The following guideline is to be seen in connection with Regulation (EU) No. 536/2014 on clinical trials on medicinal products for human use, and repealing Directive 2001/20/EC, which came into force on June 20, 2014. Since clinical trials can be designed as multi-centre studies potentially involving different member states, it is the aim of this guideline to define harmonised requirements for the documentation to be submitted throughout the European Union.