Journal Article

Pharmacokinetics and pharmacodynamics of VEGF-neutralizing antibodies

Popel, Aleksander S, Engel-Stefanini, Marianne O, Finley, Stacey D, Imoukhuede, PI

2011

Overview

Background Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis, and its role in cancer biology has been widely studied. Many cancer therapies target angiogenesis, with a focus being on VEGF-mediated signaling such as antibodies to VEGF. However, it is difficult to predict the effects of VEGF-neutralizing agents. We have developed a whole-body model of VEGF kinetics and transport under pathological conditions (in the presence of breast tumor). The model includes two major VEGF isoforms VEGF 121 and VEGF 165 , receptors VEGFR1, VEGFR2 and co-receptors Neuropilin-1 and Neuropilin-2. We have added receptors on parenchymal cells (muscle fibers and tumor cells), and incorporated experimental data for the cell surface density of receptors on the endothelial cells, myocytes, and tumor cells. The model is applied to investigate the action of VEGF-neutralizing agents (called \"anti-VEGF\") in the treatment of cancer. Results Through a sensitivity study, we examine how model parameters influence the level of free VEGF in the tumor, a measure of the response to VEGF-neutralizing drugs. We investigate the effects of systemic properties such as microvascular permeability and lymphatic flow, and of drug characteristics such as the clearance rate and binding affinity. We predict that increasing microvascular permeability in the tumor above 10 -5 cm/s elicits the undesired effect of increasing tumor interstitial VEGF concentration beyond even the baseline level. We also examine the impact of the tumor microenvironment, including receptor expression and internalization, as well as VEGF secretion. We find that following anti-VEGF treatment, the concentration of free VEGF in the tumor can vary between 7 and 233 pM, with a dependence on both the density of VEGF receptors and co-receptors and the rate of neuropilin internalization on tumor cells. Finally, we predict that free VEGF in the tumor is reduced following anti-VEGF treatment when VEGF 121 comprises at least 25% of the VEGF secreted by tumor cells. Conclusions This study explores the optimal drug characteristics required for an anti-VEGF agent to have a therapeutic effect and the tumor-specific properties that influence the response to therapy. Our model provides a framework for investigating the use of VEGF-neutralizing drugs for personalized medicine treatment strategies.

• Publisher: BioMed Central,BioMed Central Ltd
• Subject: Algorithms / Angiogenesis / Animals / Antibodies / Antibodies, Neutralizing - pharmacology / Antibodies, Neutralizing - therapeutic use / Antineoplastic Agents - pharmacology / Antineoplastic Agents - therapeutic use / Bioinformatics / Biomedical and Life Sciences / Blood platelets / Breast Neoplasms - drug therapy / Breast Neoplasms - metabolism / Cancer / Care and treatment / Cell Line / Cells, Cultured / Cellular and Medical Topics / Computational Biology/Bioinformatics / Computer Simulation / Female / Health aspects / Humans / Influence / Kinetics / Life Sciences / Mice / Models, Biological / Neovascularization / Neuropilin-2 - metabolism / Ordinary differential equations / Permeability / Pharmacokinetics / pharmacology and medicine / Physiological / Physiological aspects / Proteins / Receptors, Vascular Endothelial Growth Factor - metabolism / Receptors, Vascular Endothelial Growth Factor - physiology / Research Article / Simulation and Modeling / Systems Biology / Systems physiology / Tumors / Vascular endothelial growth factor / Vascular Endothelial Growth Factor A - antagonists & inhibitors / Vascular Endothelial Growth Factor A - immunology / Vascular Endothelial Growth Factor A - metabolism