Serious Breach
What a definition is not
A definition is SPEQ’s plain-language decode of how a term is used in practice, cited to the documents that define it. It is a practitioner reference, not legal or regulatory advice, it does not replace the definition in the source, and where a regulator’s wording differs the regulator’s wording governs.
A serious breach is a breach of GCP or the trial protocol likely to affect to a significant degree the safety or rights of a trial participant, or the reliability and robustness of the data generated. Under the EU Clinical Trials Regulation it must be reported to the competent authorities within a defined short timeframe of the sponsor becoming aware of it. It is a high-severity escalation above an ordinary protocol deviation, defined by potential consequence rather than by category of error.
The concept forces a judgment call: not every deviation is a serious breach, but any deviation — or systemic failure — that meets the "significant degree" test for safety, rights, or data reliability crosses the threshold and carries a mandatory, time-bound notification duty.
Sponsors typically define serious-breach identification and reporting in an SOP, because the clock starts on awareness and the assessment must be made quickly and documented.
- —Threshold = significant effect on safety/rights OR data reliability
- —Time-bound mandatory report to competent authorities
- —A severity escalation above routine protocol deviation
- —Requires a defined SOP so the awareness clock is met
EU Clinical Trials Regulation (EU) No 536/2014 serious-breach reporting requirements; corresponding UK serious-breach requirements.
Frequently asked questions
What is Serious Breach?
A serious breach is a breach of GCP or the trial protocol likely to affect to a significant degree the safety or rights of a trial participant, or the reliability and robustness of the data generated. Under the EU Clinical Trials Regulation it must be reported to the competent authorities within a defined short timeframe of the sponsor becoming aware of it. It is a high-severity escalation above an ordinary protocol deviation, defined by potential consequence rather than by category of error.
Which regulations cover Serious Breach?
EU Clinical Trials Regulation (EU) No 536/2014 serious-breach reporting requirements; corresponding UK serious-breach requirements.