A pivotal clinical trial investigating the use of puberty blockers for young people questioning their gender identity has been paused in the UK, following the removal of a senior health official over allegations of bias. Professor Jacob George, the chief medical and scientific officer at the Medicines and Healthcare products Regulatory Agency (MHRA), has been recused from any further involvement in the Pathways trial after gender-critical social media posts from last year surfaced.
Regulator's Intervention and Bias Allegations
According to reports, Professor George raised concerns that led to the government putting the Pathways trial on hold in February. The trial, which was set to begin recruiting participants in January, aims to assess the effects of puberty blockers on children with gender dysphoria. However, the MHRA announced on Saturday that George would step back from the trial as a precautionary measure due to his past social media activity.
In one post, he described author JK Rowling, known for her gender-critical views, as a "treasure of our time." In another, he commented on the "denial of basic biological fact" regarding questions about Olympic boxer Imane Khelif's gender. Although these posts were made before his January appointment, the regulator deemed it necessary to remove him from the trial to maintain impartiality.
Safety Concerns and Age Limits
The MHRA cited concerns over the wellbeing of children and young people participating in the trial as the reason for the pause. Initially, the youngest participants were expected to be 10 to 11 for biological females and 11 to 12 for biological males, with the trial team noting that rigorous selection might result in older participants. However, the regulator has now recommended raising the minimum age limit to 14 due to "unquantified risk" of "long-term biological harms."
The clinical trial had planned to recruit an estimated 226 young people over the next three years. This decision follows a recommendation from the Cass review into children's gender care, which highlighted the "poor" quality of existing research on the benefits of such medication for youngsters with gender dysphoria.
Expert Reactions and Trial Background
Dr. Hilary Cass, who led the review, stated that her report "uncovered a very weak evidence base" for the benefits of puberty blockers but emphasized that a trial was essential to clarify the issue, given strong beliefs among clinicians and families. In contrast, Dr. Max Davie, a consultant paediatrician formerly with the NHS Children and Young People's Gender Service, argued there is no compelling scientific reason to pause the trial.
Dr. Davie pointed out that while Professor George is entitled to his personal views, they should not influence his public duties. He noted, "To be clear, there is no compelling scientific reason to halt the Pathways trial. While Prof George's personal convictions are not the only possible explanation for the MHRA's abrupt volte-face, it is the only one for which we have evidence."
Regulatory Response and Future Steps
An MHRA spokesperson reiterated that the safety and wellbeing of trial participants are the top priority. The agency maintains continuous review of complex clinical trials and engages in active scientific dialogue with sponsors. The spokesperson confirmed that MHRA experts will continue working with King's College London to navigate the next steps constructively.
The Pathways trial represents a critical effort to address gaps in evidence regarding puberty blockers, amidst ongoing debates over gender identity and medical interventions for young people. The removal of Professor George underscores the challenges in balancing regulatory oversight with impartiality in highly sensitive healthcare areas.
