Semaglutide 2.4 mg is cost-effective for obesity in Japan with retreatment, reducing complications

Obesity is a chronic disease leading to significant morbidity and healthcare costs, particularly in Japan. Current guidelines (OUG) restrict patient eligibility and treatment duration for semaglutide 2.4 mg, raising questions about its long-term economic value. This study addresses the gap by evaluating the cost-effectiveness of semaglutide when incorporating retreatment, offering a more realistic view of its sustained benefits in managing obesity disease and its associated comorbidities like type 2 diabetes (T2D) and cardiovascular events.

Researchers employed a Markov cohort model (Core Obesity Model) to assess lifetime clinical and economic outcomes from a Japanese public payer perspective. The study included individuals with obesity disease (BMI ≥35 kg/m² with ≥1 comorbidity, or BMI ≥27 kg/m² with ≥2 comorbidities). The intervention was semaglutide 2.4 mg plus diet and exercise, compared to diet and exercise alone. They modeled 0, 1, or 2 retreatments, each followed by a fixed 1-year off-treatment period. The primary outcome was the incremental cost-effectiveness ratio (ICER) in Japanese yen per quality-adjusted life year (QALY), discounted at 2%.

In the base case, semaglutide 2.4 mg significantly reduced the incidence of various obesity-related complications, including type 2 diabetes (T2D), cardiovascular events, obstructive sleep apnea, and gout. The incremental cost-effectiveness ratio (ICER) was calculated at ¥5,300,580/QALY for patients with obesity disease without T2D. For patients with obesity disease and T2D, the ICER was ¥7,077,984/QALY. These figures indicate that the intervention provides health benefits at a cost considered acceptable within many healthcare systems. Crucially, the model demonstrated that:

Retreatment significantly improved QALY gains compared with limited or no retreatment, reflecting longer maintenance of treatment benefit and enhanced overall cost-effectiveness.