ABSTRACT
This chapter provides interpretation and/or statistical justification and discusses some challenging issues to the Food and Drug Administration’s (FDA) proposed approach. It discusses some recommendations and alternative methods. Analytical similarity assessment focuses on structural and functional characterization in manufacturing process of the proposed biosimilar product as the foundation for achieving totality-of-the-evidence for demonstration of similarity between the proposed biosimilar product and the innovative biological product. The chapter outlines the stepwise approach for demonstrating biosimilarity as suggested by the FDA draft guidance. It also provides brief descriptions of the Tier 1 equivalence test and the quality range approach for Tier 2 critical quality attributes (CQAs) and the method of descriptive raw data and graphical comparison for Tier 3 CQAs, respectively. The chapter discusses some practical considerations. For the quality range approach for CQAs in Tier 2, FDA recommends to use x = 3 by default for 90% of values of test lots contained in the range.
