From traditional biomarkers to transcriptome analysis in drug development.

Traditional biomarkers have played an important role in drug development as well as patient care. A single traditional biomarker or surrogate endpoint is unlikely to either characterize the complete pathophysiology of a complex disease or capture all the therapeutic benefits or potential adverse effects that a drug will have in a diverse patient population. Transciptome analysis, on the other hand, can provide a large-scale survey of gene expression associated with the etiology of a human disease or pharmacological responses to a therapeutic intervention. The quantitative and qualitative readouts can provide increased power to identify novel drug targets or biomarkers indicative of drug safety or efficacy. Transcriptomics has positively impacted drug development and will continue to improve the medicines of the future. Here, we describe the increasingly important roles that traditional biomarkers and transcriptome analysis have played in various phases of drug discovery and development as well as the opportunities and challenges that they present to the pharmaceutical industry.