UK Puberty Blocker Trial Paused for Young People Due to Safety Worries

The PATHWAYS trial for puberty blockers in young people is on hold. The MHRA wants to raise the minimum age from 10 to 14 due to safety concerns.
By Newsroom | Health, United Kingdom |

A planned clinical trial involving puberty blockers for young people experiencing gender incongruence has been halted due to new concerns raised by the Medicines and Healthcare products Regulatory Agency (MHRA). The pause, initiated after the MHRA communicated its reservations to the trial's sponsor, King's College London, means recruitment of participants will not commence until these issues are addressed and resolved. The MHRA's concerns are explicitly linked to the well-being of the children and young people who would be involved in the study.

Clinical trial into puberty blockers paused after ‘new concerns’ from regulator - 1

Background of the PATHWAYS Trial and Puberty Blockers

The PATHWAYS trial, aiming to recruit approximately 226 young individuals aged between 10 and nearly 16, was designed to explore the effects of puberty blockers on those experiencing gender incongruence. Puberty blockers are medications that temporarily stop the physical changes of puberty. The trial intended to administer these drugs to one group for two years, while another group would receive them after a one-year delay. A control group not receiving the blockers would also be monitored. This initiative followed a review of NHS gender services and aimed to build a stronger evidence base for the use of such treatments in this demographic.

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Clinical trial into puberty blockers paused after ‘new concerns’ from regulator - 2

Regulator's Intervention and Specific Concerns

The MHRA has communicated its concerns to the trial sponsors, King's College London. The core of these concerns appears to be the safety and well-being of young participants. Discussions between the MHRA and King's College London are scheduled for the upcoming week to address these points.

Clinical trial into puberty blockers paused after ‘new concerns’ from regulator - 3

A key area of contention, as noted in a letter from the MHRA, involves the proposed age range for participants. The regulator has expressed a desire to raise the minimum age for entry into the trial from 10 to 14 years old.

Clinical trial into puberty blockers paused after ‘new concerns’ from regulator - 4

Broader Context: Evidence Base and Previous Reviews

The pause in the PATHWAYS trial occurs within a wider debate about the use of puberty blockers for young people. Baroness Hilary Cass, who previously led a review into gender identity services for children and young people, has indicated that her report found a "very weak evidence base" for the benefits of these drugs. However, she also acknowledged that trials were considered a necessary step forward given the differing views among clinicians, children, and families.

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Legal and Political Opposition

The decision to pause the trial has also been influenced by external pressures. Legal action has been launched against the government concerning the trial, with campaigners, including notable figures like author J.K. Rowling, expressing their opposition. Separately, the Health Minister in Northern Ireland, Mike Nesbitt, independently suspended the region's participation in the trial, citing ongoing legal actions as a factor. This move, however, has drawn criticism from First Minister Michelle O'Neill, who suggested the decision should have been brought to the executive first. Health Secretary Wes Streeting has, meanwhile, rejected calls to halt the trial, underscoring a division in political and administrative approaches to the issue.

Expert Commentary and Evidence Base

Baroness Cass's assessment points to a recognized gap in robust evidence regarding the efficacy and long-term effects of puberty blockers for this population. The PATHWAYS trial was conceived, in part, to address this deficit. However, questions have been raised about the potential impact of prolonged suppression of physical and psychological development during the trial itself. Some research has indicated that certain children experienced more negative than positive effects from puberty blockers.

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Implications and Next Steps

The immediate implication of the MHRA's intervention is the indefinite delay of the PATHWAYS trial's recruitment phase. The trial will only be permitted to proceed if the MHRA, following scientific and clinical dialogue, concludes that it is both safe and necessary. The emphasis on the "safety and wellbeing of children and young people" has been reiterated by the Department of Health and Social Care as the primary consideration. Future decisions regarding the trial will hinge on the outcomes of these discussions and the evidence presented to satisfy the regulator's concerns, particularly regarding the minimum participant age.

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Sources

Frequently Asked Questions

Q: Why has the PATHWAYS clinical trial for puberty blockers been paused in the UK?
The trial has been paused because the UK's Medicines and Healthcare products Regulatory Agency (MHRA) has raised new concerns about the safety and well-being of the young people who would take part. Recruitment of participants will not start until these issues are fixed.
Q: What are the specific concerns the MHRA has about the puberty blocker trial?
The MHRA is worried about the safety of the children involved. They specifically want to increase the minimum age for participants from 10 years old to 14 years old.
Q: Who is affected by the pause of the PATHWAYS trial?
Young people aged 10 to nearly 16 who are experiencing gender incongruence and were expected to join the trial are affected. The trial sponsor, King's College London, and the NHS are also affected as they cannot proceed with the study.
Q: What happens next with the PATHWAYS trial?
Discussions are planned between the MHRA and King's College London to talk about the safety concerns. The trial can only restart if the MHRA is satisfied that it is safe and needed, especially regarding the age of participants.
Q: What is the background of the PATHWAYS trial and puberty blockers?
The PATHWAYS trial was planned to study how puberty blockers affect about 226 young people aged 10 to 16 with gender incongruence. Puberty blockers temporarily stop the body's physical changes during puberty, and the trial aimed to study their effects over two years.