A Short-Term Cost-Effectiveness Analysis of Tirzepatide Versus Semaglutide for the Treatment of Obesity in Greece

Background/Objectives: Obesity is a global health issue with profound humanistic and financial implications. Novel pharmacological treatments, such as tirzepatide and semaglutide, offer promising options for sustained weight management; however, their cost-effectiveness warrants assessment. This study investigates the short-term cost-effectiveness of tirzepatide compared to semaglutide in achieving weight loss targets over 72 weeks in Greece. Methods: A short-term cost-effectiveness analysis was conducted from the perspective of the Greek third-party payer (EOPYY), comparing treatment costs and clinical outcomes for semaglutide and tirzepatide over a 72-week horizon. Clinical efficacy was assessed by the proportion of patients achieving weight loss targets of ≥10%, ≥15%, ≥20%, ≥25%, and ≥30%, using data from the SURMOUNT-5—a 72-week, phase 3b, head-to-head study among overweight adults or those with obesity without diabetes. Only direct medical costs were included, and no discount was employed due to the short time horizon. Price scenario, deterministic, and probabilistic sensitivity analyses were performed. Results: Over 72 weeks, the deterministic analysis found the total treatment cost was EUR 5645.70 for tirzepatide and EUR 3201.68 for semaglutide. These base-case results indicated the cost per responder for tirzepatide at higher weight loss targets (e.g., EUR 28,658 and EUR 46,401 at ≥30%) and lower costs for semaglutide at lower targets (e.g., EUR 1627 lower at ≥10%). However, probabilistic sensitivity analysis revealed overlapping 95% confidence intervals at all thresholds, indicating no statistically significant difference in the cost of control between the treatments. Conclusions: Semaglutide showed a numerically lower cost of control at lower weight loss targets, while tirzepatide was favoured at higher targets; however, these differences were not statistically significant.