Assessing biosimilarity and interchangeability of biosimilar products under the Biologics Price Competition and Innovation Act

Abstract

Biological (large molecule) drug products are made via living systems and are complex and variable in nature. As a result, generic forms of biological products, also termed biosimilars in the EU or follow-on biologics by US FDA, can only be similar to the reference product, unlike generic versions of small molecule drug products that contain the exact same active ingredient as the brand-name drug. Compared with small molecule drug products, more stringent assessment of safety, purity, and potency is needed to show that a follow-on biologic is not clinically different from the reference biological product. This paper addresses statistical criteria for establishing biosimilarity and interchangeability of follow-on biologics as set forth by the Biologics Price Competition and Innovation Act. It also highlights the scientific issues regarding the assessment of follow-on biologics that are currently still unresolved within the US.