A diabetes-turned-weight-loss medication could be on the verge of scoring a hat trick: It may also be a cardiovascular wonder drug.
But limited results from a new and closely watched clinical trial have raised a flurry of questions. Who benefited from the drug and how long did they need to be treated? What were the side effects? And are the newly reported cardiovascular effects driven by weight loss, or is the medication working in some other way?
First approved as a diabetes drug, the molecule semaglutide mimics the gut hormone GLP-1. This hormone typically suffuses into our bloodstreams after we eat and makes us feel full, among other actions. Semaglutide essentially gives people an extra dose of that full-feeling hormone.
Taking the drug can lead to dramatic weight loss — and now, it appears, better cardiovascular health, even in people without diabetes. At least, that’s the take-home message of early clinical trial results released by Novo Nordisk, the drug’s maker, on August 8. Weekly injections of semaglutide in overweight or obese adults cut the risk of serious heart or blood vessel problems by 20 percent, the company, headquartered near Copenhagen, reported.
“It’s quite a big deal,” says David Strain, a physician at the University of Exeter Medical School in England who helped recruit patients for the trial but was not involved in collecting data and has not seen the study’s full results. “This is the first time that a drug for weight loss has shown benefits above and beyond the weight loss itself.”
Headlines have hailed the trial as a landmark. The study’s early results served up the tantalizing idea that semaglutide might prevent strokes or heart attacks in a broad group of people. In the United States alone, more than 795,000 people have strokes every year and about 805,000 people have heart attacks.
But Novo Nordisk’s brief report is sparse on details and has left many doctors and scientists awaiting the trial’s full findings. Scientists involved with the trial plan to present more information later this year.
Before making any judgments or recommendations, says cardiologist Michelle Albert of the University of California, San Francisco, the study needs to be peer-reviewed. “If the results seem sound,” says Albert, a former president of the American Heart Association, the study “opens the door for a wider range of folks benefiting from this medication. But this is all a big if.”
Other studies have suggested semaglutide has cardiovascular benefits
Semaglutide’s path to the public has been a long one. Since the mid-2000s, scientists have launched more than 300 clinical trials testing the drug. In 2017, the U.S. Food and Drug Administration approved semaglutide for use in people with type 2 diabetes, sold under the brand name Ozempic. It is now for sale in self-administered injector pens containing up to 2 milligrams of semaglutide.
About four years after Ozempic got the green light, the FDA approved a higher-dose, 2.4-milligram version of semaglutide (under the brand name Wegovy) specifically for weight management. People treated with the drug tend to be less hungry, have fewer cravings and feel more satiated after eating than those not on the drug — all factors that may translate to weight loss. In one 2021 study, people treated with the drug for more than a year lost about 15 kilograms. People who instead received a placebo lost less than 3 kilograms.
