Development of a GPC3-specific chimeric antigen receptor (CAR) for T lymphocytes, comprising a single-chain antibody recognizing the C-terminal epitope of GPC3, connected with CD8 or CD28 transmembrane regions and intracellular signaling domains like CD3ζ and CD137, encoded by nucleic acid sequences, to enhance specificity and efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If antibody therapy is used to treat tumor, then tumor cells can be targeted, but the treatment requires continued administration and increased dosage due to short half-life, resulting in increased treatment cost

Engineering Contradiction:
Improvetumor targeting effectivenessVSAvoidantibody half-life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent uses T lymphocytes as an intermediary carrier to deliver the anti-GPC3 antibody function. Instead of administering antibodies directly, the antibody genes are introduced into T cells, which then serve as living factories that continuously produce and secrete anti-GPC3 antibodies at the tumor site, extending the duration of action while maintaining targeting effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The modified T lymphocytes are designed to self-sustain by continuously producing and secreting anti-GPC3 antibodies autonomously after initial administration. The cells express the antibody gene permanently and function as self-renewing therapeutic agents that persist in the body without requiring repeated external dosing

Inventive Principle:
Principle #25Self-service

2Reliability

If therapeutic antibody is administered, then tumor cells can be targeted, but allergic reaction and generation of neutralizing-antibodies may occur

Engineering Contradiction:
Improvetumor targeting effectivenessVSAvoidallergic reaction and neutralizing-antibody generation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

T lymphocytes serve as a biological intermediary that produces the therapeutic antibody internally rather than receiving exogenous antibody administration. This eliminates direct exposure to foreign proteins that cause allergic reactions and neutralizing antibody formation, while still achieving the same tumor-targeting effect through the T cell-produced antibodies

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patient's own T cells are modified to produce the therapeutic antibody, making the treatment endogenous rather than exogenous. This self-produced antibody system avoids the immunogenicity issues associated with externally administered antibodies, reducing allergic reactions and neutralizing antibody formation

Inventive Principle:
Principle #25Self-service

3Reliability

If CAR T lymphocyte therapy is used, then tumor cells can be specifically targeted in MHC-independent manner, but off-target effects occur due to expression of specific antigens in normal tissues

Engineering Contradiction:
Improvetumor targeting specificityVSAvoidoff-target effects on normal tissues
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent confers antibody-producing capability only to specific T lymphocytes that are introduced into the patient's body, rather than modifying all T cells. This localized modification ensures that only the introduced CAR T cells produce the therapeutic antibody, allowing for better control and reduced off-target effects compared to universal T cell modification

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The CAR T lymphocytes act as controlled intermediaries that produce antibodies only when activated by tumor antigen recognition. This intermediary system provides spatial and temporal control over antibody production, reducing off-target effects by limiting antibody secretion to locations and times when tumor antigens are present

Inventive Principle:
Principle #24Intermediary (Mediator)

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 GPC3-specific CAR T lymphocytes demonstrate high specificity and efficacy in targeting and killing tumor cells with high GPC3 expression, reducing off-target effects and improving in vivo survival and anti-tumor responses, while maintaining safety by minimizing normal tissue damage.

Implementation Method 1

the extracellular binding domain comprises a single chain antibody, scFv(GPC3), which specifically recognizes the C-terminal epitope of GPC3

Methodology Applied
Scientific EffectAntigen-antibody recognition:

Implementation Method 2

provides the T lymphocyte which expresses said receptor with a highly specific cytotoxicity against tumor cells with high GPC3 expression

Methodology Applied
Scientific EffectCell-mediated cytotoxicity:

Data Source

PatentEP2995682A9Nucleic acid of coded GPC3 chimeric antigen receptor protein and t lymphocyte expressing GPC3 chimeric antigen receptor protein
Publication Date: 2018.12.05 CRAGE MEDICAL CO LTD
  • EP2995682A9 patent drawingFigure 1~2
  • EP2995682A9 patent drawingFigure 3~5
  • EP2995682A9 patent drawingFigure 4

AI summary

A nucleic acid encoding a chimeric antigen receptor expressed at surface of a T lymphocyte, said chimeric antigen receptor comprises, connected in the order of, an extracellular binding domain, a transmembrane region, and an intracellular signaling domain, wherein the extracellular binding domain comprises a single chain antibody, scFv(GPC3), which specifically recognizes the C-terminal epitope of GPC3. A genetically modified T lymphocyte having a chimeric antigen receptor expressed at surface thereof, and the chimeric antigen receptor is expressed by the nucleic acid described above.