Eli Lilly's Zepbound outshines Wegovy in weight loss trial results

Eli Lilly announced on Sunday that its weight-loss drug, Zepbound, outperformed Novo Nordisk's Wegovy in a head-to-head trial, showing superior results across five weight-loss targets, including waist circumference reduction.

This trial, the first of its kind comparing the two widely used obesity medications, offers Eli Lilly a competitive advantage as it aims to secure broader insurance coverage in the rapidly growing obesity drug market, which is projected to exceed $150 billion annually by the next decade.

The results revealed that Zepbound helped nearly 25% more participants achieve a weight loss of over 15% compared to Wegovy. In addition, Zepbound demonstrated a more significant reduction in waist circumference, with an average decrease of 18.4 cm. In comparison, Wegovy participants saw an average reduction of 13 cm.

Novo Nordisk, in a statement sent via email on Monday, pointed out that the weight loss achieved by Wegovy in this trial was lower than what was observed in a 2021 trial with a similar dose. However, the company emphasised that Wegovy is the only GLP-1 agonist medicine approved to prevent major cardiovascular events, such as heart attacks, a critical benefit for patients with obesity. Novo also mentioned that a trial with a higher dose of semaglutide, Wegovy's active ingredient, conducted earlier this year, showed greater weight-loss results.

Lilly had previously reported in December that its obesity drug had already surpassed Wegovy, with patients treated with Zepbound losing 47% more weight than those who received Wegovy. These findings were also shared in a press release and presented at the European Congress on Obesity.

The timing of the trial results coincides with a recent decision by CVS Health to exclude Zepbound from some of its reimbursement lists, preferring Wegovy instead. This move highlights the ongoing competition between the two pharmaceutical giants in the obesity treatment space.

Zepbound mimics two gut hormones to support weight loss, while Wegovy relies on a single mode of action. In separate trials, Lilly's Zepbound helped patients lose more than 22% of their body weight after 72 weeks, while Wegovy led to a 15% reduction in weight after 68 weeks.

The growing competition in the weight-loss drug market is also impacted by another Eli Lilly medication, Mounjaro, which has shown positive results for diabetes and weight loss. With these advancements, Eli Lilly is positioning itself as a major player in the obesity treatment landscape.

These results reflect the growing rivalry in the weight-loss drug market and may influence future decisions on treatment options for obesity patients.