{"id":446983,"date":"2026-02-26T16:49:08","date_gmt":"2026-02-26T16:49:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/446983\/"},"modified":"2026-02-26T16:49:08","modified_gmt":"2026-02-26T16:49:08","slug":"inside-the-decision-to-pause-the-puberty-blocker-trial","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/446983\/","title":{"rendered":"Inside the decision to pause the puberty blocker trial"},"content":{"rendered":"<p>        <img width=\"1038\" height=\"778\" src=\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2026\/02\/00022835-1038x778.jpg\" class=\"attachment-4x3-large-crop size-4x3-large-crop wp-post-image\" alt=\"\" decoding=\"async\" fetchpriority=\"high\"  \/><br \/>\n                Illustration by Gary Waters \/ Ikon Images<\/p>\n<p class=\"has-drop-cap\">The proposed NHS-backed \u201cPathways\u201d puberty blocker trial \u201ccould not have received more oversight and scrutiny\u201d, the Health Secretary, Wes Streeting, <a href=\"https:\/\/x.com\/RosieDuffield1\/status\/2011132765454889358\" target=\"_blank\" rel=\"noopener nofollow\">told parliamentary colleagues<\/a> in January. It had gone through \u201crigorous rounds of scientific, clinical, ethical and regulatory review\u201d. How, then, to make sense of the U-turn from the Medicines and Healthcare Products Regulatory Agency (MHRA) on 20 February? The medicines regulator had initially given its approval for Pathways, which is being led by researchers from King\u2019s College London (KCL). In a letter to KCL, the MHRA raised significant safety and ethical concerns, prompting the trial to be paused.<\/p>\n<p>On one level, this suspension can be seen as scientific scrutiny working well. After the trial was <a href=\"https:\/\/www.newstatesman.com\/politics\/2025\/11\/a-new-clinical-trial-will-test-puberty-blockers-on-children\" target=\"_blank\" rel=\"noopener nofollow\">announced<\/a> in November 2025, hundreds of clinicians voiced \u201c<a href=\"https:\/\/can-sg.org\/2025\/12\/18\/open-letter-to-wes-streeting-on-the-pathways-puberty-blockers-trial\/\" target=\"_blank\" rel=\"noopener nofollow\">grave disquiet<\/a>\u201d about the trial\u2019s design. I have <a href=\"https:\/\/www.newstatesman.com\/politics\/2025\/12\/will-the-new-puberty-blocker-trial-put-children-at-risk\" target=\"_blank\" rel=\"noopener nofollow\">scrutinised<\/a> the trial\u2019s documentation and asked, in the New Statesman, whether participants are being told enough about the <a href=\"https:\/\/www.newstatesman.com\/investigation\/2026\/01\/nhs-puberty-blocker-trial-information-ignores-or-minimises-critically-important-risks\" target=\"_blank\" rel=\"noopener nofollow\">balance of risks and benefits<\/a>. Perhaps the MHRA has listened.<\/p>\n<p>But it is also pertinent to ask why the regulator approved a study it now says risks <a href=\"https:\/\/assets.publishing.service.gov.uk\/media\/6998b06d047739fe61889efb\/Sponsor-letter110226.pdf\" target=\"_blank\" rel=\"noopener nofollow\">sterilising children, damaging their bones and impairing their cognition<\/a>. Everything the MHRA appears to now be concerned about was known at the time of approval. The true reason behind the regulator\u2019s actions is as yet unclear.\u00a0<\/p>\n<p>Hilary Cass, whose four-year review of children\u2019s gender services in England led to the trial, has suggested in an interview with the Observer that the decision to pause it seems \u201c<a href=\"https:\/\/observer.co.uk\/news\/national\/article\/pausing-puberty-blockers-trial-is-bizarre-says-cass\" target=\"_blank\" rel=\"noopener nofollow\">political<\/a>\u201d. Other sources with connections to youth gender care have pointed out to me that the MHRA\u2019s actions coincide with the introduction of a new role at the regulator in January:\u00a0<a href=\"https:\/\/www.gov.uk\/government\/news\/mhra-welcomes-professor-jacob-george-as-he-starts-chief-medical-and-scientific-officer-role\" target=\"_blank\" rel=\"noopener nofollow\">chief medical and scientific officer<\/a>. Their remit is to \u201coversee the MHRA\u2019s scientific, research and innovation activities\u201d.<\/p>\n<p>                            <a href=\"https:\/\/www.newstatesman.com\/politics\/health\/2026\/02\/javascript(void);\" rel=\"nofollow noopener\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/dl6pgk4f88hky.cloudfront.net\/2021\/09\/TNS_master_logo.svg\" class=\"img\"\/><\/a><\/p>\n<p>Subscribe to the New Statesman today for only \u00a31 a week.<\/p>\n<p>The MHRA\u2019s letter to KCL suggests its intervention is unconnected to a legal challenge that was <a href=\"https:\/\/www.telegraph.co.uk\/news\/2026\/02\/06\/campaigners-legal-action-stop-puberty-blockers-trial\/\" target=\"_blank\" rel=\"noopener nofollow\">launched<\/a> in February, which aims to stop the trial going ahead altogether. Indeed, the regulator says that its consideration of the legal case will determine whether \u201cthere are any further matters which impinge upon safety or efficacy that should also be considered\u201d.<\/p>\n<p>The legal papers calling for the trial to be scrapped show that in late summer 2025 the MHRA set out 19 grounds for not accepting the KCL team\u2019s research. Another public body, the Commission on Human Medicines, which advises ministers on the safety, efficacy and quality of drugs, agreed with the MHRA. The KCL trial team responded to the regulator\u2019s grounds for non-acceptance on 9 October; their letter, <a href=\"https:\/\/chrome-extension:\/\/efaidnbmnnnibpcajpcglclefindmkaj\/https:\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/PATHWA1_zvJrDTu.PDF\" target=\"_blank\" rel=\"noopener nofollow\">which has been made public<\/a>, includes the MHRA\u2019s objections.<\/p>\n<p>Among these were concerns that some of the language in the proposed criteria for subjects\u2019 inclusion in the trial was \u201copen to subjective interpretation\u201d; that more clarity was needed on the dosing of drugs; that additional exclusion criteria were required; and that more safety monitoring was needed. Most significantly, the MHRA argued that the study\u2019s follow-up period for the children taking part was \u201cinadequate to assess the long-term benefits and risks\u201d of suppressing puberty in this group of children and young people.<\/p>\n<p>\u201cIdentified risks include but [are] not limited to, effects on fertility preservation, bone mineral accrual, fracture risk, cognitive development and sexual function, which require monitoring,\u201d the MHRA said. It pointed out that \u201cmany of these outcomes will only become measurable in adulthood\u201d and therefore necessitated \u201ca follow-up for a period of up to 20 years or until the participant reaches the end of physical maturation (whichever is shorter)\u201d.<\/p>\n<p>Ultimately, the trial\u2019s follow-up period was not extended. The regulator accepted <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/PATHWA1_zvJrDTu.PDF\" target=\"_blank\" rel=\"noopener nofollow\">KCL\u2019s response<\/a> that follow-up into adulthood would occur through the NHS Register, which children would be encouraged to join. This, the trial team said, would \u201cprovide passively collected long-term data into adult life that includes long-term safety surveillance\u201d.<\/p>\n<p class=\"has-drop-cap\">The MHRA\u2019s late intervention raises questions about how rigorous the regulatory and ethical approval process for clinical trials really is. Any research involving the NHS must also be approved via an independent research ethics committee (REC). These committees are staffed by volunteers, at least a third of whom must be lay people, with no background in healthcare. The committee charged with approving the Pathways trial met three times. Nine of its 12 members attended the <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/London_City_and_East_Research_Ethics_Committee_meeting_minutes__4_September_20_N8iQeY1.pdf\" target=\"_blank\" rel=\"noopener nofollow\">first meeting<\/a>, in September 2025 (seven are needed for it to be quorate). A subcommittee of five constituted the <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/London_City_and_East_REC_sub-committee_meeting_minutes__28_October_2025_redact_IKnLStc.pdf\" target=\"_blank\" rel=\"noopener nofollow\">second<\/a>. When approval was granted at the <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/London_City_and_East_REC_sub-committee_meeting_minutes__6_November_2025_redact_9Y72To7.pdf\" target=\"_blank\" rel=\"noopener nofollow\">third meeting<\/a> on 6 November, just three members were present. Only one person went to all three meetings.<\/p>\n<p>People who have previously sat on RECs tell me this scenario is not necessarily out of the ordinary. Decisions are often made by smaller subcommittees, after the full committee has met. According to the <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/GAfREC_Final_v2.1_July_2021_Final.pdf\" target=\"_blank\" rel=\"noopener nofollow\">policy document<\/a> that guides the function of ethics committees, a REC is also not responsible for considering \u201cthe quality of the science\u201d of the research it is considering. That is the responsibility of a study\u2019s sponsor, in this case KCL.<\/p>\n<p>This seems like a flaw in the system. The only source of information available to the REC is the institution that seeks to carry out research. The ethics committee is not obliged to consult more widely. In this case, the study has an eminent sponsor, KCL, and a well-respected lead researcher. But researchers, quite understandably, want their projects to go ahead.<\/p>\n<p>Official minutes of a meeting of NHS England\u2019s children\u2019s <a href=\"https:\/\/www.england.nhs.uk\/commissioning\/spec-services\/npc-crg\/gender-dysphoria-clinical-programme\/implementing-advice-from-the-cass-review\/cyp-gender-dysphoria-research-oversight-board\/\" target=\"_blank\" rel=\"noopener nofollow\">Gender Dysphoria Research Oversight Board<\/a> from March 2024, seen by the New Statesman, show the trial\u2019s chief investigator Emily Simonoff\u2019s enthusiasm for it. The minutes state that the final Cass Report is \u201clikely to recommend that there should also be a formal evaluation of non-medical interventions\u201d as a way of helping children experiencing gender-related distress. \u201cWhile members were supportive of the proposition,\u201d the minutes say, \u201cSimonoff\u2019s view was that the group\u2019s efforts should be focused on establishing the puberty suppressing hormones study before reaching to other elements of the pathway.\u201d<\/p>\n<p>The scrutiny process for clinical trials is often not as robust as the public might believe. But it also seems that in this case, the ethics committee may have not followed the regulations. While decision-making can be delegated to a subcommittee, according to the official document dictating REC governance, this should be for \u201c<a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/GAfREC_Final_v2.1_July_2021_Final.pdf\" rel=\"nofollow noopener\" target=\"_blank\">proposals that present no material issues of research ethics<\/a>\u201d. A trial that carries risks to children\u2019s bones, cognitive development and future fertility would therefore seem to warrant the attention of a full committee.<\/p>\n<p>A spokesperson for the Health Research Authority (HRA), which oversees and manages the work of RECs, said that the regulations allowed a committee\u2019s final opinion to be delegated when it was seeking <a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/GAfREC_Final_v2.1_July_2021_Final.pdf\" target=\"_blank\" rel=\"noopener nofollow\">\u201cinformation further to earlier review in full committee<\/a>\u201d. Where research involves children under 16, \u00a0RECs are also required to\u00a0 \u201c<a href=\"https:\/\/www.hra.nhs.uk\/about-us\/committees-and-services\/res-and-recs\/research-ethics-committee-standard-operating-procedures\/\" target=\"_blank\" rel=\"noopener nofollow\">obtain advice before giving its [ethical] opinion<\/a>\u201d. In this case, the HRA says, the committee included a member with professional expertise in paediatric care, so outside involvement wasn\u2019t required.<\/p>\n<p>This individual, a paediatric intensive care consultant, did not attend any of the committee\u2019s three meetings, but provided \u201c<a href=\"https:\/\/s3.eu-west-2.amazonaws.com\/www.hra.nhs.uk\/media\/documents\/Expert_comments_Ffgfvyr.pdf\" target=\"_blank\" rel=\"noopener nofollow\">expert comment<\/a>\u201d to their fellow members before the proposal was considered. (The HRA say this approach is regularly used to ensure REC meetings can proceed promptly in scenarios where not all members are available.) In this case, the comments provided stretch to a little over 200 words and consists of bullet points. Several of the reflections on the KCL trial listed as \u201cpositives\u201d by the consultant have now been called into question by the MHRA\u2019s intervention.<\/p>\n<p class=\"has-drop-cap\">The legal challenge to the trial, mounted by a former patient, a psychotherapist and concerned parents of gender-distressed children, claims that the HRA \u201cactively withheld outside advice from the REC\u201d. Two groups of doctors wrote to the HRA setting out \u201cvarious highly relevant concerns and questions, none of which were passed to the REC\u201d, the submission to the court contends. The New Statesman has seen both letters. They raised concerns that the anticipated benefits of the trial did not justify the risks, that there were alternative sources of data or potential interventions that could be carried out before a trial, and that there was risk of serious and irreversible harm that could not be captured by the proposed follow-up.<\/p>\n<p>One of these letters was not shared with the REC by the HRA at all. The other was passed to the REC\u2019s chair, but only after the one meeting that involved the full committee had already taken place. Those seeking to stop the trial in court argue that this material \u201cwas unreasonably and unjustifiably withheld from the REC\u201d, denying members the opportunity to \u201cevaluate its significance (or otherwise) for themselves\u201d.<\/p>\n<p>An HRA spokesperson said that it was \u201cnot uncommon\u201d for third parties to request that their concerns be considered and that it took all such concerns seriously. However, \u201cto\u00a0protect the integrity and independence of the REC review\u00a0process\u201d, the HRA reviewed everything first \u201cto\u00a0establish\u00a0whether it raises\u00a0new information\u00a0pertinent to the REC review\u00a0that should have been accounted for\u201d. In this instance the HRA judged that the submission from KCL contained all the necessary information and there was \u201cno basis\u201d for the letters to be referred to the REC.<\/p>\n<p>Discussions between the MHRA and KCL on how to move forward with the trial are now underway. A KCL spokesperson said that the health of young people remains their priority and that the trial team will \u201cwork with the MHRA to support their further review of the trial, which has been designed by world-leading academics with scientific rigour at its core\u201d. Any changes to the study will have to be <a href=\"https:\/\/www.hra.nhs.uk\/about-us\/news-updates\/an-update-on-the-pathways-trial-20-february-2026\/\" target=\"_blank\" rel=\"noopener nofollow\">reviewed and approved again<\/a> by the REC. Streeting has said it will \u201conly be allowed to go ahead if the expert scientific and clinical evidence and advice conclude it is safe to do so\u201d.<\/p>\n<p>Whether or not the Pathways trial goes ahead, this episode raises serious questions about whether the systems we use to ensure research is safe and ethical can always be relied upon.<\/p>\n<p>[Further reading: <a href=\"https:\/\/www.newstatesman.com\/politics\/health\/2026\/02\/englands-maternity-system-not-working-for-anyone-review-says\" rel=\"nofollow noopener\" target=\"_blank\">England\u2019s maternity system not working for anyone, review says<\/a>]<\/p>\n<p>    Content from our partners<\/p>\n","protected":false},"excerpt":{"rendered":"Illustration by Gary Waters \/ Ikon Images The proposed NHS-backed \u201cPathways\u201d puberty blocker trial \u201ccould not have received&hellip;\n","protected":false},"author":2,"featured_media":446984,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[102,2960,56,54,55],"class_list":["post-446983","post","type-post","status-publish","format-standard","has-post-thumbnail","category-healthcare","tag-health","tag-healthcare","tag-uk","tag-united-kingdom","tag-unitedkingdom"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/446983","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=446983"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/446983\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/446984"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=446983"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=446983"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=446983"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}