The LEADER trial (NCT01179048) was a multi-national, multi-center, placebo-controlled, double-blind trial. In this study, 9,340 adult patients with inadequately controlled type 2 diabetes mellitus and atherosclerotic cardiovascular disease (CVD) were randomized to VICTOZA 1.8 mg or placebo for a median duration of 3.5 years. The study compared the risk of major adverse cardiovascular events between VICTOZA and placebo when these were added to, and used concomitantly with, background standard of care treatments for type 2 diabetes mellitus. The primary endpoint, major adverse cardiac events (MACE), was the time to first occurrence of a three part composite outcome which included; cardiovascular death, non-fatal myocardial infarction and non-fatal stroke. 

Patients eligible to enter the trial were; 50 years of age or older and had established, stable, cardiovascular, cerebrovascular, peripheral artery disease, chronic kidney disease or New York Heart Association (NYHA) class II and III heart failure (80% of the enrolled population) or were 60 years of age or older and had other specified risk factors for cardiovascular disease (20% of the enrolled population). 

At baseline, demographic and disease characteristics were balanced. The mean age was 64 years and the population was 64.3% male, 77.5% White, 10.0% Asian, and 8.3% Black or African American. In the study, 12.1% of the population identified as Hispanic or Latino ethnicity. The mean duration of type 2 diabetes mellitus was 12.8 years, the mean HbA1c was 8.7% and the mean BMI was 32.5 kg/m2. A history of previous myocardial infarction was reported in 31% of randomized individuals, a prior revascularization procedure in 39%, a prior ischemic stroke in 11%, documented symptomatic coronary disease in 9%, documented asymptomatic cardiac ischemia in 26%, and a diagnosis of NYHA class II to III heart failure in 14%. The mean eGFR at baseline was 79 mL/min/1.73 m2 and 41.8% of patients had mild renal impairment (eGFR 60 to 90 mL/min/1.73m2), 20.7% had moderate renal impairment (eGFR 30 to 60 mL/min/1.73m2) and 2.4% of patients had severe renal impairment (eGFR < 30 mL/min/1.73m2). 

At baseline, patients treated their diabetes with; diet and exercise only (3.9%), oral antidiabetic drugs only (51.5%), oral antidiabetic drugs and insulin (36.7%) or insulin only (7.9%). The most common background antidiabetic drugs used at baseline and in the trial were metformin, sulfonylurea and insulin. Use of DPP-4 inhibitors and other GLP-1 receptor agonists was excluded by protocol and sodium-glucose cotransporter-2 (SGLT-2) inhibitors were either not approved or not widely available. At baseline, cardiovascular disease and risk factors were managed with; non-diuretic antihypertensives (92.4%), diuretics (41.8%), statin therapy (72.1%) and platelet aggregation inhibitors (66.8%). During the trial, investigators could modify anti-diabetic and cardiovascular medications to achieve local standard of care treatment targets with respect to blood glucose, lipid, and blood pressure, and manage patients recovering from an acute coronary syndrome or stroke event per local treatment guidelines.

For the primary analysis, a Cox proportional hazards model was used to test for non-inferiority against the pre-specified risk margin of 1.3 for the hazard ratio of MACE and to test for superiority on MACE if non-inferiority was demonstrated. Type 1 error was controlled across multiple tests.

VICTOZA significantly reduced the occurrence of MACE. The estimated hazard ratio (95% CI) for time to first MACE was 0.87 (0.78, 0.97). Refer to Figure 5 and Table 13. 

Vital status was available for 99.7% of subjects in the trial. A total of 828 deaths were recorded during the LEADER trial. A majority of the deaths in the trial were categorized as cardiovascular deaths and non-cardiovascular deaths were balanced between the treatment groups (3.5% in patients treated with VICTOZA and 3.6% in patients treated with placebo). The estimated hazard ratio of time to all-cause death for VICTOZA compared to placebo was 0.85 (0.74, 0.97).

Figure 5 Kaplan-Meier: Time to First Occurrence of a MACE in the LEADER Trial (Patients with Type 2 Diabetes Mellitus and Atherosclerotic CVD)

Table 13 Treatment Effect for the Primary Composite Endpoint, MACE, and its Components in the LEADER Trial (Patients with Type 2 Diabetes Mellitus and Atherosclerotic CVD)a

aFull analysis set (all randomized patients)

bCox-proportional hazards model with treatment as a factor

cp-value for superiority (2-sided) 0.011 

dNumber and percentage of first events