Key Points
- The Agency for Healthcare Quality and Research released a study, which found that anticoagulant drugs were prescribed to more
than 4.2 million Americans at a cost of $900 million and were paid for by patients and/or third-party payers.
- Achieving correct therapeutic levels of the drugs most often used - warfarin (Coumadin, Bristol-Myers Squibb) and clopidogrel
bisulfate (Plavix, Sanofi Aventis/Bristol-Myers Squibb) - is typically described as a challenging trial-and-error process.
- The discovery that the genetic biomarker CYP2C19 affects an individual's ability to properly metabolize these agents allows
a more personalized approach, but this requires a test ordered by a physician and payor reimbursement.
Editor's note: Scientific information from studies released since this article was written have raised more questions about
the Plavix CYP2C19 genome connection as it affects some people. Watch for updates in future issues of Drug Topics.
In January, the Agency for Healthcare Research and Quality (AHRQ) released "Outpatient Prescription Anticoagulants Utilization
and Expenditures for the U.S. Civilian Noninstitutionalized Population Age 18 and Older 2007," a study from its October 2009
Medical Expenditure Panel Survey (MEPS). This report found that anticoagulant drugs were prescribed to more than 4.2 million
Americans at a cost of $900 million and were paid for by patients and/or third-party payers.
Achieving correct therapeutic levels of the drugs most often used — warfarin (Coumadin, Bristol-Myers Squibb) and clopidogrel
bisulfate (Plavix, Sanofi Aventis/Bristol-Myers Squibb) — is typically described as a challenging trial-and-error process.
The discovery that the genetic biomarker CYP2C19 affects an individual's ability to properly metabolize these agents allows
a more personalized approach, but this requires a test ordered by a physician and payor reimbursement.
A dramatic step forwardOn March 12, FDA added a boxed warning to the clopidogrel label, highlighting "reduced effectiveness in patients who are poor
metabolizers of Plavix" and encouraging physicians to consider another product and/or to test their patients for the biomarker
before prescribing the drug.
Roland Valdes
|
For many physicians, routine testing is not yet protocol. According to Roland Valdes, PhD, co-founder and chairman of PGXL
Laboratories, a pharmacogenetics company in Louisville, Ky., the millions of anticoagulant patients at risk can't afford to
wait for physicians to get on board with genomic testing.
In a novel collaboration with PBM giant CVS Caremark and its specialty pharmacy Generation Health, PGXL Laboratories will
use its expertise in anticoagulants to improve the quality of patient care through pharmacogenetic testing, physician education,
and drug-specific software programs.
The program, launched July 1, "will be a dramatic forward step in personalized medicine" for patients who may receive the
anticoagulant Plavix, Valdes said.
"The goals of our company include providing the highest level of testing and to support the tests with follow-up interpretation
at the physician level," Valdes said, adding that his laboratory was the first to be certified as an exclusive pharmacogenomic
testing facility according to the federal Clinical Laboratory Improvement Amendments of 1988.
Physician participation
Mark Linder
|
Although controversy over retail genetic testing for consumers has been in the spotlight lately, Mark Linder, PhD, vice president
and co-founder of PGXL laboratories, said, "We believe genetic testing needs to be ordered and authorized by a physician,"
adding that this "keeps the physician at the center of patient care."
Jeffrey D. Marrazzo
|
Jeffrey D. Marrazzo, vice president of marketing and development, Generation Health, said that the program will work through
integrated services to assist in the care of anticoagulant patients. The process, Marrazzo said, is a retrospective one and
will be in place for as many as 50,000 CVS Caremark members.
CYP2C19 Variants*
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"This program seeks to find patients who may be at risk if they take or are newly prescribed the drug Plavix," Marrazzo said,
adding that recent data show that up to 26% of this population may carry a variant of the biomarker CYP2, which has been shown
to affect the proper uptake and metabolism of anticoagulants.
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