Clinical trials for screening tests of a drug candidate take place at the very early clinical development, i.e. Phase I clinical study. The aim of such studies is to assess drug candidate safety, its actual fate in human body after administration (PK/PD data, metabolite identification, mechanism of elimination and excretion, etc.), its tolerance threshold (dose escalating) and its adverse effects. All of those make Phase I clinical trials crucial to the drug development process; Isabelle Decorte from Synerlab proposes that designing and executing such clinical studies needs much preparation and planning.