Eli Lilly said Aug. 28 that the Food and Drug Administration approved an additional use for Mounjaro, its tirzepatide diabetes drug, to reduce the risk of cardiovascular death, nonfatal heart attack and nonfatal stroke in adults with type 2 diabetes who are at high risk for those events.
The reported action would give Mounjaro an explicit cardiovascular-risk-reduction indication alongside its established role, with diet and exercise, in improving blood glucose in adults with type 2 diabetes. Lilly’s announcement said the decision was supported by SURPASS-CVOT, a 13,299-person trial that compared Mounjaro with dulaglutide, the active ingredient in Lilly’s Trulicity.
FDA had not posted a contemporaneous approval notice or updated prescribing information for this indication at publication. The regulatory action is therefore attributed to Lilly’s Aug. 28 announcement.
What the cardiovascular trial found
SURPASS-CVOT was designed as a randomized, double-blind Phase 3 cardiovascular-outcomes trial. It enrolled adults with type 2 diabetes and established atherosclerotic cardiovascular disease at 640 sites in 30 countries, Lilly said. Participants were assigned to once-weekly tirzepatide or once-weekly dulaglutide and followed for a median of about four years, or 210.1 weeks.
The primary endpoint was the time until a participant first had one of three events: cardiovascular death, a nonfatal heart attack or a nonfatal stroke. Lilly reported that tirzepatide had a hazard ratio of 0.92 compared with dulaglutide, with a 95.3% confidence interval of 0.83 to 1.01. A hazard ratio below 1 points toward fewer first composite events in the tirzepatide group; 0.92 corresponds to an estimated 8% lower event rate relative to dulaglutide over the study period.
But the result has an important limit. The confidence interval crossed 1.00, and Lilly said the study met its pre-specified noninferiority objective but did not establish superiority over dulaglutide under the trial’s testing plan. In practical terms, the trial supported the conclusion that tirzepatide was not worse than an established cardiovascular-benefit treatment by the study’s margin; it did not prove that Mounjaro outperformed dulaglutide.
That distinction is especially relevant because this was an active-comparator study, not a placebo-controlled trial. It can support a causal comparison of the two assigned treatments among people like those enrolled, but it does not answer how tirzepatide would compare with no such treatment, with every other diabetes medicine or in people without the trial population’s cardiovascular disease profile. Detailed event counts, subgroup results and the full peer-reviewed report were not included in Lilly’s announcement.
A new use, not a new medicine
Mounjaro contains tirzepatide, which activates GIP and GLP-1 receptors and is administered weekly. Until this reported action, its FDA-approved diabetes indication was to improve glucose control with diet and exercise. The FDA described that use in a 2024 announcement about a separate tirzepatide product.
That separate product is Zepbound, which uses the same active ingredient but is marketed under a different brand for chronic weight management. The brands should not be treated as interchangeable simply because both contain tirzepatide: approved uses, labeled populations and insurance coverage can differ.
The newly announced Mounjaro indication is also more specific than a broad claim that the medicine prevents cardiovascular disease for anyone taking it. Lilly described SURPASS-CVOT participants as having both type 2 diabetes and established atherosclerotic cardiovascular disease, while its announcement characterizes the approved population as adults with type 2 diabetes at high risk for major cardiovascular events. Updated FDA prescribing information would define the exact eligible population and treatment details.
Safety and treatment decisions remain individualized
A cardiovascular indication does not erase the drug’s existing warnings and precautions. Lilly lists gastrointestinal side effects among common adverse events and warns about risks including pancreatitis, severe allergic reactions, gallbladder problems, dehydration-related kidney problems and hypoglycemia when tirzepatide is used with certain other diabetes medicines. These warnings do not mean the drug will cause those outcomes in an individual patient, but they are part of the prescribing decision.
People should not change diabetes treatment based on this announcement alone; eligibility and safety considerations should be discussed with a clinician. If reflected in updated FDA prescribing information, the additional use would make Mounjaro a labeled option for reducing major cardiovascular events in its specified high-risk type 2 diabetes population, with trial evidence showing noninferiority to dulaglutide rather than proven superiority over it.