Drug trial aims to 'personalize' medicine

Dozens of Utahns now taking a popular blood-thinning drug will be involved in a new nationwide clinical trial using their own genetic makeup to help "personalize" medicine for millions of people.

Anyone who's ever had a headache and turned to the medicine cabinet for an aspirin knows about the dosage guidelines on the bottle — usually based on age and existing medical conditions of the person taking it.

While the bottle doesn't ask questions about ancestry, a nationwide study announced Wednesday — to include Utah patients — is designed to tell doctors whether genetic factors can help them more accurately prescribe dosages of warfarin, a common blood-thinning drug.

Dr. Jeffrey Anderson, associate chief of cardiology at Intermountain Medical Center, said the shift in health care toward more "personalized medicine" based on genetics is the foundation of a clinical trial that will soon be recruiting patients at IMC and LDS Hospital.

Warfarin is used to prevent blood clots that can lead to heart attacks or strokes, and is challenging for doctors to prescribe because the ideal dosage for each person varies widely. Too much of the drug means patients could bleed profusely; too little means they could develop life-threatening blood clots.

The study should confirm whether genetic factors can accurately help doctors determine the appropriate dosage of warfarin in individual patients, Anderson said. If so, patients would need fewer blood tests and fewer changes in medication while "experimenting" to determine how much of the drug works best for them.

Because nearly 2 million Americans take the drug each year, the simple cheek swab that reveals genetic data could not only save millions of dollars, but untold numbers of lives if the clinical trial confirms the results of earlier research, he said.

Researchers in a pilot study last year involving 1,200 patients nationwide, including 200 from Utah, suggested that using the genetic testing in addition to other clinical factors can help doctors better determine the best dosage of warfarin.

The results of the pilot study appear in the Feb. 19 issue of The New England Journal of Medicine.

"Patients are so varied (in their response to the medication) depending on these two genes," Anderson said. "We're able to get them genotyped with a cheek swab in our lab in about an hour."

Anderson sees the research in dosing warfarin as "the poster child for the whole idea of personalized medicine using our genetics and personalized characteristics to customize dosages of medication."