On statistical evaluation for interchangeability of biosimilar products

• Published in: GaBI Journal Vol. 11; no. 2; p. 1
• Main Authors: Li, Yuqi, Chow, Shein-Chung
• Format: Journal Article
• Language: English
• Published: Generics and Biosimilars Initiative 01.06.2022
• Subjects: Biological products; Drug approval; Innovations; Physiological aspects
• ISSN: 2033-6403

A biosimilar product is a biological product which is highly similar to an existing reference product in structure and function and has no clinical meaningful difference in terms of safety, purity or potency. By the Biologics Price Competition and Innovation Act of 2009 (BPCI Act), the Food and Drug Administration (FDA)-approved interchangeable biosimilar products can be expected to produce the same clinical result as the reference product in any given patient. In practice, although it is impossible to demonstrate that a proposed interchangeable biosimilar can meet this criterion due to differences in patient physiological conditions and subtle differences between products, it is possible to demonstrate that the interchangeable biosimilar can produce the same clinical result as the reference product in any given patient with certain assurance. In this article, we derived a statistical method, which we refer to as an interchangeability index, for evaluation of the interchangeability of a biosimilar product with a certain statistical assurance. The proposed method was evaluated via extensive simulation studies. The results indicate that the proposed interchangeability index could be a good indication for biosimilar interchangeability when the mean clinical results with moderate variability due to subject by product produced by test and reference product are within a narrow effect equivalence limit. Keywords: biosimilars, interchangeability, logarithmic transformation, statistical evaluation