Clinical Trials for Medicines: Ending a Clinical Trial in the UK

1. Legal Status and Scope

This guidance explains the process for ending a clinical trial under the Medicines for Human Use (Clinical Trials) Regulations, as amended by the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025. These amendments will come into force on 28 April 2026; until then, the guidance remains in draft to help sponsors prepare for implementation of the new regulations.
Source: Clinical trials for medicines: ending a clinical trial - GOV.UK

2. Notifying Authorities That a Trial Has Ended

2.1 End of Trial Notification Requirements

Per regulation 27 of the Clinical Trials Regulations, the sponsor must provide written notice that a clinical trial has ended to:

• the licensing authority, and
• the ethics committee that reviewed the trial.
  The timing depends on how the trial ended:
• 90 calendar days after a trial ends according to the protocol;
• 15 calendar days after a trial is terminated before the protocol-specified end.
  Source: Clinical trials for medicines: ending a clinical trial - GOV.UK

2.2 Notification Process

If the trial was approved through a combined review process, the end of trial declaration form should be submitted via the Integrated Research Application System (IRAS).
If approved through separate applications, submit the end of trial declaration to the licensing authority via MHRA Submissions and to the ethics committee by email.
After submission, an acknowledgement will be issued by email or through IRAS (for combined review).
Source: Clinical trials for medicines: ending a clinical trial - GOV.UK

3. Publication of Results

Under regulation 25(2) of the Clinical Trials Regulations, within 12 months of the day after the trial’s conclusion, the sponsor must:

• Publish a summary of the results in the public registry where the trial was registered; and
• Offer an accessible summary of the results to trial participants.
  Sponsors may apply for a deferral or waiver of one or both requirements before the deadline, providing justification. Phase I trials may be eligible for automatic deferral arrangements.
  Source: Clinical trials for medicines: ending a clinical trial - GOV.UK

4. Lapse of Clinical Trial Approval

Under regulation 26, if no participants have been recruited to a clinical trial within two years of approval, the trial approval will lapse.
The licensing authority monitors approval status and, if it lapses, will contact the sponsor by email to confirm this. The sponsor must then submit an end of trial notification.
To help enable this monitoring, sponsors must notify authorities of the date the first participant was recruited via a modification of important details.
Source: Clinical trials for medicines: ending a clinical trial - GOV.UK

5. Summary

Overall, formally ending a clinical trial in the UK involves:

• submitting notification within specified timelines;
• publishing trial results within a regulated timeframe; and
• handling circumstances where trial approval lapses due to lack of recruitment.
  Adhering to these steps supports regulatory compliance and transparency of clinical research results under UK law.
  Source: Clinical trials for medicines: ending a clinical trial - GOV.UK