Novo Nordisk's Next-Gen CagriSema Fails Head-to-Head Phase 3 Obesity Trial Against Lilly's Zepbound
In a major clinical setback for Novo Nordisk, its next-generation weight-loss candidate, CagriSema (a once-weekly combination of 2.4 mg semaglutide and 2.4 mg of the amylin analogue cagrilintide), failed to meet its primary endpoint of demonstrating non-inferiority against Eli Lilly's dual GLP-1/GIP agonist Zepbound (tirzepatide) in the pivotal head-to-head Phase 3 REDEFINE 4 clinical trial.
The topline results, announced on February 23, 2026, revealed that while CagriSema achieved an impressive 23% mean body-weight reduction after 84 weeks of treatment, tirzepatide outperformed it, achieving a mean body-weight reduction of 25.5%.
When treatment adherence was excluded (on a product estimand basis), tirzepatide maintained its lead, driving 23.6% weight loss compared to CagriSema's 20.2%. The disappointing results triggered a 15% plunge in Novo Nordisk's share price in pre-market trading immediately following the announcement, while Eli Lilly's stock surged.
Novo Nordisk Defends CagriSema's Marketability
Despite the head-to-head loss, Novo Nordisk executives rigorously defended the drug's clinical value and commercial viability. CagriSema has already been submitted to the U.S. FDA based on the positive, placebo-controlled REDEFINE 1 and REDEFINE 2 Phase 3 trials, where it demonstrated highly competitive weight loss. The FDA is expected to make an approval decision on CagriSema by late 2026 / December 2026, with a commercial launch anticipated in early 2027.
Novo Nordisk is also pinning its future hopes on REDEFINE 11, an ongoing Phase 3 trial evaluating a higher-dose formulation of CagriSema. The company believes that a higher dose, combined with operational learnings from across the REDEFINE clinical program, will unlock further weight-loss potential and yield superior results, with readouts expected in the first half of 2027.
Verbatim Quotes and Interpretation
“To say it’s obsolete is quite belittling a fantastic drug, in all honesty. When CagriSema will make it to the market early next year as the first amylin-based product, it will have the best weight loss label than any product marketed at that time,” stated Maziar Mike Doustdar, CEO of Novo Nordisk, during an analyst conference call defending the drug against claims that the head-to-head loss made it market-obsolete.
“That’s maybe why we have seen these surprisingly good data for the comparative drug in part—we probably also have to ascribe this to biology. So obviously, this is the one off,” remarked Martin Holst Lange, Chief Scientific Officer at Novo Nordisk, attributing the loss to tirzepatide's unexpectedly strong showing, which exceeded its previous clinical trial benchmarks.
For healthcare investors, the REDEFINE 4 results cement Eli Lilly's near-term clinical dominance in the injectable obesity market. While CagriSema represents a massive step forward compared to semaglutide alone (Wegovy), it fell short of Zepbound's dual GLP-1/GIP biological efficacy. However, CagriSema's unique amylin-based mechanism of action may still carve out a significant market share, particularly for patients who do not tolerate dual-incretin therapies or those who benefit from amylin's distinct metabolic profile.