New European pharmacogenetics guidelines published for pharma

European regulators have published guidance advising companies how to take genetic variability between patients into account when evaluating the way the human body handles medicines.

The European Medicines Agency's (EMA) guidelines on the use of pharmacogenetic methodologies in the pharmacokinetic evaluation of medicinal products is a response to an increase in the understanding of the influence of genes on differences between individuals in a drug's performance.

This can include variability in the way patients absorb, distribute and metabolise medicines, which can affect both the efficacy and the safety of pharmaceutical products.

Genetic variations can include single-nucleotide polymorphism (SNP) - a variation in DNA sequencing – and copy-number variation (CNV), where a cell has an abnormal number of copies of one or more sections of an individual's DNA.

The guidelines, which were adopted by the EMA's Committee for Medicinal Products for Human Use (CHMP) in January 2012 following public consultation, will come into effect from August 1, 2012.

Pharmaceutical companies are advised to follow its guidance, which applies predominantly to small molecule drugs, when applying for marketing authorisation of products.

It is suggested a study into the effects of pharmacogenetics on the pharmacokinetics of a medicines should be a requirement when the "magnitude of the inter-individual variation in drug exposure is so high as to likely influence the safety and/or efficacy of the drug in genetically variable populations".

These factors include situations where early studies (either in vivo or in vitro) have suggested that a polymorphic enzyme or transporter gene is likely to be an important pathway in the body's handling of the drug.

Such studies are also required if in vivo studies have indicated differences between individuals in the pharmacokinetics of the medicine are likely to affect the safety or efficacy of the product, and cannot be explained by non-pharmacogenetic factors.

The guidelines also outline several circumstances where pharmacogenetic studies are recommended rather than required and these include instances where major differences in pharmacokinetics are observed in different ethnic groups and cannot be explained by other factors.

The document also features advice on how pharmacogenetic studies should be designed and carried out; how the impact of genetic differences in patients should be evaluated; and how dosing or treatment recommendations for genetic subpopulations should be studied.

Information regarding what to include on a product's dosing recommendation and label following a pharmacogenetic review is also included.

• Read the EMA's Guideline on the use of pharmacogenetic methodologies in the pharmacokinetic evaluation of medicinal products