David Skomo, and Nick Page, PharmD, of WellDyne offered their perspectives on recent developments in precision medicine at the 2022 Asembia Specialty Pharmacy Summit.
The session, titled “The New Generation of Precision Medicine,” was moderated by David Skomo, chief operating officer, and Nick Page, PharmD, chief clinical and strategy officer of the company.
Rather than focus on genetic testing and its insights on disease risk, Skomo elaborated on the importance of pharmacogenomics, or the use of genetic testing to indicate a specific treatment’s likely efficacy in certain patients based on their genes. He defined pharmacogenomics under the umbrella of precision medicine as an “emerging approach for disease treatment and prevention that takes into account individual variability in genes,” while precision medicine is “also going to take into account a person's lifestyle and their environment.”
Utilization of biomarker testing and companion diagnostics is also crucial in precision medicine as these practices can help further understanding the efficacy of particular drugs or biologics in individual patients. As Skomo explained, companion diagnostics are of particular import in the oncology field where providers have to continually weigh the risks and benefits of treatment regimens.
Currently in the United States, genetics have an impact on 18% of prescriptions dispensed on an annual basis, he said. He went on to highlight findings of a study conducted among retired teachers in Kentucky.
These individuals were prescribed an average of 15 medications, and after conducting analyses, researchers found nearly 70% of this population was taking a drug recommended to be discontinued or changed as a result of genetic testing.
Reducing hospitalizations and health care visits driven by inappropriate medication interactions will help cut down on health care spend, Skomo said, adding “as you introduce more in the way of precision medicine you can drive those medical interventions down.”
Furthermore, in this cohort, about a third of adverse drug interactions were caused not by drug-drug interactions but by patient genetics. Additional research has put the estimated financial impact, or additional health care spend, of nonoptimized medication in the United States at $528 billion.
Precision medicine offers potential for benefits in many different fields, including mental health where 30% to 50% of patients fail initial antidepressant therapy due to ineffectiveness or intolerance, Skomo said. Individual differences in metabolization of certain medicines will result in time and drug waste “because the medication is not optimized for that patient.”
Heart disease poses another area of opportunity as 40% to 75% of patients stop taking statin therapy within the first year due to intolerance and adverse effects, he explained.
Overall, precision medicine can help improve prescribing and clinical outcomes for patients, align patients to the right therapy using genetic panels and metabolic metrics, and cut down on drug waste by eliminating trial and error prescribing.
For his section of the talk, Page explained the future of medicine moving from an art to a science. “We're actually able to use science, laboratory testing, and unique diagnostics to better predict whether or not the patient is going to respond to therapy,” he said.
Because genetics don’t change over time, an additional plus of pharmacogenomics is that it is based on a 1-time test for patients and findings can be archived. Genetic testing is also becoming more cost-effective, Page explained.
Data have revealed that unnecessary health care utilization resulting from nonoptimized medicine (based on genetic testing) costs an estimated $1000 to $3000 annually per patient. These savings increase to around $7000 in the cardiovascular setting “just by making sure that we're using the right drugs in the right patients,” Page said.
In the United States, 261 FDA-approved medications reference genetic information in some form on their label. According to Page, on the PBM side, researchers will look into the claim histories of particular populations and communicate to payers or plans the percentage of individuals who may benefit from this type of genetic testing based on medications taken.
However, because uptake of these tests is voluntary, low rates opt into the testing, prompting the need for increased member education, Page said. Some individuals may only be familiar with the disease risk aspect of genetic testing and be unaware of the benefits of pharmacogenomics.
In addition, while advancements of pharmacogenomics have thus far been focused in the nonspecialty space, additional opportunities for precision medicine in different specialties are beginning to crop up, with advancements falling outside of differences in metabolic pathways.
“Over 100 specialty medications have a companion diagnostic,” Page said. These drugs have FDA indications for patients that only have specific genetic polymorphisms. But having these alterations does not guarantee 100% effectiveness of said drug, he cautioned.
Molecular signature tests and disease activity metrics also constitute additional forms of precision medicine that have applications in the specialty setting. Citing the example of a biomarker test for psoriasis, Page explained how a patch put on an area of psoriasis can, after lab evaluation, determine which of the 3 key mechanisms of action for psoriasis treatment the patient is most likely to respond.
Although tests such as these are most useful prior to any prescription being written, challenges remain in trying to educate physicians about these tests. Common concerns brought up include cost coverage and a lack of training in curriculums on genetic testing.
Additional tests are being developed in other disease states such as rheumatoid arthritis, ulcerative colitis, Crohn disease, and inflammatory bowel disease.