Implementation of the EU Clinical Trials Regulation and CTIS in Europe: a Comparative Regulatory Analysis (2013-2024)

Europe's relative share of global clinical trial activity declined between 2013 and 2024 during a period that encompassed implementation of the EU Clinical Trials Regulation (CTR) and the Clinical Trials Information System (CTIS).

To examine clinical trial activity and early implementation of the CTR and CTIS in Europe, with particular attention to regulatory harmonisation, operational implementation, and institutional capacity.

We conducted a comparative regulatory and policy analysis using secondary aggregate data from international registries, regulatory and institutional documents, sectoral reports, and peer-reviewed literature. The United States was used as the principal external comparator, while Spain and Germany provided contrasting European cases. Analyses were descriptive and no trial-level registry merging, inferential modelling, or causal analysis was performed.

The CTR and CTIS established a common legal framework, a single digital submission pathway, and coordinated assessment procedures across the EEA. Early implementation evidence nevertheless indicates substantial administrative workload and persistent operational heterogeneity across Member States and sponsor types. Europe's declining relative global position reflected differential international growth rather than absolute contraction, with variation by development phase and therapeutic area. Divergent trajectories in Spain and Germany under the same European regulatory framework further highlighted the relevance of country-specific institutional and operational factors.

The CTR and CTIS represent a major restructuring of European clinical trial governance, but regulatory harmonisation alone appears insufficient to ensure operational convergence or long-term competitiveness. Their practical impact depends on institutional capacity, digital readiness, regulatory expertise, and national implementation.