Health care as unique as DNA
How personalized medicine revolutionizes care with treatments tailored to the individual
Imagine you are diagnosed with a disease or other health condition. You need to take medication to manage the illness, or maybe even to stay alive. Testing and analysis is done to study your unique DNA and other factors. Your doctor then prescribes you the exact right medication at the exact right dose, uniquely selected for you.
The Personalized Medicine team in London, Ontario is working to make this a reality.
Located at London Health Sciences Centre (LHSC), they study the genetic differences between individual patients to provide more effective treatments with fewer side effects.
Most medical treatments are designed with a ‘one-size-fits-all-approach.’ They may be successful for some patients, but not for others. A percentage of people will not process the medication as intended. This can reduce the effect, or worse, cause an adverse reaction.
Personalized medicine is an emerging field that uses an individual’s genetic profile, medical history, environment and lifestyle to guide prevention, diagnosis and treatment of disease.
“The focus of our research has been on pharmacogenomics-based personalized medicine. We look at differences in genes to see how an individual will metabolize a drug and the body’s response to it,” explains Dr. Richard Kim, a Lawson researcher and clinical pharmacologist, and director for the Personalized Medicine Program.
They do this by analyzing the person’s genotype. Drug levels are also measured using mass spectrometry, a chemistry technique that identifies the amount and type of chemicals present in the blood.
“We know that everyone harbours unique genetic differences. There can be a lot of variation in how individuals respond to a medication, even if they have a similar genetic makeup. This can put someone at risk for severe toxicity even at a standard dose of a medication,” says Dr. Kim. “The most effective drug treatments should work with, not against, a patient’s own genetic code.”
Prescribing methods are often based on how the majority of patients with similar traits respond to the drug.
“Medication dosing is usually carried out in a trial and error fashion. A physician starts with a low dose and incrementally ups the amount to an effective range where they can also avoid an adverse reaction.”
While most patients respond well, it’s almost impossible to predict the response for those patients whose bodies process the medication differently.
In those cases the drug doesn’t work, or worse, causes difficult side effects or a dangerous reaction. It is estimated that adverse drug reactions are the fourth leading cause of death in Canada.
The team has focused on common medications, such as those for lowering blood pressure, anti-cancer drugs, and medications taken following a heart attack, stroke or coronary bypass procedure. They’ve also addressed some treatments for depression and inflammatory bowel disease, and worked on adverse drug reaction prevention.
They have successfully helped to tailor drug therapies for over 4,000 patients so far.
Personalized medicine is having the right dose of the right treatment, at the right time.
Dr. Kim opened the first personalized medicine research clinic in Canada.
In 2006, the team offered dosing guidance for the blood-thinner warfarin, used to prevent clots and embolism. Warfarin interacts with many commonly used medications and chemicals in some foods.
In 2010, testing was studied for tamoxifen, an anti-estrogen used to treat breast cancer. Some women with a genetic defect in a particular metabolizing enzyme, called CYP2D6, have trouble converting the drug to its active form, blocking the desired effects.
“There is an increased cost to the health care system when a medication is ineffective or causes an adverse reaction,” says Dr. Kim. “As healthcare costs overall increase at an unsustainable rate, we must leverage innovations like personalized medicine to provide quality health care that is affordable.”
Until recently, implementing pharmacogenomics into routine clinical care was a challenge. Advances in genomics technology have made it possible to tailor the selection and dose of common medications quickly and more cost-effectively.
“Depending on the clinical situation, we can provide rapid test results and dosing guidance in less than 24 hours.” A detailed report analyzes the patient’s ability to metabolize the prescribed drug and offers suggestions for alternative treatments where needed.
Current research by Lawson includes a personalized approach for enhancing drug safety for the elderly and a more comprehensive approach for chemotherapy medications for adults and children. They are also looking at how pharmacogenomics testing results can be more seamlessly integrated into electronic medical records and medication order entry.
“We hope to more broadly and systematically introduce our approach to patients at LHSC,” adds Dr. Kim. “Gene testing for precise diagnostics improves treatment options and increases patient safety. We have the potential to fundamentally transform the way care is provided in hospitals and the community.”
Dr. Richard Kim leads the Personalized Medicine research program at Lawson. He holds the Wolfe Medical Research Chair in Pharmacogenomics and is a Professor in the Departments of Medicine, Physiology and Pharmacology, and Oncology, Schulich School of Medicine & Dentistry at Western University.