Scientific
Factors for Assessing Biosimilarity and Interchangeability of Follow-on
Biologics
Department of Biostatistics and Bioinformatics
Duke University School of Medicine
When an innovator biological product is going off patient, biopharmaceutical and/or biotech companies may file applications for regulatory approval of biosimilar products. Unlike the small molecular drug products, the complexity and heterogeneity of the molecular structure, complicated manufacturing process, different analytical methods, and possibility of severe immunogenecity reactions make evaluation of biosimilar products a great challenge for both scientific community and regulatory agencies. In this presentation, I will provide an overview of scientific/statistical factors regarding design and analysis of biosimilar products for regulatory approval of biosimilar products. These scientific/statistical issues include, but are not limited to, fundamental biosimilarity assumption, criteria, design and analysis for assessment of biosimilarity and drug interchangeability based on the concept of switching and/or alternating. In addition, a newly developed biosimilar index based on reproducibility probability of claiming biosimilarity proposed by Chow et al. (2011) is discussed. The proposed biosimilar index can not only address the question regarding “how similar is similar?” but also the issue of drug interchangeability in terms of the concept of switching and/or alternating under appropriate study design.