The UK regulatory framework for clinical trials changed on April 28, 2026. The amended Clinical Trials Regulations introduce a more streamlined, proportionate, and transparent approach to clinical trial approvals and conduct.
For sponsors planning clinical trials of investigational medicinal products, CTIMPs, in the UK, the changes affect initial applications, review timelines, trial modifications, and transparency requirements.
A streamlined combined review
Clinical trial applications follow a combined review process. A single application and supporting documentation are submitted through the Integrated Research Application System, IRAS.
The application is reviewed in parallel by the Medicines and Healthcare products Regulatory Agency, MHRA, and a suitable Research Ethics Committee. The maximum validation period is seven calendar days, followed by an initial combined decision within 30 calendar days of validation.
If a request for further information is issued, the applicant has up to 60 calendar days to respond. A decision is then expected within 10 calendar days after the response is received.
A new pathway for lower-risk trials
The regulations introduce notifiable trials, a pathway for clinical trials that meet defined lower-risk criteria.
Eligible trials may receive automatic authorization from the licensing authority. The sponsor is responsible for assessing eligibility and documenting the justification. A completed confirmation form must accompany the application, and the cover letter must identify the submission as a notifiable trial.
Automatic authorization from the licensing authority does not allow the trial to begin on its own. A positive combined decision is still required because the Research Ethics Committee follows the same review process used for non-notifiable trials.
From amendments to modifications
Changes to an approved clinical trial are now described as modifications. They fall into three main categories:
- Substantial modifications: Changes that may substantially affect participant safety or rights, or the reliability and robustness of trial data. These are further divided into Route A and Route B.
- Modifications to an important detail: Changes communicated to the Research Ethics Committee for administrative or oversight purposes without requiring approval.
- Minor modifications: Changes that may be implemented without notifying the MHRA or Research Ethics Committee at the time of implementation.
Selecting the correct category and review route is an important part of regulatory planning.
Stronger transparency requirements
The amended regulations introduce legal transparency requirements for CTIMPs. Sponsors must register a trial in a public registry before the first participant is recruited or within 90 calendar days of approval, whichever occurs first.
Transparency activities should therefore be considered early in study planning and incorporated into the overall submission strategy.
Preparing a robust UK submission
The updated framework offers opportunities for a more efficient and proportionate review. However, submission quality remains essential.
Sponsors should ensure that documents are complete, correctly categorized, and consistent across the application package. Areas requiring particular attention include dose justification, contraception recommendations, emergency unblinding procedures, safety reporting, risk mitigation, and dose-stopping criteria. The IMP dossier should also align with supporting documents, including labeling, manufacturing authorizations, and the Qualified Person declaration.
Early preparation and a clear understanding of the UK requirements can reduce validation issues and support a smoother review.
Your link to UK regulatory support
LINK Medical supports biotech, pharmaceutical, and CRO companies throughout the clinical development chain. Our team can support with:
- UK regulatory strategy and submission planning
- Preparation and review of submission documentation
- IRAS applications and combined review submissions
- Assessment of notifiable trial eligibility
- Responses to requests for further information
- Classification and submission of modifications
- Regulatory support throughout the clinical trial lifecycle
Planning a clinical trial in the UK? Contact our Group Manager Study Start Up Hanna Tolf to discuss how our experts can support your next submission.
