A clinical trial investigating the use of puberty blockers in children with gender incongruence will proceed after a High Court judge dismissed a legal challenge aimed at halting the study. The trial, known as the Pathways trial, is set to involve approximately 220 participants, including children as young as 11 years old. It will examine the effects of puberty-suppressing hormones on young people diagnosed with persistent gender incongruence.
The trial is commissioned by NHS England and led by King's College London. It follows recommendations from the Cass review, which highlighted insufficient evidence on the benefits and risks associated with puberty blockers for children experiencing gender dysphoria. The review called for more robust research to help clinicians and families make informed treatment decisions.
The legal challenge was brought forward by the Bayswater Support Group, consisting of parents and guardians of transgender and non-binary youth, alongside psychotherapist James Esses and Keira Bell, who previously underwent puberty blocker treatment and later detransitioned. They argued that regulators had acted unlawfully in approving the trial, citing concerns about inadequate safeguards and potential long-term adverse effects, including infertility and psychological harm.
Mr. Justice Chamberlain rejected the bid for judicial review, stating that the trial was carefully commissioned and designed with input from specialist services and expert bodies. He noted that all participating children would be thoroughly assessed by specialist doctors over several months and that the medical teams involved believed each child had a reasonable prospect of clinical benefit. The judge emphasized that ethical, safety, and design considerations fell within the remit of specialist regulatory authorities rather than the courts.
The trial is endorsed by former health secretary Wes Streeting, who had previously restricted the use of puberty blockers for under-18s in clinical settings following advice from the Commission on Human Medicines, which cited an "unacceptable safety risk." However, the Pathways trial was supported to assess the drugs' side effects under controlled conditions.
Critics of the trial describe it as "deeply unethical" and "highly dangerous," expressing concern that vulnerable children are being subjected to experimental treatments with unknown long-term consequences. They have expressed intentions to appeal the court's decision. Supporters, including clinicians and regulatory bodies, argue the trial addresses a critical knowledge gap and is conducted with careful oversight to prioritize patient safety.
Recruitment for the trial is expected to begin imminently, with girls as young as 11 and boys from age 12 eligible to participate. The study aims to contribute valuable data to inform future clinical guidelines regarding puberty suppression treatment in young people with gender incongruence.