Presentation (CTI)

OBJECTIVES: To compare health technology assessments (HTAs) for the weight-management drugs semaglutide and liraglutide (glucagon-like peptide-1 agonists [GLP-1]), and tirzepatide (dual gastric inhibitory peptide [GIP]/GLP-1 agonist), highlighting differences in clinical evidence interpretation, cost-effectiveness assessments, and access restrictions.
METHODS: Publicly available HTAs for semaglutide, liraglutide and tirzepatide from England, Scotland, the United States (US), Canada, Australia and the Netherlands were reviewed in May 2025 for approval status, clinical and economic justifications, patient eligibility criteria, treatment conditions, stopping rules and incremental cost-effectiveness ratios (ICERs).
RESULTS: Liraglutide and semaglutide were conditionally approved in most countries, whilst the most recent drug to market, tirzepatide, had only been assessed in England, Scotland, and the US. Common approval conditions included use alongside lifestyle interventions, overweight/obese body mass index (BMI) thresholds (≥30-40 kg/m²) with at least one weight-related comorbidity, and stopping rules typically requiring a minimum weight loss within a specified time frame. England and Scotland deemed all three drugs cost-effective, supported by clinical evidence demonstrating superior weight loss outcomes compared to lifestyle interventions alone. In contrast, Canada approved semaglutide with strict renewal and price conditions, while rejecting liraglutide due to limited long-term data and uncertain cost-effectiveness. The Netherlands approved liraglutide with restrictions but rejected semaglutide due to long-term uncertainty and high budget impact concerns. Australia rejected semaglutide over insufficient clinical and cost-effectiveness evidence. In the US, despite high ICERs, all three drugs were approved.
CONCLUSIONS: HTA agencies recognised the short-term clinical benefits of liraglutide, semaglutide, and tirzepatide, with consistent use of approval conditions, such as stopping rules and requirements for lifestyle interventions, reflecting broadly aligned clinical expectations. However, uncertainty around long-term efficacy and safety, cost-effectiveness, and overall budget impact led to notable disparities in reimbursement decisions across countries, which contribute to growing international health inequalities in the management of obesity.