A new type of injected weight loss drug is moving into late-stage clinical trials, and it works differently from GLP-1 medicines like Ozempic, Wegovy, Mounjaro, and Zepbound.
On the basis of these results, the company said it plans to start late-stage clinical trials next month.
How Is Eloralintide Different?
The popular injected drugs semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) target the gut hormone GLP-1 (glucagon-like peptide-1) and aid weight loss by curbing appetite and slowing digestion. Eloralintide is in a different family of medicines that work by mimicking the pancreatic hormone amylin to slow digestion and reduce hunger.
“Given the high rates of obesity and diabetes, additional treatment options are very welcome,” says Marilyn Tan, MD, a clinical professor of endocrinology at the Stanford University School of Medicine and the chief of the endocrine clinic at Stanford Health Care in California.
An existing drug mimicking amylin, pramlintide (Symlin) has been available in the United States for years as a diabetes treatment, Dr. Tan says. But it hasn’t been used much because it requires shots three times daily with meals.
People on the Highest Dose Lost Nearly 50 Pounds
In a mid-stage clinical trial, researchers randomly assigned 263 adults with obesity but not diabetes to receive weekly shots of eloralintide or a placebo for 48 weeks. At the beginning of the study, participants weighed an average of about 240 pounds (lb).
By the end of the study, people taking the lowest dose of eloralintide lost 9.5 percent of their body weight on average, or about 23 lb. People on the highest dose lost about 20 percent, or around 47 lb, according to results reported by Eli Lilly.
People taking eloralintide also experienced improvements in other risk factors for obesity-related health problems, according to Lilly, including:
- Waist circumference
- Blood pressure
- Blood sugar
- Inflammation
The most common side effects with eloralintide were mild to moderate gastrointestinal issues and fatigue, which occurred more often with higher doses of the drug, per the company. Gradually increasing the dosing of the drug helped to minimize side effects, the company also said.
Weight loss results so far with eloralintide aren’t as dramatic as what patients can achieve with bariatric surgery, but do seem in line with some other obesity medicines, says Melanie Jay, MD, a professor of population health at New York University Langone Health in New York City and the director of the NYU Langone obesity research program.
“We don’t have long-term data on this particular medicine, but the rate of weight loss seems to be similar to tirzepatide,” Dr. Jay says.
Rapid Weight Loss May Lead to Muscle Loss
There is worry among obesity doctors that rapid weight loss such as that caused by eloralintide may present issues. “Whether weight loss can be sustained over time is complex, and also often depends on whether patients stay on the medications that helped them lose the initial weight,” Tan says. “With rapid weight loss, there is also concern for loss of lean muscle mass.”
This doesn’t happen to everyone, and there isn’t enough research yet to determine which individuals may be most at risk for losing muscle when they take weight loss medications, says Jay. For this reason, it’s important for people to do exercises designed to build up muscles while they’re taking GLP-1 drugs or amylin drugs like eloralintide, Jay advises.
“We need to make sure people are doing resistance training, which we hope will stave off too much muscle mass loss,” Jay says.
Amylin vs. GLP-1 Drugs for Weight Loss
Because eloralintide is still an experimental medicine that hasn’t yet been tested in late-stage human trials, it’s really too soon to say for sure whether it’s safer or more effective than GLP-1 medicines, Jay says.
Uncomfortable stomach side effects have been seen with both GLP-1 drugs and with the eloralintide data released so far, Tan notes. This makes it possible that side effects could lead some patients to discontinue treatment whether they take a GLP-1 or an amylin drug, Tan says.
“Cost and tolerability are common reasons for patients to discontinue GLP-1 agonists or not even be able to start them in the first place,” Tan says. Similar issues are likely with an amylin drug like eloralintide, Tan adds, noting that new medicines also tend to be expensive.
Still, competition and new treatment options should benefit patients with obesity, Jay says. “It would be great someday to be able to tell which medications may work best for different individuals so we could help decide which meds to start,” Jay says.
