Parameters Affecting the Enhanced Permeability and Retention Effect: The Need for Patient Selection

Area of Science:

• Nanomedicine
• Oncology
• Pharmacology

Background:

• The enhanced permeability and retention (EPR) effect is the basis for tumor-targeted nanomedicine delivery.
• Clinical translation of nanomedicines has underperformed, potentially due to incomplete understanding and exploitation of the EPR effect.

Purpose of the Study:

• To systematically analyze clinical data and identify key parameters influencing the EPR effect.
• To understand factors affecting nanomedicine accumulation in tumors.

Main Methods:

• Analysis of clinical data from 17 studies.
• Evaluation of nanomedicine accumulation based on tumor type, size, perfusion, and other factors.

Main Results:

• The EPR effect magnitude varied significantly across tumor types and sizes.
• Pancreatic, colon, breast, and stomach cancers exhibited the highest nanomedicine accumulation.
• Medium-sized tumors showed the highest incidence (100%) of the EPR effect, while large tumors had higher accumulation than medium and very large tumors.
• Tumor perfusion, angiogenesis, and inflammation were identified as additional influencing factors.

Conclusions:

• Tumor characteristics critically impact the EPR effect and nanomedicine accumulation.
• Strategies for patient subpopulation identification are proposed to optimize therapeutic outcomes by leveraging the EPR effect.