Abstract
An increasing number of innovative oncology monoclonal antibodies (mAbs) have been introduced into the global market, and biosimilar versions have now also been approved in Europe. Being complex to develop and difficult to manufacture, the biosimilar is a drug similar but not identical in physicochemical characteristics, efficacy, and safety to an original biological drug already approved in the European Union, for which marketing exclusivity rights have expired. Generally, the safety monitoring of biosimilars follows the same requirements that apply to all biologicals, even if specific pharmacovigilance measures exist and some of them are still being debated. The manufacturing process, immunogenicity, traceability, and extrapolation of indication are keywords which may impact on the achievement of additional knowledge about the safety of a biosimilar mAb. In this article, we aim to discuss elements that play a central role in the pharmacovigilance legislation of biosimilar mAbs.