The use of biomarker immunoassays to support drug-safety assessment studies is rapidly gaining momentum. Supported by regulatory
authorities, industry is moving forward with developing new, translational, noninvasive biomarkers.
THE GENESIS OF BIOMARKER IMMUNOASSAYS
The Biomarkers Definitions Working Group defines a biomarker as "a characteristic that is objectively measured and evaluated
as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention"
(1). The Predictive Safety Testing Consortium (PSTC), led by the nonprofit Critical Path Institute (C–Path), is bringing together
pharmaceutical companies to share and validate safety testing methods under the advice of FDA and EMA. The 18 corporate members
of the PSTC are sharing internal experiences with preclinical and clinical safety biomarkers in six working groups: cardiac
hypertrophy, kidney, liver, skeletal muscle, testicular toxicity, and vascular injury. The goal of the collaboration is to
translate findings in animal studies to measurable risks in humans through the use of novel, translational, noninvasive biomarkers.
Roger N. Hayes
An ideal biomarker would monitor a protein, enzyme, or metabolite in an accessible fluid (blood or urine) that would allow
detection of toxicity before real injury occurs. A milestone was achieved in 2008 when FDA accepted urinary kidney biomarkers
(e.g., KIM-1, albumin, total protein, β2-microglobulin, cystatin C, clusterin, and trefoil factor-3) for the detection of
acute drug-induced nephrotoxicity in rat toxicology studies.
Mark J. Cameron