From January 31 2025, all clinical trials in the European Union (EU), including ongoing trials that were approved under the previous legal framework, the Clinical Trials Directive (CTD), are governed by the Clinical Trials Regulation (CTR). This marks the end of a three-year transition period, during which more than 5,000 clinical trials were transitioned to the CTR through submission to the Clinical Trials Information System (CTIS), the single-entry point for sponsors and regulators for the submission and assessment of applications for clinical trials in the EU.