Courtesy Novo Nordisk
A study found that a 2.4-milligram weekly dose of semaglutide, sold as Wegovy for weight loss, led to an improvement of 17 points on a 100-point scale that’s used to assess symptoms of a condition known as heart failure with preserved ejection fraction.
CNN  — 

The diabetes and weight loss drug semaglutide significantly reduced symptoms and improved quality of life in people with obesity and the most common form of heart failure in a clinical trial, potentially expanding the already wildly popular drug’s use beyond diabetes and weight loss and offering a new treatment option where few are available.

The study of 529 patients, funded by drugmaker Novo Nordisk, found that a 2.4-milligram weekly dose of semaglutide, sold as Wegovy for weight loss, led to an improvement of 17 points on a 100-point scale that’s used to assess symptoms of a condition known as heart failure with preserved ejection fraction. By comparison, participants who got a placebo had a 9-point improvement. The study was published Friday in the New England Journal of Medicine.

In real terms, that difference means Wegovy helped people with heart failure have less shortness of breath, fatigue, trouble exerting themselves and swelling, as well as better exercise function and quality of life, all part of a scale known as the Kansas City Cardiomyopathy Questionnaire clinical summary score, said Dr. Mikhail Kosiborod, cardiologist and vice president for research at Saint Luke’s Mid America Heart Institute, Kansas City, Missouri, who led the trial.

“This is the largest treatment benefit we’ve ever seen for that endpoint in this patient population with any drug,” Kosiborod told CNN ahead of the European Society of Cardiology meeting in Amsterdam, where the results are being presented.

There are 64 million people globally living with heart failure, Novo Nordisk said in a statement about the trial results. It’s a condition in which the heart can’t pump enough blood to meet the body’s needs.

Preserved ejection fraction means the heart can pump normally but is too stiff to fill properly. This type of heart failure accounts for more than half of all cases in the US and is increasing in prevalence, according to Kosiborod and his co-authors.

He noted that 80% of patients with this kind of heart failure in the US have obesity or are characterized as overweight. Another goal of the study was weight loss, and the drug succeeded there, too: Participants on semaglutide lost about 13% of their body weight, compared with 2.6% for those on placebo, over the course of the year-long trial.

Until recently, the main treatment options for people with this kind of heart failure were diuretics, sometimes called water pills, Kosiborod said. They increase urination to reduce the amount of fluid in the body and can temporarily alleviate symptoms, but they are “woefully insufficient,” he explained.

Another class of drugs known as SGLT2 inhibitors, also used for Type 2 diabetes, has been shown to reduce the risk of heart failure hospitalization, but “it’s not enough for most people,” Kosiborod said. The improvements in symptoms “are relatively modest.”

The trial of semaglutide assessed exercise function using a metric known as the six-minute walk test. It found that by the end of the trial, the drug helped participants walk 20 meters farther than people who got a placebo.

There were fewer serious safety events in the drug group than in the placebo group, although more patients stopped taking semaglutide, primarily because of gastrointestinal issues that are common side effects with this class of medicines, known as GLP-1 receptor agonists.

One limitation in the trial was its lack of diversity: 96% of the participants were White.

“We as a clinical trial community know that we need to do better in terms of patients that are Black, Hispanic, and from other backgrounds that are underrepresented in clinical trials,” Kosiborod said.

He noted another heart failure trial of semaglutide that includes patients with diabetes should have results soon, and pooling the data together could give a better picture of how the drug works for people of different racial and ethnic backgrounds.

The new data builds on other recent results suggesting Wegovy could be prescribed for reasons beyond weight loss. In early August, Novo Nordisk announced that Wegovy reduces the risk of heart attack, stroke or heart-related death in people with cardiovascular disease and obesity by 20%, a result expected to boost use of the medicine even further. Already, the company can’t keep up with demand and has had to restrict access to some lower starter doses of the medication so it can meet supply needs for established patients.

Wegovy and its sister drug for Type 2 diabetes, Ozempic, as well as a similar drug from Eli Lilly called Mounjaro, have been transforming the way doctors approach weight loss with medicines after decades of drugs with weak efficacy and dangerous safety issues.

Get CNN Health's weekly newsletter

Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

They’re also changing the way researchers think about obesity, and the results in heart failure contribute to that paradigm shift, Kosiborod said.

“Clearly, we cannot continue to treat obesity just as something that accidentally happens to occur in these patients,” he said. “It’s likely a root cause of the complications and should be treated as such.”

He pointed out, though, that the drug may be helping in ways beyond those related to weight loss: through reducing inflammation and congestion, for example.

Kosiborod said that as a physician taking care of patients, he found the results “extremely gratifying, because what I now can tell them is that we have pretty definitive evidence that if we prescribe this medication, you will feel better and be able to do more, and it’s going to have a significant impact on your quality of life.”