The impact of genomics on therapeutic drug development

Genomics can be defined as a set of related technologies that are focused on the discovery of genes implicated in human disease. Although many of the estimated 100,000 genes in the human genome have been at least partially identified by nucleotide sequence, elucidation of biological function has been achieved for only a small percentage of these. An even smaller percentage of genes discovered by these methodologies have become valid drug targets. This review discusses the various genomics technologies and their likelihood of yielding therapeutic drugs. Emerging advances in microarray "chip" technology have allowed the parallel analysis of gene expression patterns for thousands of genes simultaneously. Sequence information derived from the genomes of many individuals is leading to the rapid discovery of single nucleotide polymorphisms or SNPs. Detection of these human polymorphisms will fuel the discipline of pharmacogenomics, resulting in an increase in the success of clinical trials, the rescue of drugs that have previously failed in clinical trials because of adverse reactions from patient subpopulations, and ultimately, in the development of more personalized drug therapies. The impending identification of all human genes will signal the end of the structural genomics phase and usher in the function genomics phase. Technologies have already begun to move toward high-throughput elucidation of gene relationships, interactions and, it is hoped, toward their functions.