UK Clinical Trials Regulations 2026:
What Sponsors Need to Know.
Summary
The UK has taken a major step toward modernizing its clinical research framework, with the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 signed into law on 10 April 2025. These changes are designed to create a more streamlined, proportionate, and transparent system.
Following a 12-month implementation period, the amended regulations will come into force on 28 April 2026.
Table of Contents
What’s changing
- Alongside the existing Combined Review pathway, the amended regulations introduce a new, more streamlined notification scheme for certain initial applications and amendments.
- Improved transparency and reporting, strengthening the expectations around openness and accountability.
- Mandatory registration of clinical trials, bringing the UK closer to EU-style transparency requirements.
- Simplified arrangements for obtaining consent in clinical trials.
- Updates to the labelling and manufacturing requirements of Investigational Medicine Products (IMPs) and Non-Investigational Medicinal Product (NIMPs).
Will this affect my clinical trial?
Clinical Trials with a last patient last visit (LPLV) after 28 April 2026 will need to comply with the new regulations.
How will this affect my clinical trial?
Clinical Trial Applications
Researchers and Sponsors will continue to submit applications through Combined Review via the IRAS portal, the integrated system for obtaining both MHRA authorization and Research Ethics Committee (REC) approval.
However, for clinical trials applications submitted on or after 28 April 2026, the timeline for MHRA/REC combined review for initial approvals has been extended from a maximum of 60 days to 100 days. This revised timeline now includes up to 60 days for sponsors to respond to Requests for Further Information (RFIs), an increase from the previous 14-day limit. This gives sponsors significantly more time to assess RFIs and provide thorough, well-considered responses.
For substantial modifications (previously known as substantial amendments) submitted on or after 28 April 2026, the new clinical trials regulations allow both the MHRA and the REC to request further information during their assessment. As a result, the review timeline has been extended in cases where a Request for Further Information (RFI) is issued.
Notification Scheme
A new fast-track notification scheme is being introduced for certain low-risk Phase 3 and Phase 4 clinical trials. The aim is to offer a faster, more streamlined, and efficient regulatory pathway for low-risk studies. Under this scheme, eligible initial applications can be processed by the MHRA within 14 days, rather than the standard 30-day statutory timeline.
To use the scheme, sponsors will need to demonstrate that their trial meets the MHRA’s eligibility criteria.
Initial applications will continue to be submitted through IRAS, using the same core documentation required for all clinical trials. Sponsors wishing to access the notification route will also need to complete and submit a separate form to register their interest.
Modifications (formerly “amendments”)
Under the new regulations, “amendments” will now be referred to as “modifications.” One of the most significant changes to the clinical trial application process relates to how these modifications are submitted and assessed
From 28 April 2026, there will be two routes for substantial modifications:
- Route A: Modifications requiring assessment by the REC and/or MHRA
- Route B: Modifications that can be automatically authorized by the MHRA and only require REC approval
Substantial modifications will continue to be submitted through IRAS when they are being reviewed via the Combined Review route.
The updated framework is designed to support a more streamlined, risk-proportionate assessment of substantial modifications. Route A covers changes that need regulatory or ethical review, while Route B allows lower-risk changes to proceed through automatic MHRA authorization.
Modification of an important detail.
In addition, a new type of change has been introduced: a “modification of an important detail.”
This refers to adjustments that do not significantly affect participant safety or rights and are submitted for information only. These do not undergo review by the MHRA or REC, and no formal outcome will be issued. However, they may still require other approvals, such as HRA or HCRW approval.
Regulator-requested modifications
The new regulations also allow the REC or MHRA to request changes to an ongoing clinical trial. Such requests may be issued when concerns arise regarding:
- Compliance with Good Clinical Practice principles
- Participant safety
- The scientific validity of the trial
If a REC receives concerns from a third party about an active study, it will first contact the sponsor to notify them and begin a discussion about the issues raised.
If the REC concludes that a modification is required, it will formally issue a request to the sponsor.
Transparency requirements
Under the amended regulations, clinical trials submitted on or after 28 Apr 2026, sponsors will be legally required to register their clinical trial on a public registry before the first participant is recruited, or within 90 days of receiving approval
Sponsors will also be required to publish a summary of the trial results within 12 months of the trial’s end and offer participants an accessible, easy-to-understand summary of the results.
For clinical trials submitted before 28 April 2026 that end on or after 28 April 2026, the Sponsor must register the study on a public registry either before the first participant signs consent, or within 90 calendar days of 28 April 2026 if recruitment began before that date. The sponsor must publish the summary of results in the same public registry where the study was originally registered, however, lay summaries are not required, although this is encouraged.
Simplified arrangements for obtaining consent in clinical trials
The new UK clinical trials regulations introduce the option for sponsors to use simplified arrangements for seeking and evidencing informed consent, but only for trials that meet specific conditions. The aim is to reduce unnecessary burden whilst still protecting patients.
If a sponsor intends to use simplified consent arrangements, this must be clearly described in the trial protocol.
With 20 years of experience in clinical research, Claire has led and supported Phase 1–4 clinical trials, non‑interventional and observational studies, and compassionate use programmes across a wide range of therapeutic areas, with a particular focus on rare diseases. Her experience collaborating with regulatory agencies such as the EMA, MHRA, and FDA ensures that clinical development plans and outcomes align with client expectations. By managing and delivering complex global studies and working closely with regulatory, medical, and clinical teams, she has developed a thorough understanding of the challenges of clinical drug development and how to navigate them effectively.
Need support with UK clinical trial readiness?
Our experts help sponsors understand regulatory changes, assess impact, and prepare clinical trial processes for the new 2026 requirements.
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