International audienceWhile Advanced Therapy Medicinal Products (ATMPs), a European legal classification of medicinal products based on genes, cells and tissues, raise specific quality issues, the latter are particularly acute in the context of clinical trials of ATMPs. In comparison to more traditional medicinal products, ATMPs have been subject to specific regulatory provisions in the European Union (EU) since 2007. In addition, many new guidelines have also been adopted to consider the issues raised by ATMPS. Most importantly for investigational ATMPs, the European Commission has adopted and published Guidelines on Good Clinical Practice specific to ATMPs in 2019. Not only are these guidelines targeting ATMPs, they also have a dedicated...