Purpose: Adverse drug reactions are the fifth leading cause of death in the United States, and thousands of additional patients are prescribed medications from which they derive no benefit. Pharmacogenomics is the study of genetic factors governing drug response and toxicity. This field has led to discovery of genetic variants for hundreds of drugs, but the information has infrequently been utilized in prescribing decisions.
Method: We hypothesized that the creation of a novel genomic prescribing system (GPS) which translates pharmacogenomic results into clinically usable summaries would facilitate the consideration of pharmacogenomic information during drug prescribing decisions. To test this model, we initiated a clinical trial in which consenting patients agree to comprehensive, preemptive pharmacogenomic testing and a group of early-adopter physician-subjects and their tested patients are studied to determine the feasibility and utility of pharmacogenomic results delivery using a GPS.
Result: In 15 months, >700 patients receiving routine outpatient medical care from one of 12 early-adopter study physicians agreed to participate. A custom-designed genotyping panel of hundreds of pharmacogenomic variants having published evidence of their potential clinical utility was created. The custom panel was designed based upon interrogation of 3,520 pharmacogenomic studies in the medical literature regarding 674 common drugs. Pharmacogenomic results in these studies allowed creation of genotype-specific clinical summaries for each drug-variant pair which translate raw genotype results into instantaneously-available clinical pharmacogenomic interpretations, comprising the content of the GPS. Each summary was given a level of evidence rating and an interpretive “favorable/cautionary/warning” designation for the pharmacogenomic result. Study physicians are being prospectively monitored for use of the GPS during medical care of their enrolled patients. Physician-patient pairs are being followed and surveyed to measure impact on decision-making and health outcomes.
Conclusion: We have successfully developed within a research context a novel healthcare delivery device which relies on the use of preemptive genotyping to provide pharmacogenomic decision-support to physicians considering treatment decisions. The GPS fulfills at once a test result function, an interpretive function, and an educational function for physicians, all aimed to overcome primary barriers to the routine implementation of more personalized medicine. Measures of the rate of use of the GPS by study physicians, its impact on drug prescription choices, on shared decision-making, and on patient-reported satisfaction with care are ongoing.
See more of: The 34th Annual Meeting of the Society for Medical Decision Making