Clinical trials for medicines: ending a clinical trial
Source: gov.uk (2025-10-01)

Guidance on the process for ending a clinical trial.

This guidance accompanies the Medicines for Human Use (Clinical Trials) Regulations 2004 (“the Clinical Trials Regulations”), as amended by the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 (https://www.legislation.gov.uk/uksi/2004/1031/contents).

These amendments come into force on 28 April 2026.

Until this date, this guidance is in draft and should only be used to support sponsors in preparing for the implementation of the new regulations. Please see Clinical trials for medicines: apply for authorisation in the UK (https://www.gov.uk/guidance/clinical-trials-for-medicines-apply-for-authorisation-in-the-uk) and Clinical trials for medicines: manage your authorisation, report safety issues (https://www.gov.uk/guidance/clinical-trials-for-medicines-manage-your-authorisation-report-safety-issues) for the guidance that should be followed prior to 28 April 2026.

Legal status of this guidance

The following guidance accompanies the Medicines for Human Use (Clinical Trials) Regulations 2004 (https://www.legislation.gov.uk/uksi/2004/1031/contents) (“the Clinical Trials Regulations”), as amended by the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 (https://www.legislation.gov.uk/uksi/2025/538).. These amendments come into force on 28 April 2026. For assistance in determining whether a clinical trial is within the scope of these Regulations, see the Is it a clinical trial of a medicinal product? (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/949145/Algorithm_Clean__1_.pdf) algorithm.

Part 2 of Schedule 1 to the Clinical Trials Regulations requires that the investigator and sponsor (https://www.hra.nhs.uk/planning-and-improving-research/research-planning/roles-and-responsibilities/) have regard to all relevant guidance with respect to commencing and conducting a clinical trial. Investigators and sponsors (and any individual or organisation that the sponsor delegates trial-related activities to) must, therefore, ensure that they are fully aware of the information within this guidance and act accordingly to achieve and maintain regulatory compliance.

Notifying the authorities that a trial has ended

Timelines for notification

Per regulation 27 of the Clinical Trials Regulations, the sponsor must provide written notice to the licensing authority that a clinical trial has ended (and this notice should also be provided to the ethics committee). This refers to the global end of the trial.

The notice must be provided within:
- 90 calendar days, where a clinical trial ends in accordance with the date or event specified in the protocol
- 15 calendar days, where a clinical trial is terminated prior to the date or event specified in the protocol
While local end of trial declarations can optionally be submitted, they will not be reviewed by the licensing authority and relevant safety updates and substantial modifications must continue until the global end of trial notification is received, unless agreed otherwise via a substantial modification.

Notification process

If the clinical trial that has ended was:
- approved through the combined review process, submit the end of trial declaration form through IRAS. Guidance on using IRAS to submit an end of trial declaration form can be found in the Step-by-step guide to using IRAS for combined review (https://www.hra.nhs.uk/planning-and-improving-research/policies-standards-legislation/clinical-trials-investigational-medicinal-products-ctimps/combined-ways-working-pilot/step-step-guide-using-iras-combined-ways-working-cwow/#usm)
- approved through separate applications to the licensing authority and the ethics committee, submit the end of trial declaration form to the licensing authority via MHRA Submissions (https://www.gov.uk/guidance/register-to-make-submissions-to-the-mhra#gaining-access-to-mhra-submissions) and to the ethics committee via email
After submission, an acknowledgement will be issued by email (and through IRAS for combined review trials). No acknowledgement will be issued if the submission was related to the local end of trial.

For trials terminated in accordance with the protocol, details of where the results have been published in a public registry should be provided to the licensing authority and ethics committee within 12 months of trial completion (except for some paediatric trials involving the use of authorised medicinal products, see below).

For trials terminated prior to the date or event specified in the protocol:
- the end of trial declaration will be reviewed by the licensing authority and requests for additional information may be raised
- once the licensing authority has sufficient information, the sponsor will be informed that the end of trial declaration has been accepted
- details of where the results have been published should be provided to the licensing authority and ethics committee within 12 months of trial completion (except for some paediatric trials involving the use of authorised medicinal products, see below).
Please note that where a deferral to the requirement to publish the results is in place, the sponsor should still provide a summary of the trial results to the licensing authority within 12 months of trial completion (which will be kept confidential). This may be required as a condition of approving the deferral.

If the trial is sponsored by the holder of a UK marketing authorisation and involves the use of that authorised medicinal product use in a paediatric population, the results must be submitted to the licensing authority within the 6 months beginning with the day on which the trial ended. The details of where the results have been published should still be submitted to the ethics committee within 12 months of trial completion.

Please note that once the global end of trial notification has been received by the authorities, it is not possible to submit any further clinical documents other than a summary of results (if the sponsor chooses to submit this).

Publication of results

Under regulation 25(2) of the Clinical Trials Regulations, within 12 months from the day after the conclusion of the trial, the sponsor must:
- publish a summary of the results in the same public registry that the trial was registered in (https://www.gov.uk/guidance/clinical-trials-for-medicines-apply-for-approval-in-the-uk#registration-of-a-clinical-trial) (per regulation 25(2)(a))
- offer an accessible summary of the results to the trial participants (per regulation 25(2)(b))
At any point before the 12-month deadline, sponsors may apply to the HRA for a deferral or waiver to one or both requirements, explaining why this is needed. Phase I clinical trials may be eligible for an automatic deferral of up to 30 months from the conclusion of the trial, which may be further extended on request.

See detailed guidance from the HRA on the requirement to publish the results of a clinical trial (https://www.hra.nhs.uk/planning-and-improving-research/policies-standards-legislation/clinical-trials-investigational-medicinal-products-ctimps/clinical-trial-regulations-reform/guidance-on-changes-to-the-clinical-trials-regulations/research-transparency-requirements-for-clinical-trials/).

Under regulation 17(2)(b) of the Clinical Trials Regulations, the licensing authority can take into account any outstanding failures to comply with regulation 25(2)(a) (unless a deferral or waiver has been approved by the ethics committee) when assessing future applications by the same sponsor.

Lapse of clinical trial approval

Procedure

Under regulation 26 of the Clinical Trials Regulations, a clinical trial approval will lapse two years from the date on which the trial was approved if no participants have been recruited (i.e. have signed the consent form) to take part in the UK trial.

The licensing authority will monitor the status of the trial’s approval. If the approval lapses, the sponsor will be contacted via email to confirm this. The sponsor will then need to submit an end of trial notification (https://www.gov.uk/guidance/clinical-trials-for-medicines-ending-a-clinical-trial#notifying-the-authorities-that-a-trial-has-ended).

Applying for an extension

Sponsors can apply to the authorities for an extension of this period by emailing xxx@xxx.xx, explaining both why the extension is needed and the length of the proposed extension.

The authorities can grant:
- an initial extension of up to 36 months beyond the lapse date
- a further extension of up to 24 months, which must be requested (through the same process) before the previous extensions ends
The authorities will respond to extension requests via email within 30 calendar days or, if the trial is awaiting approval, at the same time as the outcome of the application for clinical trial approval is issued.