Final Thoughts

Effective retention of the Investigator Site File (ISF) is important to maintain clinical trial integrity, ensure regulatory compliance, and support inspection readiness. While the Principal Investigator holds the primary responsibility for managing the ISF at the site, successful retention is a collaborative effort involving sponsors, monitors, archivists, and quality assurance teams.

With regulators such as the MHRA, EMA, and FDA setting clear ISF retention requirements now commonly aligned around a 25-year period it is important that both sponsors and investigators ensure that these timelines are met.

In parallel, clearly defining and documenting roles and responsibilities related to ISF management is essential for ensuring accountability and compliance.

By implementing best practices such as early role definition, thorough training, contingency planning for turnover, continuous auditing, and standardisation of documentation clinical trial teams can ensure their ISFs remain complete, accessible, and inspection-ready throughout the entire retention period. It is also worth noting that the CDISC ISF Reference Model V1 is currently under public review but there is no doubt it will provide valuable guidance, not only on roles and responsibilities but also on best practices for managing and retaining ISFs.