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FDA Approves Mounjaro for Cardiovascular Risk Reduction on the Back of SURPASS-CVOT

Tirzepatide is now the first dual GIP/GLP-1 agonist with an FDA cardiovascular indication, after a 13,000-participant head-to-head trial against Trulicity.

The incretin approvals of 2026 keep stacking cardiovascular credentials onto these drugs, and late August added another one. On August 28, the FDA approved a label expansion for Mounjaro (tirzepatide) to reduce the risk of major adverse cardiovascular events - heart attack, stroke, or cardiovascular death - in adults with type 2 diabetes at high cardiovascular risk.

Why this one is worth attention: it’s the first cardiovascular indication for any dual GIP/GLP-1 receptor agonist, and the trial behind it wasn’t a placebo comparison. It was incretin versus incretin.

What the Research Says

The approval rests on SURPASS-CVOT (NCT04255433), which Lilly describes as the first cardiovascular outcomes trial to compare two incretin medicines head-to-head rather than against placebo. The design from Lilly’s announcement:

  • 13,299 participants with type 2 diabetes and established atherosclerotic cardiovascular disease, randomised 1:1 across 640 sites in 30 countries
  • Median follow-up of roughly four years - the largest and longest tirzepatide study to date
  • Tirzepatide (15 mg or maximum tolerated dose) versus Trulicity (dulaglutide 1.5 mg), both once-weekly injections
  • Primary endpoint: MACE-3, a composite of cardiovascular death, non-fatal heart attack, or non-fatal stroke

The result: tirzepatide met the prespecified non-inferiority threshold against dulaglutide, with a hazard ratio for time to first MACE of 0.92 (95.3% CI: 0.83, 1.01) - an 8% relative reduction that did not reach statistical superiority. Full results published in the New England Journal of Medicine showed the primary endpoint occurred in 12.2% of tirzepatide patients versus 13.1% on dulaglutide (P=0.003 for non-inferiority, P=0.09 for superiority), per BioPharm International’s coverage.

Reading the Trial Design

The head-to-head design is what makes SURPASS-CVOT unusual. Most cardiovascular outcomes trials for these drugs tested against placebo, which establishes “does this drug reduce events compared with doing nothing.” Testing against dulaglutide - a GLP-1 agonist with established cardiovascular benefit - asks a harder question: is tirzepatide at least as good as the existing standard?

It passed that bar. The trade-off in interpretation is that an 8% relative reduction versus an active comparator is a much narrower claim than the 20-30% reductions seen in placebo-controlled trials of semaglutide and dulaglutide themselves. The confidence interval brushing 1.01 tells you the true effect could plausibly be anywhere from a meaningful reduction to essentially no difference versus dulaglutide.

Practically, the approval means tirzepatide now carries three stacked indications in the US: glycaemic control, weight management (as Zepbound), and cardiovascular risk reduction in high-risk type 2 diabetes. Lilly also won FDA approval in August for Mounjaro to reduce cardiovascular risk, and Reuters noted the timing alongside Lilly’s broader cardiometabolic push.

The Australian Angle

Mounjaro has been available in Australia since 2025, and the TGA approved tirzepatide for type 2 diabetes here first - the cardiovascular indication discussed here is a US FDA label change, and any equivalent TGA label expansion would follow separately if Lilly pursues it. Worth watching, because cardiovascular outcome data changes how these drugs get positioned and prescribed, and PBS listing conversations in Australia increasingly reference outcome-trial evidence rather than just HbA1c and weight endpoints.

For the research interest community, the notable thing is the trial design trend: 2026 has moved from “incretin versus placebo” to “incretin versus incretin,” and head-to-head data is where the real differentiation between compounds will come from. We’ve covered the competitive landscape in our tirzepatide overview and the semaglutide side of the comparison in our semaglutide page.

Sources

Disclaimer: This article is for educational and informational purposes only. It does not constitute medical advice, therapeutic recommendations, or endorsements of any compound. Grey Highway is a research-education community. We do not sell, supply, or promote the use of research compounds. Always consult a qualified healthcare professional regarding health decisions. For Australian regulatory information, visit the TGA website.