Eli Lilly’s obesity drug Zepbound has demonstrated superior weight loss results compared to Novo Nordisk’s Wegovy in the first direct clinical comparison between the two weekly injectable treatments.
According to results from a phase three trial, patients using Zepbound lost an average of 20.2% of their body weight over 72 weeks, compared to 13.7% for those taking Wegovy.
In the head-to-head trial involving 751 participants, Zepbound achieved a 47% greater relative weight reduction compared to Wegovy. On average, patients lost approximately 50 pounds with Zepbound, versus 33 pounds with Wegovy. Additionally, more than 31% of participants on Zepbound shed at least a quarter of their body weight, compared to 16% for Wegovy users.
Dr. Leonard Glass, Eli Lilly’s senior vice president of global medical affairs, emphasized the trial’s importance:
“Given the increased interest around obesity medications, we conducted this study to help health care providers and patients make informed decisions about treatment choice.”
Zepbound and Wegovy differ in how they work. Zepbound activates two gut hormones, GIP and GLP-1, which help regulate appetite and blood sugar, while Wegovy targets only GLP-1. Both drugs share similar side effects, primarily gastrointestinal issues that are generally mild to moderate in severity.
The trial results provide Eli Lilly with a strategic advantage in the rapidly growing weight loss drug market, which analysts project could reach $150 billion annually by the early 2030s. Despite entering the market two years after Wegovy, Zepbound is projected to become a top-selling drug, with GlobalData forecasting $27.2 billion in annual sales by 2030, compared to Wegovy’s estimated $18.7 billion.
Both Eli Lilly and Novo Nordisk have faced high demand for their weight loss drugs, leading to supply challenges. However, recent manufacturing expansions have improved availability, as confirmed by the FDA’s drug shortage database. Despite improved supply, access remains an issue due to inconsistent insurance coverage. Without insurance, both Zepbound and Wegovy cost around $1,000 per month.
Eli Lilly plans to publish the trial results in a peer-reviewed journal and present the findings at a medical conference next year.
CNBC and Market Watch contributed to this report.
