New clinical trials regulations
On 28 April 2025, the UK Parliament and Northern Ireland Assembly approved the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025. These new regulations introduce changes to the Medicines for Human Use (Clinical Trials) Regulations 2004 which govern the regulation of clinical trials of investigational medicinal products (CTIMPs) in the UK. The updated legislation came into force on 28 April 2026. For further information on the changes, we recommend you access the dedicated guidance published on the MHRA website and HRA website.
New Clinical Trials of an Investigational Medicinal Product (CTIMPs)
Clinical trial approval is required for any CTIMP to be conducted in the UK. All applications for approval of a CTIMP must now be made using the combined review service. Please use the guidance on the HRA website and MHRA website for instructions on how to apply for combined review. Researchers already using the combined review service should login to the new part of IRAS. If you have an existing CTIMP or IMP/device trial and have not yet submitted your application, you will no longer be able to do so here.
If you have any queries related to applying for combined review, please contact cwow@hra.nhs.uk.
In exceptional circumstances, a sponsor may submit separate applications to the MHRA for a clinical trial authorisation and to a REC for a favourable opinion. Written approval must be obtained in advance by contacting the MHRA at clintrialhelpline@mhra.gov.uk. Further guidance is provided on the MHRA website.
MHRA notifiable trials: Guidance for submitting notifiable trials for automatic authorisation by the MHRA is provided on the MHRA website
Ionising radiation and IMP/device trials: If your combined review application will involve either ionising radiation or an investigational medical device, you should also review our separate instructions in IRAS help.
Existing CTIMPs that were initially submitted using the standard part of IRAS
For existing CTIMPs and IMP/device trials that were previously submitted using this part of IRAS, you will still be able to access your project in the system. This might be necessary, for example, when making a modification that requires changes to the initial application. For further guidance on making modifications to an existing CTIMP prepared in this part of IRAS, please refer to the relevant section on ‘Notifying modifications to MHRA Medicines’ on our help pages.
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