A Pharmacogenomic Promise

Pharmacogenomic testing is an increasingly significant part of many laboratory medicine professionals’ work. The more we learn about genes that affect drug efficacy, metabolism, or even the likelihood of adverse events, the more we can test to ensure that each patient receives the appropriate dose of the appropriate drug with the appropriate monitoring. However, not all tests are equal; some have a greater evidence base behind them or may simply be easier for clinicians or patients to understand. As a result, the Association for Molecular Pathology (AMP) has developed a set of best practices for clinical pharmacogenomic testing. We spoke to Jordan Laser, Medical Director of Long Island Jewish Medical Center – Pathology and Laboratory Medicine and Chair of AMP’s Professional Relations Committee, to learn more.

How is the rise in pharmacogenomic testing affecting pathologists and laboratory medicine professionals?

AMP members are among the early adopters of molecular diagnostic testing in clinical settings, and we are committed to improving professional practice and patient care. Our members have accumulated substantial knowledge and expertise that is useful for laboratories performing pharmacogenomictests, and our goal is to promote standardization of pharmacogenomic testing across clinical laboratories.

AMP continues to evaluate the evolving landscape of pharmacogenomic testing. As part of this evaluation, a group of leaders determined that clinically meaningful pharmacogenomic tests are poised to improve patient care and professional practice – provided that certain conditions are met. The set of conditions include:

• All health-related pharmacogenomic claims must have well-established clinical validity.
• The pharmacogenomic testing provider must comply with the Clinical Laboratory Improvement Amendments statute and regulations.
• The pharmacogenomic test report should be easily understood by healthcare providers and include the interpretation of the findings, the significance of the results, and the limitations of the test.
• Patients should not change their treatment plan without first talking to their healthcare provider.

What defines a clinically meaningful pharmacogenomic test?

Clinical pharmacogenomic tests are valuable tools that can help healthcare providers determine the optimal medication or treatment for a specific patient. As in all other practices of medicine, supporting clinical validity must be determined before the test is offered to patients. Evidence may be demonstrated through peer-reviewed literature, clinical practice guidelines, and/or FDA drug labels. One organization that develops clinical practice guidelines for pharmacogenomic testing is the Clinical Pharmacogenetics Implementation Consortium (CPIC). CPIC has developed a number of gene-drug practice guidelines to help determine a clinically meaningful test.

AMP encourages the use of such clinical practice guidelines. The AMP Pharmacogenetics (PGx) Working Group is also working on a series of evidence-based expert consensus opinion recommendations designed to help standardize alleles that should be included in clinical testing for frequently used genotyping assays. The Working Group started with CYP2C19 and CYP2C9 genotyping panels due to the widespread adoption of these tests and our desire to help physicians, pharmacists, researchers, and other stakeholders better understand what these panels include and what the test results mean.

We recognize that this is a quickly evolving field and that patients gain the most benefit from pharmacogenomic testing when healthcare providers can easily determine when a patient’s genotype indicates an actionable treatment decision. For this reason, AMP supports test reports that include the metabolizer status based on the genotype for the genes that affect drug metabolism; a list of the drugs for which responsiveness may be affected by the genotype; a generalized statement to alert healthcare providers when alternate dosage or drug treatment may be considered based on the results; and a list of resources and references that healthcare providers can use to learn more about the genotyping results.

What advice do you have on playing an active role in this testing?

We’re just beginning to realize the full potential of clinical pharmacogenomics in the era of precision medicine. These groundbreaking tests provide substantial benefits to patients when the drug-gene association is supported by strong scientific evidence and the healthcare provider is easily able to determine the actionable prescribing decision. Our new position statement on pharmacogenomic testing leverages our community’s collective expertise in this rapidly developing field and reflects AMP’s ongoing commitment to improving professional practice and patient care.