ABSTRACT
In recent years, as more biological products are going off patent protection, the assessment of biosimilarity between biosimilar products (or follow-on biologics) and an innovative (reference) product has received considerable attention. For the approval of biosimilar products, the European Medicines Agency (EMA) has published several product-specific concept papers as regulatory guidelines for the approval pathway of biosimilar products (EMA, 2006a-g). In the United States, the Biologics Price Competition and Innovation (BPCI) Act (as part of the Affordable Care Act) has given FDA the authority to approve biosimilar drug products. As indicated in the BPCI Act, a biosimilar product is defined as a product that is highly similar to the reference product notwithstanding minor differences in clinically inactive components and there are no clinically meaningful differences in terms of safety, purity, and potency. However, no discussion regarding the criterion for similarity and how similar is considered highly similar is given in the BPCI Act.
