It’s All in the Genes:
Putting Pharmacogenetics into Practice
DELRAY BEACH, FL – Pharmacogenetic testing in routine clinical care remains limited due to varying opinions on the level of evidence needed for clinical implementation. Some argue for randomized controlled trial (RCT) data before supporting testing, while others believe pharmacogenetics is held to a higher standard than other patient-specific factors.
Early 2020 saw the release of the FDA’s Table of Pharmacogenetic Associations, categorizing medications and gene associations based on therapeutic management recommendations, safety and response impact, and pharmacokinetic properties. Organizations like CPIC and PharmGKB have developed clinical guidelines with graded evidence for gene-drug pairs, aiding in prescribing decisions. Standardization efforts, such as those by CPIC, DPWG, and AMP, have been made to accelerate pharmacogenetic adoption and enhance consistency in the field.
Despite progress, some gaps in pharmacogenetic information in FDA-approved prescribing information remain. Differences in recommendations among resources can be attributed to variations in evidence evaluation methods and organizational approaches. Harmonization efforts, like the STRIPE Collaborative Community, aim to standardize pharmacogenetic testing-related practices and resources. The varied perspectives on pharmacogenetic evidence can significantly impact patient care, and it is crucial for providers to be educated on pharmacogenetic evidence. It is important to consider patient preferences and knowledge when integrating pharmacogenetic testing into clinical practice, as patients may advocate for their own testing based on information from other sources.
Pharmacogenetic evidence and its limitations have been studied extensively. Randomized controlled trials (RCTs) are considered the gold standard for evaluating the clinical utility of new interventions, including pharmacogenetic testing. Many RCTs have shown improved outcomes with pharmacogenetic testing compared to usual care. However, RCTs have limitations in pharmacogenetics, such as the need for a larger sample size to account for patients without the genetic variant of interest. They are also expensive and time-consuming to conduct.
Clinicians and patients consider various factors when determining whether to implement pharmacogenetic testing, including the clinical value of the test result, patient characteristics, specialty, and patient needs. Patients’ perspectives on pharmacogenetic evidence vary, and better reimbursement and understanding of the value of testing are crucial for patient acceptance. Pharmacogenetic evidence is essential for guiding clinical decisions, but the requirements for evidence may vary based on the specific clinical scenario and patient needs. Alternative approaches to evidence generation and patient perspectives play a crucial role in advancing pharmacogenetics in clinical practice.
The future of pharmacogenetic evidence is shifting towards pre-emptive panels covering multiple drug-gene pairs, as they offer potential cost efficiency and benefits. Clinical implementation of these panels has shown promising results in preventing adverse drug events and generating annual savings per patient. However, it’s essential to ensure strong evidence supports each gene-drug pair included in the panels to guide patient care effectively. Additionally, addressing the lack of pharmacogenetic education is crucial to promoting clinical implementation. Many healthcare providers are not confident in interpreting test results and lack awareness of available resources. Efforts to educate providers and include pharmacogenetics in medical school curricula are underway to enhance acceptance and adoption into standard practice.
Various factors influence the clinical implementation of pharmacogenetics, including patient perspectives, evidence from organizations curating pharmacogenetic data, and pharmacogenetic recommendations in practice guidelines. Shifting towards pre-emptive panel-based tests shows promise, but strong evidence for individual gene-drug pairs remains vital. Addressing education gaps will be essential to realize the full potential of pharmacogenetics in patient care.
- Luzum JA, Petry N, Taylor AK, Van Driest SL, Dunnenberger HM, Cavallari LH. Moving Pharmacogenetics Into Practice: It’s All About the Evidence!. Clin Pharmacol Ther. 2021;110(3):649-661. doi:10.1002/cpt.2327