MHRA Statement on PATHWAYS Puberty Blocker Trial Safety

MHRA Guidance & Safety

Published February 20th, 2026

Detected February 21st, 2026

Summary

The MHRA has issued a statement regarding the PATHWAYS puberty blocker trial, expressing concerns about participant wellbeing and initiating scientific dialogue with the trial sponsor, King's College London. The agency is applying high scrutiny to ensure the safety of potential child and young person participants.

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What changed

The MHRA has issued a statement concerning the PATHWAYS clinical trial involving puberty blockers, highlighting that the agency has raised concerns related to participant wellbeing and is engaging in scientific dialogue with the trial sponsor, King's College London. The MHRA is applying the highest scrutiny to this trial due to the age of potential participants and its complex nature, emphasizing its priority for the safety and wellbeing of those involved.

This statement indicates a heightened level of regulatory oversight for the PATHWAYS trial. While not an enforcement action, it signals potential modifications or further requirements for the trial to proceed. Healthcare providers, researchers, and drug manufacturers involved in or considering similar paediatric trials should note the MHRA's cautious approach and rigorous scrutiny of participant safety, particularly concerning vulnerable populations. The agency's dialogue with the sponsor suggests that the trial's continuation is contingent on addressing the identified concerns.

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News story

MHRA statement on the PATHWAYS puberty blocker trial

With all complex clinical trials, MHRA’s top priority is the safety and wellbeing of the trial participants

From: Medicines and Healthcare products Regulatory Agency Published 20 February 2026

An MHRA spokesperson commented:

With all complex clinical trials, MHRA’s top priority is the safety and wellbeing of the trial participants.

It is part of the usual process that clinical trials are kept continuously under review and for us to have active scientific dialogue with the trial sponsors.

The safety and wellbeing of the participants to be recruited into the PATHWAYS clinical trial is paramount, particularly in view of the age of the children and young people who may be involved. For this reason, the MHRA is applying the highest scrutiny and taking a cautious and measured approach. We have raised some concerns related to the wellbeing of participants and scientific dialogue will now follow with the trial sponsor. We rely on the best scientific evidence to ensure all trials are as safe as possible for those participating.