U.K.: MHRA Launches Route B Notification Pilot (1 Oct 2025 – 31 Mar 2026)

The Medicines and Healthcare products Regulatory Agency (MHRA) has announced the launch of a Route B notification pilot, a key step in preparing for the rollout of the U.K.’s new clinical trials regulations. The pilot will run from 1 October 2025 to 31 March 2026, and is designed to help sponsors adapt to a streamlined process for managing substantial modifications.

Under the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025, which take effect on 28 April 2026, certain substantial modifications to approved clinical trial applications will qualify for automatic approval through the Route B process.

The aim is to build on the MHRA’s risk-proportionate framework by allowing specific, low-risk modifications to be approved more efficiently. During the pilot, sponsors submitting eligible modifications can expect a response within 14 days, giving them the chance to test the system while becoming familiar with the new criteria.

Transition from Type A Trial Notifications

As part of this transition, the current voluntary notification scheme for Type A trials will close on 30 September 2025.

Type A trials typically involve medicinal products already licensed in an EU Member State and used within their approved indications, dosage, and form. Going forward, these trials will be consolidated under the new “Notifiable Trials” category, which also incorporates the existing notification schemes.

This consolidation is intended to simplify regulatory processes while maintaining patient safety and scientific integrity.

Route B Substantial Modifications

Once the new regulations are in force, all sponsors submitting substantial modifications that fall within the Route B eligibility criteria must follow this process.

Key features include:

• Automatic approval for eligible modifications under section 11B of the amended regulations

• 14-day response window during the pilot, providing faster clarity for sponsors

• Draft guidance available via the Clinical Trials Hub, which outlines the criteria for substantial modifications

  
  

The MHRA has worked closely with the Health Research Authority (HRA) and engaged with a wide range of stakeholders to develop this framework. Feedback from public consultations has been incorporated to ensure the system is agile, patient-centred, and fit for future innovation.

How to Join the Pilot

Sponsors interested in participating can register easily by completing the pilot registration form available on the MHRA’s guidance page. Eligible modifications will be assessed under the Route B pathway, giving sponsors valuable experience ahead of the full regulatory rollout in April 2026.

Shaping a Future-Ready Clinical Trials Framework

The new clinical trials regulations, approved in April 2025, are designed to create a regulatory environment that is both innovative and supportive of research while ensuring patient safety remains central.

Importantly, the changes will only apply to new applications submitted after the regulations come into effect. Existing submissions will continue to follow the current process.

By launching this pilot, the MHRA is signaling its commitment to a smooth transition for sponsors, while laying the foundation for a faster, more efficient system that enables clinical innovation to reach patients sooner.

Source: Medicines and Healthcare products Regulatory Agency (MHRA)