A monthly weight loss drug from Amgen helped people lose about 20% of their body weight, according to the results of a phase 2 clinical trial.
If approved, the drug, called MariTide, could make Amgen the first new entrant into a market that’s been dominated by Novo Nordisk, which makes Ozempic and Wegovy, and Eli Lilly, which makes Mounjaro and Zepbound.
These powerful weight loss and Type 2 diabetes medications are all GLP-1 drugs. MariTide is, too, but differs in that it also contains a monoclonal antibody, which helps the drug stay in the body longer so people can take it monthly, rather than weekly.
“It’s always just easier for patients to only have to take something once per month,” said Dr. Michelle Ponder, an assistant professor of medicine at Duke University School of Medicine in North Carolina who wasn’t involved in Amgen’s trial. “A lot of patients we see in endocrinology are diabetes patients, and so they’d be taking multiple shots of insulin per day. And so, every last shot matters, even if it’s three less shots per month.”
Amgen’s results were published Monday in the New England Journal of Medicine and presented at the American Diabetes Association’s annual meeting in Chicago.
The trial included nearly 600 adults split into two groups: people with Type 2 diabetes and obesity, and people with obesity alone.
Participants got one of three doses of MariTide or a placebo, taken once a month for a year. Some of the people in the obesity group started at a lower dose that was gradually increased over several weeks.
The trial found that participants with obesity alone who got MariTide lost up to 20% of their body weight, on average, after 52 weeks, compared with just 2.6% in the placebo group. Among participants with diabetes, people who got MariTide lost up to 17% of their body weight, on average, compared with 1.4% in the placebo group.
The results place MariTide on par with Wegovy, which reduced body weight by about 15% after 68 weeks in trials in people without diabetes, and Zepbound, which led to an average weight loss of 22.5% after 72 weeks. (These are not direct comparisons, however, as the drugs were not tested against each other in head-to-head trials.)
Beyond weight loss, MariTide also lowered A1c — a key marker of blood sugar — by as much as 2.2 percentage points in people with diabetes. Ozempic and Mounjaro saw A1c reductions of around 1.5 to 2 percentage points in trials.
Participants also saw improvements in heart disease risk factors, including blood pressure, inflammation and cholesterol levels.
Ponder said that all the GLP-1 medications have shown heart benefits, likely due in part to the amount of weight loss patients experienced.
Side effects reported for MariTide were similar to those seen with other GLP-1 medications, mainly gastrointestinal issues.
Dr. Jay Bradner, Amgen’s executive vice president of research and development, said that weight loss with MariTide hadn’t yet plateaued at the one-year mark, suggesting the potential for further weight loss with longer treatment.
The company is also testing the drug with every-other-month dosing. Early results, Bradner said, showed weight loss was comparable to the monthly version, although patients reported more side effects.
A growing field
MariTide is part of the next generation of highly effective treatments for diabetes and weight loss that aim to offer greater weight loss with fewer side effects than semaglutide (the drug in Ozempic and Wegovy) and tirzepatide (in Mounjaro and Zepbound).
Most of these new drugs are still likely several years away from approval. Amgen, for example, plans to run a 72-week long Phase 3 trial of MariTide as its next step, Bradner said.
Lilly and Novo Nordisk also presented findings at the diabetes conference.
An experimental drug from Lilly, eloralintide, led to an average 11.3% weight loss over 12 weeks in a Phase 1 study, according to new results published last week at the diabetes conference.
Unlike drugs that target the GLP-1 hormone, eloralintide targets amylin, a hormone that slows stomach emptying. Lilly said the drug’s side effects were less common compared with other drugs it has studied, with 8% of patients on the drug reporting nausea and 4% reporting vomiting.
Another drug from Lilly, called retatrutide, was shown to help people lose about 24% of their body weight, on average, in a mid-stage trial. A Phase 3 trial is expected to be completed later this year.
Lilly also found that a combination of semaglutide and bimagrumab — a monoclonal antibody that promotes muscle growth — helped preserve lean muscle mass in patients in a Phase 2 trial.
And the company’s experimental weight loss pill, orforglipron, was shown to lower A1c in people with Type 2 diabetes, according to Phase 3 trial results published Saturday in the New England Journal of Medicine.
Novo Nordisk’s newest drug, CagriSema, led to greater weight loss than semaglutide, according to results presented Sunday at the conference.
The two Phase 3 trials tested CagriSema — a combination of semaglutide and another drug called cagrilintide — in more than 4,500 adults with obesity. In people without diabetes, those who took CagriSema lost an average of 20.4% of their body weight after 68 weeks. Among adults with Type 2 diabetes, average weight loss was 13.7%.
Dr. Shauna Levy, a specialist in obesity medicine and the medical director of the Tulane Bariatric Center in New Orleans, said the growing number of options is a bonus for patients who may not respond well to one of the existing treatments.
“It’s long been thought that obesity is an easy disease to treat, but in reality, it’s actually very difficult,” Levy said. “There’s not going to be one right answer for the patients, so the more tools we have to treat the disease, the more likely you will be successful in hopefully eliminating or significantly decreasing this epidemic.”
Dr. Christopher McGowan, a gastroenterologist who runs a weight loss clinic in Cary, North Carolina, said growing competition could also push drugmakers to lower their prices.
Wegovy and Zepbound, for example, can cost patients more than $1,000 a month. But in recent months, both Novo Nordisk and Lilly have introduced lower-cost options for those paying out of pocket.
“Access, affordability, remains the No. 1 barrier for patients obtaining any of these medications,” he said.
Ponder, of Duke University, said: “The more options, the better. Even if new options come out that aren’t necessarily stronger, just having an additional manufacturer making the medicine is really helpful to expand access to patients.”
CORRECTION (June 23, 2025, 4:29 p.m. ET): An earlier version of this article misstated which drugmaker is studying the combination of semaglutide and bimagrumab. It is Eli Lilly, not Novo Nordisk.
This article was originally published on NBCNews.com
