Physicians' recognize benefits of genetic testing; say formal education required to put it into practice

Oct 23 2009

Medco Health Solutions, Inc.(NYSE: MHS) and the American Medical Association (AMA) today announced the findings of a national benchmark survey on physicians' acceptance, use and education regarding pharmacogenomic testing.

The survey revealed that physicians almost unanimously recognize the role that genes play in affecting a patient's drug response; however, few felt they had the necessary training and education to prescribe genetic tests that could provide valuable information to guide the prescribing and dosing of medications.

Pharmacogenomic tests analyze a person's genetic make-up to determine how they metabolize certain medications; using this genetic information can help improve the safety and effectiveness of drug therapies.

The survey findings, based on responses from more than 10,000 physicians nationwide, were presented at the 59th Annual American Society of Human Genetics (ASHG) Conference. Results from the survey found that only 26 percent (about one in four) of physicians have had any type of education in the field known as pharmacogenomics (PGx), and only 10 percent of physicians currently believe they have the necessary information and training to put pharmacogenomics testing to use. In addition, while the survey found that only 13 percent of physicians had ordered or recommended PGx testing for their patients in the preceding six months, more than 26 percent planned to do so within the next six months. Among total respondents, 10 percent reported that PGx tests had benefited their patients by improving drug effectiveness, and another 10 percent said their patients benefited from reduced drug toxicity due to testing.

"This research generates important insight about where physicians stand on pharmacogenomic testing," said Dr. Robert Epstein, Medco's chief medical officer. "It's clear that there is wide acceptance that genetic testing has a role in patient care, but the need for formal training and education among physicians is necessary to obtain greater adoption and implementation of these tests in clinical practice. This survey with the AMA is the first to identify the role that education can play in physician use of these tests to improve patient care; and with the number of new drugs coming to market with a companion diagnostic, it's paramount that this education take place."

Other survey findings show that physicians who feel well-informed about PGx testing are more than twice as likely to recommend or order a genetic test. Physicians who currently use genetic tests tend to be older males who have been out of medical school for 15 to 29 years and oncologists.

"The ability of genetic technology to assist in diagnosis and appropriate therapy is well-recognized, and the AMA has been involved in assisting physicians in integrating genetic technology into routine clinical practice for several years," said AMA Board of Trustees Member Joseph P. Annis, M.D. "The AMA is committed to providing education and resources to physicians in this growing and important area of medical science so that they can appropriately use genetically-based technology, such as pharmacogenomic testing."

The Present and Future of Genetic Testing

About one of every four patients in the United States were prescribed medications with PGx information in the label of the drug in 2006. These medications include antidepressants, analgesics, cancer treatments, cardiovascular drugs and gastrointestinal medicines. For example, one enzyme - CYP2D6 (part of the cytochrome p450 system of liver enzymes) - may be involved in the metabolism of 30 percent of all drugs used today. In a case showing a genetic connection to drug metabolism, a test is recommended for patients using the blood thinner warfarin since they can experience serious bleeds or blood clots if given the wrong dose; a genetic test can help determine the accurate dosage based on the patient's genetic profile and prevent these potentially life-threatening incidents. Genetic testing is also important for breast cancer patients on tamoxifen since about 10 percent of those women won't respond well to the medication because of their genetic make-up. Provided with this information, physicians can find the appropriate treatment that will be effective for individual breast cancer patients. Variations in numerous other genes beyond those regulating liver enzymes have also been found to be important in determining the safe and effective use of drugs.

In the future, even more drugs may be linked to genetic tests. From the second half of 2009 through the first half of 2010, seven drugs paired with genetic tests are expected to be up for FDA approval, as well as approximately 10 to 20 percent of new drugs being labeled with PGx-related information over the next five-to-ten years. In particular, the field of oncology will see many more of these drugs in the coming years, with roughly 50 percent of cancer drugs in the pipeline expected to be orally administered by 2013 and 85 percent of those will rely on a genetic biomarker.