Drugmaker Novo Nordisk has released two new study results that could strengthen the case for insurers and government agencies to cover the cost of Wegovy, the popular but expensive weight-loss treatment. Patients taking the drug maintained an average weight loss of 10% after four years, and results from a previous study showed that Wegovy reduced the risk of serious heart problems, such as strokes and heart attacks, by 20%.

“This is the longest study we have conducted to date on semaglutide for weight loss,” said Martin Holst Lange, Novo’s head of development, referring to the active ingredient in Wegovy and the company’s diabetes drug Ozempic. “We see that once most of the weight loss is achieved, you don’t go back and start to gain weight if you continue taking the drug.”

According to the report, “clinically meaningful weight loss” was achieved across all genders, races, body sizes and participants across different geographic regions. Wegovy mimics the hormone GLP-1, which causes insulin secretion and regulates appetite. To date, approved uses for GLP-1 agonists include treating diabetes, obesity and, most recently, reducing the risk of major cardiovascular events. People taking Wegovy enjoyed these benefits regardless of their weight when they first started taking the drug or how much weight they lost while taking it.

“Our findings show that the magnitude of this treatment effect with semaglutide is independent of the amount of weight lost, suggesting that the drug has other actions that lower cardiovascular risk than reducing unhealthy body fat,” says Professor John Deanfield of University College London , who led the study.

Results from the same multinational study, sponsored by Novo Nordisk, were cited earlier this year by the U.S. Food and Drug Administration when it approved Wegovy for reducing the risk of serious cardiovascular events.

Previous studies have shown that stopping use of GLP-1 agonists results in patients regaining some or all of the weight they lost while taking the medication. A 2022 study found that participants regained about two-thirds of the weight they lost about a year after finishing treatment. Researchers in the new trial acknowledged some limitations, including the lack of figures on racial subgroups that could reveal “potential differential effects.” The study also did not take into account information about body composition, such as fat mass and muscle mass.

Much of the discussion about Wegovy and similar weight loss drugs has been less about efficacy than about cost. The United States list price for Wegovy is $1,349 for a month’s supply.

“The implications of weight loss of this magnitude in such a diverse population suggest that it may be possible to impact the public health burden of the multiple morbidities associated with obesity,” the report said.