Pharmacogenomics & Precision Medicine

January 25, 2018

Personalized drug prescribing program expands, upgrades

Vanderbilt University Medical Center (VUMC) has expanded and relaunched genetic testing to predict patient responses to drugs.

Vanderbilt University Medical Center (VUMC) has expanded and relaunched genetic testing to predict patient responses to drugs.

PREDICT, or Pharmacogenomic Resource for Enhanced Decisions in Care and Treatment, was originally launched in 2010. The new PREDICT clinical test looks at 32 common variants across eight genes, including CYP2D6, a gene responsible for the metabolism and elimination of approximately 25 percent of commonly used drugs.

“The intention was to have an assay that was cheaper, faster and more pertinent to the kind of care we deliver at Vanderbilt. With the new test we’re measuring fewer genetic variants, but every single variant that we’re measuring we’re eventually going to be reporting in the medical record. There are no trivial ones,” said Josh Peterson, MD, MPH, associate professor of Biomedical Informatics and Medicine and leader for development and evaluation of PREDICT.

Some people metabolize drugs abnormally, to the point of deriving no benefit from a particular drug or responding dangerously to a normal dose. These different drug responses increasingly are associated with different common genetic variants, such that more than 130 drugs now carry pharmacogenomic information in their U.S. Food and Drug Administration labeling.

A Vanderbilt study published in 2012 found that patients who repeatedly returned for outpatient care here had a 65 percent probability, over a five-year period, of receiving one or more of the 56 drugs that had pharmacogenomic information in their FDA labeling at that time, and had a 12 percent chance of receiving four or more of these drugs.

The new one-time genetic test has been configured by the manufacturer according to specifications set out by a team at VUMC. Members of that team say the new test marks a new chapter in Vanderbilt’s continuing effort to foster clinical pharmacogenomics, a cornerstone of personalized medicine.

“The addition of CYP2D6, in particular, is a big win for our pediatric patients,” said Sara Van Driest, MD, PhD, assistant professor of Pediatrics and Medicine. “Many of the medications used in children, including antidepressants and some stimulants, are impacted by this gene. Now we have the test available to make informed decisions about which drug and which dose to give our patients.”

Formerly, PREDICT promoted prospective clinical genotyping for patients whose medical records indicated they had a high probability (within five years) of becoming candidates for certain drugs. Under the relaunched program, to meet insurance requirements, testing is available once a patient actually becomes a candidate for a drug with a known genetic association.

“We continue to monitor the changing landscape of reimbursement for genetic testing. We are considering the patient and institutional perspectives to ensure that testing remains accessible and beneficial to this community. We hope to further collaborate with payers to provide the evidence needed to increase the awareness of the utility of pharmacogenomic testing,” said Sarah Bland, MBA, MPH, project manager with PREDICT.

When a PREDICT test result is available, Vanderbilt’s electronic prescribing systems will provide immediate pharmacogenomic decision support to clinicians ordering the anti-platelet drug clopidogrel (Plavix), the anti-coagulant warfarin, the immunosuppressive drug tacrolimus, or thiopurine drugs, which are used to treat certain cancers and autoimmune disorders. PREDICT will continue to collaborate with clinical teams regarding opportunities for development of new pharmacogenomic clinical decision support tools, Peterson said.

“Almost all of the genes we assay and report apply to more than one drug. We’ve been rolling out decision support for one drug at a time, but the test results have always applied to other drugs,” said Dan Roden, MD, Senior Vice President for Personalized Medicine.

To promote awareness of the new test, the PREDICT team will be meeting with clinicians in selected practice groups across VUMC.

“As we get farther along, we believe the pharmacists here can help our providers use the test data effectively,” Peterson said. “That’s typically true across the nation with these new programs. Pharmacists have a lot of training and content knowledge in these areas, and can advise clinicians about what they should do with genetic results.”

The “PREDICT Personalized Medicine Initiative” website provides information tailored for VUMC clinicians (employee login required). For more information about PREDICT, visit My Drug Genome at

The switch to the new test was arranged by the PREDICT team and Vanderbilt Clinical Laboratories with oversight from the Pharmacy and Therapeutics Committee and the Laboratory Formulary Committee.