Kristine Ashcraft on Pharmacogenetics

OurBlook talks with Kristine Ashcraft, director of sales and marketing for Genelex Corp. in Seattle.

Editor's Note: Kristine is a molecular biologist by training.

Your promotional video mentions that 100,000 people a year die from adverse reactions to prescribed medications, as not all people respond the same. Please tell us about the personalized medicine concept, or pharmacogenetics, and how it can deal with this problem.

KA: Research shows that of all the clinical factors such as age, sex, weight, general health and liver function that alter a patient's response to drugs, genetic factors are the most important. Approximately half of all Americans have genetic defects that affect how they process these drugs, and over 59 percent of the medications cited in adverse drug reaction studies are processed by enzymes with known genetic variants.

Currently, medications are prescribed in a one size fits all manner, so some patients get too high of a dose and some not enough. If the genetics are known in advance, physicians can use this information to personalize the dose and medication to the patient ... reducing the risk of adverse reactions.

A good example of this currently in the news is Plavix, a very commonly prescribed heart medication. Several recent studies have shown that approximately one third of patients with a genetic variation in a gene called CYP2C19 (pronounced sip 2c!19) are at double the risk of a serious cardiac event such as stroke when taking Plavix. With personalized medicine, a simple test could determine this ahead of time so dose adjustment or alternative medications could be used.

How widespread is this movement? Is it growing?

KA: It typically takes about 10 years to move technology from the lab into medical practice. Pharmacogenetic testing has now been available since 2000. Although more physicians are ordering the tests, it is not typically used. The main adopters at this juncture are oncologists and psychiatrists who are very concerned about finding the right medication as quickly as possible.

Consumers really need to be proactive about this. If someone has a history of bad reactions or treatment failures with medication, they should research the testing and ask their physician about it.

Are there any disadvantages to pharmacogenetics?

KA: As with any genetic test, there is the possibility that these genetic variations may later be found to increase risk of something other than ability to process medications. If people are concerned about this, it is always advisable to speak with a genetic counselor prior to testing.

Does the major health care reform bill that has been considered by Congress this year touch on the pharmacogenetics concept? If so, how, and if not, should provisions be added?

KA: Everyone in the personalized medicine community is excited about the appointment of Francis Collins to the head of the NIH. He is a proponent of personalized medicine and will certainly help usher in more widespread adoption.

In reference to major health care reform, one of the main blocks to the adoption of new technologies is that private insurers by necessity have a short-range view. Most patients switch health insurance companies before savings that take five years or more can be recouped. This makes genetic tests that are used for a lifetime unattractive from an insurer’s ROI perspective, even though the long-term savings are substantial. This needs to be addressed.

Is there anything else you'd like to say about personalized medicine or health reform or medical economics generally?

KA: Yes, one thing people need to understand about pharmacogenetics is that a small, fairly inexpensive panel of tests can be used to guide safer prescribing for an entire lifetime. Currently, the ROI is considered in silos ... does testing make sense for warfarin, does it make sense for tamoxifen, for Plavix? We need to move past this silo mentality. The question should be ... does this test make sense when it helps guide rational prescribing of more than half of the most commonly prescribed drugs for a person’s lifetime?

(Note: Kristine Ashcraft is a molecular biologist by training.)

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