Role of Biomarkers in Drug Discovery

A biomarker is a characteristic that can be objectively measured and evaluated as an indicator of a physiological and also a pathological process or pharmacological response to a therapeutic intervention. Any specific molecular alteration of a cell on DNA, RNA, metabolite or protein level can be referred to as a molecular biomarker.
Among the current applications of biomarkers, those for drug discovery and development are one of the most important types. Biomarkers can be used to predict and confirm target binding, to determine mechanism of action of a drug, pharmacokinetics and toxicity. Their role continues into the drug development stage to determine treatment efficacy in clinical trials. It is worthwhile to develop biomarkers for exploring the pharmacology of new molecules and to develop potential biomarkers of efficacy. A molecule that does not have the intended pharmacological effect is unlikely to have the desired efficacy and its development should be terminated. Discovery efforts would then be directed at understanding the reasons for the lack of pharmacological effect and finding improved molecules. For those molecules that have the intended pharmacological effect but then fail to show efficacy, it is possible to say with confidence that the molecular target is ineffective and that discovery efforts should be directed to other targets. Such an approach will increase the overall success rates of the candidate molecules delivered into clinical development.