Biomarkers of endothelial cell activation serve as potential surrogate markers for drug-induced vascular injury.

Drug-induced vascular injury (DIVI) is a nonclinical finding that often confounds the toxicological evaluation of investigational drugs, but there is an absence of qualified biomarkers that can be used to detect and monitor its appearance in animals and patients during drug development and clinical use. It is well known that endothelial cell (EC) activation plays a key role in the expression and evolution of DIVI, and the various immunological and inflammatory factors involved in its expression may serve as potential biomarker candidates. Activated ECs change their morphology and gene expression, generating endothelial adhesion molecules, pro-coagulant molecules, cytokines, chemokines, vasodilators, nitric oxide, and acute-phase reactants.

Renal biomarker qualification submission: a dialog between the FDA-EMEA and Predictive Safety Testing Consortium.

The first formal qualification of safety biomarkers for regulatory decision making marks a milestone in the application of biomarkers to drug development. Following submission of drug toxicity studies and analyses of biomarker performance to the Food and Drug Administration (FDA) and European Medicines Agency (EMEA) by the Predictive Safety Testing Consortium's (PSTC) Nephrotoxicity Working Group, seven renal safety biomarkers have been qualified for limited use in nonclinical and clinical drug development to help guide safety assessments. This was a pilot process, and the experience gained will both facilitate better understanding of how the qualification process will probably evolve and clarify the minimal requirements necessary to evaluate the performance of biomarkers of organ injury within specific contexts.

Endothelial injury in the initiation and progression of vascular disorders.

Endothelial cell dysfunction is considered to be an early event which subsequently leads to vascular wall disorders. Ultrastructural studies indicate that the endothelial cell changes involve membrane damage, increased permeability, swelling and necrosis. The endothelial cell loss of function could be as a result of changes in hemodynamic forces (shear and/or hoop stress), direct drug-induced cytotoxicity, mechanical device implant-induced injury and/or immune-mediated mechanisms.