by Eleanor Hayward, The Times
Recruitment of 250 girls and boys aged between ten and 16 raised fears that some would be asked if they wanted to freeze sperm or eggs
An NHS trial of puberty blockers has been halted after health officials raised concerns about “long-term biological harms” to children.
Up to 250 girls and boys as young as ten were due to be recruited to join the clinical trial of hormone-suppressing drugs run by King’s College London. However, on Friday the UK’s medical regulator wrote to King’s raising concerns and arguing for a minimum age of 14. The Department of Health said that, as a result, “preparations for the trial have now been paused”, although it could still go ahead if the issues are resolved.
The study, due to be the biggest trial yet of puberty blockers, was due to involve children being put on the drugs for up to two years and monitored until early adulthood, with their brain development, quality of life and physical and mental health compared with those not given them. The trial had been facing a legal challenge from campaigners who said it was unethical.
The letter from the Medicines and Healthcare products Regulatory Agency (MHRA) highlighted concerns including the “very likely” loss of fertility and permanent bone damage to children. The drugs pause the physical changes of puberty, such as breasts, periods or facial hair.
The MHRA said: “We would like to discuss the inclusion of a minimum age for participation in the trial … since potentially significant and, as yet, unquantified risk of long-term biological harms is present to participants and biological safety has not been definitively demonstrated in this proposed cohort, at the very least, there should be a graded … approach starting with those aged 14 as the lower limit of eligibility.”