Phentermine/Topiramate More Cost-Effective than Semaglutide for Teen Obesity

Obesity presents a growing challenge in the United States, particularly in childhood and adolescence. About 22% of children aged 12 to 19 have a body mass index (BMI) that qualifies as obese, according to recent estimates from the CDC.

Adolescents often encounter mental health challenges such as anxiety and depression due to their stage of development. Now, an increasing number of teenagers face a higher risk of physical health problems related to obesity, such as diabetes and heart disease.

To help address this crisis, medication-based therapies have emerged over the past two decades designed to promote weight loss. While many studies show varying ranges of successful weight loss with these agents, there is a lack of evidence regarding the cost-effectiveness of these medications.

In an effort to address questions about the cost-effectiveness of popular weight loss medications, investigators from Columbia University and the University of Minnesota conducted an analysis using computer modeling to determine which of the prominent anti-obesity drugs indicated for adolescents offered the most cost-effective weight loss treatment. The study, published in JAMA Network Open, looked at the simulated impact and cost of lifestyle interventions (diet and exercise coaching) alone and lifestyle changes in combination with specific medications.

To better understand the cost-effectiveness of these medications, researchers used a tool called a microsimulation model.

Francesca Lim, MS

“A microsimulation model simulates a large number of patients, tracking their individual costs and health outcomes over time, allowing us to aggregate results over the whole population,” Francesca Lim, MS, first author and researcher at the Columbia University Irving Medical Center, told Formulary Watch.

The model simulated patient outcomes and costs for each treatment option, allowing for direct cost and benefit analysis between the different therapeutic choices for obesity in adolescents through quality-adjusted life years (QALYs), a standardized method for assessing improvements in overall health or quality of life.

After designing the model with data derived from past clinical trials, published literature, and national data sources, the team simulated outcomes and costs for 100,000 adolescents aged 15 and with BMIs of 37. The researchers were interested in the model outcomes at specific time points: 13 months, 2 years, and 5 years after initiating the anti-obesity treatment.

Lifestyle interventions remained the most cost-effective weight loss method at 13 months and two years. Although the model initially expected that lifestyle counseling would not decrease BMI, it determined that the cost of other treatment options was too high relative to the BMI reduction offered.

At five years, the simulation study found that phentermine/topiramate (with the name of Qsymia) taken at the maximum dosage, emerged as the most cost-effective treatment option, with an estimated healthcare cost of nearly $57,000 per QALY. (Editor’s note: This study assessed Qsymia, a combination product of phentermine/topiramate, at two different doses. Generics of phentermine and topiramate are also available. Both are used to treat obesity. Topiramate is also used to treat patients with epilepsy and migraine.)

Semaglutide (Ozempic and Wegovy) showed the most effectiveness for weight loss, producing an almost 10% greater reduction in BMI compared with max-dose phentermine and topiramate. However, with a cost of $1.1 million per QALY, the model expects 5 years of semaglutide treatment to result in costs 20 times greater than that of max-dose phentermine and topiramate.

Related: Semaglutide for Weight Loss: To Cover or Not Cover?

While this study helps contextualize the cost-effectiveness of weight loss medications in adolescents, the actual long-term value still needs to be determined.

“Our findings underscore the need for longer-term clinical trials as there are limited data on whether weight reduction is maintained during long-term treatment and how weight reduction during adolescence may prevent or delay comorbidities into adulthood,” Lim said.

While semaglutide and other GLP-1 agents represent expensive options for weight loss, the cost savings associated with potential lifelong health improvements from weight loss with these medications may shift the balance of cost-effectiveness.