Statistical Methods for Assessment of Biosimilars

Abstract

Biosimilar assessment has received much attention since the Biologics Price Competition and Innovation (BPCI) Act passed by the United States (US) Congress in 2009. For assessment of biosimilar products, the US Food and Drug Administration (FDA) recommends a stepwise approach for obtaining the totality-of-the-evidence of the safety and efficacy of a proposed biosimilar product as compared to the original innovative biologic product for regulatory review and approval of the proposed biosimilar product. The stepwise approach consists of the assessment of analytical similarity, pharmacokinetic/pharmacodynamics (PK/PD) similarity and clinical similarity including immunogenicity. In this chapter, statistical methods for assessment of biosimilar products in terms of analytical similarity, PK/PD similarity and clinical/immunogenicity similarity are studied. Also included in this chapter are statistical issues that are commonly encountered in biosimilar assessment. These issues include, but are not limited to, possible reference product change, switching designs for interchangeability in terms of switching and alternation of biosimilars and reference products, selection of similarity margin, extrapolation across indications, and non-medical switching.