Fast-track changes to running clinical trials take seven days on average, MHRA says
Six months after the UK's new clinical trials regulations took effect, the medicines regulator has published its first figures on the fast-track route for amending studies.
Eligible changes to clinical trials that are already running are being approved in seven days on average, the Medicines and Healthcare products Regulatory Agency (MHRA) said in an update marking six months of the UK's new clinical trial rules.
The amended Clinical Trials Regulations took full effect on 28 April 2026. Under them, a sponsor makes one application through the IRAS system, and the MHRA and a research ethics committee review it in parallel and issue a combined decision.
The fast route for amendments
When a trial needs a substantial change, for example to its safety information, sponsors must now use what the MHRA calls Route B if the change is eligible. To qualify, the sponsor must not be aware, after reasonable enquiries, of any significant new safety concerns about the medicine since the trial was first approved.
The legal maximum for Route B is 21 days: up to 7 for validation and up to 14 for review. In a pilot covering its first six months, the MHRA reports averages of 3 days for validation, 4 days for review and 7 days from start to finish. Most objections it raises relate to safety information, especially updates to a trial's Reference Safety Information that add new expected side effects.
New applications
For a brand new trial the statutory timetable is longer:
- Validation within 7 calendar days of submission
- A combined decision within 30 calendar days of validation
- If more information is requested, 60 days for the sponsor to respond and a decision within 10 days of that response
Those periods can be extended where expert advice is needed. Higher-risk medicines, including some advanced therapies, go to the Commission on Human Medicines for advice.
The MHRA says about 3% to 5% of applications fail validation, most often because documents are missing, forms are unsigned or files cannot be read by its text recognition software. It also lists recurring problems found at assessment, such as unclear emergency unblinding procedures, contraception advice that does not match the guidance on how long it should continue after the last dose, and protocols that do not say investigators must report serious adverse events to the sponsor within 24 hours.
Sponsors with questions can contact the MHRA's clinical trials helpline at clintrialhelpline@mhra.gov.uk.
