November 10, 2011

Project seeks to apply gene testing to drug prescribing

Project seeks to apply gene testing to drug prescribing

Your genetic make-up decides much more than your height or hair color. It can determine how you respond to the medication your doctor prescribes, or whether you will have a serious side effect.

As the list of known gene-drug interactions continues to grow, scanning a patient’s genome, or body of genetic material, for variations that affect drug response may soon become a prescribing prerequisite. This field is known as pharmacogenomics.

Few doctors, however, can access the kind of genomic testing services that could help them determine which drug is the best “fit” for their patients. Even if they did, raw genetic data is not particularly helpful.

To meet this challenge, the U.S. Centers for Disease Control and Prevention (CDC) has awarded a two-year, $1 million grant to Vanderbilt University Medical Center to develop a model for applying genomic testing to drug prescribing in “real-world” settings.

Vanderbilt already is pioneering this area. Last year it launched a personalized medicine program that alerts physicians if their patients have genetic variations that may affect their response to the anti-platelet drug clopidogrel.

Josh Peterson, M.D., MPH

Josh Peterson, M.D., MPH

Michael Laposata, M.D., Ph.D.

Michael Laposata, M.D., Ph.D.

The CDC grant is designed to take this program to the next level. Its goal is to develop a “clinician-friendly” genomic test report with supportive clinical, educational and laboratory practices that could be widely disseminated.

“The CDC has recognized that laboratory reporting of genetic variation will require new approaches to information delivery and support for interpretation and clinical decision making,” said Josh Peterson, M.D., MPH, assistant professor of Medicine and Biomedical Informatics.

Peterson is co-principal investigator of the grant with principal investigator Michael Laposata, M.D., Ph.D., executive vice chair of Pathology. Jill Pulley, MBA, executive director for Vanderbilt’s Clinical and Translational Science Award (CTSA), is program manager.

Other leaders include Dan Roden, M.D., assistant vice chancellor for Personalized Medicine, and John McPherson, M.D., associate professor of Medicine

Roden, the William Stokes Professor of Experimental Therapeutics, oversees development of a personalized medicine program called PREDICT, for Pharmacogenomic Resource for Enhanced Decisions in Care and Treatment.

Since September 2010, more than 3,000 patients scheduled for cardiac catheterization at Vanderbilt have been “genotyped” or screened for variations that can affect their response to clopidogrel. Variations were identified in nearly 700 patients, and an alternative drug was recommended to their physicians.

The PREDICT program is now being applied to the anticoagulant warfarin and to simvastatin, the generic form of the statin Zocor.

Laposata, the Edward and Nancy Fody Professor of Pathology, helped develop another program essential to the CDC grant – “diagnostic management teams,” groups of faculty and resident physicians in Pathology who guide clinicians through the ever-increasing complexity of diagnostic testing.

By correlating and integrating test results in an easily accessible way, they help clinicians make faster and more accurate diagnoses, determine the most appropriate therapy and avoid unnecessary tests.

Medical informatics was crucial for the development of Vanderbilt’s patient-specific clinical decision support infrastructure, in place for more than a decade. Fewer than 2 percent of health care facilities in the country have this capability.

“We recognize that in the scheme of human health, genomics is just one piece of the puzzle,” Pulley said. Yet “clinical decision support at the point of care (is) the only plausible strategy to accommodate an explosively growing body of knowledge of human biomarkers and individual molecular variation.”