Tirzepatide Demonstrates Greater Cost-Effectiveness Than Semaglutide for Patients with Knee Osteoarthritis and Obesity

A recent study utilizing a microsimulation model evaluated the economic efficiency of two glucagon-like peptide-1 receptor agonists (GLP1RAs), tirzepatide and semaglutide, in managing patients suffering from knee osteoarthritis combined with obesity. The research compared these medications against standard care, which includes diet, exercise, and weight loss surgeries. The findings reveal that both GLP1RAs are cost-effective options, with tirzepatide providing a more favorable financial return.

The analysis, published in the Annals of Internal Medicine, was conducted by researchers from the Orthopedic and Arthritis Center for Outcomes Research at Brigham and Women's Hospital. It employed the validated Osteoarthritis Policy (OAPol) Model—a widely used Monte Carlo microsimulation—to project lifetime outcomes, including quality-adjusted life-years (QALYs) and medical costs based on current US dollars.

Six treatment strategies were examined: usual care, usual care combined with diet and exercise, usual care with semaglutide, usual care with tirzepatide, laparoscopic sleeve gastrectomy (LSG), and Roux-en-Y gastric bypass (RYGB). The model incorporated clinical data from the STEP-9 study to simulate weight loss and adverse events associated with the medications.

Results indicated that adding semaglutide or tirzepatide to usual care increased QALYs, with tirzepatide achieving an even higher value—10.68 QALYs compared to 10.48 for semaglutide. Cost-effectiveness was assessed through incremental cost-effectiveness ratios (ICERs), with tirzepatide showing an ICER of $57,400 per QALY, which is considered economical.

In secondary analyses, for patients with a BMI over 35 kg/m², weight loss surgery such as RYGB appeared to be more cost-effective for thresholds exceeding $30,700 per QALY, given the sustained weight reduction post-surgery. These findings highlight the importance of tailored treatment decisions for managing knee osteoarthritis in obese patients.

Overall, the study underscores the economic advantages of tirzepatide over semaglutide in the context of obesity and knee osteoarthritis treatment, providing valuable insights for clinicians and healthcare policymakers. The results advocate for considering tirzepatide as a preferred pharmacological option within the comprehensive management of these conditions.

Source: https://medicalxpress.com/news/2025-09-tirzepatide-effective-semaglutide-patients-knee.html