A review of bridging clinical studies between different presentations of biological products approved by the United States Food and Drug Administration (US FDA)

There is growing interest in the development of multiple presentations for biological products for subcutaneous (SC) injection for life cycle management and product differentiation. Bridging clinical studies are required to extrapolate the existing data package to new presentations.This review compiles information of bridging clinical studies conducted for biological products administered by the SC route and approved in more than one presentation by the United States Food and Drug Administration's Center for Drug Evaluation and Research up until 31 December 2021. Information regarding indication(s), presentation(s), approval pathways, approval timelines, and various aspects of bridging clinical studies was collected from published documents.The type of bridging clinical study can depend on the extent of differences between presentations, existing data packages, and the stage of the product development. Design of a bridging clinical study should be based on the characteristics of a biological product and should be aimed at detecting the relevant differences between presentations. Single-dose comparative pharmacokinetics in normal healthy volunteers is the most common bridging clinical study design. Covariates like body weight and injection site should be considered during the design of these studies. The impact of the different user interfaces of presentations should also be considered.