Cost-Effectiveness of Tirzepatide As an Adjunct to a Reduced-Calorie Diet and Increased Physical Activity Versus Diet and Exercise Alone in Patients With Obesity or Overweight From a UK Perspective

OBJECTIVES: This study estimated the cost-effectiveness of tirzepatide (5mg, 10mg, 15mg) as adjunct to a reduced-calorie diet and increased physical activity (diet and exercise [D&E]) compared to D&E alone in patients with a body mass index (BMI) ≥30kg/m² (obesity), or with a BMI ≥27kg/m² to <30kg/m² (overweight) + ≥1 weight-related complication using UK inputs.

METHODS: A lifetime patient simulation model evaluated the costs and long-term clinical outcomes of tirzepatide adjunct to D&E versus D&E alone. The modelled population were at risk of developing weight-related complications including type 2 diabetes mellitus (T2DM), cardiovascular disease, obstructive sleep apnoea, knee replacement and non-alcoholic fatty liver disease. These outcomes were modelled using risk factors—weight, systolic blood pressure, high-density lipoprotein and total cholesterol—assessing their direct and indirect impact on healthcare costs, quality of life, and mortality. Efficacy and safety of all tirzepatide doses were informed by the pivotal, phase 3, placebo-controlled trial, SURMOUNT-1, and published risk equations were used to evaluate the incidence of complications. Incremental cost-effectiveness ratios (ICERs; cost/quality-adjusted life year [QALY]) were calculated and uncertainty was assessed through sensitivity and scenario analyses.

RESULTS: Estimated ICERs for each dose of tirzepatide were £14,233 (5mg), £13,792 (10mg), and £15,819 (15mg) versus D&E alone. At the UK willingness-to-pay (WTP) threshold of £20,000/QALY, probabilistic analyses predicted that tirzepatide was cost-effective in 100% of simulations. All modelled obesity-related complications, with the exception of stroke, were estimated to decrease for patients receiving tirzepatide, with the greatest reductions seen in knee replacement (44–56%) and T2DM (40–46%).

CONCLUSIONS: At the UK WTP threshold, our model predicted that tirzepatide is a cost-effective use of resources compared to D&E alone for the treatment of overweight and obesity, with lower incidences of six of the seven obesity-related complications estimated in the model. Sensitivity and scenario analyses confirm the robustness of the analyses.