A Development Safety Update Report (DSUR) is an annual safety report for an investigational medicinal product in clinical development. It summarises the safety information available during a reporting period and assesses whether the benefit-risk profile within the development programme has changed. In the EU, the DSUR is an established element of safety reporting for clinical trials and helps sponsors keep authorities and Ethics Committees consistently informed.
Objectives and core components of a DSUR
The DSUR connects operational safety data with an overarching medical assessment. It is deliberately structured as periodic (typically annual) and supplements time-critical individual reports such as SUSARs. A good DSUR makes transparent which data basis underlies the report, which risks have been identified, and what consequences follow for further action.
- Safety data from trials: serious adverse events, discontinuation rates, laboratory and vital sign trends
- Cumulative overview: exposure (patient-years), subgroups, dose levels, particular risk groups
- Signals and risk analysis: new safety signals, potential mechanisms, class effects
- Measures: planned protocol amendments, additional safety monitoring elements, adjustments to the Investigator’s Brochure
Consistency between the DSUR, the Investigator’s Brochure (IB) and the clinical study protocol is important. In practice, this often means parallel updating of safety sections, clear version control, and traceable approvals within the quality management system.
A further practical point is the delineation of data sources: which trials fall within the scope of the DSUR (e.g. all interventional trials, specific indications, specific dosage forms)? Which data from compassionate use or named-patient programmes are taken into account? The clearer this logic is described, the better queries can be avoided during audits.
DSUR in the EU context of the Clinical Trials Regulation
With Regulation (EU) 536/2014 (Clinical Trials Regulation, CTR) and the Clinical Trials Information System (CTIS), processes for clinical trials have been harmonised. The DSUR remains a central document of ongoing safety assessment within this framework. Sponsors must ensure that reports are prepared on time, assessed internally, and submitted in line with national requirements or procedures as applicable.
In Germany, cooperation with the BfArM or PEI as well as the competent Ethics Committees is relevant, particularly where the DSUR describes significant new risks. The DSUR can then trigger a substantial amendment or make additional risk-minimisation measures necessary within the trial.
Operationally, the DSUR should be linked to defined timelines: a fixed data lock point, standardised data extraction, a documented medical review of cases, quality control, and formal final approval. Common errors include inconsistent case counts, missing follow-up of outstanding information, or an unclear rationale for why certain events were classified as clinically relevant.
Distinction from SUSAR, Annual Safety Report and PSUR
In practice, terminological confusion frequently arises. For a clean compliance set-up, roles and document types should be clearly separated:
- SUSAR: an individual, time-critical report of a suspected unexpected serious adverse reaction in a clinical trial.
- DSUR: an annual, aggregated safety assessment of an investigational medicinal product across all trials and data sources.
- PSUR/PBRER: a periodic safety or benefit-risk report for an authorised medicinal product in the post-marketing phase.
The DSUR is thus a link between operational pharmacovigilance and strategic development steering. It should not be a mere enumeration of cases, but should provide a reasoned medical interpretation.
Relevance for clinical trials
The DSUR has a direct impact on the conduct of clinical trials. It influences whether monitoring plans are adjusted, whether certain assessments are performed more frequently, or whether additional exclusion criteria are required. Training and communication with investigational sites can also be derived from DSUR findings, for example in the case of new laboratory risks or potential interactions.
From the sponsor’s and CRO’s perspective, the DSUR is also a focus area for audits and inspections. Authorities expect data from safety databases, clinical data management systems and Medical Writing to converge consistently. Typical review points include defined data lock points, traceable signal discussion, and a robust review and approval process. In projects where mediconomics combines operational trial support with Medical Writing, the DSUR is often used as an interface to align safety assessment, document control and regulatory communication.
A good DSUR also addresses common misunderstandings: not every clustering of events is automatically a safety signal; a plausible hypothesis, an examination of confounders, and, where appropriate, stratification by dose, site or population are required. This analytical reasoning should be visible in the report, even where the data situation remains limited.
Frequently Asked Questions (FAQ)
What data belong in a DSUR?
The DSUR incorporates safety data from all relevant clinical trials, where applicable from compassionate use programmes, literature data, and relevant non-clinical and CMC-related safety aspects. A traceable, consistent data basis with a defined data lock point is essential.
How does a DSUR differ from an annual safety report under national requirements?
The DSUR is an internationally harmonised format (including under ICH E2F) and is frequently used as the standard for annual safety reporting in clinical development. National requirements may involve additional submission pathways or formats, but the substantive core remains the DSUR.
What are common inspection findings relating to DSURs?
Common findings include late completion, lack of consistency with the Investigator’s Brochure, unclear risk assessments, or inadequately documented reviews. Discrepancies between reported case numbers and database extracts also frequently lead to findings.
Regulatory references
- Regulation (EU) 536/2014 (Clinical Trials Regulation): legal framework for clinical trials in the EU, including safety reporting and procedures.
- ICH E2F: guideline on the Development Safety Update Report (DSUR), structure and minimum content.
- ICH E6(R3) Good Clinical Practice: requirements for sponsor and quality processes, which also concern DSUR preparation and documentation.