Pharmacogenomics: Using genetics to personalize prescriptions

We are very excited about individualized medicine as a way of providing better care and reducing costs. This post, we're talking about the field of Pharmacogenomics. What the heck is that? After you read on, you'll be a fan too.

Today, genetic testing is commonly used to determine ancestry, predict the risk of some cancers, and to determine which chemo treatments may provide a better outcome for a specific patient.  Now, genetics can also be used to predict a patient’s response to more than 60% of commonly prescribed drugs– through a field called pharmacogenomics. I first learned about pharmacogenomics at the 2018 ISCEBS Symposium in Boston. Veronika Litinski, the CEO of Toronto—based GeneYouIn, spoke about this emerging field of genetics. 
 
Pharmaco-what?
Pharmacogenomics (also referred to as pharmacogenetics, or PGx) uses a patient’s genetic information to individualize medication as well as dosages. A cheek swab is used to test different genes, providing information about how fast (or slow) a patient metabolizes drugs. For a large percentage of the population, a specific drug will be metabolized normally. But for those who metabolize the drug rapidly or slowly, it can cause serious consequences. Those who are fast metabolizers don’t receive the benefit of the drug since their body breaks down the drug too quickly. Slow metabolizers can end up with drug toxicity. In the US, adverse drug reactions are the 4th leading cause of death.

​PGx testing covers prescriptions in such treatment areas as mental health, pain management, digestive system, heart disease, oncology, rheumatology, and more. The list of medications added to the testing is growing rapidly, and because a person’s genetics don’t change, the test results can be updated over time without requiring retesting. 

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Return on Investment
A typical PGx test costs between $250 and $500 per person. A reputable company will continue to provide additional drug metabolism updates as new drugs come on the market. This cost is small, especially when considering these statistics:

• In Canada, adverse drug reactions kill more than 10,000 Canadians every year and put 200,000 more in the hospital, costing about $13 billion annually. They estimate the use of PGx would reduce adverse reactions by 1/3. That’s more than $4 billion in potential savings every year! 
• North America spends $390 billion annually on drugs, with an estimated 30% wastage because the results do not lead to improved outcomes. It is estimated that about half of this drug waste could be eliminated through genetic drug matching. That’s nearly $60 billion in annual savings!

Another area where PGx could assist is in polypharmacy, where a patient is prescribed 5 or more drugs at a time. The risk of mortality, falls, adverse drug reactions, length of hospital stays, emergency room visits, and hospital readmissions increase with every additional drug taken. Some patients end up taking drugs to counteract the side effects of other prescriptions. If they were prescribed the best drug for their genetic makeup, not only would this reduce over prescribing, but also lead to better outcomes, and healthier, happier patients – and reduced healthcare costs.
 
Reducing Disability Claims
One US study, in 2013, found that people taking antidepressants matched to their genetic profile had 69% fewer healthcare related visits and one-fourth the disability claims compared to people who took an antidepressant that was a genetic mismatch.

Recognizing the potential to lower disability claim costs, Canada’s three largest disability insurers have launched PGx studies:

• In August, 2018, Sunlife gave their clients the option to join their mental health PGx IMPACT study
• In December, 2018, Great West Life launched a pilot PGx project for those with disabilities related to chronic pain or mental health issues
• In early 2019, Manulife is rolling out a study focused on the effects of PGx for disabilities caused by depression, anxiety and chronic pain

​Countries Courting PGx
If the positive impacts are resoundingly clear, why aren’t more PGx tests conducted in the U.S. where skyrocketing drug costs are driving up healthcare expenses? While the United States allows licensed healthcare providers to order a PGx test, most insurance companies will not cover the cost. As in other areas of healthcare, other countries have adopted a much broader stance:

• Croatia introduced PGx into all their hospitals in 2018. They were able to do this because the government owns the country’s hospitals.
• In Canada and Australia, PGx screening is available direct to consumers through their local pharmacy.
• In Norway, physicians can order a PGx test as part of routine practice.

In the various articles and medical studies that I’ve reviewed, it is stated over and over that the key to PGx testing success is inter-professional collaboration between the testing company, the PGx pharmacist, and the patient’s medical providers. A PGx pharmacist receives comprehensive training to understand the results of the PGx test in order to provide an actionable report to the patient and their medical team.  

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​The Bottom Line
I’ve said it before, and I will say it again. The future of medicine – both for better patient outcomes and cost reduction - is “individualized care”. The PGx test is another great example of this. It seems a “no brainer” to include as part of hospital pre-admission testing, for those in home healthcare, and patients taking five or more drugs. A case can also be made to automatically test those who are taking, or are in need of taking, pain medications, antidepressants, or other drugs where “trial and error” is required to land on the right drug and dosage. While US health insurance carriers may not see the return on investment yet, I wager that employers with self-funded medical plans will be early adopters, as well as US-based long term disability carriers. 
 
PGx Testing Companies:

• GeneYouIn recommends Pillcheck – currently covering 179 medications in 19 treatment categories; $599 per test
• The Mayo Clinic and OneOME co-developed the RightMed test – currently covering 244 drugs for 30 conditions; $449 per test, lowered with a sliding-scale available based on financial need

 
Want to Learn More?

• The Mayo Clinic has a great short video I have seen explaining the basic concepts of pharmacogenomics
• GeneYouIn and Banyan World Health Solutions contributed a comprehensive article in the Benefits Quarterly publication, first quarter 2017