Survodutide cut body weight by 8% to 10% in people with type 2 diabetes, and most had gut side effects

Another weekly injection for weight loss has reached the last stage of testing, and this one works a little differently from the drugs already in pharmacies. Survodutide switches on the same gut-hormone receptor as semaglutide and adds a second, the receptor for glucagon. Its first large trial in people with type 2 diabetes was published in the New England Journal of Medicine on October 1.

The drug worked. People taking it lost more than twice as much weight as people on placebo, and their blood sugar improved. Two things complicate the picture. The weight loss the company put in its headline is larger than the figure the paper leads with, for a reason worth understanding. And stomach and bowel side effects were frequent enough that up to 18% of those on the drug gave up treatment because of them.

What survodutide is and why it was tested in type 2 diabetes

Excess weight and type 2 diabetes travel together, and treating the first helps the second. The paper begins there: for persons living with both type 2 diabetes and obesity, weight management may be the most effective therapy for type 2 diabetes.

The current drugs copy a gut hormone. Glucagon-like peptide-1 (GLP-1) receptor agonists have potent weight-reducing effects, the authors write, an agonist being a compound that switches a receptor on. Semaglutide is the best known. Tirzepatide adds a second hormone target.

Survodutide takes a different second target. The paper describes it as an investigational glucagon receptor-GLP-1 receptor dual agonist with potential weight-reducing and metabolic benefits. Glucagon is a hormone that acts on the liver and on how the body uses energy. Investigational means still being tested.

People with diabetes are a harder test for these drugs than people without it. They tend to lose less weight on the same medicine, so each drug is tried in a separate diabetes trial.

The trial was called SYNCHRONIZE-2. It enrolled adults with type 2 diabetes and a body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) of 27 or more. They were assigned by chance, in equal numbers, to receive once-weekly subcutaneous survodutide (3.6 mg or 6.0 mg) or placebo. Subcutaneous means injected under the skin. Neither participants nor investigators knew who was receiving which.

There were 752 participants in all. Among them the mean age at baseline was 55.7 years, and the mean BMI was 36.5; 49.3% were men.

Two goals were set in advance. The two primary end points were the percent change in body weight and a reduction in body weight of at least 5% from baseline to week 76. An end point is the outcome a trial is designed to measure.

How much weight people lost on survodutide

At 76 weeks	Survodutide 3.6 mg	Survodutide 6.0 mg	Placebo
Participants	250	251	251
Average change in body weight	8.2% lower	9.8% lower	3.9% lower
Lost at least 5% of body weight	57.6%	64.5%	35.1%
Change in HbA1c, from 7.4%	0.9 points lower	0.8 points lower	0.2 points lower
Stomach and bowel side effects	72.8%	77.7%	38.6%

Weight fell in all three groups, and it fell furthest on the higher dose. The plausible range around the 9.8% figure ran from 8.8% to 10.8%, and around the placebo figure from 2.9% to 4.9%. Set against placebo, the higher dose took off an extra 5.9 percentage points and the lower dose an extra 4.3.

In everyday terms, a person starting at 220 pounds would lose about 22 pounds on the higher dose by this measure, against about 9 on placebo.

The second goal was met as well. Weight reduction of at least 5% occurred in 57.6%, 64.5%, and 35.1% of the participants, respectively. About a third of people on placebo reached that mark too, which is a reminder that everyone in such a trial also receives advice on diet and activity.

Why the company’s weight figure is higher than the paper’s

The announcement of these results led with a different number. A trade report on the presentation said survodutide led to average weight loss of up to 13.1% at 76 weeks in adults with obesity or overweight and type 2 diabetes (T2D), against 3.1% on placebo.

Both numbers come from the same trial. They answer different questions. Statisticians call each question an estimand.

The 9.8% figure uses what the paper calls the treatment-regimen estimand. It assessed effects regardless of whether the trial regimen was discontinued or interrupted or whether other antiobesity therapies were used. Everyone assigned to the drug is counted, including people who stopped taking it. It describes what happened to the group as a whole.

The 13.1% figure uses the efficacy estimand, which estimates what would have happened had everyone kept taking the drug as intended. It describes what the drug can do for someone who stays on it.

Neither is wrong. The trial met both coprimary end points using the treatment-regimen and efficacy estimands. But the gap between them is unusually wide here, more than three percentage points, and that gap is itself a result. It is the mark left by the people who stopped.

Blood sugar and side effects of survodutide

Blood sugar control improved along with weight. The measure was glycated hemoglobin, usually written HbA1c, a blood test that reflects average blood sugar over about three months. The mean change in the glycated hemoglobin level (from a baseline level of 7.4%) was -0.9 percentage points in the 3.6-mg group, -0.8 percentage points in the 6.0-mg group, and -0.2 percentage points in the placebo group.

On the stay-on-treatment measure the trade report gives larger figures, and adds that up to 29.5% of those receiving survodutide reverted to normoglycemia, meaning blood sugar in the normal range, against 4.0% on placebo. Waist circumference decreased by 11.1 cm vs 3.5 cm with placebo.

Sean Wharton, director of Wharton Medical Clinic and the paper’s first author, drew the link in a company statement. “Seeing improvements in glycemic control and insulin sensitivity alongside weight loss provides evidence that tackling obesity can positively influence broader metabolic health,” Wharton said. Glycemic control means control of blood sugar.

The cost was to the gut. The most common adverse events were gastrointestinal (generally mild to moderate and transient), which occurred in 182 participants (72.8%) in the 3.6-mg group, 195 (77.7%) in the 6.0-mg group, and 97 (38.6%) in the placebo group. An adverse event is any medical problem recorded during a trial, and gastrointestinal means of the stomach and bowel.

Mild or not, they drove people out. Gastrointestinal (GI) events were the most commonly reported adverse events, the trade report says, and discontinuations due to GI adverse events reached 18% with survodutide vs 1.2% with placebo.

The company points to the timetable on which the dose was stepped up. According to the same report, treatment was stopped most often during the dose-escalation phase, when the trial’s rules left little room to adjust for side effects. Boehringer Ingelheim, the drug’s maker, says its ongoing and planned trials build in more individual adjustment of the dose. Whether that keeps more people on treatment is something those trials will have to show.

How survodutide compares with other obesity drugs in diabetes

No trial has put survodutide against the drugs already on the market. What exists is each drug’s own trial in people with type 2 diabetes, run by its own maker.

Drug and trial	Length	Weight loss on the drug	On placebo
Semaglutide 2.4 mg, STEP 2	68 weeks	9.6%	3.4%
Survodutide 6.0 mg, SYNCHRONIZE-2	76 weeks	9.8%	3.9%
Tirzepatide 10 mg and 15 mg, SURMOUNT-2	72 weeks	12.8% and 14.7%	3.2%

The semaglutide trial screened 1,595 people, of whom 1210 were randomly assigned to semaglutide at one of two doses or to placebo. The tirzepatide trial enrolled 938. Its authors summed up their result as coming from a 72-week trial in adults living with obesity and type 2 diabetes in which the weight reduction was large and clinically meaningful.

On these figures survodutide lands close to semaglutide and short of tirzepatide. That reading needs care. The trials differ in their participants, their length and how they handled people who dropped out, and the placebo groups did not behave identically. A table like this shows roughly where a drug sits. It cannot rank drugs a few points apart.

Survodutide’s own earlier results had suggested more. In its phase 2 trial in people without diabetes, weight fell by up to 14.9% in under a year, though only six in ten participants completed the 46-week treatment period. In a sister phase 3 trial, also in people without diabetes, the stay-on-treatment figures were 15.3% and 16.6%. The diabetes trial’s 13.1% on that measure is lower, which fits the usual pattern for this class.

Part of the interest in the drug lies in the liver. Glucagon acts there, and an earlier phase 3 trial included 216 adults (131 female and 85 male) with obesity and fatty liver disease. In that trial liver fat fell by at least 30% in most of those treated. For a person whose main problem is weight and blood sugar, that is a side benefit. For someone with liver disease it could be the point.

What the trial leaves open about survodutide

Heart attacks and strokes. Weight and blood sugar are stand-ins for the outcomes that matter most. A trial designed to count those events is under way, and the company expects to present results from its cardiovascular outcomes trial later this year.

Tolerability outside a trial. Up to 18% of those on the drug stopped because of gut side effects, in a setting with close support. More flexible dosing has not yet been shown to help.

Head-to-head evidence. The comparison with semaglutide and tirzepatide rests on separate trials.

After stopping. The trial covers 76 weeks on treatment. It does not show what happens to weight or blood sugar when the injections end.

Who paid. The trial was funded by Boehringer Ingelheim, which makes the drug. Each comparison trial cited here was likewise funded by the maker of the drug it tested.

Approval. The drug is not available. The trade report is plain about it: survodutide remains investigational and is not approved for use, and its efficacy and safety have yet to be established.

Which diabetes or weight medicine is right for a person depends on their other conditions and how they tolerate treatment, which is assessed by their doctor. Do not stop or change a prescribed medicine without talking to your doctor.

In a company-funded trial of 752 adults with type 2 diabetes, weekly survodutide lowered body weight by 8.2% to 9.8% over 76 weeks against 3.9% on placebo and improved blood sugar, with stomach and bowel side effects in about three-quarters of those treated and no evidence yet on heart outcomes or how it compares directly with drugs already in use.