What does LEADER stand for?

LEADER stands for Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results. The trial was registered as NCT01179048 and published in the New England Journal of Medicine in 2016.

How long did patients take liraglutide in the LEADER trial?

The median treatment duration was 3.5 years, with a median follow-up of 3.8 years. Some patients discontinued the study drug early but continued to be followed for outcomes.

Was liraglutide given alone or with other diabetes medications?

Liraglutide was added on top of existing diabetes treatment. Patients continued metformin, insulin, sulfonylureas, and other medications as prescribed by their doctors. Investigators could adjust background therapy throughout the trial.

Did liraglutide reduce heart attacks specifically?

Nonfatal heart attacks trended lower with liraglutide (HR 0.88) but did not reach statistical significance on their own. The significant reduction was in the composite endpoint and in cardiovascular death specifically.

What were the most common side effects of liraglutide in LEADER?

Gastrointestinal symptoms, primarily nausea, vomiting, and diarrhea, were the most common adverse events. These led to higher discontinuation rates in the liraglutide group (9.5% vs. 7.3%). Rates of pancreatitis and pancreatic cancer were similar between groups.

Does LEADER apply to patients without heart disease?

Only about 19% of LEADER participants lacked established cardiovascular disease. The trial was not powered to draw firm conclusions in lower-risk subgroups. The REWIND trial of dulaglutide later enrolled a broader population and also found a MACE reduction, providing additional evidence for patients without established CV disease.

How does LEADER compare to SUSTAIN-6 for semaglutide?

SUSTAIN-6 tested semaglutide in 3,297 patients and found a 26% MACE reduction (HR 0.74). SUSTAIN-6 was smaller and designed only for non-inferiority, so the comparison is not straightforward. Both trials supported cardiovascular benefit for GLP-1 receptor agonists in high-risk type 2 diabetes.

Is liraglutide the same drug used for weight loss (Saxenda)?

Liraglutide is the active ingredient in both Victoza (1.8 mg, for type 2 diabetes) and Saxenda (3.0 mg, for weight management). LEADER studied the 1.8 mg dose in patients with type 2 diabetes. The cardiovascular findings apply to the diabetes indication specifically.

Did LEADER change FDA labeling for liraglutide?

Yes. In 2017, the FDA approved a new indication for Victoza to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes and established cardiovascular disease. This was based directly on the LEADER trial results.

What is the number needed to treat from LEADER?

The absolute risk reduction was approximately 1.9 percentage points over 3.8 years, giving a number needed to treat of about 53. This means roughly 53 high-risk patients would need to take liraglutide for about 4 years to prevent one additional MACE event.

LEADER Trial: A Plain-English Overview of What It Established

By HealthRX.com Medical Team

Published May 25, 2026Updated May 25, 2026Last reviewed May 25, 2026

Clinical image for LEADER Trial: A Plain-English Overview of What It Established Image: HealthRX.com clinical image

LEADER Trial: A Plain-English Overview of What It Established

At a glance

| Detail | Value | |---|---| | Participants | 9,340 adults with type 2 diabetes | | Intervention | Liraglutide 1.8 mg subcutaneous daily | | Comparator | Matching placebo (both added to standard care) | | Median follow-up | 3.8 years | | Primary endpoint | First occurrence of 3-point MACE (CV death, nonfatal MI, nonfatal stroke) | | Key result | HR 0.87 (95% CI 0.78 to 0.97; p = 0.01 for superiority) | | Registration | NCT01179048 |

The Question LEADER Set Out to Answer

By 2010, the FDA required every new diabetes drug to prove it did not increase cardiovascular risk before or shortly after approval. This rule, formalized in a 2008 FDA guidance, came after the rosiglitazone safety crisis. Liraglutide (brand name Victoza) had already been on the market, but its long-term cardiac safety profile was unresolved. LEADER was designed to answer a two-part question. First, does liraglutide cause cardiovascular harm? Second, does it actually protect the heart?

The trial was sponsored by Novo Nordisk and run across 410 sites in 32 countries. It enrolled adults aged 50 and older with established cardiovascular disease or aged 60 and older with at least one cardiovascular risk factor. This population was deliberately high-risk so that enough cardiovascular events would occur to power the statistical analysis within a feasible timeframe.

Who Got In and Who Was Excluded

Eligible participants had type 2 diabetes with an HbA1c of 7.0% or higher. Roughly 81% of enrolled patients had established cardiovascular disease, chronic kidney disease, or heart failure at baseline. The remaining 19% were older adults with risk factors like hypertension or dyslipidemia but no prior cardiac event.

Key exclusion criteria: type 1 diabetes, use of a GLP-1 receptor agonist or DPP-4 inhibitor within 90 days, familial or personal history of medullary thyroid carcinoma, or an estimated GFR below 15 mL/min. Patients on insulin, sulfonylureas, or metformin could continue those medications. Investigators adjusted background therapy as needed throughout the trial, which reflected real-world clinical practice rather than a rigid protocol.

Baseline characteristics were balanced between arms. Mean age was 64 years. Mean BMI was 32.5 kg/m². Mean HbA1c was 8.7%. Mean diabetes duration was about 13 years. Roughly two-thirds were male.

What Participants Received

Randomization assigned 4,668 patients to liraglutide and 4,672 to visually identical placebo, both given as once-daily subcutaneous injections. The dose started at 0.6 mg daily for one week, increased to 1.2 mg, and reached the target of 1.8 mg by week three. This dose-escalation schedule was designed to reduce gastrointestinal side effects, a well-known tolerability concern with GLP-1 receptor agonists.

Both groups received standard-of-care treatment for diabetes and cardiovascular risk. This meant investigators could add or adjust insulin, statins, antihypertensives, and other medications freely. The trial measured the effect of liraglutide on top of optimized medical therapy, not in place of it.

Median exposure to the study drug was 3.5 years. Discontinuation rates were higher in the liraglutide group (about 9.5% for adverse events vs. 7.3% for placebo), mainly driven by gastrointestinal complaints like nausea and vomiting.

How the Primary Endpoint Was Defined and Adjudicated

The primary composite endpoint was time to first occurrence of any component of 3-point MACE: death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. An independent, blinded committee adjudicated every suspected event using standardized definitions.

The statistical plan tested non-inferiority first (upper bound of 95% CI for hazard ratio <1.30). If that cleared, the trial would test for superiority. This sequential gating is standard for cardiovascular outcomes trials and prevents false-positive inflation from running both tests simultaneously. The required sample size assumed a placebo event rate of about 2.7% per year and 80% power to detect a hazard ratio of 0.85 or lower.

Results: What the Numbers Actually Show

Primary Endpoint

The primary analysis reported 608 first MACE events in the liraglutide group (13.0%) versus 694 in the placebo group (14.9%), yielding a hazard ratio of 0.87 (95% CI 0.78 to 0.97; p <0.001 for non-inferiority; p = 0.01 for superiority).

Individual Components

| Outcome | Liraglutide (%) | Placebo (%) | HR (95% CI) | |---|---|---|---| | CV death | 4.7 | 6.0 | 0.78 (0.66-0.93) | | Nonfatal MI | 6.0 | 6.8 | 0.88 (0.75-1.03) | | Nonfatal stroke | 3.4 | 3.7 | 0.89 (0.72-1.11) | | All-cause death | 8.2 | 9.6 | 0.85 (0.74-0.97) |

Cardiovascular death drove most of the benefit. Nonfatal MI and nonfatal stroke trended in the right direction but did not individually reach statistical significance. All-cause mortality was also significantly lower in the liraglutide arm (HR 0.85), a finding that carried clinical weight because mortality reductions are difficult to achieve in diabetes trials.

Metabolic and Safety Outcomes

HbA1c dropped by about 0.4% more in the liraglutide group than placebo over the trial. Systolic blood pressure fell by roughly 1.2 mmHg more. Body weight decreased by about 2.3 kg more. Heart rate increased by about 3 beats per minute, consistent with the known pharmacology of GLP-1 receptor agonists.

Rates of severe hypoglycemia were lower in the liraglutide group. Pancreatitis occurred in 18 liraglutide patients versus 23 placebo patients, a finding that did not signal excess risk. Gallbladder-related events were slightly more common with liraglutide (145 vs. 139 events).

What the Trial Did Not Prove

LEADER had important limitations that clinicians should weigh.

The benefit was modest in absolute terms. The absolute risk reduction for the primary endpoint was about 1.9 percentage points over 3.8 years, translating to a number needed to treat of roughly 53. For individual patients, the probability of benefit is real but not large.

Component-level significance was limited. Only cardiovascular death reached significance on its own. Nonfatal MI and stroke did not. This raises a fair question: did liraglutide primarily reduce fatal events, or was the trial simply underpowered to detect differences in non-fatal outcomes?

Population was very high-risk. Over 80% of participants had established cardiovascular disease. Whether the same benefit applies to lower-risk patients with type 2 diabetes remains uncertain. The 2018 ADA/EASD consensus report later recommended GLP-1 receptor agonists with proven CV benefit specifically for patients with established atherosclerotic cardiovascular disease, not for all patients with type 2 diabetes.

Mechanism is unclear. LEADER was not designed to explain why liraglutide reduced cardiovascular events. The modest improvements in HbA1c, weight, and blood pressure likely contributed, but the effect appeared early in the Kaplan-Meier curves, before metabolic differences would fully manifest. Anti-inflammatory effects and direct vascular actions of GLP-1 receptor agonists have been proposed but remain under investigation.

Industry-sponsored. Novo Nordisk funded the trial, employed some of the authors, and participated in study design and data collection. The steering committee had academic oversight, and endpoint adjudication was independent. Sponsorship alone does not invalidate results, but it is standard practice to note it.

How LEADER Changed Clinical Practice

Before LEADER, GLP-1 receptor agonists were prescribed mainly for glucose lowering and weight management. After LEADER reported in June 2016, treatment guidelines shifted. The FDA updated the Victoza label in 2017 to include a cardiovascular risk reduction indication for adults with type 2 diabetes and established cardiovascular disease. This was the first GLP-1 receptor agonist to earn such a label indication.

The 2019 ACC/AHA guidelines on primary prevention of cardiovascular disease and the ADA Standards of Care both incorporated LEADER's findings into treatment algorithms. For patients with type 2 diabetes and established atherosclerotic cardiovascular disease, a GLP-1 receptor agonist with proven benefit (liraglutide or semaglutide, per the SUSTAIN-6 trial) became a recommended second-line agent after metformin, independent of HbA1c level.

LEADER also set the stage for later cardiovascular outcomes trials in the GLP-1 class. SUSTAIN-6 (semaglutide), HARMONY Outcomes (albiglutide), and REWIND (dulaglutide) each built on the template LEADER established. The class-level evidence grew stronger with each positive result, though not every GLP-1 receptor agonist has shown the same degree of benefit. The ELIXA trial of lixisenatide, for example, demonstrated non-inferiority but not superiority, reinforcing that cardiovascular benefit is not automatic within the class.

The Bottom Line for Patients and Clinicians

LEADER showed that adding liraglutide 1.8 mg daily to standard care reduced cardiovascular events and death in high-risk adults with type 2 diabetes. The effect was statistically significant and clinically meaningful, though modest in absolute terms. It did not prove that liraglutide prevents heart attacks or strokes on its own. It proved that, on top of already-optimized therapy, liraglutide moved the needle enough to matter at a population level.

For a patient sitting in a clinic today, LEADER's relevance depends on their cardiovascular risk profile. If they have established heart disease and type 2 diabetes, current guidelines support a GLP-1 receptor agonist with proven CV benefit as a preferred treatment option. If they are lower-risk, the evidence is less direct, and the decision weighs cost, injection burden, and gastrointestinal tolerability against potential but unproven cardiovascular protection.

Frequently asked questions

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References

Marso SP, Daniels GH, Poulter NR, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes. N Engl J Med. 2016;375(4):311-322. PubMed
Victoza (liraglutide) prescribing information. Novo Nordisk. Revised 2017. FDA Label
Marso SP, Bain SC, Consoli A, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes (SUSTAIN-6). N Engl J Med. 2016;375(19):1834-1844. PubMed
Davies MJ, D'Alessio DA, Fradkin J, et al. Management of hyperglycemia in type 2 diabetes, 2018: a consensus report by the ADA and EASD. Diabetes Care. 2018;41(12):2669-2701. PubMed
Gerstein HC, Colhoun HM, Dagenais GR, et al. Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND). Lancet. 2019;394(10193):121-130. PubMed
American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes, 2023. Diabetes Care. 2023;46(Suppl 1). PubMed