MHRA Issues Draft Guidance on Amended UK Clinical Trials Regulations

On 25 June 2025, the Medicines & Healthcare products Regulatory Agency (MHRA) published draft guidance to support the operation of the amended United Kingdom (UK) clinical trials regulations, which become effective on 28 April 2026. At present, the guidance is in draft and is provided to support sponsors preparing for the new arrangements. Feedback is invited until 30 July 2025 > (Feedback Survey).

The available guidance is sub-divided into:

• applying for approval (including an extension to the time allowed for responding to requests for further information),
• requirements for expert advice,
• labelling requirements for investigational medicinal products (IMPs) and non-IMPs (NIMPs),
• notifiable trials (certain trials deemed to be low risk and subject to automatic authorisation by MHRA),
• maintaining and ending a clinical trial,
• transitional arrangements (which defines ‘old rules’ and ‘new rules’ clinical trials in terms of applicability of the revised regulations),
• safety reporting,
• NIMPs.

Some aspects of this guidance relate to systems already in place, for example the combined review procedure [underpinned by the new part of the Integrated Research Application System (IRAS)] which now becomes mandatory, save in exceptional circumstances. Other changes reflect the European Union (EU) Clinical Trials Regulation (CTR); for example a clinical trial approval will now lapse two years after the approval date if no subjects are recruited and the sponsor has not requested an extension, and the introduction of non-substantial modifications requiring notification (modification of an important detail).

Of note, the regulations introduce Route A and Route B substantial modifications, where Route B effectively allows the MHRA to rely, provided certain criteria are satisfied, on assessment of the same substantial modification in the EU, European Economic Area, or United States of America, and so provide automatic approval. Another significant update is that publishing a summary of the trial results becomes mandatory, as does offering an accessible results summary to trial subjects.

Navigating the amended UK regulations can pose challenges for sponsors new to clinical trials in the UK, or to the EU clinical trials environment in general. If you have questions or face challenges with your clinical trial applications, tranScrip regulatory and clinical experts are at the ready to guide and advise you; we are ready to expedite your development programmes and bring effective medicines to patients across the UK, EU and beyond.