Practice Management Will Pharmacogenetics Impact Your Practice? Provided By First Professionals Insurance Company Pharmacogenetics is the science that studies, among other things, how an individual may react to medications based on their genetic profile. Referred to as “personalized medicine” by some, pharmacogenetics offers the potential to recommend drug treatment based on a patient’s particular genetic background. The goal is to determine the right treatment at the right dose for the right patient. Benefits of Pharmocogenetic Testing In an ideal world, drugs would be effective in all patients, would not cause toxicity, and the same dose would be optimal for all patients. Unfortunately, we live in a real world and in the real world the majority of drugs work in 30 to 50% of patients. As a result, more than 2 million patients per year are hospitalized due to drug toxicity or adverse reactions, resulting in the death of over 100,000 patients. Pharmocogenetic testing has the potential to offer many benefits: • Making better medication choices • Safer dosing options • Improvements in drug development An individual’s genetic make-up determines their reaction to a medication. This reaction may cause the drug to metabolize longer than normal, causing serious side effects. In addition, a genetic variation can cause drugs to be rapidly metabolized making the medication less potent or completely ineffective. Utilizing pharmacogenetics, physicians have the ability to perform genetic testing before writing a prescription to identify poor responders and drug toxicity for the patient. Bob White, president of First Professionals Insurance Company states, “Although the use of pharmacogenetics does not represent the current standard of care, physicians should consider its use because of the potential benefits for increased patient safety, improved medical outcomes, cost savings and reduced exposure to malpractice claims.” FDA Participation The FDA is already involved in drug label warnings that include pharmacogenetic testing for certain medications. The first drug was 6-MP, a drug to treat acute lymphoblastic leukemia. Without testing to determine the presence a specific gene, a standard dose could kill some patients. The label recommends that patients consider testing and the dose reduced accordingly. For the anti-clotting drug Plavix, the FDA label contains a warning that the use of other medications with Plavix makes the drug less effective. Another widely-used medication, warfarin, contains an FDA message on its label indicating that patients with variations in two different genes might need a lower dose. Although the FDA has not placed a label on tamoxifen, it seems likely that it will do so in the near future. The FDA’s advisory panel initially recommended a label to inform patients without specific fully working genes that a high-
er breast cancer recurrence is possible and that certain antidepressants could make the drug less effective. While the FDA did not support the initial research behind the recommendations, subsequent research has caused the FDA to reconsider the label warning. Cost Benefit Analysis An excellent example of a significant cost benefit involves the drug warfarin. It is estimated that formally integrating genetic testing into routine warfarin therapy could prevent 85,000 serious bleeding events and 17,000 strokes annually. The cost benefit of integrating genetic testing into warfarin therapy is approximately $1 billion annually. Performing genetic testing before writing a prescription may avoid repeated visits by patients to determine the most efficient medication and dosage, resulting in cost savings for physicians. Routine – or even periodic – testing has the potential to save doctors the added expense of additional testing and the possibility of a decrease in office visit time. Pharmacy benefits managers and 200 employers nationwide who manage their own health insurance programs have been working together since 2008 to test the benefits of genetic testing. They focused on two drugs, warfarin and tamoxifen. Their data showed that 25% of people placed on warfarin had excessive bleeding or a blood clot within six months of starting warfarin therapy. Their research showed that 10% of women using tamoxifen don’t metabolize the drug and have a 30% higher rate of recurrence within two years. In the case of warfarin users, a $300 test can identify those patients that carry the genes that cause them to be slow metabolizers of the drug and they can be placed on a lower dose. Health insurers save $39,000 on average for each stroke that is prevented and $13,500 for each bleeding event that is prevented. From a medico-legal perspective, complications from warfarin therapy are a frequent cause for suits against physicians and these cases are very difficult to defend because the standard of care is ill-defined. In the case of tamoxifen, identifying non-responders will allow alternative drugs or treatment modalities to be considered early on in the process and create the opportunity for better outcomes. Obstacles Pharmacogenetic testing is still in its early stages. How a patient responds to a particular medication is very complex and may not be determined by just one gene. Consequently, identifying them all could take many years and will be expensive and time-consuming. Before paying for pharmocogenetic testing, some insurers want more evidence that it leads to better patient care. Current research is beginning to establish the case for genetic testing to be routinely utilized for certain drugs. Currently, there is a lack of physician experience with genetic testing. The United States has only 500 board certified medical geneticists in clinical practice. Few practicing physicians have had pharmacogenetic instruction continued on next page