In the United States, when an innovative (brand-name) drug or biological product is going off patent, pharmaceutical and/or generic/biotech companies may file an abbreviated new drug application (ANDA) for approval of generic drugs FDA [1] or a Biologic License Application (BLA) for approval of biosimilar products of the brand-name drug product [2]. As more and more generic drugs (biosimilar products) become available in the marketplace, it is a public concern that (i) whether the quality, safety, and/or efficacy of these generic drugs (biosimilar products) work as well as that of the brand-name drug product and (ii) whether these generic drugs (biosimilar products) can be used interchangeably among generic drugs (biosimilar products) and the brand-name drug product. This article provides a comprehensive review of the concept, criteria, design, and analysis method for assessment of drug interchangeability of generic drugs and biosimilar products. In addition, some challenging issues that are commonly encountered when assessing drug interchangeability are discussed.
Author(s): Shein-Chung Chow, and Yuqi Li