Biosimilarity for Follow-on Biologics

Abstract

With dramatic increased spending on biologics and approaching patent expirations for existing biological products, there is a need to consolidate thinking on the regulatory approval pathway of biosimilars. However, biologics have much greater complexity by nature. The traditional paradigm currently used for generic chemical drugs, where bioequivalence is the focus, cannot be extrapolated to biologics. In the biosimilars scenario, the comparability of pharmacokinetic and pharmacodynamic parameters, and the comparability of efficacy and safety from clinical trials are the keys for the success of follow-on biologics. Developing sensitive bioanalytical methods to detect small, meaningful differences is critical. This article proposes a novel reference-scaled method to evaluate the comparability of pharmacokinetics parameters, and illustrates the method using a study comparing a test drug to a reference drug in a cancer study.