Protease-Activated EGFR T Cell Engagers With Reduced Cytokine Toxicity
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Solution Overview
Problem
Existing T cell engager (TCE) therapeutics face challenges in treating solid tumors due to overactivation of the immune system leading to cytokine release syndrome, on-target healthy tissue toxicities, and poor pharmacokinetics, including short half-life, limiting their effectiveness and safety in clinical applications.
Innovation Solution
Development of polypeptide complexes that include a first antigen recognizing molecule binding to an effector cell antigen, a peptide that impairs binding to the effector cell antigen, a tumor-specific protease-cleavable linking moiety, a half-life extending molecule, and a second antigen recognizing molecule binding to EGFR, designed to enhance specificity and longevity while minimizing systemic toxicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If T cell engager therapeutics are used to treat solid tumors, then tumor cell killing activity is improved, but cytokine release syndrome and systemic toxicity occur due to overactivation of the immune system
Solution Approach 1:
The patent applies preliminary action by incorporating a peptide blocker that pre-occupies the effector cell antigen binding site on the T cell engager. This blocker is designed to be cleaved by tumor-specific proteases, so the T cell engager is prepared in advance with the blocking mechanism in place, but the actual activation is delayed until the blocker is removed at the tumor site. This prevents premature immune system activation and cytokine release syndrome while maintaining tumor cell killing capability.
Solution Approach 2:
The patent uses a tumor-specific protease-cleavable peptide linker as an intermediary between the peptide blocker and the effector cell antigen binding site. This intermediary mechanism allows controlled release of the blocker only in the presence of tumor-specific proteases, mediating between the need for potent tumor cell killing and the need to avoid systemic toxicity. The intermediary ensures that the blocking function is transient and location-specific.
2Reliability
If T cell engager therapeutics are administered systemically, then tumor targeting capability is improved, but on-target healthy tissue toxicities occur
Solution Approach 1:
The patent applies local quality by making the T cell engager's binding activity local rather than systemic. The peptide blocker is designed to be present throughout the system but becomes inactive only at the specific location where tumor-specific proteases are present. This creates a spatial gradient of activity where the T cell engager is blocked in healthy tissues but activated at the tumor site, thereby achieving local quality control over the therapeutic effect.
Solution Approach 2:
The patent utilizes parameter changes by exploiting the differential presence of tumor-specific proteases as a switching parameter. The peptide linker contains a specific cleavage site recognized by tumor-specific proteases, so the binding affinity parameter of the T cell engager changes from blocked to unblocked based on the local protease environment. This parameter change allows the same molecule to have different functional states in different tissue contexts.
3Reliability
If T cell engager therapeutics are used, then immune system activation is improved, but short half-life and poor pharmacokinetics limit effectiveness
Solution Approach 1:
The patent employs the principle of disposable short-living objects by using a transient peptide blocker that is designed to be temporary and sacrificial. The peptide linker is engineered to be cleaved by tumor-specific proteases, making the blocker a short-lived component that serves its purpose during circulation and then is disposed of at the tumor site. This allows the use of a simple, small molecule blocker rather than a complex, stable inhibition mechanism, improving pharmacokinetics while maintaining immune activation capability.
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 polypeptide complexes effectively target and kill tumor cells with reduced systemic toxicity and improved pharmacokinetics, offering a safer and more effective off-the-shelf therapeutic option for solid tumors.
Implementation Method 1
L1 comprises a linking moiety that connects A1 to P1 and is a substrate for a tumor specific protease
Data Source
AI summary
Provided herein are multispecific antibodies that selectively bind to EGFR and effector cell antigens such as CD3, pharmaceutical compositions thereof, as well as nucleic acids, and methods for making and discovering the same.