3 OCT 2026 — Obesity drug trials can report weight loss in two ways: as if every patient stayed on the drug, or counting everyone randomised, including those who stopped. Boehringer Ingelheim's announcement of its survodutide trial in people with type 2 diabetes led with the first, a loss of up to 13.1% over 76 weeks. The paper, published on 1 October in the New England Journal of Medicine, leads with the second: 9.8% at the higher dose, against 3.9% on placebo.
Both figures are accurate. The difference comes from how the trial counts people who stopped the drug or changed treatment.
What the trial tested
SYNCHRONIZE-2 enrolled 752 adults with type 2 diabetes and a body-mass index of 27 or more, with an average BMI of 36.5 and an average age of 55.7. They were randomly assigned to weekly injections of survodutide at 3.6 mg or 6.0 mg, or to placebo, for 76 weeks.
Survodutide acts on two hormone receptors: GLP-1, the target of drugs such as semaglutide, and glucagon. Boehringer says the glucagon action helps reduce liver fat. The drug is not approved anywhere.
The two numbers
Counting everyone regardless of whether they kept taking the drug, the paper reports average weight loss of 8.2% at 3.6 mg and 9.8% at 6.0 mg, against 3.9% on placebo. At least 5% of body weight was lost by 57.6%, 64.5% and 35.1% of participants in those groups.
Boehringer's announcement reports the measure that assumes patients remained on treatment for the whole study: up to 13.1% against 3.1% on placebo, with up to 79.3% losing at least 5%. Both ways of counting met the trial's goals.
Why so many stopped
Gut side effects, including nausea, vomiting, diarrhoea and constipation, were reported by 72.8% of people at 3.6 mg and 77.7% at 6.0 mg, against 38.6% on placebo. The paper describes them as generally mild to moderate and transient.
Even so, 18% of people on survodutide stopped treatment because of them, compared with 1.2% on placebo, according to Boehringer. The company says most stopped while the dose was being raised, and that the trial's protocol allowed little flexibility to manage side effects. Later trials allow more flexible dose increases, it says.
Blood sugar and other measures
Counting everyone, average HbA1c, a measure of long-term blood sugar, fell by 0.9 percentage points at 3.6 mg and 0.8 at 6.0 mg from a starting level of 7.4%, against 0.2 on placebo. Boehringer also reports smaller waist measurements and improved insulin sensitivity.
People with type 2 diabetes are a population in which weight loss is typically more challenging, Boehringer says. It also presented new body-composition results from SYNCHRONIZE-1, its companion trial in people without diabetes, which showed preferential loss of visceral and liver fat, according to the company.
What comes next
Boehringer says it expects to report its cardiovascular outcomes trial, SYNCHRONIZE-CVOT, later this year. That trial is meant to establish the drug's cardiovascular safety. Survodutide is also being tested for MASH, a form of fatty liver disease, where the company says its effect on liver fat could help. It faces a crowded field, including safiglipron, a Chinese oral GLP-1 drug whose phase 3 results we covered on 30 September.
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