North Carolina State University, USA
Aijing Zhang is a professor at North Carolina State University, USA.
When an innovative biological drug product is going off patent, biopharmaceutical companies may fi le an application for regulatory approval of biosimilar products. Unlike small molecule drug products, biosimilars are not exact copies of their brand-name counterpart, and have greater variability due to their complexity and sensitivity to manufacturing process and environmental factors. Facing these challenges, a biosimilarity index based on reproducibility probability is proposed to assess biosimilarity. We recommend that reference standard is fi rst to be established in an R-R study in which biosimilarity is assessed comparing the reference product with itself. Biosimilarity between test and reference product is then assessed in relative to this reference standard. Similarity index approach has the advantage of allowing us to assess bio similarity without a well-accepted criterion and to assess the degree of similarity.