Real-World Study Finds Low Patient Adherence for Weight Loss Drugs

Patients taking weight loss drugs such as Wegovy (semaglutide) and Saxenda (liraglutide) had low patient adherence and higher total cost of care, according to an analysis of real-world integrated pharmacy and medical claims data by Prime Therapeutics.

At one year, 68% of patients who had started taking Wegovy or Saxenda for weight loss were no longer taking the medication. Those who initiated the glucagon-like peptide-1 agonist (GLP-1a) drugs at one year follow-up had higher total cost of care.

Currently, only two GLP-1a therapies are approved for weight loss: Novo Nordisk’s Wegovy (approved in June 2021) and Saxenda (approved in December 2014). Liraglutide is also available as Victoza to treat type 2 diabetes. Semaglutide is also available Ozempic to treat patients with diabetes. Additionally, Novo Nordisk sells Rybelsus, an oral semaglutide, to treat diabetes.

The GLP-1a products have gotten a lot of media coverage because of their ability to help with weight loss, and some have been used off-label for that purpose. These products work by mimicking a hormone that targets areas of the brain that regulate appetite and food intake.

David Lassen, Pharm.D.

The high number of patients who stopped the medication is concerning, David Lassen, Pharm.D., chief clinical officer at Prime Therapeutics, said in an interview with Formulary Watch.

“In the primary studies that were done for FDA approval for the weight loss medications, those studies I would characterize as highly managed, meaning they had support for the patients, which helped with adherence and lifestyle modification,” he said. “We need to work together to make sure that we get the right members on the medication, and they need to be successful.”

Prime Therapeutics and MagellanRx analyzed integrated pharmacy and medical claims data from 16 million commercially insured members; the analysis was limited to members with newly initiated a GLP-1a between Jan. 1, 2021, and Dec. 31, 2021. They included 4,255 commercially insured members and assessed total costs of care compared with costs in a matched control group of 12,379 members. Patient adherence and costs were assessed at one year and also at a post year follow up.

The Prime analysis found that GLP-1a treated members’ post-period annual total costs averaged $19,657, a $7,286 (59%) increase. The control group averaged $11,150, a $440 (4%) decrease.

Lassen said the analysis is a good first start to understanding the real-world use of weight-loss therapies for weight loss. “We don't have enough information to assume that these medications have a return on investment or who are the right patients for these medications,” he said.

A return on investment in this sense would be an improvement in outcomes or reduction of unwanted events. This would, he said, include lower costs or lower total cost of care; fewer hospitalizations or office visits; improved blood pressure; fewer cardiovascular conditions or joint replacements, as well as fewer bariatric surgeries.

About 42% of U.S. adults are identified as obese by the CDC and prevalence has been increasing. Conditions such as stroke, heart disease, type 2 diabetes — among the leading causes of preventable death — are related to obesity.

Wegovy and the GLP-1a products, however, are high-cost therapies. The list price of Wegovy, for example, is $1,349.02 per package, or $16,188.24 per year. And more GLP-1a drugs for weight loss are coming. One is Lilly’s Mounjaro (tirzepatide), which is already available to treat type 2 diabetes. Lilly has completed its submission to the FDA for a weight loss indication. A study published in The Lancet in June found that tirzepatide (10 mg and 15 mg) led to weight reduction for both doses. Tirzepatide met both co-primary endpoints and all key secondary endpoints compared with placebo, with those taking tirzepatide achieving a mean weight reduction of 13.4% on 10 mg and 15.7% on 15 mg compared with 3.3% on placebo.

For patients to be successful on these weight loss drugs, Lassen said it will be important to provide support for patients to ensure continued use and lifestyle changes. “Lifestyle modification is a big piece of this. In the clinical trials, patients had an intensive lifestyle modification and a restrictive diet,” he said.

Prime plans to continue real-world research of weight-loss medications. Lassen said they are assessing the parameters of the study design to determine whether adjustments need to be made.

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

Prime, however, is not the only PBM assessing coverage of semaglutide for weight loss. Last month a survey by Pharmaceutical Strategies Group (PSG) found that employers, health plans and unions are grappling with how to cover the newer weight loss drugs. Of those surveyed, 22% require members to participate in a lifestyle modification program as a prerequisite for medication coverage. Another 20% said participation in such a program is voluntary.