Evaluating AE Reporting of Two Off-Patent Biologics to Inform Future Biosimilar Naming and Reporting Practices

Historical studies of voluntary, spontaneous drug reports show poor attribution of adverse events to generic versions of commonly prescribed medications. As biosimilars enter the market place, it may be similarly difficult to accurately attribute adverse events to their respective reference products. At this time, lack of global consensus with regard to biosimilar naming conventions may result in drug reporting confusion, misattribution of adverse events and insufficient active monitoring of safety signals. Now, with the first biosimilar approval in the USA and many biosimilars expected to be launched globally in the near future, US Food and Drug Administration (FDA) guidance on biosimilar naming conventions will be essential. To inform the FDA and the global drug development community, the Tufts Center for the Study of Drug Development (Tufts CSDD) examined primary suspect reports sent to the FDA's Adverse Event Reporting System (FAERS) from US reporters for two biologics that have lost patent exclusivity--somatropin and human insulin--and extracted 4703 insulin reports and 6487 somatropin reports from FAERS. The results show that reporting practices are inconsistent between the two biologics that were evaluated and that manufacturer identifiability and traceability are lacking. Ways to improve biosimilar naming conventions and improve reporting practices are suggested.