title: Clinical evidence supporting pharmacogenomic biomarker testing provided in US Food and Drug Administration drug labels.
abstract: OBJECTIVE
  Genetic biomarkers that predict a drug's efficacy or likelihood of toxicity are assuming increasingly important roles in the personalization of pharmacotherapy, but concern exists that evidence that links use of some biomarkers to clinical benefit is insufficient. Nevertheless, information about the use of biomarkers appears in the labels of many prescription drugs, which may add confusion to the clinical decision-making process.
  
  
  OBJECTIVE
  To evaluate the evidence that supports pharmacogenomic biomarker testing in drug labels and how frequently testing is recommended.
  
  
  METHODS
  Publicly available US Food and Drug Administration databases.
  
  
  METHODS
  We identified drug labels that described the use of a biomarker and evaluated whether the label contained or referenced convincing evidence of its clinical validity (ie, the ability to predict phenotype) and clinical utility (ie, the ability to improve clinical outcomes) using guidelines published by the Evaluation of Genomic Applications in Practice and Prevention Working Group. We graded the completeness of the citation of supporting studies and determined whether the label recommended incorporation of biomarker test results in therapeutic decision making.
  
  
  RESULTS
  Of the 119 drug-biomarker combinations, only 43 (36.1%) had labels that provided convincing clinical validity evidence, whereas 18 (15.1%) provided convincing evidence of clinical utility. Sixty-one labels (51.3%) made recommendations about how clinical decisions should be based on the results of a biomarker test; 36 (30.3%) of these contained convincing clinical utility data. A full description of supporting studies was included in 13 labels (10.9%).
  
  
  CONCLUSIONS
  Fewer than one-sixth of drug labels contained or referenced convincing evidence of clinical utility of biomarker testing, whereas more than half made recommendations based on biomarker test results. It may be premature to include biomarker testing recommendations in drug labels when convincing data that link testing to patient outcomes do not exist.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts2Department of Pharmacy, University of Washington, Seattle.
authors.forename: William J
authors.initials: WJ
authors.lastname: Canestaro
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
mesh_terms: D015415:Biomarkers; D016208:Databases, Factual; D004348:Drug Labeling / Q000592:standards*; D019317:Evidence-Based Medicine; D005820:Genetic Testing; D006801:Humans; D010597:Pharmacogenetics; D055553:Prescription Drugs / Q000592:standards*; D015203:Reproducibility of Results; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D015415:Biomarkers; D055553:Prescription Drugs