Cytochrome P450 pharmacogenetics in drug development: in vitro studies and clinical consequences.
Members of the human cytochrome P450 (CYP) superfamily play a role in the metabolism of many drugs and several of them, CYP2D6, CYP2C9 and CYP2C19, have been shown to be polymorphic as a result of single nucleotide polymorphisms (SNPs), gene deletions, and gene duplications. These polymorphisms can impact the pharmacokinetics (PK), metabolism, safety and efficacy of drugs, and because of the availability of automation, genotyped human tissue, recombinant CYP preparations (rCYPs) and reagents, most pharmaceutical companies have increasingly screened out compounds that are metabolized solely by polymorphic CYPs. In the absence of suitable animal models, it has been widely accepted that such in vitro data are useful because one can obtain information prior to dosing in man and select the most appropriate clinical studies with prospectively genotyped and phenotyped subjects. Overall, current trends in the industry have been fueled by increased managed healthcare, the desire to minimize the need for therapeutic drug monitoring and CYP genotyping in medical practice, and a very competitive market place. In the past, such paradigms have not been as influential and there are numerous examples of marketed drugs that are metabolized by polymorphic CYPs.
Rodrigues
A David
AD
Drug Metabolism, Merck Research Laboratories, West Point, PA 19486, USA. david_rodrigues@merck.com
Rushmore
Thomas H
TH
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism; D065731:Cytochrome P-450 CYP2C19; D065729:Cytochrome P-450 CYP2C9; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D015195:Drug Design; D006801:Humans; D066298:In Vitro Techniques; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D010597:Pharmacogenetics; D010601:Pharmacology, Clinical; D010641:Phenotype; D011110:Polymorphism, Genetic
D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19