Prevalence and types of inconsistencies in clinical pharmacogenetic recommendations among major U.S. sources

Tyler Shugg,Jasmine A. Luzum,Amy L. Pasternak,Bianca London

doi:10.1038/s41525-020-00156-7

Abstract

Clinical implementation of pharmacogenomics (PGx) is slow. Previous studies have identified some inconsistencies among clinical PGx recommendations, but the prevalence and types of inconsistencies have not been comprehensively analyzed among major PGx guidance sources in the U.S. PGx recommendations from the Clinical Pharmacogenetics Implementation Consortium, U.S. Food and Drug Administration drug labels, and major U.S. professional medical organizations were analyzed through May 24, 2019. Inconsistencies were analyzed within the following elements: recommendation category; whether routine screening was recommended; and the specific biomarkers, variants, and patient groups involved. We identified 606 total clinical PGx recommendations, which contained 267 unique drugs. Composite inconsistencies occurred in 48.1% of clinical PGx recommendations overall, and in 93.3% of recommendations from three sources. Inconsistencies occurred in the recommendation category (29.8%), the patient group (35.4%), and routine screening (15.2%). In conclusion, almost one-half of clinical PGx recommendations from prominent U.S. guidance sources contain inconsistencies, which can potentially slow clinical implementation.

Highlights

Advances in pharmacogenetics (PGx) over the past two decades have rapidly enhanced our understanding of the effects of genetics on drug disposition, therapeutic efficacy, and toxicity
In the U.S, clinicians primarily receive PGx clinical recommendations from three major sources: guidelines published by the Clinical Pharmacogenetics Implementation Consortium (CPIC); U.S Food and Drug Administration (FDA) drug labels; and clinical practice guidelines (CPGs) published by professional medical organizations and technology assessors (e.g., the National Comprehensive Cancer Network (NCCN) and Evaluation of Genomic Applications in Practice and Prevention Working Group (EGAPP))
Inconsistencies in the biomarker or gene are important because it is unclear to the clinician which genetic tests should be ordered for the drug that is being prescribed

Summary

Introduction

Advances in pharmacogenetics (PGx) over the past two decades have rapidly enhanced our understanding of the effects of genetics on drug disposition, therapeutic efficacy, and toxicity. Research from academic implementation efforts has shown that the major factors slowing the widespread implementation of PGx include lack of clinician PGx training and lack of clinician confidence in interpreting PGx results3–6 These findings are consistent with the results from a nationwide survey in 2012 that found ~90% of U.S physicians felt inadequately informed about PGx testing. The prevalence and types of inconsistencies among current clinical PGx recommendations from the major U.S sources (CPIC, FDA, and CPGs) have not been thoroughly investigated. This issue is perhaps more timely than ever since the FDA recently approved direct-to-consumer PGx testing by the company 23andMe11. The objective of this study was to characterize the prevalence and types of inconsistencies among current clinical PGx recommendations from the three major U.S sources: CPIC, FDA, and CPGs

Objectives

Methods

Results

Conclusion