Two UK clinical trials to assess impact of puberty blockers in young people | Medical research
Two studies to investigate the impact of puberty blockers on young people with gender incongruity have been announced by British researchers after an expert said gender medicine was “built on shaky foundations”.
Puberty blockers were originally used to treat precocious puberty in children, but have also been used off-label in children with gender dysphoria or incongruence.
However, the 2024 Cass review of NHS gender identity services for children and young people found there was “insufficient/inconsistent evidence on the effects of puberty suppression on psychological or psychosocial wellbeing, cognitive development, cardio-metabolic risk or fertility”.
NHS England subsequently announced that children with gender dysphoria would no longer receive puberty blockers as standard practice, with their use limited to research settings.
Researchers have now announced two new studies as part of a wider ‘Pathways’ program to explore the impact of these drugs in young people treated in specialist NHS children and young people’s services.
Pathways Trial is a clinical study that will recruit approximately 226 young people over the next three years. The youngest participants are expected to be between 10 and 11 years old for biological females and between 11 and 12 years old for biological males – although the team notes that the rigorous selection process means participants will likely be older – and that the upper age limit for joining the study is 15 years and 11 months.
Participants will be randomized to start puberty blockers immediately or start using the drugs after a year’s delay, alongside a wider package of care and support.
In all cases, their health, wellbeing and development will be carefully monitored for 24 months, with each participant screened individually and clinically at the end of the trial to consider their ongoing care needs – which the team believe could include remaining on puberty blockers.
Participants’ results will also be compared to another group of gender-incongruent youth who are not receiving puberty blockers.
The second study, called Pathways Connect, will involve approximately 150 of the Pathways trial participants, as well as approximately 100 gender-incongruent youth who are not receiving puberty blockers, undergoing MRI brain imaging, with the results analyzed against their cognitive task and test scores.
The team says it will take at least four years before the results of the studies are known.
Chay Brown, health director of the advocacy group TransActual, raised ethical concerns about the trial, describing it as “coercive in nature.”
“This is, and will be for a long time, the only way young people can access puberty blockers through the NHS,” he said.
“Even worse, the fact that this is a randomized controlled trial, which means letting some young people wait an extra year for puberty suppression, is not a neutral act. Those in this group will experience distressing pubertal changes that those in the other group will not.”
“While we are pleased that some young people can access the care they need without being criminalized, we fear this will be bad news for trans young people in the UK. »
Emily Simonoff, professor of child and adolescent psychiatry at King’s College London and chief investigator of the new studies, said it was often the case that new drugs were only available through a clinical trial.
“You could argue that puberty suppression should never have been offered to young people outside of a clinical trial 10 or 15 years ago, and that the most ethical thing would have been to do a trial at that time,” she said.
