The development of personalized medicines tailored to an individual's genetic makeup is being severely hampered because drug companies do not have the incentive to develop the required genetic tests, it has been claimed.
The promise of bespoke medicines was sold as one of the major benefits of decoding the entire human genome. By developing genetic tests, drug companies hoped they could identify which patients would benefit most from a drug, and who was at greatest risk of suffering potentially dangerous side-effects.
But according to a study, while drug companies have begun to develop genetic tests for experimental drugs, many of which have yet to go into clinical trials, common pharmaceuticals already widely prescribed by family doctors and hospital doctors are largely being neglected.
"Drug companies are putting all their efforts into creating tests for new drugs that won't be on the market for years. Basically, there's no commercial incentive for the big companies selling existing drugs to go to the expense and effort of developing a test that will ultimately narrow down the number of people who take their drug," said Paul Martin, deputy director of the Institute for the study of Genetics, Biorisks and Society at Nottingham University, England.
Pharmacogenomics, as the science of personalized medicine is known, works by identifying the genetic differences that determine whether a drug cures a patient, has no effect or, at worst, causes a severe adverse reaction.
In Britain alone, an estimated 10,000 people die each year from the side effects of drugs, with tens of thousands more becoming seriously ill. Martin, who was due to present his findings at a Wellcome Trust conference in Hinxton, Cambridge, England, on Thursday, said: "This is an issue of market failure. Things could get a lot better, with safer, more cost-effective medicines, but the benefits of this technology might not be realized thanks to this."
The lack of pharmacogenomic tests for drugs already on the market has caused problems for the pharmaceutical industry as well as those taking their medications. Last month, the American drug company Merck was ordered to pay $253m to the wife of a triathlete who died after taking the firm's painkiller Vioxx. And earlier this year, the European Medicines Agency told doctors not to give the anti-depressant drug Pozac to children amid fears it can make some feel suicidal and aggressive.
Because the patents have expired on most of the drugs in use today, any drug company can legally produce them, meaning there is even less incentive for one company to produce a pharmacogenomic test. Without a commercial incentive, Martin believes the UK's state-funded National Health Service should fund more studies to cover those drugs the industry is ignoring.
"There are significant public health benefits that could be gained from implementing pharmacogenetics," he said. "If a drug is going to have no effect or a dangerous effect in many people, it is a waste of money and that isn't helping anybody.
"The bottom line is it's fantasy that people will walk into a doctor's office, have a test and then they'll be given the right prescription. Let's be realistic. This talk of a revolution in personalized medicine is nonsense. It's a long, long way off."