Redefining Risk Stratification and Endpoints for Clinical Trials in Kidney Transplantation. Rationale and Methodology of Proposals Submitted to the European Medicines Agency by the European Society for Organ Transplantation

The European Society for Organ Transplantation (ESOT) submitted a Broad Scientific Advice request to the European Medicines Agency (EMA) in 2018, to explore whether updating guidelines on clinical trial endpoints would encourage innovations in kidney transplantation research, thereby improving long-term outcomes for allograft recipients. The request was refined collaboratively by the EMA and ESOT, with the EMA issuing a final response in December 2020. This Transplant International special issue explores the topics that were the focus of these interactions between the EMA and ESOT. Articles explore the current issues and dilemmas in kidney transplantation, primarily relating to unclear or outdated risk stratification and markers of transplantation success, although several potential improvements for outcomes assessment are also suggested. Discussions between the EMA and ESOT and recommendations are summarized, in the hope that this project will generate further discussion eventually generating a consensus on clinical trial endpoints and risk stratification, increase the quality of research in transplantation medicine, and improve long-term outcomes for kidney transplant recipients.