Biosimilars: An Emerging Category of Biologic Drugs for Emergency Medicine Practitioners

Biologics are the fastest growing segment of annual United States (US) drug expenditure. Biologics are complex proteins derived from living sources that are important therapy for a variety of diseases. The US is now poised to introduce biosimilars, which are copies of biologics that are not manufactured by the innovator company and are approved under an abbreviated regulatory process. Biosimilars are intended to offer comparable safety and efficacy to the reference biologic at a lower cost. Because of the complexity of producing biologics, the manufacturing process for biosimilars may differ from that of the reference biologic, which may result in subtle changes in biological characteristics and clinical activity. Questions exist regarding whether these slight differences allow the products to be interchanged with the reference product and if unique adverse events will occur with use. While the Biologics Price Competition and Innovation Act outlined the abbreviated approval pathway for biosimilars, guidance from the US Food and Drug Administration (FDA) is needed on specific details of the approval process. The FDA has recently provided guidance about the scientific and quality requirements for demonstrating biosimilarity, but a number of unanswered questions still remain, including concerns about immunogenicity, product naming, and the exact cost savings from biosimilars. Emergency Medicine practitioners must have a sound understanding of these issues to ensure patient safety and avoid complications in care.