If your biotech is in Phase 3, your team already produces a DSUR every year. What changes at approval is that the DSUR does not simply stop — it is replaced by a different periodic report with a different scope, a different reference document, and a different regulatory clock.
The short answer: DSUR covers a product during clinical development. PBRER is the international format for periodic post-authorisation benefit-risk reporting. PSUR is what the EU legally requires post-authorisation — and in the EU, the PSUR is a PBRER. They are not three competing documents; they are two life-cycle stages, with the EU using the PBRER format to satisfy its PSUR obligation.
This guide explains what each report is, which one applies at each stage, and what a Phase 3 biotech should put in place before its first post-marketing reporting cycle.
The One-Paragraph Distinction
- DSUR — Development Safety Update Report. An annual safety report for products under clinical investigation. Defined by ICH E2F. It exists to keep regulators and ethics committees informed about the evolving safety profile of an investigational product during trials.
- PBRER — Periodic Benefit-Risk Evaluation Report. The internationally harmonised format for periodic post-authorisation safety and benefit-risk reporting. Defined by ICH E2C(R2).
- PSUR — Periodic Safety Update Report. The EU legal term for the post-authorisation periodic report. Under GVP Module VII, the EU PSUR is prepared in the PBRER format. In practice, "PSUR" and "PBRER" describe the same EU document.
The clean way to hold it in your head: DSUR is the development-stage report. PSUR/PBRER is the marketed-stage report. The transition happens at marketing authorisation.
Side-by-Side Comparison
| Factor | DSUR | PSUR / PBRER |
|---|---|---|
| Life-cycle stage | Clinical development (investigational) | Post-authorisation (marketed) |
| Governing guideline | ICH E2F | ICH E2C(R2) / GVP Module VII |
| Primary purpose | Inform regulators and ethics committees of evolving trial safety | Periodic benefit-risk re-evaluation of the marketed product |
| Reference safety document | Investigator's Brochure (IB) | Reference safety information (e.g., the relevant section of the company core data sheet) |
| Data sources | Clinical trial data, plus relevant non-trial data | Worldwide post-marketing exposure, spontaneous reports, trials, literature |
| Reporting cycle | Annual, from the Development International Birth Date (DIBD) | Set by the EU reference dates list (EURD list) — typically 6-monthly early, lengthening over time |
| Who receives it | Competent authorities, ethics committees | EMA / national competent authorities; assessed under the PRAC single assessment where applicable |
| Benefit-risk focus | Emerging safety signals during development | Formal, structured benefit-risk evaluation |
When Each Report Applies — The Transition at Approval
This is the part that most often surprises first-time MAHs.
During Phase 3: You produce a DSUR annually, anchored to the Development International Birth Date. Your reference document is the Investigator's Brochure.
At marketing authorisation: The product now has an International Birth Date (IBD) and a marketing authorisation. Your periodic reporting obligation shifts from DSUR to PSUR. But two things are not automatic and catch teams out:
- The DSUR does not necessarily stop immediately. If the product remains under active clinical investigation in any indication (line extensions, paediatric studies, new indications), DSUR obligations for the investigational use can continue in parallel with PSUR obligations for the authorised use. A product can legitimately be in both worlds at once.
- PSUR timing is set by the EURD list, not by your approval date. The EU reference dates list (EURD list) dictates your data lock point and submission deadline. You do not get to pick the cycle. Your first PSUR data lock point may fall sooner than a team assumes if they anchor planning to the authorisation date.
Practical takeaway for Phase 3 planning: Before approval, identify your product's expected EURD entry and the active-substance grouping it falls into. This tells you your first PSUR data lock point — and therefore when the medical writing, case data, and benefit-risk analysis must be ready.
What Goes Into a PSUR / PBRER — The Required Structure
The PBRER format under ICH E2C(R2) has a defined section structure. The substantive sections a Head of PV should make sure are resourced:
- Worldwide marketing authorisation status
- Actions taken for safety reasons during the interval
- Changes to reference safety information
- Estimated exposure and use patterns — patient exposure data is often the weakest part of a first PSUR because biotechs underinvest in exposure estimation
- Data in summary tabulations — interval and cumulative case data
- Signal evaluation — new, ongoing, and closed signals
- Benefit evaluation, risk evaluation, and integrated benefit-risk analysis
- Conclusions and actions
The benefit-risk integration section is where a PSUR is genuinely assessed. A document that tabulates cases but does not deliver a coherent benefit-risk argument is the most common quality weakness PRAC assessors flag.
For support on periodic report authoring, see our Overview of PV medical writing.
DSUR vs PSUR: Common Mistakes Biotech Teams Make
- Assuming the DSUR "becomes" the PSUR. It does not. They are different documents with different reference safety information and different data scopes. The PSUR is built fresh in the PBRER format.
- Anchoring the first PSUR to the approval date. The EURD list governs timing. Teams that plan around the approval date sometimes discover the first data lock point is only a few months away.
- Underestimating exposure data. Post-marketing exposure estimation requires sales/distribution data feeds that did not exist during trials. Set this data pipeline up before the first reporting interval ends, not after.
- No reference safety information ready. The PSUR needs a defined reference safety document. If the company core data sheet is not finalised, the periodic report has no anchor.
- Treating the PSUR as a clerical tabulation. Assessors evaluate the integrated benefit-risk argument. The report needs a medical author who can write that argument, not only collate appendices.
- Late QPPV involvement. The QPPV is accountable for the PV system that produces these reports. Bringing the QPPV in only to sign the finished PSUR is too late.
Key Takeaways
- DSUR = development stage. PSUR/PBRER = marketed stage. In the EU, the PSUR is written in the PBRER format — they are the same document.
- The transition happens at marketing authorisation, but the DSUR may continue in parallel if the product is still under clinical investigation.
- PSUR timing is dictated by the EURD list, not your approval date — confirm your first data lock point early.
- The integrated benefit-risk evaluation is the section that matters most to assessors.
- A Phase 3 biotech should have reference safety information, an exposure-data pipeline, and a periodic report author identified before the first post-marketing interval ends.
Frequently Asked Questions
Is a PSUR the same as a PBRER?
In the EU, effectively yes. The PBRER is the internationally harmonised format defined by ICH E2C(R2). The EU's legal term for the periodic post-authorisation report is "PSUR," and GVP Module VII specifies that the EU PSUR is prepared in the PBRER format. So an EU PSUR is a PBRER. The two terms are used interchangeably in EU practice — "PSUR" is the legal/regulatory term, "PBRER" describes the format.
Does the DSUR stop when a product is approved?
Not automatically. The DSUR covers investigational use. If the product is still under active clinical investigation — for example, ongoing trials in new indications, line extensions, or paediatric studies — DSUR obligations for that investigational use continue alongside the PSUR obligations for the authorised use. Only when there is no remaining clinical development does the DSUR obligation end.
When is my first PSUR due after EU approval?
Your first PSUR data lock point and submission deadline are determined by the EU reference dates (EURD) list, which groups products by active substance. The cycle is typically more frequent in the early post-authorisation period (often 6-monthly) and lengthens as the safety profile matures. Confirm your product's EURD entry before approval — the first data lock point can fall sooner than teams expect if they plan around the authorisation date instead.