Sources of Evidence Triggering and Supporting Safety-Related Labeling Changes: A 10-Year Longitudinal Assessment of 22 New Molecular Entities Approved in 2008 by the US Food and Drug Administration.

introductionNew safety issues concerning US FDA-approved drugs are commonly communicated through safety-related labeling changes. Therefore, to optimize and refine postmarket safety surveillance strategies, it is important to comprehensively characterize the sources of data giving rise to safety-related labeling changes.

objectivesOur objective was to characterize the sources of data triggering and supporting the identification of new safety risks of FDA-approved drugs communicated through safety-related labeling changes.

methodsWe conducted a retrospective study with a 10-year observation period using FDA's internal electronic data repositories for all prescription new molecular entities (NME) approved in 2008. We collected and analyzed information on new safety issues, the section of the full prescribing information updated, initiators (FDA, drug manufacturer), and triggering and supporting sources of evidence.

resultsAmong 22 NMEs approved in 2008, 189 new safety issues for 18 NMEs were identified. Compared to drug manufacturer, FDA initiated safety-related labeling changes in nine of the ten changes to the Boxed Warnings, 28 of the 52 changes to the Warnings and Precautions, and 43 of the 134 changes to the Adverse Reactions sections of the full prescribing information. The most frequent triggering sources of evidence included the drug manufacturer safety database (32.3%) and FDA Adverse Event Reporting System (FAERS) safety reports (15.3%) for all relevant sections of the full prescribing information, and class-labeling changes (17.5%) for Boxed Warnings and the Warnings and Precautions sections. The most frequent triggering source of evidence was FAERS safety reports (69%) in the first year after drug approval and the drug manufacturer safety database in subsequent years.

conclusionsOur findings emphasize the continued importance of safety reports from FAERS and drug manufacturer safety databases and a comprehensive drug safety surveillance program throughout a drug's lifecycle.