It’s been six months since the UK’s new clinical trials regulations came into force on 28 April 2026, and the MHRA has published an update on how the changes are working in practice.
The early results are encouraging, with the new framework supporting a more flexible, risk-proportionate approach to clinical trial assessment. However, the update also highlights where delays are still occurring and what sponsors can do to avoid them.
Assessment Timelines
Under the new framework, sponsors submit a single clinical trial application for review by both the MHRA and a Research Ethics Committee through the Integrated Research Application System.
Once validated, applications enter an assessment phase of up to 30 calendar days, although the MHRA reports that complete, good-quality submissions are often assessed sooner.
Sponsors also have up to 60 days to respond to requests for information, with a final decision issued within 10 days of receiving a response.
The MHRA also highlighted the performance of Route B substantial modifications, which provide a faster assessment process for eligible changes to approved clinical trials. Results from the six-month pilot showed an average end-to-end approval time of just seven days, compared with the regulatory maximum of 21 days.
Submission Quality
While these improvements are encouraging, the MHRA has also identified several common issues that continue to cause avoidable delays.
Around 3-5% of applications fail validation, often because of missing documentation, unsigned forms or files that do not meet the required standards.
Other issues identified during assessment include incomplete information relating to investigational medicinal products, manufacturing and GMP requirements, as well as gaps in contraception requirements, safety reporting and dose justification.
Many of these issues can be addressed before an application is submitted. For sponsors and CROs, thorough pre-submission checks and consistency across regulatory documentation are therefore essential to making the most of the quicker assessment timelines.
Dr Shoona Vincent, VP Clinical Science at MAC Clinical Research, explains:
“The early results are encouraging, particularly for early-phase drug development in the UK. However, the MHRA’s update also makes it clear that incomplete or inconsistent submissions are still causing avoidable delays.
For sponsors and CROs, the key takeaway is to get it right first time. That means carrying out thorough quality checks before submission and making sure the protocol, Investigator’s Brochure, IMPD and other supporting documents are complete and consistent. These are things we can address before an application reaches the regulator, helping to avoid unnecessary delays and make the most of the faster assessment timelines.”
Six months on, the new framework is showing encouraging signs for UK clinical research. The quicker assessment processes are a positive development, but ensuring submissions are properly prepared remains an important part of making them work.
You can read the full update from the MHRA here.
