Equivalence Test for Two Emax Curves in Biosimilar Studies
Kerry Barker, Pfizer Inc.   *Bo Jin, Pfizer Biotechnology Clinical Development 

Keywords: Emax Model, Equivalence Testing

The 2014 FDA draft guidance of clinical pharmacology data to support a demonstration of biosimilarity to a reference product considers clinical pharmacology studies as a critical part in the clinical evaluations on similarity between a potential biosimilar and the reference product. While bioequivalence approach can be applied to PK similarity assessment in clinical pharmacology studies as indicated in the draft guidance, there remains to be a few unsettled problems to evaluate the similarity in terms of pharmacodynamics activities, specifically, including the problem to demonstrate the similarity on response profiles between two products. In this presentation, we describe a new procedure to test equivalence of two E-max curves which can be applied to both time-response and dose-response similarity assessments. Simulations results will be presented to compare the new procedure to other traditional procedures in terms of both Type I error and power performance. Discussions will also be provided on endpoint and dose selections from E-max response profile to provide sensitive assessment on similarity.