Tirzepatide, sold under the brand name Mounjaro, was studied in people without diabetes in three doses: 5, 10 and 15 milligrams. Obese or overweight participants who took the 5-milligram dose lost an average of 35 pounds (16 kilograms), those on the 10-milligram dose lost an average of 49 pounds (22 kilograms), and participants on the 15- milligram dose lost an average of 52 pounds (23.6 kilograms).
“Nearly 40% of individuals lost a quarter of their body weight,” co-author Dr. Ania Jastreboff, associate director of the Yale Center for Weight Management, said in a media briefing.
“The data were quite impressive,” said Dr. Robert Gabbay, chief medical officer of the American Diabetes Association, speaking to CNN from the ADA’s 82nd Scientific Sessions in New Orleans, where the study results were presented.
“The weight loss they got in this study was even greater than what was seen in the previous studies of people with diabetes,” said Gabbay, who was not involved in the study.
“The middle range of weight loss for people in this new study was 49 pounds — 49 pounds is a lot,” he said. “This is the magnitude of weight loss that we typically think is only possible through surgery.”
“This is a not unusual observation,” he said. “The impact of previous weight loss medications is less effective in people with diabetes, and we honestly don’t know exactly why.”
However, the impact of tirzepatide on people with diabetes is still “profound,” Gabbay said, “providing much more than other tools we’ve had.”
For the new study, weekly injections of tirzepatide were tested in more than 2,500 people without diabetes who had a body mass index (BMI) of more than 30 or a BMI of more than 27 and had at least one weight-related health condition such as high blood pressure . , high cholesterol or cardiovascular disease. A measure of a person’s height-to-weight ratio, a BMI of 25 or higher is considered overweight in adults.
At the start of the study, the participants had an average weight of 231 pounds (104.8 kilograms) and an average BMI of 38.
Adults in the study injected themselves with tirzepatide or a placebo once a week, using “a little pen-like device with a little, little needle,” Gabbay said. “The prick of that needle is less painful than, say, people pricking their fingers to measure blood glucose.”
People in the study also received counseling sessions to help them stick to a healthy diet with a daily 500-calorie deficit, as well as at least 150 minutes of physical activity each week. While that certainly helped, it doesn’t explain the magnitude of the weight loss seen in the study, Gabbay said.
“The kind of weight loss we see when people exercise and change their caloric intake is somewhere on the order of 5% to 7%,” he said. “This study showed a significantly greater weight loss, far beyond what we would think with lifestyle changes.”
The most common side effects reported were nausea, diarrhea and constipation. Between 2.6% and 7.1% of participants discontinued treatment due to adverse events.
Mounjaro carries a boxed warning about thyroid tumors and should not be used by people with a family history of certain thyroid conditions.
“Obesity needs to be treated like any other chronic disease — with effective and safe approaches that target the underlying (causes of) disease … and these results highlight that tirzepatid may be doing just that,” said Jastreboff of the Yale Center for Weight Management . in an American Diabetes Association news release.
“These results are an important step forward in potentially expanding effective therapeutic options for people with obesity.”