From 28 April 2026, sponsors of clinical trials of investigational medicinal products (CTIMPs) need to publish a summary of results within 12 months of the end of the trial.
This 12 month timeframe also applies to paediatric CTIMPs. The only exception is if sponsors have a deferral or waiver.
Although the new legislation requires sponsors to publish a summary of results for their trial, there is not a legislative requirement to publish interim results for the trial.
Which trials this requirement applies to
If a sponsor submitted an application for clinical trial authorisation and an ethics committee opinion for a CTIMP before 28 April 2026 and its end of trial date is before this date, this requirement does not apply. However, it’s still considered best practice to publish trial results.
If a sponsor submits a CTIMP application from 28 April 2026, or it’s submitted before then but its end date is after 28 April 2026, the sponsor needs to publish a summary of the trial results in line with the 2025 regulations. An exception to this is if the trial does not recruit any participants in the UK within 2 years and the approval lapses. In this case, the sponsor is not expected to publish summary results for the trial.
How to publish a summary of trial results
Sponsors need to publish the summary of trial results in the same registry the trial was registered with, making sure they follow the procedures and requirements set out by the registry.
If the sponsor registered a trial with more than 1 registry, they need to publish a summary of the trial results in all those registries.
It is not acceptable for a sponsor to publish the summary of results in another location (for example the sponsor's website) and insert a link to that in the registry.
It is also not acceptable for a sponsor of a trial registered in both ClinicalTrials.gov and ISRCTN to publish the results in one and insert a link in the other. The full summary of results must be published in all public registries the trial was registered with.
While publishing trial results satisfies the legislative requirements, we also strongly encourage sponsors to publish a plain language summary of the trial results where possible. You should follow our guidance on how to write a plain language summary of research finding.
If a sponsor registered a trial with the ISRCTN then both the summary of trial results and the plain language summary of results should be uploaded.
We recommend that sponsors also make a plain language summary of the results publicly available in their Final Report for their trial.
Trials registered in EudraCT
EudraCT is not considered a public registry as defined in the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025.
This means that if a trial is still running by 28 April 2026 and has been previously registered with EudraCT, there is no legislative requirement for the sponsor to publish a summary of trial results in EudraCT. The sponsor of this trial does however need to make sure it's registered with a public registry, and publish the summary of trial results there within the timeframes dictated by the legislation.
Informing the HRA that the trial results have been published
Sponsors should let us know they have published their summary results in the registry when completing their Final Report. However, if the Final Report has already been submitted, sponsors should contact us at research.transparency@hra.nhs.uk to confirm the summary results have been published.
What a sponsor should do if a registry does not publish the results in time
If a sponsor submits their summary of trial results to a public registry and the registry does not publish them within the required timeframe, the sponsor should notify the HRA by emailing research.transparency@hra.nhs.uk.
The email from the sponsor should include confirmation that the sponsor has submitted their summary of results and evidence of this (for example an email confirming submission or a screenshot of the submission page). We'll then share this information with the MHRA.
Requesting a deferral or waiver for this requirement
In some circumstances, sponsors can request a deferral or a waiver. For further information, please see our guidance on the deferrals and waiver process for transparency requirements.
If the trial is a Phase 1 CTIMP only involving healthy volunteers, it will automatically be given a deferral for the transparency requirements for 30 months after the end of the trial.