MHRA launches Route B notification pilot as part of clinical trials regulations rollout
Source: gov.uk (2025-08-27)

The pilot will help sponsors prepare for a new substantial modifications process under upcoming regulations, with responses delivered within 14 days.

The Medicines and Healthcare products Regulatory Agency (MHRA) is launching a pilot from 1 October 2025 to 31 March 2026 to streamline the approval process for certain changes to clinical trials, as part of preparations for new clinical trials regulations coming into effect on 28 April 2026.

The pilot will expand the MHRA’s risk-proportionate approach to include the review of modifications to approved clinical trial applications. Under the new regulations, substantial modifications can be granted automatic approval through the Route B substantial modification process, providing they meet eligibility criteria.

Changes to notification of Type A trials

As part of the transition to the new regulatory framework, the existing voluntary notification scheme for Type A trials will close on 30 September 2025. Type A trials involve medicinal products licensed in any EU Member State, and relate to the licensed range of indications, dosage, and form.

Under the new regulations, the notification scheme for Type A trials and the ‘new notification scheme’ will be consolidated into ‘Notifiable Trials (https://www.gov.uk/guidance/clinical-trials-for-medicines-notifiable-trials)’.

Risk proportionate support for reviewing Route B substantial modifications

The MHRA is also expanding its current risk proportionate approach to include the review of modifications to approved clinical trial applications. Once implemented under the new regulations, substantial modifications which meet pre-defined criteria will be eligible for automatic approval from the MHRA through the Route B substantial modification process.

This process will need to be followed by everyone submitting an eligible modification to a clinical trial. Draft guidance supporting the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 is available on the Clinical Trials Hub (https://www.gov.uk/government/collections/medicines-clinical-trials). The section on modifying a clinical trial covers the Route B substantial modifications criteria (https://www.gov.uk/guidance/clinical-trials-for-medicines-modifying-a-clinical-trial-approval).

A wide range of stakeholders helped to produce the draft guidance and were invited to provide comments and feedback throughout the process.

Join the pilot

A Route B substantial modification pilot will run from 1 October 2025 to 31 March 2026 and joining is simple.

Any modification eligible under section 11B (https://www.legislation.gov.uk/uksi/2025/538/regulation/11/made) of the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 can be included. By joining the pilot, sponsors will benefit from receiving a response from the MHRA to their amendment within 14 days while, at the same time, familiarising themselves with the eligibility criteria.

Eligible sponsors who are interested in taking part should visit our pilot guidance page (https://www.gov.uk/government/publications/route-b-substantial-modification-pilot/route-b-substantial-modification-pilot#how-to-register) and complete the registration form (https://forms.office.com/pages/responsepage.aspx?id=XOon5Vhi0kyif4vSN-xMJjQ9D9vhy6tJqyos9g2GZChUN0NDOFlWUUFHUDVGNEtMUlRWVFdSSkZZNy4u&route=shorturl).

Background to the new regulations

The new clinical trials regulations were approved by Parliament in April 2025 and will come into effect on 28 April 2026. They will provide a regulatory framework that is agile, innovative, and patient-centred.

Legislation was developed by the MHRA in collaboration with the Health Research Authority (HRA) and received stakeholder input via public consultation.

Changes will only affect new applicants, with existing submissions continuing under the current process. Sponsors interested in participating in the pilot and who expect to meet the eligibility criteria can complete a registration form.

For more information, visit: Medicines: clinical trials hub - GOV.UK (https://www.gov.uk/government/collections/medicines-clinical-trials)