ISPOR Europe 2025 highlighted a growing consensus across the RWE and HEOR communities: credible multi-country RWE depends on data harmonization, methodological alignment, and thoughtful cross-regional evidence strategies. Discussions emphasized the need for interoperable data infrastructures, transparent analytic decisions, and frameworks that enable consistent interpretation across countries and health systems.

What stood out this year was a shift from concept to practice. The session “Harmonizing and Enabling Cross-Border Real-World Evidence Studies in Europe” illustrated the real-world complexity of working with multi-country datasets—where variable definitions, coding standards, and clinical pathways continue to diverge in ways that challenge comparability. Compelling case studies illustrated how harmonizing structured and unstructured variables using a federated model can enable shared analyses while protecting patient privacy, offering a glimpse of what practical harmonization can look like at scale.

The overarching message: harmonization is not a data-cleaning exercise but a global coordination challenge that must be embedded throughout the RWE lifecycle. Landmark was pleased to contribute to this topic by presenting our work on real-world data harmonization: Best Practices Framework for Real-World Data in Regulatory & HTA Submissions: A Global Perspective.

Continued collaboration across data partners, regulators, and researchers will be key to advancing harmonized RWE at scale. Landmark is ready to support sponsors with the tools, frameworks, and methodological expertise needed to operationalize harmonization in 2026 and beyond.