Tripeptide Cleavable Linkers for Selective Drug Release
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Solution Overview
Problem
Traditional Ligand Drug Conjugates face challenges in reducing premature release of cytotoxic compounds, leading to undesired side effects due to non-specific proteolysis in normal tissues, which can result in on-target or off-target toxicity, and fail to exploit differences in proteolytic environments between tumor and normal tissues.
Innovation Solution
Development of Ligand Drug Conjugates with improved peptide sequences that enhance selective proteolysis in tumor tissues over normal tissues, reducing exposure to cytotoxic compounds in normal tissues while maintaining efficacy in cancer treatment, achieved through specific peptide sequences in the Peptide Cleavable Unit that confer differential biodistribution and pharmacokinetic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional dipeptide-based Ligand Drug Conjugates are used to achieve selective delivery to tumor cells, then the conjugate can be internalized by targeted cells through binding to the targeted moiety, but premature release of the cytotoxic compound occurs in normal tissues due to non-specific proteolysis, resulting in undesired side effects and toxicity
Solution Approach 1:
The patent changes the peptide sequence parameters from traditional dipeptides (e.g., Val-Cit, Val-Ala) to improved tripeptide sequences (e.g., P3-P2-P1 where P1 is negatively charged or serine, P2 has aliphatic side chain with hydrophobicity no greater than leucine, and P3 has hydrophobicity lower than leucine). This parameter change in the peptide structure confers differential susceptibility to proteolysis between tumor and normal tissues, reducing premature release in normal tissues while maintaining selectivity for targeted cells
Solution Approach 2:
The patent applies local quality by making the peptide sequence specifically optimized for tumor tissue environment. The improved peptide sequences are designed to be more prone to proteolysis by tumor tissue proteases compared to normal tissue proteases, creating localized differential release properties that reduce systemic toxicity while maintaining targeted efficacy
2Reliability
If traditional dipeptide sequences are designed to be selectively acted upon by intracellular proteases upregulated in cancer cells, then some selectivity is achieved, but the sequences are still capable of being acted upon by proteases in normal tissue, resulting in on-target or off-target toxicity
Solution Approach 1:
The patent changes the peptide sequence from dipeptide to tripeptide format with specific amino acid constraints (P1 negatively charged or serine, P2 with aliphatic side chain hydrophobicity ≤ leucine, P3 with hydrophobicity < leucine). This parameter change creates a peptide structure that is selectively recognized and cleaved by tumor-associated proteases while resisting cleavage by normal tissue proteases, thereby reducing both on-target and off-target toxicities
Solution Approach 2:
The patent inverts the traditional approach by designing peptides that are deliberately MORE susceptible to proteolysis in tumor tissue rather than less susceptible. This inversion exploits the unique proteolytic environment of tumor tissue to achieve selective activation, turning the previously harmful non-specific proteolysis into a beneficial selective activation mechanism
3Object-affected harmful factors
If improved peptide sequences are used to reduce exposure to cytotoxic compounds in normal tissues, then tolerability is improved, but the conjugate must maintain efficacy in tumor tissues
Solution Approach 1:
The patent changes the peptide sequence parameters to create differential biodistribution and pharmacokinetic properties. The improved tripeptide sequences are designed to be more prone to proteolysis by tumor tissue, ensuring rapid release and efficacy in tumor tissues, while being more resistant to normal tissue proteases, reducing exposure and toxicity in normal tissues. This parameter optimization achieves both reduced normal tissue exposure and maintained tumor efficacy
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 improved peptide sequences in Ligand Drug Conjugates achieve reduced toxicity in normal tissues and retained efficacy in tumor tissues, leading to enhanced tolerability and therapeutic outcomes by preferentially retaining the conjugate in tumor tissues and eliminating it from normal tissues.
Implementation Method 1
When conditional release of a cytotoxic compound, which otherwise would cause undesired side effects, from traditional dipeptide-based Ligand Drug Conjugates is to be affected by an intracellular protease
Data Source
AI summary
The invention relates to conjugates of biologically active compounds, wherein such a conjugate is comprised of a sequence of amino acids containing a tripeptide that confers selective cleavage by tumor tissue homogenate for release of free drug and/or improves biodistribution into the tumor tissue in comparison to normal tissue homogenate from the same species, wherein the normal tissue is the site of an adverse event associated with administration to a human subject in need thereof of a therapeutically effective amount of a comparator conjugate whose amino acid sequence is a dipeptide known to be selectively cleavable by Cathepsin B.