BSPED2025 Poster Presentations Diabetes 5 (10 abstracts)
1University of Birmingham, Birmingham, United Kingdom; 2Birmingham Childrens Hospital, Birmingham, United Kingdom; 3Queen Elizabeth Hospital, Birmingham, United Kingdom; 4Birmingham Heartlands Hospital, Birmingham, United Kingdom; 5Addenbrookes Hospital, Cambridge, United Kingdom; 6Leicester Royal Infirmary, Leicester, United Kingdom; 7Royal Hallamshire Hospital, Sheffield, United Kingdom; 8Sheffield Childrens Hospital, Sheffield, United Kingdom
Background: Despite advances in insulin therapy and diabetes technology, only 12.8% of children and young people with type 1 diabetes (CYPD) in England and Wales achieved the NICE HbA1c target (≤ 48 mmol/mol) in 2022/2023. GLP-1 receptor agonists, such as liraglutide and semaglutide, have demonstrated glucose-lowering effects in adults with type 1 diabetes and are approved for use in children with obesity and type 2 diabetes.
Methods: The Smile T1D trial is a multi-centre, randomised, open-label, parallel-group, superiority trial designed to evaluate the glucose-lowering efficacy and safety of once-weekly semaglutide as an adjunct to insulin in CYPD with suboptimal glycaemic control. Eligible participants (aged 1024 years) with type 1 diabetes (≥12 months), HbA1c between 5886 mmol/mol, insulin dose ≥0.5 units/kg/day on any regimen, and using a continuous glucose monitor, will be randomised (3:2) to semaglutide plus insulin or insulin alone for 26 weeks, across 7 NHS sites, using a treat-to-range approach. Key exclusions include low BMI, severe hypoglycaemia, recent DKA, pancreatitis, renal impairment, proliferative retinopathy, thyroid cancer risk, gastroparesis, pregnancy, and DIY closed-loop systems. The primary outcome is change in HbA1c at 26 weeks. Other outcomes include HbA1c at earlier timepoints, time-in-range, insulin dose, BMI-SDS, diabetes-related patient-reported outcome measures, beta cell function, and safety outcomes including hypoglycaemia, DKA and growth. A sample size of 240 will provide 90% power to detect a 5.45 mmol/mol HbA1c difference, accounting for 10% attrition, using a mixed-effects linear regression model. Analysis will follow the intention-to-treat principle.
Results: A trial-specific PPI group involving CYPD was established to review trial documents. Global semaglutide shortages since 2022 delayed approvals. Regulatory bodies (REC and MHRA) required key protocol amendments, including a 5-week post-discontinuation follow-up, monthly pregnancy testing with contraception review, an additional pregnancy information leaflet, and enhanced participant education on pancreatitis, thyroid tumour risks, and renal function-based age-specific exclusion criteria.
Conclusion: The Smile T1D trial is expected to start recruitment at end of 2025. It will provide critical evidence on the role of semaglutide in improving glycaemic control and quality of life in CYPD, potentially informing future treatment guidelines.