White paper: Pharmacogenomic testing in precision medicine

Two areas of medicine that have exciting potential in terms of targeting therapy to specific conditions are precision medicine and pharmacogenomics. Precision medicine is an innovative discipline that aims to optimize treatment of individuals or patient subgroups by use of genetic testing and disease-specific biomarkers. Genetic testing can find disease-causing mutations, both environmentally induced and inherited. Biomarkers are substances that correlate with the risk or progression of a disease. Identification of these biomarkers is key to the success of precision medicine, especially in cancer treatment.

Biomarkers that enable personalized treatments have been identified across a wide range of therapeutic areas.¹ The proportion of drugs with genomic biomarker labeling has increased nearly threefold in the last two decades.² Of these, only a minority have been incorporated into the labeling recommendations for dosing and administration. The clinical utility of a biomarker depends upon the development of reliable evidence from well-run scientific studies that using the biomarker enables better condition management or helps improve outcomes.

Pharmacogenomics, the branch of genetics that studies ways in which an individual's unique genetic makeup influences the response to medications, is the second area of targeted therapeutic medicine with rapidly growing interest. However, metabolism is also influenced by the environment, limiting the utility of pharmacogenomic testing in clinical decision making. Many biomarkers included in drug labeling in cancer prescribing have been validated and incorporated into clinical care. Other areas of medicine for which pharmacogenomics has potential are being studied, but further research is required before entering into wider clinical use.

Our Transform Oncology Care program uses the results of broad-panel Next-Generation Sequencing and the latest National Comprehensive Cancer Network treatment and Supportive Care Guidelines to help providers select the most precise and effective chemo- and immune-therapies. Our recommended approach is to prioritize the use of validated biomarkers for targeted therapies as supported by published, peer-reviewed literature and guidance from medical professionals and health agencies.

For therapy classes where the FDA has recommended incorporating required testing recommendations into drug labels, we incorporate those requirements into our specialty guideline management (SGM) criteria. Test results and appropriate documentation are required at the time of submitting a prior authorization (PA) request for specific indications and diagnosis for more than 160 treatments, but further research is required before broad-based testing for variations, including the impact of pharmacogenomics in pharmacokinetics, are demonstrated to have clinical effectiveness. This will help address some of the current challenges and identify additional areas where such testing can deliver better outcomes in a cost-effective manner.

Using disease-specific biomarkers to optimize treatment, precision medicine holds enormous promise for patients with conditions like cancer and hereditary diseases. Due to the enormous expense of these therapies, starting therapy with certainty is critical; ensuring the right patient receives the right treatment for the correct diagnosis can enhance quality of care and outcomes while lowering overall costs.