Shedding Pounds, Counting Costs: A Comparative Analysis of Semaglutide and Tirzepatide in Obesity Management

Obesity is prevalent in the U.S. population and contributes significantly to morbidity and mortality. The management of obesity involves lifestyle modifications, pharmacological interventions, and in some cases, surgical approaches. There are disparities in access to obesity treatment and prevention programs where low-income and marginalized communities often have higher rates of obesity and face greater challenges in accessing effective treatment. The escalating costs associated with obesity and its related complications highlight the urgent need for effective and cost-effective treatment strategies. Moreover, there is a need to develop effective public health policies and programs that address the root causes of obesity, including diet, physical inactivity, and environmental factors.

Pharmacoeconomics is a branch of health economics, focusing specifically on the evaluation of the cost-effectiveness of pharmaceuticals and drug therapies. It combines various aspects like pharmacology, economics, and health outcomes research to provide a comprehensive view of the value of drugs and other medical treatments. It helps in understanding the cost versus benefits of a drug or treatment. This includes not only the direct costs, like the price of the drug, but also indirect costs, such as the impact on a patient’s quality of life or productivity. By providing a detailed analysis of the economic impact of drug therapies, pharmacoeconomics ensures that both patients and healthcare systems derive the maximum benefit from investments in drug therapy.

Semaglutide and tirzepatide are two medications that belong to a class of drugs known as incretin mimetics and represent a novel approach in obesity management. These drugs function by mimicking the effects of hormones that regulate appetite and glucose metabolism. Semaglutide, a GLP-1 analog, and tirzepatide, a dual GLP-1 and GIP analog, have shown considerable efficacy in weight reduction, as evidenced by the results of the STEP-1 and SURMOUNT clinical trials. These trials demonstrated significant weight loss in participants, outperforming placebo groups and highlighting the potential of these drugs in treating obesity.

While the clinical efficacy of semaglutide and tirzepatide is clear, their pharmacoeconomic impact warrants attention. Obesity management incurs substantial costs, and the introduction of these drugs adds a new dimension to the economic analysis. The cost of treatment per percentage of weight loss varies between these drugs, with tirzepatide presenting as a more cost-effective option. However, the broader economic implications extend beyond direct medication costs to include indirect costs like frequent medical visits, management of side effects, and societal impacts such as reduced workforce productivity due to obesity-related health issues.

In a new study published in the American Journal of Therapeutics by Professor Timothy Nguyen, Elaine Wong, and Rebecca Cope from the Arnold & Marie Schwartz College of Pharmacy and Health Sciences at Long Island University performed a comprehensive analysis the efficacy and pharmacoeconomics of semaglutide and tirzepatide, exploring their impact in the context of obesity treatment.

The researchers conducted a literature review using PubMed and Google Scholar, focusing on semaglutide, tirzepatide, pharmacoeconomics, and obesity. They specifically examined data from the STEP-1 and SURMOUNT clinical trials to assess the efficacy of these medications. For the STEP-1 Study (Semaglutide), it was a multicenter, randomized, double-blinded, placebo-controlled trial that involved 1961 overweight or obese adults. Participants received once-weekly subcutaneous semaglutide 2.4 mg or placebo, alongside lifestyle modifications. Semaglutide was titrated monthly to reach the maintenance dose. The clinical trials showed the mean percentage change in baseline body weight at 17 months was -14.9% for semaglutide compared to -2.4% for placebo. Moreover, there were significant reductions in body weight across various thresholds (5%, 10%, 15%) compared to placebo. For the SURMOUNT Studies, it was a series of clinical trials evaluating tirzepatide for weight management in adults with or without diabetes. There were 2539 adults in SURMOUNT-1, randomized to receive different doses of tirzepatide or placebo. The studies showed significant changes in mean baseline body weight across all tirzepatide dosing arms compared to placebo at 18 months. Weight reductions of ≥5% were seen in 85.1% to 90.9% of patients on tirzepatide, versus 34.5% on placebo.

The authors conducted cost of treatment per percentage of weight loss and found that semaglutide: $1845 per 1% weight loss while tirzepatide: $985 per 1% weight loss. This means the annual costs were $17,495 for semaglutide and $12,658 for tirzepatide (as of October 2022).  This means treating a fraction of the obese population with semaglutide could lead to billions of dollars in annual Medicare costs. Additionally, there are also indirect costs which Include frequent office visits, management of adverse drug reactions, and potential lost wages from side effects.

The researchers concluded that both semaglutide and tirzepatide are effective in managing obesity, offering significant weight loss compared to placebo. However, the cost of these medications is a considerable factor in the overall healthcare expenditure, with tirzepatide emerging as a more cost-effective option compared to semaglutide. The study also highlighted the need for policy interventions to address the cost and accessibility of these medications, given their potential impact on the healthcare system.