What is Pharmacogenomics?
Pharmacogenomics is the study of how a person’s genetic make-up determines his or her response to medications. The effects of medications vary from person to person, and to some degree depend on variations within genes. This is one of the reasons why a medication may work well for some people and not for others, or why some people experience negative side effects while others do not. The three major drug effects that pharmacogenomics attempts to predict are efficacy (how well a drug works), toxicity (negative side effects), and dosing (the correct amount of a drug to administer to a patient).
Until recently, medications were developed and administered in a “one size fits all” approach to meet the needs of an “average” patient. With the help of personalized research, clinicians have the ability to select the medications that work best for each patient.
“…Precision medicine — in some cases, people call it personalized medicine — gives us one of the greatest opportunities for new medical breakthroughs that we have ever seen. Doctors have always recognized that every patient is unique, and doctors have always tried to tailor their treatments as best they can to individuals. You can match a blood transfusion to a blood type. That was an important discovery. What if matching a cancer cure to our genetic code was just as easy, just as standard? What if figuring out the right dose of medicine was as simple as taking our temperature?
And that’s the promise of precision medicine — delivering the right treatments, at the right time, every time to the right person.
-President Barack Obama, January 30, 2015
Individualized drug therapy based on a person’s unique genetic makeup is desirable because of the variability of patient response to medications and the potential for life-threatening drug toxicities; adverse drug reactions are one of the leading causes of death in the United States. If clinicians could better predict which individuals are at risk of suffering drug-related toxicities, while also identifying those most likely to benefit, then the overall care of patients could be improved considerably.
Goals of Pharmacogenomics Research
The Center for Personalized Therapeutics researches pharmacogenomics on two levels: Discovery and Implementation. Pharmacogenomic discovery research seeks to find new genetic associations that affect patient responses to medications. For example, CPT members identified a variant within the KDR gene that affects patient rsponse to pazopanib, a cancer medication. Implementation research, on the other hand, attempts to find ways to utilize pharmacogenomic discovery research in the clinic. The 1200 Patients Project is an example of implementation research. In this project, we have synthesized previous pharmacogenomic research to build an online Genomic Prescribing System (GPS) to be used by clinicians so that they can easily use patients’ genetic information when making medication decisions.
Challenges to Pharmacogenomic Research
Genotyping: Genotyping patients accurately is a primary challenge to pharmacogenomic research. To address this challenge, The Center for Personalized Therapeutics, in conjunction with the Pathology Department, has developed an in-house Clinical Laboratory Improvement Amendments (CLIA) certified laboratory to do pharmacogenomics testing. We have developed a DNA panel that focuses on genes known to have pharmacogenomic significance. Impressively, this panel has the most extensive and precise testing in the world for CYP2D6, a gene that plays a large role in drug metabolism, as well as other genes. Running this genotyping platform in an in-house CLIA lab allows the CPT to genotype patients quickly and accurately, so clinicians can promptly access high-quality information.
Clinician and Patient Knowledge: Another barrier to pharmacogenomic implementation research is clinician and patient knowledge. Clinicians may not know when a pharmacogenomic test is available for a certain drug, for example. The CPT works to provide informative materials to clinicians and patients to educate them on the benefits and uses of pharmacogenomics.
Information Security and Patient Privacy: The CPT understands that patient information is highly sensitive and takes care to ensure patient privacy and security. The 1200 Patients Project, for example, has earned the highest Certificate of Confidentiality from the National Institue of Health, which protects patient genetic information and guarantees that it cannot be distributed to any external institutions.