Zepbound outperforms Wegovy in weight loss clinical trial

Eli Lilly's Zepbound was superior to Novo Nordisk's Wegovy for weight loss, according to data from the SURMOUNT-5 study. Among the available glucagon-like peptide-1 drugs, Zepbound and Wegovy are commonly compared because both drugs have been approved for patients with overweight and obesity. However, Zepbound's active ingredient is tirzepatide, a dual glucagon-like peptide-1 and glucose-dependent insulinotropic peptide receptor agonist, while Wegovy's active ingredient is semaglutide, a glucagon-like peptide-1 receptor agonist.

The SURMOUNT-5 study is a phase 3b clinical trial evaluating and comparing the safety and efficacy of Zepbound and Wegovy in weight loss for patients with overweight or obesity who also have hypertension, dyslipidemia, obstructive sleep apnea or cardiovascular disease. No patient in the multicenter, randomized, open-label trial was diagnosed with type 2 diabetes.

For this evaluation, researchers randomized 751 participants to the maximum tolerated dose of Zepbound or Wegovy in a 1:1 ratio.

In a recent press release, Eli Lilly highlighted data from the study that revealed that patients on Zepbound had an average weight loss of 20.2% over 72 weeks, while the average weight loss for patients on Wegovy was 13.7%, marking a 47% greater relative weight loss for Zepbound patients.

Beyond weight loss, the press release highlighted that Zepbound was superior to Wegovy on all five secondary endpoints, including the percentage of patients who achieved various percentages of body weight reduction. However, the Eli Lilly press release specifically highlights that 31.6% of participants on Zepbound achieved 25% or greater weight loss. Comparatively, only 16.1% of those taking Wegovy achieved 25% or greater weight loss.

"Given the increased interest around obesity medications, we conducted this study to help health care providers and patients make informed decisions about treatment choice," said Leonard Glass, M.D., senior vice president of global medical affairs at Lilly Cardiometabolic Health, in the press release. "We are thrilled that today's findings showed the superior weight loss of Zepbound, which helped patients achieve 47% more relative weight loss compared to Wegovy. Zepbound is in a class of its own as the only FDA-approved dual [glucose-dependent insulinotropic peptide] GIP and [glucagon-like peptide-1] GLP-1 receptor agonist obesity medication, and it's changing how millions of people manage this chronic disease."

Despite this data and insight into GLP-1 medications, more research is necessary to explain how patients might react to different medicines. At the 2024 World Medical Innovation Forum, industry leaders and GLP-1 experts emphasized that this category of medications does not yield the same results for all patients.

Fatima Cody Stanford, M.D., obesity medicine physician-scientist at Massachusetts General Hospital and associate professor of medicine and pediatrics at Harvard Medical School, told conference attendees that these drugs are not a magical cure. While some patients might achieve great results, others might have a negative response or not see any change in their weight.

As the attention on GLP-1 medications continues, it is critical to understand how these medications impact patients differently. For providers, having data on which drugs might be better for meeting a patient's individual needs can help guide treatment plans and patient care.

Veronica Salib has covered news related to the pharmaceutical and life sciences industry since 2022.