1. Ethnic sensitivity assessments in biosimilar monoclonal antibodies clinical development programmes: necessary or not?

Abstract-

Ethnic sensitivity assessments in the form of bridging pharmacokinetics (PK) studies are often needed for biosimilar monoclonal antibodies (mAbs) to meet regulatory requirements in regions like East Asia. However, mAbs exhibit properties that make them less likely to be affected by ethnic differences, as they do not undergo traditional drug-related metabolism like liver and gut metabolism, unlike small molecule drugs. Current literature indicates that ethnicity generally does not influence the PK, pharmacodynamics (PD), safety, and efficacy of most mAbs. For instance, the recommended doses for most mAbs are similar or have no difference between non-Japanese and Japanese patients. Despite these findings, dedicated Ethnic Sensitivity Studies (ESSs) are still routinely required for approval in countries/territory of East Asia such as Japan, South Korea, China and Taiwan. This article argues that such requirements should be reconsidered based on the available data on the reference drug rather than being a default obligation in biosimilar development of mAbs. ESSs are not only questionable but also costly and time-consuming for biosimilar mAbs. Eliminating such a requirement could accelerate the development of biosimilar drugs while maintaining safety and efficacy standards, facilitating access to these life-saving therapies across the globe.