Clinical efficacy and safety of biosimilar epoetin: focus on epoetin zeta

Ashraf Mikhail , Christopher BrownRenal Unit, Morriston Hospital, Wales, UK Abstract: Biosimilars have been developed for several biologic therapeutic agents, including erythropoiesis-stimulating agents. Biosimilars cannot be assumed to be completely identical to the reference product. Several regulatory bodies have issued stringent guidelines to regulate the licensing of biosimilars. These guidelines, although share a unified aim of ensuring the safety and efficacy of biosimilars, show several differences. Such differences may reflect the difficulties facing regulatory bodies in defining a biosimilar, identifying sensitive means to assess equivalence in efficacy, and designing robust methodologies to monitor long-term safety. This review will discuss some of the aspects of differences in licensing requirements for biosimilars, comparing the European Medicines Agency guidelines and the American Food and Drug Administration guidelines. The pathway adopted by the manufacturer of a biosimilar (epoetin zeta) to gain licensing within the European market will be assessed, analyzing its compliance with the European Medicines Agency guidelines for the approval process. Since many patients are likely to be switched from original drugs to biosimilars in future, there is a need to establish strict guidelines on interchangeability and substitution of biosimilars and original products and to make it an integral part of the pre-registration assessment of any biosimilar in future. Eventually, long-term, observational post-marketing data will provide further reassurance on safety and tolerability of biosimilars. Keywords: biosimilars, erythropoiesis-stimulating agents, epoetin zeta, biologic therapeutic agents