The Lancet November 9, 2026

Cardiovascular outcomes with survodutide in adults with obesity at increased cardiovascular risk (SYNCHRONIZE-CVOT): a double-blind, randomised, placebo-controlled, phase 3 trial

Biykem Bozkurt, Carel W. le Roux, Sean Wharton, et al.

Bottom Line

In the phase 3 SYNCHRONIZE-CVOT trial, the novel glucagon/GLP-1 receptor dual agonist survodutide demonstrated cardiovascular safety by meeting non-inferiority criteria for major adverse cardiovascular events in adults with obesity, despite significant gastrointestinal side effects.

Key Findings

1. The primary composite endpoint (cardiovascular death, non-fatal stroke, non-fatal myocardial infarction, ischaemia-related coronary revascularisation, or heart failure event) occurred in 3.7% (136 of 3671) of participants in the survodutide group compared to 4.1% (76 of 1836) in the placebo group.

2. Survodutide successfully demonstrated non-inferiority to placebo for the primary cardiovascular safety endpoint (HR 0.89, 95% CI 0.67-1.18; p<0.0001).

3. Gastrointestinal adverse events were significantly more frequent with survodutide, with nausea reported in 48.0% (3.6 mg dose) and 49.0% (6.0 mg dose) of participants versus 12.1% for placebo, and vomiting in 31.7% and 34.0% versus 4.8%, respectively.

4. Gastrointestinal adverse events leading to treatment discontinuation occurred in 19.3% of the 3.6 mg group and 20.8% of the 6.0 mg group, compared to just 1.9% in the placebo group.

5. Serious adverse events (22.5% on 3.6 mg, 20.8% on 6.0 mg vs 23.9% on placebo) and fatal adverse events (0.9% for both survodutide doses vs 0.6% on placebo) were comparable across treatment arms.

Study Design

Design

RCT

Double-Blind

Sample

5,530

Patients

Duration

22.0 mo

Median

Setting

34 countries

Population Adults aged ≥18 years with BMI ≥27 kg/m² and established cardiovascular disease, or ≥2 obesity complications/CVD risk factors; those with chronic kidney disease were eligible if BMI ≥30 kg/m².

Intervention Once-weekly subcutaneous survodutide, up-titrated to maintenance doses of 3.6 mg or 6.0 mg.

Comparator Once-weekly subcutaneous placebo.

Outcome Composite of death from cardiovascular causes, non-fatal stroke, non-fatal myocardial infarction, ischaemia-related coronary revascularisation, or heart failure event.

Study Limitations

• The trial was an event-driven safety study designed strictly for non-inferiority (targeting 189 primary endpoint events) and was not powered to detect cardiovascular superiority.

• The median follow-up of 22.0 months was relatively short, limiting the ability to assess long-term cardiovascular outcomes beyond this timeframe.

• There was a substantial rate of early treatment discontinuation, with over 40% of participants not remaining on the study drug until closeout.

• The enrolled population was predominantly White (78.7%), which may limit the generalizability of these safety findings to more diverse ethnic populations.

Clinical Significance

This landmark trial validates the cardiovascular safety of survodutide, the first glucagon/GLP-1 receptor dual agonist to complete a phase 3 cardiovascular outcomes trial. By demonstrating non-inferiority for a 5-point composite cardiovascular endpoint without an increase in severe cardiac events, it establishes a reassuring safety baseline for this novel incretin-based mechanism. However, the substantial rates of gastrointestinal-related treatment discontinuations underscore the critical clinical necessity for careful dose-titration protocols and proactive patient counseling to manage tolerability.

Historical Context

Historically, the development of anti-obesity pharmacotherapy has been hindered by off-target cardiovascular toxicities, as famously observed with earlier generation drugs like sibutramine and fen-phen. Consequently, regulators mandate stringent cardiovascular safety trials for novel weight-loss agents. While GLP-1 mono-agonists (e.g., semaglutide) and dual GIP/GLP-1 agonists (e.g., tirzepatide) have recently transformed obesity management with proven cardiovascular safety, survodutide represents a new class combining GLP-1 agonism with glucagon receptor agonism. Because direct glucagon agonism theoretically poses unique cardiovascular challenges (such as increased heart rate), the successful completion of the SYNCHRONIZE-CVOT trial represents a vital regulatory and clinical milestone for validating the safety of this complementary mechanism.

Guided Discussion

High-yield insights from every perspective

Med Student

Medical Student

How does the addition of a glucagon receptor agonist to a GLP-1 receptor agonist in survodutide theoretically enhance weight loss while mitigating the hyperglycemic effects traditionally associated with glucagon?

Key Response

Glucagon increases energy expenditure and lipolysis, promoting weight loss, but it also stimulates hepatic glycogenolysis and gluconeogenesis. The GLP-1 component stimulates glucose-dependent insulin secretion, which counteracts the hyperglycemic potential of glucagon while synergistically reducing appetite.

Resident

Given the significant gastrointestinal side effects reported in the SYNCHRONIZE-CVOT trial, how should a clinician approach dose titration and patient counseling when initiating survodutide for a patient with obesity and high cardiovascular risk?

Key Response

GI adverse events like nausea and vomiting are the primary reasons for discontinuation. Management requires a strict start low, go slow titration schedule, preemptive counseling about dietary modifications such as avoiding high-fat meals, and utilizing antiemetics during titration to ensure patients can tolerate therapeutic doses.

Fellow

Survodutide demonstrated cardiovascular safety through non-inferiority in this trial. How does this finding contrast with the cardiovascular outcomes of semaglutide in the SELECT trial, and what physiological differences of dual agonism might explain these distinct profiles?

Key Response

While semaglutide showed superiority for MACE reduction in SELECT, survodutide only met non-inferiority for safety. Glucagon agonism increases heart rate and has complex chronotropic effects that might blunt the cardioprotective benefits seen with pure GLP-1 RAs, making safety a critical hurdle.

Attending

With multiple incretin therapies available, how should the demonstration of cardiovascular non-inferiority rather than superiority for survodutide influence our shared decision-making process for patients with established atherosclerotic cardiovascular disease?

Key Response

For patients with established ASCVD, agents with proven MACE superiority should remain first-line. A drug showing only non-inferiority might be reserved as second-line for patients requiring greater weight loss than pure GLP-1s offer, weighing profound weight loss against the lack of superior CV benefit.

Scholarly Review

Critical appraisal through the lens of expert reviewers and guideline development

PhD

In cardiovascular outcome trials for weight loss medications, how does the high rate of drug discontinuation due to gastrointestinal adverse events complicate the intention-to-treat analysis of MACE, and what statistical estimands best address this?

Key Response

High dropout rates due to GI distress can dilute the observed treatment effect in an ITT analysis, biasing results toward the null, which makes non-inferiority easier to achieve. Researchers must utilize robust treatment-policy estimands and tipping point sensitivity analyses to handle missing data.

Journal Editor

When reviewing the non-inferiority margins in the SYNCHRONIZE-CVOT trial, what specific concerns should be raised regarding the upper bound of the 95 percent confidence interval for the hazard ratio in the context of the drug's chronotropic effects?

Key Response

A critical reviewer would scrutinize whether the non-inferiority margin is sufficiently tight to rule out clinically meaningful harm, particularly because glucagon agonism elevates resting heart rate. If the upper bound is close to the margin, it raises questions about unacceptable long-term cardiovascular risk.

Guideline Committee

Current ACC and AHA guidelines recommend GLP-1 RAs with proven cardiovascular benefit for patients with obesity and CVD. Based on SYNCHRONIZE-CVOT, where should survodutide be positioned in upcoming treatment algorithms compared to agents with Class I recommendations for MACE reduction?

Key Response

Since survodutide achieved non-inferiority but not superiority for MACE, it should receive a lower strength of recommendation for CV risk reduction compared to semaglutide. Guidelines should position it as an alternative for severe obesity when first-line CV-protective agents are insufficient for weight goals.

Clinical Landscape

Noteworthy Related Trials

2016

LEADER Trial

n = 9,340 · NEJM

Tested

Liraglutide up to 1.8mg daily

Population

Patients with type 2 diabetes and high cardiovascular risk

Comparator

Placebo

Endpoint

3-point MACE (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke)

Key result: Liraglutide significantly reduced the risk of the primary composite outcome and death from cardiovascular causes among patients with type 2 diabetes.

2016

SUSTAIN-6 Trial

n = 3,297 · NEJM

Tested

Semaglutide 0.5mg or 1.0mg weekly

Population

Patients with type 2 diabetes and high cardiovascular risk

Comparator

Placebo

Endpoint

3-point MACE (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke)

Key result: Subcutaneous semaglutide significantly lowered the rate of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke compared with placebo.

2023

SELECT Trial

n = 17,604 · NEJM

Tested

Semaglutide 2.4mg weekly

Population

Adults with preexisting cardiovascular disease and overweight or obesity but no diabetes

Comparator

Placebo

Endpoint

3-point MACE (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke)

Key result: Semaglutide reduced the risk of major adverse cardiovascular events by 20 percent compared to placebo.

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