Variant IL13 CAR T Cells for Selective IL13Rα2 Tumor Targeting

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Solution Overview

Problem

Existing IL13-based chimeric antigen receptors (CARs) face challenges in selectively targeting IL13Rα2 over IL13Rα1, leading to safety concerns and reduced efficacy in treating systemic diseases due to wide expression of IL13 binding partners in healthy tissues, necessitating further mutations to enhance specificity.

Innovation Solution

Development of variant IL13 CARs with specific mutations, including amino acid sequences such as GPVPPSTAVRELIEELVNITQNQKAPLCNGSMVWSINLTAGMYCAALESLINVSGCSA IEKTQRMLSGFCPHKVSAGQFSSLHVRDTRIEVAQFVKDLLNHLKELFTEGQFN (SEQ ID NO: 26) and GPVPPSTAARELIEELFNITQNQKAPLCNGSMVWSINLTAGMYCAALESLINVSGCSA IEKTKRMLSGFCPHKVSAGQFPSLHVKKTRIEVAQFVKDLLIHLRKLFKEGQFN (SEQ ID NO: 27), combined with spacers, transmembrane domains, co-stimulatory domains, and CD3 zeta signaling domains, to enhance IL13Rα2 specificity and reduce off-target binding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If IL13-based CAR is used to target IL13Rα2, then therapeutic efficacy against cancer is improved, but off-target binding to IL13Rα1 in healthy tissues increases causing safety concerns

Engineering Contradiction:

Improvetherapeutic efficacyVSAvoidoff-target binding toxicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by introducing specific amino acid mutations (E13K, R109K, and additional mutations) into the IL13 sequence to alter the binding parameters of the CAR. These mutations change the electrostatic and structural properties of the IL13 binding interface, thereby increasing selectivity for IL13Rα2 over IL13Rα1 while maintaining therapeutic efficacy against cancer.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by making targeted mutations at specific positions (E13, R109, and other key residues) within the IL13 sequence. Each mutation locally modifies the binding interface properties to enhance specificity for IL13Rα2, while the rest of the IL13 structure remains intact to preserve overall binding function and therapeutic activity.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If multiple mutations are introduced to enhance IL13Rα2 specificity, then selectivity is improved, but the complexity of CAR development and validation increases

Engineering Contradiction:

ImproveIL13Rα2 specificityVSAvoidCAR development complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing in silico modeling and computational analysis to predict the effects of multiple mutations on IL13Rα2 specificity before experimental validation. This preliminary computational screening allows researchers to identify promising mutation combinations and prioritize them for testing, thereby reducing the overall complexity and time required for CAR development and validation.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20260000764A1TARGETED CHIMERIC ANTIGEN RECEPTOR MODIFIED T CELLS FOR TREATMENT OF IL13Ralpha2 POSITIVE MALIGNANCIES

Publication Date: 2026.01.01 THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIV

AI summary

Chimeric antigen receptor molecules that include a variant IL-13. The variant IL-13 are more selective for IL13Rα2 than IL13Rα1 by virtue of weaker binding to IL13Rα1. The chimeric antigen receptors can be used to treat IL13Rα2 expressing cancers.