GLP-1 Drugs for Obesity May Not Have to be All or Nothing

Transitioning patients who have taken GLP-1 therapies to lose weight to lower-cost medications, behavioral health and support programs for weight loss maintenance could lower lifetime healthcare spending significantly. But clinical benefits could decrease as well, finds a new simulation model published recently in Health Affairs Scholar.

David Kim, Ph.D.

“We know these drugs represent a massive breakthrough in our long fight against obesity-related clinical conditions, but their high cost has been the subject of substantial debate,” David Kim, Ph.D., an assistant professor of medicine and a health economist at the University of Chicago Medical Center, said in a news release.

GLP-1 drugs such as Ozempic (semaglutide), approved as Wegovy for weight loss and Mounjaro (tirzepatide), approved as Zepbound for weight loss. They have gained a lot of attention for their ability to help people lose weight but also for reducing the risk factors associated with obesity.

As more data becomes available about how GLP-1 therapies impact the metabolic system, demand and use is expected to grow. Obesity is associated with type 2 diabetes, cardiovascular disease, the fatty liver disease nonalcoholic steatohepatitis (NASH) and chronic kidney disease.

Spending on the GLP-1 class of therapeutics is expected to grow by 378% to $8.1 billion by 2027, according to IQVIA. The pipeline for obesity medications full, with more than 120 medications in development from preclinical to phase 3. One third of these are oral medications.

Related: Payers Recognize the Benefits, but Still See Weight Loss Drugs through a Cost Lens

The GLP-1 drugs have higher costs than older weight drugs. Zepbound is available for a list price of $1,059.87, which is about 20% lower than Wegovy.

Without some controls coverage for therapies such as Wegovy or Zepbound, the costs associated with the GLP-1 drugs could have a large impact on payers and the healthcare system as a whole. IPD Analytics estimates a per-member-per month (PMPM) cost increase of about $15 for a 1-million-member health plan if 10% of eligible adults take GLP-1 therapies for weight loss. If uptake increased to one-third of eligible adults, the cost could increase to $50.

Kim and his colleagues proposed an approach in which GLP-1 therapies could be prescribed for an initial period of weight loss with patients transitioned to lower-cost medications, behavioral health programs and support from nutritionists.

“We wanted to challenge the assumption that once you’re on a GLP-1RA drug, you have to keep taking it forever,” Kim said. “That’s where some of the affordability concerns are coming from: large populations are potentially eligible to take these drugs, and we can’t pay for a lifetime supply for everyone.”

Kim and his colleagues wanted to quantify the level of savings that could be achieved by switching patients from higher-cost GLP-1 drugs to lower-cost medications for the maintenance of weight loss.

They used the Diabetes, Obesity, and Cardiovascular Disease Microsimulation (DOC-M) model to estimate the potential long-term health and economic outcomes of two weight-maintenance programs for patients who have reached a weight-loss plateau after using GLP-1 drugs. The model is a validated microsimulation model that is used to measure the health, equity, and the economic impact of interventions on clinical risk factors for obesity, diabetes, and cardiovascular disease.

The researchers estimated costs for two scenarios: continued, long-term full-dose of GLP-1 treatment and an alternative maintenance program. For the full-dose GLP-1 scenario, researchers used data from the Semaglutide Treatment Effect in People with Obesity (STEP) 1 and SURMOUNT-1 trials to estimate weight-loss maintenance and long-term improvement in blood pressure, fasting glucose, cholesterol, triglycerides, and reduction in cardiovascular adverse events.

Researchers applied a 50% discounted list price of GLP-1/drugs (for example $530 monthly costs for tirzepatide) to account for net price after discounts and rebates.

For the alternative programs, researchers assumed a cost of $53 a month. They also assumed that the clinical benefits with the continued use of GLP-1 therapies would be lost proportionally to the weight regained after discontinuing use.

The modeling found that costs, compared with continuous long-term full-dose GLP-1 use, the use of a less expensive alternative weight-maintenance program following an initial weight loss would significantly reduce related spending and produce minimal reductions in lifetime quality of life years (QALY) over a wide range of effectiveness indices.

“By moving away from an ‘all or nothing’ approach for covering innovative anti-obesity medications, a considerable potential savings incurred,” the authors wrote. “Moreover, the available evidence supports that not all individuals who stopped the GLP-1–based anti-obesity medications would regain all the weight they lost during the trial period.”

The results found by Kim and his colleagues follows a separate modeling done last year with adolescents. In this study, 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 August 2023 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. These researchers found that Qsymia, a combination of phentermine/topiramate, was more cost-effective than semaglutide for teen obesity. 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.

Researchers in the current study highlighted several limitations, including their use of “best price” to assess cost differences. The model also did not take into account any decreased costs that might results from increased competition, Medicare price negotiation or generic entry.