OBJECTIVES: The objective of this study was to assess the cost-effectiveness of semaglutide 2.4mg versus diet and exercise (D&E) in Canada using the Core Obesity Model (COM) and clinical outcomes from the STEP 1 and 2 studies, both of which demonstrated significantly greater weight loss with subcutaneous semaglutide 2.4mg injection versus D&E alone.

METHODS: The validated Markov COM was populated with data of STEP 1 (normal glucose tolerance [NGT] and prediabetes) and STEP 2 (diabetes). Average starting age and body mass index (BMI) were 50 years and 37.5kg/m². Treatment duration with semaglutide 2.4mg and D&E was 1 year, after which weight was regained progressively over 3 years. The societal perspective, including public and private funding, patient co-pay, and indirect costs, was taken. Cost (2021 values) and utility data were sourced via desk research. An annual discount rate of 1.5% for costs and outcomes was applied, as per Canadian guidelines (CADTH). A weighted incremental cost-effectiveness ratio (ICER) was calculated based on estimates that 26.0% of Canadians living with obesity had NGT, 46.4% had prediabetes, and 27.6% had diabetes.

RESULTS: Over a 40-year time-horizon the use of semaglutide 2.4mg resulted in 0.070 life-years and 0.091 QALY gained versus D&E for an additional cost of CAD2,900. The ICER was CAD31,861/QALY which can be considered cost-effective at a willingness-to-pay (WTP) threshold of CAD50,000/QALY. Key driver of the analysis was treatment duration, with increase of the ICER to CAD44,206/QALY for a treatment duration of 2 years. The probabilistic sensitivity analysis showed a 99% chance of cost-effectiveness at the assumed WTP.

CONCLUSION: In comparison with D&E, based on the assumptions applied and considering limitations, subcutaneous semaglutide 2.4mg seems a cost-effective therapy for weight management in Canadians living with obesity.