Role of Biomarkers in Relation to Stage of Drug Discovery and Development

The stage for biomarker discovery varies across the pharmaceutical industry, but the trend is definitely toward conducting it early in the drug development phases. The time a compound is identified as a serious candidate for advancement into the clinic is when biomarker discovery begins. Once a candidate biomarker is identified, an assay is developed and the biomarker is extensively tested and validated both at the preclinical stage using animal models and in patients during clinical trials.

Validation in patients is certainly most crucial because it helps establish the association of the biomarker with a certain disease and its severity. It is also the most difficult part because validation involves linking together a number of different studies. Biomarker validation is easier when working with are biologicals such as proteins or antibodies because cycle times are much shorter and there is continuous feedback between discovery and development. Role of biomarkers in drug development in therapeutic areas of cardiovascular and neurological disorders will be discussed briefly in the following sections and drug development in oncology will be discussed in Chap. 13.