An FDA perspective on the nonclinical use of the X-Omics technologies and the safety of new drugs.

Work in the field "omics" (toxicogenomics, proteomics, and metabolomics) has exploded. It is hoped that 'omics' could be a tool for evaluation of general toxicology, reproductive toxicology, the carcinogenicity potential of pharmaceuticals and several other types of toxicity, eventually replacing the use of animals. Although much progress has been made in the standardization of procedures, challenges remain for evaluation of pharmaceuticals for regulatory purposes, because of off-target toxicologic effects, as well as issues of interpretation and the large number of biologic variables that can affect results. Such variables include species/strain, genetic variations, diet, age, dose, duration, and weight of animals. These variables also confound database compilations of expression profiles. The most promising use in the near future would be to clarify pathways for the various types of toxicity and carcinogenicity and get biomarkers for these pathways, to help assess relevance of nonclinical findings to humans.