Boehringer/Zealand obesity drug delivers Phase III weight loss, but side effects raise questions
Boehringer Ingelheim has reported new Phase III data for survodutide, its once-weekly dual GLP-1/glucagon receptor agonist for obesity, highlighting reductions in body weight, visceral fat and liver fat. The results, presented at the American Diabetes Association Scientific Sessions, strengthen the company’s case that survodutide could offer a differentiated profile in metabolic disease, although gastrointestinal tolerability remains a key question.
In the Phase III Synchronize-1 trial, adults with obesity or overweight without type 2 diabetes treated with survodutide lost up to 16.6% of body weight after 76 weeks, compared with 3.2% in the placebo group. Boehringer also reported reductions of up to 34% in visceral fat, the fat surrounding internal organs, compared with 12% for placebo. The company said weight loss was mainly driven by reductions in fat mass, with no more than 10.8% of total tissue-mass change coming from lean tissue at the highest dose.
The liver data may be the more distinctive part of the readout. In a prespecified analysis of Synchronize-1, survodutide reduced liver fat by up to 63.1%, compared with 25% for placebo. In the separate Phase III Synchronize-MASLD trial, conducted in adults with overweight or obesity and metabolic dysfunction-associated steatotic liver disease, up to 84.2% of patients receiving survodutide achieved at least a 30% relative reduction in liver fat, compared with 24.3% in the placebo arm.
The mechanism gives Boehringer a potential positioning angle in an increasingly crowded obesity market. Unlike GLP-1-only drugs, survodutide activates both the GLP-1 receptor, linked to appetite and satiety, and the glucagon receptor, which is thought to play a role in energy expenditure and liver-fat metabolism. That could make the drug relevant beyond weight loss alone, particularly for patients with obesity-related liver disease.
A question of competitiveness
However, the Phase III update also underlined the challenge of competing with established incretin drugs. In Synchronize-1, 19% of patients discontinued survodutide because of gastrointestinal side effects, compared with 2.9% in the placebo group. The main side effects were consistent with the GLP-1 class, including nausea, vomiting and diarrhoea, and Boehringer said most occurred during dose escalation.
The tolerability profile is likely to shape how the data are interpreted commercially. Survodutide’s weight-loss effect appears broadly in the range of earlier GLP-1 therapies, but below the levels reported for Eli Lilly’s tirzepatide in obesity. Its clearest differentiation may therefore come from fat quality and liver effects rather than from headline body-weight reduction alone.
Survodutide was originally discovered by Zealand Pharma and licensed to Boehringer Ingelheim, which is responsible for global development and commercialisation. The drug is being developed for obesity and related metabolic conditions, including metabolic dysfunction-associated steatohepatitis. Boehringer said the latest data support survodutide’s potential to address long-term metabolic health, but the next test will be whether regulators, physicians and patients see enough benefit to offset its gastrointestinal burden.
