Pharmaceutical Medicine

, Volume 33, Issue 5, pp 379–388 | Cite as

Design and Analysis of Biosimilar Switching Studies

  • Shein-Chung ChowEmail author
  • Sang Joon Lee
Leading Article


Under the US Biologics Price Competition and Innovation Act of 2009 (BPCI), the development of biosimilar (test) products provides affordable alternatives to innovative biological (reference) products for the general patient population. However, in practice, as the number of biosimilar products available on the market increases, whether these biosimilars can be used interchangeably is a concern. Thus, using switching studies to evaluate the risk of reduced efficacy and increased safety concerns with and without switch(es) in the development of biosimilar products is of interest. For this purpose, the US FDA, in its recent draft guidance on interchangeability, suggested using a 2 × 2 crossover design (RT, RR) to evaluate a single switch and (RTR, RRR) and (RTRT, RRRR) to evaluate multiple switches. In this article, we examine the statistical properties, analyses, and sample size requirements of these switching study designs. We also investigate the relative efficiencies of these switching designs compared with the complete  n-of-1 trial design.


Compliance with Ethical Standards


No funding was received for the preparation of this research article.

Conflict of interest

Dr. Shein-Chung Chow and Dr. Sang Joon Lee have no conflicts of interest that are directly relevant to the content of this article.

Supplementary material

40290_2019_296_MOESM1_ESM.pdf (185 kb)
Supplementary material 1 (PDF 184 kb)


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Biostatistics and BioinformaticsDuke University School of MedicineDurhamUSA
  2. 2.Celltrion, IncIncheonRepublic of Korea

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