Pharmacogenomics (PGx) 101: What You Need to Know for Rx Programs

Justin Venneri

Justin Venneri

Pharmacogenomics (PGx) has likely been on your radar over the last few years if you’re involved in patient care and tracking the evolution of Personalized Medicine. Or perhaps you’re interested in genetic testing, companion diagnostics (CDx), or other similar topics and keep an eye on anything with a “next-gen” label in health care?  

Regardless of why you’re here and interested in PGx, I connected with Sara Izadi, PharmD, SVP, Pharmacy at Capital Rx for a Q&A to shed some light on what PGx is, why it’s important, how it can help patients, what the barriers to adoption have been, and what’s being done to integrate PGx into care and benefits programs.

The pace of scientific advancement and study data highlighting the potential benefit of tailoring patients’ medication regimen(s) are two items to track. Managing and integrating massive quantities of data more efficiently and having more support for reimbursement will help push PGx forward.

Of course, pharmacy benefit managers (PBMs) have a part to play.

What is Pharmacogenomics?

Pharmacogenomics, commonly abbreviated PGx, is the study of how a person's unique genetic profile influences their response to medication. Its origins date back thousands of years to Pythagoras’ observation that ingesting fava beans could be dangerous.

Okay, and why is PGx important? Are there any good examples of how it can work?

Leveraging PGx, prescribers can practice Precision Medicine. As the name suggests, Precision Medicine is the personalization of health care, with decisions and treatments tailored to each patient. There are several benefits of moving toward more personalized care.

Precision Medicine reduces the need for a “trial and failure” approach to treating many medical conditions. For example, the treatment of depression presently relies on a trial and failure approach that includes multiple rounds of therapy, with each trial lasting 4-6 weeks. Unfortunately, fewer than 40% of patients achieve remission following their first trial round, and only 67% achieve remission after up to four trials. Worse yet, the probability of experiencing an adverse event increases each time a patient tries a new medication regimen.1

Continuing with the example, applying Precision Medicine to the treatment of depression should decrease the total cost of care because patients are more likely to respond to tailored treatments (vs. fail). Subsequent wasteful trials are no longer needed, the rate of adverse events declines, and patient response and satisfaction improve.

Why hasn’t there been more support for or progress with PGx? Or, what have the barriers to adoption been?

First, there is growing support for PGx. However, there’s friction with the management of PGx through the medical benefit. Tests are often ordered multiple times, and physician fees can increase overall costs. If PGx is reimbursed through medical billing, it can often cost $5,000 or more. If a similar PGx program is run through the PBM, the cost can be roughly $500, which is obviously a huge difference.

Another barrier for PGx is that it isn’t included in association guidelines, so prescribers have limited or no actionable clinical guidelines to rely on. That said, health insurers have been looking for novel ways to address concerns around increasing care costs. 2, 3 In recent years, the Center for Medicare and Medicaid Services (CMS) and several private insurers have determined that PGx testing is medically necessary, has clinical utility, and is eligible for broader coverage. 4Additionally, many Clinical Pharmacists are trained to combine PGx results with their extensive knowledge of pharmacology, drug-drug interactions, and drug dosing. So, when presented with the relevant information, a Clinical Pharmacist with additional pharmacogenomics training can provide well-informed, individualized treatment recommendations to streamline care and reduce waste as part of a comprehensive pharmacy program.

Slowly but surely, PGx is gaining some momentum as resources and incentives align.

How many drugs are we talking about here, and what are the hottest specialties for PGx?

The FDA maintains a Table of Pharmacogenomic Biomarkers in Drug Labeling that lists over 300 products with pharmacogenomic information in the labeling. That list has been growing since early 2020, when it was just over 100 products.

Psychiatry is one area of focus, per the depression example above. There are over 35 drugs with PGx information in their labeling in psychiatry, making it the second-largest specialty behind oncology, which has over 110 drugs meeting the criteria (as of July 2022). There are ~130 biomarkers with at least one approved drug, and that’s likely on a one-way path higher. The next-largest specialties are neurology and infectious disease.

If one-size-fits-all formularies go by the wayside, what should we watch for in the future?

Using PGx, we know that we can determine how individual patients metabolize medications. It is possible to preemptively identify the medications best suited to an individual’s genetic predisposition and which medications may be unsafe or wasteful at the patient level. With integrated data, trial and error prescribing declines, and the number of “genetic blueprints” rises. Tech-forward PBMs can weave much of this together, so the future may be closer to reality than people think.

Finally, what is Capital Rx doing in and around PGx and Precision Medicine?

Capital Rx’s PGx program, Rx Helix, utilizes an at-home panel test of 25+ high evidence genes that inform the prescribing of over 100 medications.

JUDI®, our cloud-native enterprise pharmacy platform, can flag plan members who may benefit from pharmacogenomic testing during the existing drug utilization review processes. Patients enroll through a streamlined process and receive a follow-up call from a PGx-trained Capital Rx clinical pharmacist who employs decision support software to offer optimal medication recommendations aligned with each member’s formulary and benefit plan structure.

CLICK HERE if you’d like to learn more about Rx Helix and what Capital Rx is doing to help advance Precision Medicine.

1 Rush AJ, et al. Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: a STAR*D report. Am J Psychiatry. 2006 Nov;163(11):1905-17.

2 Brown, Lisa C, et al. “Economic Utility: Combinatorial Pharmacogenomics and Medication Cost Savings for Mental Health Care in a Primary Care Setting.” Clinical therapeutics vol. 39,3 (2017): 592-602.e1. doi:10.1016/j.clinthera.2017.01.022

3 Jarvis, Joseph P, et al. “Real-World Impact of a Pharmacogenomics-Enriched Comprehensive Medication Management Program.” Journal of personalized medicine vol. 12,3 421. 8 Mar. 2022, doi:10.3390/jpm12030421

4 Center of Medicare and Medicaid Services. “Local Coverage Determination (LCD) -
Pharmacogenomics Testing” accessed June 10, 2022.