Blog: Clinical trials regulations – research transparency and transitional arrangements

Clive Collett, Head of Policy and Engagement

New legal research transparency requirements are being introduced as part of upcoming changes to clinical trials regulations which come into force in the UK on 28 April 2026.

The new requirements are a big step forward in promoting and regulating openness in clinical trials.

Greater transparency helps to build and earn people’s trust in research, leading to more people taking part clinical trials and participants feeling more valued.

It supports a UK research sector where researchers can easily find and learn from previous studies, where industry and organisations want to invest and innovate, and where vital research could lead to new and better treatments for patients.

Transitional arrangements

As we approach 2 weeks until the regulations come into effect, we’re taking this opportunity to outline the transitional arrangements for clinical trials and what requirements sponsors and researchers must meet depending on the status of their study.

Trials that end before 28 April 2026

These types of trials are referred to as ‘old rules’ clinical trials.

If a trial ends before the regulations come into force, the new legal transparency requirements do not apply. However, sponsors still need to fulfil the conditions of the Research Ethics Committee (REC) favourable opinion which includes registering their trial within 6 weeks of recruiting the first participant.

Trials that are ongoing on 28 April 2026

If an application was submitted or approved before 28 April 2026 and ends on or after this date, the following transitional arrangements apply:

• the trial must be registered in a public registry, either before the date on which the first participant signs the consent form or within 90 calendar days of 28 April 2026 (by 27 July 2026) – whichever comes first
• ongoing trials that have already recruited the first participant before 28 April 2026, if not already registered, must be registered within 90 days of the regulations coming into force (by 27 July 2026)
• a summary of the results of the clinical trial must be published in the same public registry that it was registered in
• the requirement to provide an accessible lay summary of results for participants or other relevant people does not apply, although sponsors are still encouraged to do so
• the automatic deferral for phase 1 trials applies, provided that the sponsor registers the required minimum information in a public registry before the deadline for registering the trial
• if a trial has an existing deferral in place for registration and is ongoing on 28 April 2026, the deferral end date will be automatically extended to 30 months after the end of the trial and will apply to both registration and publication of the summary of results (after this date, sponsors will need to apply to extend the deferral or publish both the registration and summary of results)

New trials post 28 April 2026

All trials that are submitted (even if not yet approved) on or after 28 April 2026 are referred to as ‘new rules’ clinical trials.

These trials must follow all of the new legal requirements set out in the amended clinical trials regulations. Transitional arrangements do not apply to these trials.

When the regulations come into force

Sponsors and researchers must comply with the new legal requirements from 28 April 2026. It will be an offence under the regulations if the requirements to register or publish a summary of results are not complied with.

The Medicines and Healthcare products Regulatory Agency (MHRA) can take enforcement action, and uses a graduated approach to compliance using measures up to and including the use of infringement notices and potential prosecution.

They will also have the ability to not approve trials where the sponsor has not complied with the registration and publication of results requirements in their other trials and have failed to rectify this.

The HRA will be working with the MHRA to support compliance with the new regulations.

For further information on how regulations can be enforced, read the MHRA's guidance.

Registering a trial

The new legislation requires a sponsor to register a trial in a ‘public registry’. This means a World Health Organization International Clinical Trials Registry Platform primary/partner registry or data provider that enables public access to UK trial information.

Both ISRCTN and ClinicalTrials.gov are registries that would meet the definition, however we recommend using ISRCTN for a number of reasons. ISRCTN allows sponsors to:

• publish a lay summary of their protocol
• add a plain language summary of the trials results
• fully register the trial or publish a minimal record if a trial has an agreed deferral

The HRA has a partnership with the ISRCTN registry which means that the trial information sponsors enter into the new part of IRAS as part of an initial trial application will be sent directly to ISRCTN for registration. It is the sponsor’s responsibility to make sure that registration of their clinical trial is complete and correct.

Registering a trial on EU Clinical Trials Information System (CTIS) does not meet the new registration requirements.

Publishing a summary of results

The summary of trial results must be published in each registry that the trial was originally registered in, within 12 months of the study ending.

We understand that there are sometimes delays from posting the results to the registry to when they become visible on the registry to the public.

As long as the summary of results has been submitted within the 12 month timeline, then the sponsor will normally be considered to have met the legal requirements. We will ask sponsors to let us know if the registry has not published the summary of results within the timeframe so we can note for our own records.

Again, for this reason, we recommend registering with ISRCTN as it’s usually more responsive and quicker at updating.

We’ve recently updated our guidance to clarify that sponsors should let us know they have published their summary results in the registry when completing their Final Report.

For studies submitted through Combined Review, the Final Report can be found and submitted in the Integrated Research Application System (IRAS).

There’s no need for sponsors to contact us separately, unless they have submitted the Final Report before publishing the summary results. In this case, we’ll ask sponsors to contact us at research.transparency@hra.nhs.uk to confirm the summary results have been published.

Preparing for the changes

There are a number of things sponsors can do ahead of the regulations coming into effect to help them prepare for both the ‘transitional’ and the ‘new rules’ changes.

Carry out a transparency audit of all UK clinical trials

• identify all ‘old rules’ clinical trials and their expected end date and make sure they’re registered
• identify all trials that will fall under the transitional arrangements, make sure they’re registered and start the 12-month results clock from the end of trial
• identify all ongoing phase 1 healthy volunteer studies with existing deferrals that will receive automatic deferral and note the new end date

Update registration processes

• update standard operating procedures, start-up checklists, and contracts so that registry selection, required data fields, user permissions, and lay summary of results plans are all agreed upon before the first participant is recruited
• put procedures in place to make sure trials are registered before the first participant or within 90 days of approval (whichever is sooner)

Make clear plans for the 12-month results deadline

• choose clear owners and timelines for both the scientific results summary and the lay summary
• if seeking a deferral, document the justification and set reminders well ahead of each 30-month decision point and keep the 10-year total deferral limit in mind

Prepare for offering lay summaries of results to participants

• plan how and when the offer will be made and recorded
• make sure lay summaries are written in plain language which the participant or other relevant people can understand, and plan for any translation or accessibility needs early
• co-design the summaries with patient partners and test for clarity (refer to existing HRA guidance on Informing participants)
• retain evidence of registration and submission in the trial master file and consider establishment of centralised tracking of this information to support potential future compliance requests