Eli Lilly and Company (Lilly) said that the SUMMIT Phase 3 clinical trial of tirzepatide injection has shown patients benefits in adults with heart failure (HF) with preserved ejection fraction (HFpEF) and obesity.
Tirzepatide is a once-weekly glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist.
The US Food and Drug Administration (FDA) approved tirzepatide under the brand name Mounjaro in 2022 for adults with type 2 diabetes to enhance glycaemic control. It was later approved under the brand name Zepbound in November 2023 for adults with obesity or those who are overweight with a weight-related comorbidity.
The SUMMIT study evaluated the efficacy and safety of tirzepatide compared to placebo in adults with HFpEF and obesity, including those with or without type 2 diabetes.
In this late-stage trial, 731 participants were randomly assigned in a 1:1 ratio to receive either tirzepatide or a placebo.
The two primary objectives were to reduce the risk of the composite endpoint, which included the time to the first occurrence of an urgent HF visit, HF hospitalisation, intensification of oral diuretics, and cardiovascular death up to the study’s completion.
The second objective was to assess the change in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) from baseline to week 52.
According to the results, tirzepatide showed statistically significant improvements in both primary endpoints compared to placebo.
It reduced the risk of HF outcomes and enhanced heart failure symptoms and physical limitations. All key secondary endpoints were also achieved.
For the efficacy estimand, the drug delivered a 15.7% reduction in body weight compared to 2.2% for placebo.
On the other hand, the injection led to a 13.9% body weight reduction compared to 2.2% for placebo for the treatment regimen estimand.
Lilly product development senior vice president Jeff Emmick said: “HFpEF accounts for nearly half of all heart failure cases, and in the US almost 60% of those impacted also live with obesity. Despite a continuing increase in the number of people with both HFpEF and obesity, treatment options remain limited.”
The drug is currently being assessed for its effects on chronic kidney disease (CKD) and its impact on morbidity and mortality associated with obesity (MMO).
Earlier this year, Lilly provided data to the FDA and other international regulatory agencies regarding tirzepatide’s use for obstructive sleep apnoea and obesity.
In June, Lilly announced positive results for the antidiabetic medication in a Phase 2 trial of patients with metabolic dysfunction-associated steatohepatitis (MASH) and stage 2 or 3 fibrosis.
