Evans Blue-PSMA Conjugates for Longer-Circulating Prostate Radiotherapy
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Solution Overview
Problem
Current PSMA-targeting small molecules for prostate cancer treatment face challenges such as rapid clearance from circulation, leading to low tumor accumulation and limited diagnostic/therapeutic efficacy, with existing agents like 177< Lu-PSMA-617 showing partial response rates of up to 70%-80% that are short-term and long-term toxicity unknown.
Innovation Solution
Development of Evans Blue derivatives conjugated with PSMA ligands, such as EB-PSMA-617, which have increased blood half-life and tumor uptake, utilizing a residue derived from (((R-)-1-carboxy-2-mercaptoethyl)carbamoyl)-L-glutamic acid to enhance urinary tract clearance and albumin binding, resulting in improved tumor targeting and radiotherapy efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PSMA-targeting small molecules are used for prostate cancer treatment, then tumor targeting is achieved, but rapid clearance from circulation occurs leading to low tumor accumulation
Solution Approach 1:
The patent creates a composite molecule combining Evans Blue (EB) derivative with PSMA ligand (e.g., glutamate-urea-lysine). This composite structure leverages the albumin-binding property of EB to extend circulation half-life while maintaining PSMA-targeting capability of the ligand, thereby increasing tumor accumulation despite rapid clearance of conventional small molecules
Solution Approach 2:
The Evans Blue derivative acts as an intermediary that binds to serum albumin in circulation, creating an EB-albumin complex. This intermediary mechanism protects the PSMA ligand from rapid renal clearance and extends its circulation time, allowing sufficient time for the ligand to bind to PSMA receptors on tumor cells and accumulate in the tumor
2Productivity
If conventional PSMA ligands are used, then rapid urinary tract clearance is achieved, but blood half-life is short limiting therapeutic efficacy
Solution Approach 1:
The Evans Blue derivative serves as a circulating intermediary that binds to serum albumin, creating a temporary reservoir in the bloodstream. This intermediary complex delays renal clearance while maintaining the ability to deliver the PSMA ligand to the tumor, effectively extending blood half-life without compromising urinary tract clearance of unbound ligand
Solution Approach 2:
The EB-PSMA ligand conjugate exhibits periodic binding and release dynamics: it binds to albumin for extended circulation, periodically releases to bind PSMA on tumor cells, and allows cleared portions to be eliminated through urinary tract. This periodic action pattern maintains therapeutic levels in blood longer while preserving clearance mechanisms
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 modified Evans Blue derivatives demonstrate significantly higher tumor uptake and improved survival rates in PSMA-positive tumor models, offering a more effective treatment strategy with enhanced therapeutic outcomes.
Implementation Method 1
utilizing a residue derived from (((R-)-1-carboxy-2-mercaptoethyl)carbamoyl)-L-glutamic acid to enhance urinary tract clearance and albumin binding
Implementation Method 2
chemical conjugates of Evans blue derivatives and their use as radiotherapy and imaging agents
Data Source
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AI summary
A compound of Formula (I) or a pharmaceutically acceptable ester, amide, solvate, or salt thereof, or a salt of such an ester or amide or a solvate of such an ester amide or salt wherein the definitions of R1-R13 and L1-L4 are provided in the disclosure, and wherein R14 is a group capable of binding to prostate-specific membrane antigen (PSMA).