An experimental weekly injection called survodutide helped adults with obesity or overweight and type 2 diabetes lose up to 13.1% of their body weight over 76 weeks, compared with 3.1% on placebo. The phase 3 results were published Oct. 1 in The New England Journal of Medicine and presented at the European Association for the Study of Diabetes annual meeting.
The drug is not approved by the FDA, and the trial was run by its developer, Boehringer Ingelheim. It also had a notable drawback: 18% of people on survodutide stopped treatment because of stomach side effects, compared with 1.2% on placebo.
For the millions of Americans living with both obesity and type 2 diabetes, more treatment options could eventually help if current drugs are hard to tolerate, unavailable, or not covered. That possibility is still years away, and the results do not change current care.
SYNCHRONIZE-2 Trial Results
The SYNCHRONIZE-2 trial enrolled 755 adults with obesity or overweight and type 2 diabetes. Participants received weekly injections of survodutide at 3.6 mg or 6.0 mg, or a placebo, according to AJMC's report on the study.
Up to 79.3% of people on survodutide lost at least 5% of their body weight, compared with 32.7% on placebo. Average blood sugar, measured by HbA1c, fell by up to 1.21 percentage points from a starting level of 7.4%, compared with 0.03 points on placebo.
Up to 29.5% of people taking survodutide reached an HbA1c below 5.7%, the normal range, compared with 4.0% on placebo. Waist size dropped by 11.1 centimeters, compared with 3.5 centimeters on placebo.
People with type 2 diabetes often lose less weight on these drugs than people without it, and that pattern appeared here. In the earlier SYNCHRONIZE-1 trial, which enrolled adults with obesity or overweight but without type 2 diabetes, survodutide produced up to 16.6% average weight loss, according to Zealand Pharma figures reported by BioSpace.
The 13.1% figure is based on what researchers call the efficacy estimand, which assumes patients stayed on treatment for the entire study. Results that count everyone, including people who stopped the drug, are typically smaller, and the company's headline figure does not show that difference.
"Seeing improvements in glycemic control and insulin sensitivity alongside weight loss provides evidence that tackling obesity can positively influence broader metabolic health," said Dr. Sean Wharton, coordinating investigator of the SYNCHRONIZE-2 trial.
Two Hormone Pathways in One Shot
Survodutide acts on two hormone receptors. Like semaglutide, it activates the GLP-1 receptor, which slows stomach emptying, reduces appetite, and helps the body release insulin after meals.
It also activates the glucagon receptor. Glucagon is a hormone that raises energy use and acts on the liver, one reason the company is also testing survodutide for metabolic dysfunction-associated steatohepatitis (MASH), a serious form of fatty liver disease.
That second pathway sets it apart from tirzepatide, sold as Zepbound and Mounjaro, which pairs GLP-1 with a different hormone called GIP. Whether adding glucagon helps patients more in the long run has not been shown.
The company also reported body composition data from a 75-person substudy of SYNCHRONIZE-1. Muscle accounted for no more than 10% of total tissue lost, and reductions in fat around the organs and in the liver were also reported, according to AJMC's coverage of the metabolic data. That substudy was small and did not include people with type 2 diabetes.
MedicalDaily Evidence Check
SYNCHRONIZE-2 was a randomized, double-blind, placebo-controlled phase 3 trial, the strongest design short of long-term outcome studies. It was sponsored by Boehringer Ingelheim, which licensed the drug from Zealand Pharma. Both companies stand to profit if it reaches the market. The trial is registered as NCT06066528.
The trial measured weight and blood sugar, not heart attacks, strokes, or deaths. A separate cardiovascular outcomes trial is ongoing. The 76-week length also cannot show what happens over many years or after people stop the drug.
Comparisons with approved drugs are uncertain. Results from separate trials suggest survodutide falls between semaglutide and tirzepatide for weight loss in people with type 2 diabetes, European Biotechnology Magazine reported, but differences between trials prevent firm conclusions. Analysts at William Blair, quoted by BioSpace, described the earlier SYNCHRONIZE-1 results as "more akin to Wegovy than Zepbound."
Tolerability is the clearest open question. The discontinuations from nausea, vomiting, diarrhea, and constipation happened mostly while doses were being increased, and Boehringer said the study protocol allowed limited flexibility to manage side effects. Current and upcoming trials allow more flexible dosing schedules, but they have not yet shown whether slower increases reduce dropouts.
Guidance for People with Diabetes
Survodutide is not available outside clinical trials, and no FDA filing date has been announced. People with type 2 diabetes should not change their current medication based on these results.
Several approved drugs already treat both blood sugar and weight, including semaglutide and tirzepatide. A clinician can explain which fits a person's health history, other medications, and insurance coverage.
Cost and access remain barriers for current drugs, and there is no price for survodutide. People who qualify for an approved GLP-1 drug but face a coverage denial can ask their clinician about prior authorization, appeals, or manufacturer savings programs. People interested in joining a trial can search ClinicalTrials.gov or ask their endocrinologist.
Anyone using an approved GLP-1 drug who has severe stomach pain, persistent vomiting, or signs of dehydration should contact a clinician promptly.
Boehringer expects results from the cardiovascular outcomes trial later in 2026. Those data, along with full regulatory review, will help determine whether survodutide becomes an option for patients.
Key Questions Answered
What is survodutide? An experimental weekly injection from Boehringer Ingelheim that activates both GLP-1 and glucagon receptors to reduce weight and improve blood sugar.
How much weight did people lose? Up to 13.1% of body weight over 76 weeks, compared with 3.1% on placebo, in adults with obesity or overweight and type 2 diabetes.
Is survodutide approved? No. It is not FDA-approved, and no filing date has been announced.
What were the side effects? Mostly nausea, vomiting, diarrhea, and constipation. About 18% stopped treatment because of stomach side effects, compared with 1.2% on placebo.
Who funded the study? Boehringer Ingelheim sponsored the trial. It licensed survodutide from Zealand Pharma.
Should I switch my diabetes medication? No. Talk with a clinician about approved options, and do not change medication based on these results.
Published by Medicaldaily.com
