Eli Lilly's Zepbound has outperformed Novo Nordisk's Wegovy in a pivotal clinical trial, marking a significant milestone in the competitive obesity treatment market. The study revealed that adults taking Zepbound experienced an average weight loss of 20% of their body weight, compared to 14% among Wegovy users, a difference of 47%. The findings have set a new benchmark for the effectiveness of weight-loss medications.
The trial, which tracked 751 participants from the United States and Puerto Rico over 18 months, showcased Zepbound's potential to deliver greater results. On average, participants on Zepbound lost 50 pounds, compared to 33 pounds for those on Wegovy. Furthermore, 32% of Zepbound users achieved at least a 25% reduction in body weight, doubling the 16% success rate observed in Wegovy users.
Zepbound, known generically as tirzepatide, operates by mimicking the gut hormone GLP-1 to stimulate insulin production, slow digestion, and suppress appetite. Unlike Wegovy's semaglutide, Zepbound also targets a second hormone, GIP, which enhances its weight-loss effects. Both drugs are approved by the U.S. Food and Drug Administration (FDA) for treating obesity and type 2 diabetes, but Zepbound's dual mechanism offers a distinct advantage.
Dr. Leonard C. Glass, senior vice president of global medical affairs at Lilly Cardiometabolic Health, emphasized the importance of the findings. "Zepbound is in a class of its own as the only FDA-approved dual GIP and GLP-1 receptor agonist obesity medication," he said. "It's changing how millions of people manage this chronic disease."
The results come amid skyrocketing demand for weight-loss medications, with Eli Lilly and Novo Nordisk vying for dominance in this lucrative market. Zepbound's sales reached $1.3 billion in the third quarter of this year, less than a year after its launch. The trial results are expected to accelerate its growth and reinforce its position as a leader in obesity treatment.
The study's findings are consistent with earlier research comparing tirzepatide and semaglutide, but this trial exclusively involved participants without diabetes. Instead, it focused on individuals living with obesity or overweight who also had related health conditions such as hypertension or cardiovascular disease. While both drugs demonstrated efficacy, Zepbound's superior performance is likely to influence patient and provider choices.
The trial also highlighted some common side effects, with both drugs causing mild to moderate gastrointestinal symptoms. Despite this, the outcomes are expected to further fuel Zepbound's popularity among patients seeking significant and sustainable weight loss.
The news sent Eli Lilly's stock up by 2.4%, closing at $833.21 on Wednesday. Novo Nordisk's U.S.-traded shares also rose slightly. Analysts predict that Zepbound's performance will continue to drive investor confidence in Eli Lilly, which has seen its stock hit record highs this year.
