SYNCHRONIZE-1 Phase III Readout on Survodutide

Key Takeaways

• Boehringer Ingelheim said survodutide met both co-primary endpoints in SYNCHRONIZE-1 under the efficacy and treatment-regimen estimands.
• A key secondary endpoint showed a statistically significant reduction in waist circumference versus placebo at 76 weeks, alongside company-reported weight loss.
• Gastrointestinal events were expected and generally mild to moderate and temporary, discontinuations were more frequent during dose escalation, and ADA 2026 data plus additional readouts are expected in 2026.

In a SYNCHRONIZE-1 Phase III readout, Boehringer Ingelheim said up to 85.1% of adults receiving survodutide achieved at least 5% weight reduction at 76 weeks under the efficacy estimand, compared with 38.8% on placebo (nominal p<0.0001). The company said the trial also met both co-primary endpoints in adults with obesity or overweight without type 2 diabetes. The topline update covered 76-week efficacy results.

SYNCHRONIZE-1 was a Phase III, double-blind, placebo-controlled, 76-week efficacy and safety trial in 725 adults with obesity or overweight without type 2 diabetes. Participants received weekly injections of survodutide or placebo, and the company identified survodutide as BI 456906, a glucagon/GLP-1 receptor dual agonist. The co-primary endpoints were percentage change in body weight from baseline to week 76 and achievement of at least 5% weight reduction. Boehringer Ingelheim said both endpoints were assessed using the efficacy estimand and the treatment-regimen estimand.

For mean weight change, Boehringer Ingelheim reported sustained weight loss of up to 16.6% after 76 weeks on the efficacy estimand versus 3.2% with placebo, with nominal p<0.0001. The company also highlighted an absolute reduction of up to 39.2 lb, or 17.8 kg, from baseline. Initial analysis suggested the reduction was driven predominantly by fat loss, with lean mass accounting for only a small share. A key secondary endpoint also showed a statistically significant reduction in waist circumference versus placebo after 76 weeks. Together, these findings summarized the main efficacy results beyond the responder endpoint.

Safety details were limited in the topline update. Gastrointestinal events occurred, and discontinuations were more frequent during dose escalation. The company said those events were generally mild to moderate and temporary. It also reported no new safety concerns beyond what is expected for the GLP-1 class. Survodutide remains investigational and is not approved.

Boehringer Ingelheim said full SYNCHRONIZE-1 data will be presented at the American Diabetes Association’s 2026 Scientific Sessions in June. The company also said additional trial results are expected during 2026. It described SYNCHRONIZE-1 as part of a broader global Phase III obesity program for survodutide. That program includes studies in other key subpopulations, according to the company. Upcoming presentations and additional readouts are the next reported milestones through 2026.