Lilly's Mounjaro Shows Promise in Cardiovascular Outcomes Trial, Eyes Expanded Approval

Eli Lilly's diabetes blockbuster Mounjaro (tirzepatide) has demonstrated encouraging results in a highly anticipated Phase III cardiovascular outcomes trial, paving the way for potential expanded approval. While the drug met its primary endpoint of non-inferiority compared to Lilly's older incretin therapy Trulicity, it fell short of achieving statistical superiority in reducing major adverse cardiovascular events (MACE-3).

Trial Results and Implications

The SURPASS-CVOT trial, which included over 13,000 adults with type 2 diabetes and established atherosclerotic cardiovascular disease, showed that Mounjaro reduced certain cardiovascular risks by 8% compared to Trulicity. Notably, the rate of all-cause mortality was 16% lower for Mounjaro than for Trulicity, a statistically significant benefit (P=0.002).

Secondary endpoints of the trial revealed compelling results. Mounjaro demonstrated a greater reduction in A1C levels from baseline than Trulicity (1.73% vs. 0.90%) at 36 months. Additionally, patients taking Mounjaro lost an average of 25.2 lbs compared to 10.25 lbs on Trulicity.

Kenneth Custer, Lilly's head of cardiometabolic health, expressed confidence in the data, stating, "We feel very, very confident in these results." The company intends to submit these findings to global regulatory authorities by the end of this year, seeking expanded approval for Mounjaro in preventing cardiovascular events.

Market Impact and Analyst Perspectives

While the results were deemed "good enough" by some analysts, including BMO Capital Markets' Evan David Seigerman, the failure to demonstrate statistical superiority on the primary endpoint may be received negatively by investors. Seigerman noted, "We've consistently framed Trulicity as a very good drug for diabetic patients and [it] represents a tough bar to beat."

Leerink Partners analysts focused on the trial's secondary endpoints, which they called "compelling." They concluded that despite not showing statistically significant superiority on the primary endpoint, the results support "tirzepatide continuing to be preferred by physicians and patients over other GLP-1s, including Trulicity."

Competitive Landscape

The cardiovascular outcomes trial results for Mounjaro come in the wake of recent developments in the GLP-1 market. Notably, Novo Nordisk's Wegovy (semaglutide) secured FDA approval in March 2024 to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease who are obese or overweight. This approval was based on the Phase III SELECT trial, which demonstrated a 20% reduction in MACE compared to placebo when added to standard of care.

As Eli Lilly prepares to report its second-quarter earnings on August 7, the pharmaceutical industry watches closely to see how these latest results will impact the competitive landscape in the diabetes and cardiovascular disease markets.