The US Food and Drug Administration recommends that doctors genotype patients before prescribing more than 70 commonly-used medications for specific genetic biomarkers. These tests, the agency suggests, can help physicians identify those in which the drug is less efficacious, poorly metabolized, or dangerous. But medicine is still far from a day when drugs and treatment regimes are fitted precisely to a patient’s genomic profile.
According to a 2008 survey conducted by the American Medical Association (AMA) and Medco Research Institute, even though 98 percent of physicians agreed that the genetic profiles of their patients may influence drug therapy, only 10 percent believed they were adequately informed about how to test their patients for biomarkers that may predict the safety and/or efficacy of a particular drug.
“Less than 1 percent of all opportunities are being realized with respect to genetic testing,” said Felix Frueh, president and head of genomics initiatives at Medco. “There’s a long way until this new technology is going to see the translation.”
Indeed, while new biomarkers are identified everyday, and researchers are continuing to collect more and more information about genetic variants that confer some amount of disease risk or predict a specific response to a treatment, that information has yet to be widely implemented in the clinic. The AMA states on its website that physicians today can use more than 1,200 genetic tests for more than 1,000 different diseases to help diagnose and treat their patients, but only 13 percent of the 10,000 doctors who responded to the survey had ordered a genetic test for a patient in the preceding 6 months.
But while physicians by and large have been slow to adopt the practice of screening patients to search for genetic information of relevance to drug treatments, known as pharmacogenomics, neither research nor regulation has stalled, as evidenced by the FDA’s relabeling of dozens of approved drugs with biomarkers that affect their safety or efficacy in specific patient populations. “Pharmacogenomics is probably an area where personalized medicine is really able to deliver,” Frueh said, “and it is able to do so because those are tests that can be clearly associated with a particular therapy.” Read more…