New bedside genetic tests pick the right drug, right away

April 5, 2012

It is being billed as the world's first bedside genetic test for heart patients. A nurse merely swabs the inside of a patient's mouth and places the saliva sample into a compact machine that's the size of a toaster. In less than an hour, the device analyzes the DNA and determines the best drug option for the patient.

Normally, this type of test would be sent to a lab that could take up to a week to return the results.

"In cardiology, especially with patients coming into the hospital with heart attacks, we often have to make decisions very quickly" said Derek So, an assistant professor at the University of Ottawa Heart Institute. "This is essentially the first step to making fast decisions based on genetics."

The genetic test, developed by researchers at the heart institute and Ottawa-based Spartan Bioscience, helps predict how patients will respond to Plavix, a widely-prescribed blood thinner.

Plavix is often given to people with advanced cardiovascular disease to prevent blood clots that cause heart attacks and strokes. It is also used to keep blood flowing freely through stents – devices that prop open narrowed blood vessels.

Plavix, or its genetic equivalent clopidogrel, is considered to be standard therapy. But not everyone does well on the treatment. In fact, research has revealed some people carry a genetic variant that can impede Plavix from working to its full potential.

And that's where the new rapid genetic test could come in handy, said Dr. So. It can pinpoint those individuals who should be getting an alternative anti-clotting agent such as Effient or Brilinta, he said.

Dr. So, along with his co-investigator Jason Roberts, recently completed a "proof-of-concept" study to see if the genetic test worked in a real hospital setting. As part of the study, nurses were given 30 minutes of training on how to collect the saliva samples and use the DNA analyzing machine.

The findings, published last week in The Lancet medical journal, showed the system can produce the desired results. Accurate bedside tests were performed on almost 200 patients.

"The same technology could be applied to other areas of medicine where there are genetic associations to either a diagnosis or a treatment," said Dr. So.

"If we can administer a simple, rapid genetic test at the bedside, doctors can prescribe the right drug to the right patient at the right time."

The Ottawa researchers have already begun a follow-up study to see if the equipment can search for numerous genetic variants at the same time and complete the task in less than an hour.

Although they are the first researchers to develop and demonstrate the effectiveness of a bedside genetic test, others are not far behind. Several biotech firms are working on similar tests. Dr. So predicts it won't be long before portable genetic screening devices become commonplace.

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