Eli Lilly's tirzepatide shows promise in phase 3 heart failure study

Eli Lilly has announced encouraging top-line results from a late-stage study of its once-weekly GIP/GLP-1 receptor agonist, tirzepatide, conducted in adults with heart failure with preserved ejection fraction (HFpEF) and obesity.

HFpEF, which constitutes almost half of all heart failure cases, affects nearly 60% of individuals in the US who are also living with obesity. This condition arises when the left pumping chamber of the heart becomes stiff, impairing its ability to fill properly. Consequently, affected individuals often experience fatigue, shortness of breath, and a diminished capacity for physical activities.

Tirzepatide, administered via subcutaneous injection, already has regulatory approvals for managing weight and treating type 2 diabetes. The phase 3 SUMMIT trial enrolled over 730 HFpEF patients with obesity, including those with and without type 2 diabetes. Participants were randomized to receive one of three doses of tirzepatide or a placebo.

The trial results revealed a 38% reduction in the risk of heart failure events, such as hospitalization and cardiovascular death, for those receiving tirzepatide compared to the placebo group. Additionally, the drug showed statistically significant benefits in alleviating heart failure symptoms and physical limitations, as assessed by the Kansas City Cardiomyopathy Questionnaire clinical summary score.

Moreover, all key secondary endpoints were met. These included improvements in exercise capacity, as measured by the six-minute walk-test distance, and a reduction in mean body weight from baseline after 52 weeks of treatment.

Jeff Emmick, Senior Vice President of Product Development at Lilly, remarked, “Previous incretin studies in this population focused on symptoms and physical limitations. In a first-of-its-kind trial, tirzepatide reduced the severity of symptoms and improved heart failure outcomes in people with HFpEF and obesity.”

Lilly has indicated that it will further analyze the SUMMIT trial results and intends to submit the data to the US Food and Drug Administration and other regulatory bodies later this year.

This announcement comes on the heels of promising data for tirzepatide as a potential treatment for metabolic dysfunction-associated steatohepatitis (MASH), a fatty liver disease. Mid-stage SYNERGY-NASH trial results showed that 51.8%, 62.8%, and 73.3% of patients taking 5mg, 10mg, and 15mg doses of tirzepatide, respectively, achieved an absence of MASH with no worsening of liver fibrosis, compared to 13.2% in the placebo group at 52 weeks.