ABSTRACT
This chapter outlines a traditional approach based on power analysis for sample size calculation. It summarizes Food and Drug Administration’s (FDA) current thinking on selection of test and reference lots for Tier 1 equivalence tests, as well as FDA's recommendation for sample size calculation. The chapter discusses a method for selection of test and reference lots proposed by Chow et al. It includes a recent development for sample size requirements for analytical similarity assessment. The chapter provides some numerical studies for illustration of sample size calculation based on different criteria. FDA's recommendation attempts to select a sample size for achieving a desired power at a pre-specified level of significance by knowing that clinically meaningful difference and variability are varying. For assessment of biosimilarity of biosimilar products, FDA recommends a stepwise approach for obtaining the totality-of-the-evidence in order for demonstration of biosimilarity between a proposed biosimilar product and an innovative biological product.
