What UK DSUR Transparency Expectations Mean for Sponsors

The Development Safety Update Report (DSUR) is one of the most important annual safety deliverables during clinical development. It provides regulators with an integrated view of the safety profile of an investigational medicinal product (IMP), including cumulative knowledge, interval safety information, emerging risks and the sponsor’s ongoing assessment of participant safety.

For sponsors submitting DSURs in the United Kingdom, annual safety reporting also needs to reflect UK-specific requirements around safety oversight and transparency. These requirements are designed to help regulators understand not only what safety information was identified during the reporting period, but also how that information was evaluated, managed and acted upon.

The UK regulatory framework for clinical trials changed on 28 April 2026, when the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 took full effect. The amended framework strengthens the emphasis on participant protection, proportionate regulation and transparency, while introducing more explicit requirements around how sponsors demonstrate ongoing safety oversight in annual safety reporting.

Why transparency matters in DSUR preparation

ICH E2F provides a common standard for periodic safety reporting on drugs under development. In the UK, the amended Clinical Trials Regulations add further emphasis to demonstrating the safety review and oversight processes behind the annual report.

Under Regulation 35, sponsors are required to provide an annual report on the safety of participants receiving each IMP tested in UK clinical trials. Current MHRA guidance confirms that this annual safety report should be submitted in the form of a DSUR.

The report must include records and evaluation of serious adverse reactions and serious adverse events occurring during the reporting year, as well as relevant measures taken in response to identified risks. Importantly, sponsors must also describe how safety concerns have been assessed and managed, the overall safety profile of the IMP and the processes used to monitor that profile.

This reinforces the role of the DSUR as more than a static annual document. A strong DSUR should demonstrate an active safety surveillance process and show that the sponsor has maintained appropriate oversight throughout the reporting period, rather than simply assembling information at the end of it.

What changed under the UK Clinical Trials Regulations in 2026?

The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 introduced a modernised regulatory framework for clinical trials in the UK, which took full effect on 28 April 2026.

The reforms are intended to strengthen participant protection while supporting a more streamlined, proportionate and transparent approach to clinical trial regulation.

For annual safety reporting, the amended requirements place greater emphasis on demonstrating how safety information has been interpreted and managed. The DSUR should provide a clear picture of:

• serious adverse reactions and serious adverse events occurring during the reporting year, including suspected unexpected serious adverse reactions (SUSARs);
• the evaluation of these events, including consideration of changes to the overall risk-benefit profile;
• measures taken to investigate, minimise or prevent identified risks;
• how serious and non-serious safety concerns have been assessed and managed;
• the overall safety profile of the IMP; and
• the processes adopted by the sponsor to monitor that safety profile.

These changes reinforce the importance of maintaining clear, traceable safety evaluation and decision-making processes throughout the reporting period.

What sponsors should be able to demonstrate

To support transparent and defensible annual safety reporting, sponsors should be able to demonstrate:

Clear data provenance: Where safety data came from, how they were captured and how they were reconciled for inclusion in the report.

Documented safety review: How safety information was assessed during the reporting period, including cumulative review, medical evaluation and consideration of any changes in the overall risk-benefit profile.

Transparent signal status: Whether safety signals were newly identified, ongoing, closed or still under evaluation, with sufficient context to support their classification.

Documented management of safety concerns: How identified safety concerns were assessed, what actions or mitigation measures were taken where appropriate, and how these decisions contributed to the ongoing assessment of the IMP’s overall safety profile.

Appropriate governance: How safety discussions, escalation pathways, safety meetings, protocol amendments, urgent safety measures or other risk mitigation activities were documented.

Consistency across documents: How DSUR content aligns with the Investigator’s Brochure, protocol, informed consent materials and emerging Risk Management Plan considerations.

Common challenges for sponsors

DSUR preparation can become challenging when source data are dispersed across clinical, pharmacovigilance, medical review, regulatory and partner systems. It can also be difficult when safety decisions are made throughout the year but are not documented in a way that can easily be translated into the annual report.

Sponsors may also struggle to present safety concern and signal evaluation clearly. A signal that is closed, ongoing or awaiting further data should be described in a way that is concise, transparent and clinically meaningful.

The updated UK requirements make this underlying documentation particularly important. Sponsors need to be able to demonstrate not only the conclusions reached, but also how relevant safety concerns were assessed and managed throughout the reporting period.

Tables and structured summaries can support this process, but only when they are underpinned by robust review, clear governance and consistent terminology.

How PrimeVigilance supports DSUR transparency

PrimeVigilance supports sponsors with DSUR preparation that is structured, transparent and aligned with global and region-specific requirements.

Our approach connects aggregate report writing with medical review, signal evaluation, safety data analysis, quality control and cross-functional document alignment.

Support may include DSUR planning, data request coordination, safety data review, signal status tabulation, cumulative safety assessment, UK-specific content development, quality review and preparation of clear, submission-ready report content.

The objective is to help sponsors produce DSURs that are not only complete, but defensible: reports that clearly demonstrate how safety information was monitored, evaluated and managed throughout the reporting period.

Conclusion

With the amended UK Clinical Trials Regulations now in effect, transparent and well-documented safety oversight has become even more important.

Sponsors should be prepared to demonstrate not only what safety information was identified, but how safety concerns were evaluated, managed and incorporated into the ongoing assessment of the IMP’s overall safety profile.

For DSUR preparation, this reinforces the value of strong governance, traceable safety decision-making and clear alignment between source data, safety evaluation and the final report.

PrimeVigilance helps sponsors prepare DSURs that reflect disciplined safety governance, clear safety evaluation and current UK and global reporting requirements.

Preparing a DSUR for UK submission or looking to strengthen your annual safety reporting process? Speak to PrimeVigilance about transparent, submission-ready DSUR support.

 

Author

Dhiraj Rajak, Medical Writer I

 

Recommended source links

• The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025
• Clinical trials for medicines: collection, verification and reporting of safety events – GOV.UK
• ICH E2F – Development Safety Update Report: https://database.ich.org/sites/default/files/E2F_Guideline.pdf
• MHRA/Health Canada – DSUR transparency guidance: https://www.gov.uk/guidance/clinical-trials-for-medicines-manage-your-authorisation-report-safety-issues