Cost-Effectiveness of Tirzepatide Versus Liraglutide, Both Adjunct to Diet and Exercise, for Patients with Obesity or Overweight: A UK Perspective.

INTRODUCTION: This study estimated the cost-effectiveness from a UK healthcare system perspective of tirzepatide (5 mg, 10 mg, 15 mg) compared to liraglutide (3 mg) both adjunct to a reduced-calorie diet and increased physical activity in patients with a body mass index (BMI) ≥ 30 kg/m (obesity), or with a BMI ≥ 27 to < 30 kg/m (overweight) + ≥ 1 obesity-related complication ('trial population'). A subgroup analysis was performed in liraglutide's National Institute of Health and Care Excellence (NICE) recommended population (patients with a BMI of ≥ 35 kg/m with non-diabetic hyperglycaemia and a high risk of cardiovascular disease [CVD]). METHODS: A lifetime simulation model evaluated the costs and long-term clinical outcomes of each treatment. The base-case population was aligned to the population from the SURMOUNT-1 trial. The subgroup analysis included a 2-year stopping rule for liraglutide to reflect the NICE reimbursement criteria. Treatment efficacy was informed by a network meta-analysis. Patients were at risk of developing obesity-related complications such as diabetes and cardiovascular complications, calculated using published risk equations applied to modelled changes in risk factors. Incremental cost-effectiveness ratios (ICERs; cost/quality-adjusted life year [QALY]) were calculated. RESULTS: In the trial population, all doses of tirzepatide were dominant to liraglutide, with estimated cost savings and QALY gains. In liraglutide's UK recommended population the estimated ICERs for tirzepatide vs liraglutide were £5401-7864/QALY gained across doses; the change in results is primarily due to the 2-year stopping rule for liraglutide in this population. In both populations, all doses of tirzepatide demonstrated reductions in at least five of seven complications compared to liraglutide, most notably for knee replacements (29-46% reduction) and diabetes (25-48% reduction). CONCLUSION: On the basis of this simulation model, at the UK willingness-to-pay threshold (£20,000/QALY gained), tirzepatide is a cost-effective treatment compared to liraglutide for overweight and obesity, in both the full license SURMOUNT-1 trial population and in liraglutide's specific NICE reimbursed population.