Update 19 June 2026
PATHWAYS is a programme of research aiming to help find out how the NHS can better support children and young people with gender incongruence.
A part of the programme of research is PATHWAYS Trial, a Clinical Trial of an Investigational Medicine Product (CTIMP) investigating the effects of puberty-suppressing medication on young people's physical, social and emotional wellbeing.
On 6 November 2025 an application for the trial received a favourable opinion from a Research Ethics Committee (REC), as well as the Medicine and Healthcare products Regulatory Agency (MHRA) as the UK’s medicines regulator.
The approval was given via the Combined Review process, where both the HRA and MHRA review applications for CTIMPs in parallel, and provide a single combined outcome of both reviews.
In February 2026 the MHRA raised some concerns about the trial and began a scientific dialogue with the trial sponsor, King’s College London (KCL).
Whilst this scientific dialogue was ongoing, recruitment to the trial was temporarily put on hold by the research team, though the original approval remained in place.
The scientific dialogue between KCL and the MHRA resulted in the sponsor proposing changes to the previously approved study protocol and associated documents for the trial.
Changes to previously approved research applications are known as modifications (previously these were referred to as amendments). These may be substantial, minor or modifications of an important detail. For CTIMPs, substantial modifications are considered to be a modification to a clinical trial approval which is likely to have a substantial impact on the safety or rights of participants, or on the reliability or robustness of the data generated by the trial. This type of modification requires submission to both the REC and the MHRA.
Modifications to a clinical trial after it has been approved are common. In 2025, the HRA reviewed more than 20,000 modifications to approved applications.
The proposed modification was initially reviewed at a full REC meeting on 7 May 2026 where a request for further information was issued. The REC delegated the review of the applicant's response to a sub-committee of named REC members.
The sub-committee gave a final opinion on the proposed modification on Thursday 18 June 2026.
The committee gave a favourable opinion with additional conditions that must be met before the modification can be implemented.
Minutes of this meeting, and other supporting documentation around the modification will soon be made available alongside all the other documents relating to PATHWAYS, on the dedicated page on our website.
As with the original application, the outcome of the REC review was provided alongside the outcome of the MHRA’s scientific review, as part of the Combined Review process.
Recruitment to the trial is not due to begin until 1 August 2026.
Update 20 February 2026
The Department of Health and Social Care has announced that the PATHWAYS TRIAL of puberty supressing hormones has been paused.
PATHWAYS TRIAL is a Clinical Trial of an Investigational Medicine Product (CTIMP) and was approved via combined review from the HRA and a Research Ethics Committee entirely independent of the research team, sponsor and funder; as well as the Medicine and Healthcare products Regulatory Agency (MHRA) as medicines regulator.
The REC reviews its ethics opinion if new information is received about a trial which might have changed its original decision. This includes anything which leads to amendments to the trial design and which might be submitted to or required by MHRA. MHRA has also shared information about its active scientific dialogue with the trial sponsors . Amendments, or changes to a study, must be reviewed and approved by the REC to ensure that the study still has ethics approval.
As the PATHWAYS study has been paused, we will review the study again, in line with our standard operating procedures, before it can restart. We continue to work closely with MHRA to manage and respond to concerns raised about the trial.