Our growing understanding of how genetic factors influence the way in which an individual may respond to medicines is collectively referred to as pharmacogenetics; genetics may affect drug absorption, distribution, metabolism, excretion and toxicity – the ADMET factors so crucial in drug development.
The new guidance for companies from the EMA’s Committee for Medicinal Products for Human Use (CHMP) will take effect from August 1, 2012. They propose that studies examining the pharmacogenetic impact on drug pharmacokinetics should be performed where variability between individual patients is high enough to influence the safety and/or efficacy of the drug. This possibility may be apparent from earlier studies that show either that genes subject to significant variation are involved in processing of the drug by the body, or that there is unexplained variability in patient response to the drug.
The guidelines also set out other situations where pharmacogenetic studies are advisable, proposals for the design and performance of such studies to reveal the impact of genetic differences in patients, and how to review drug dosing and labelling where appropriate.