Novo Nordisk’s CagriSema Falls Short Against Zepbound in Head-to-Head Trial

Novo Nordisk’s next-generation combination drug CagriSema did not outperform Eli Lilly’s Zepbound (tirzepatide) in the closely watched REDEFINE 4 head-to-head clinical trial. The results, released in February 2026, represent a significant setback for Novo Nordisk’s strategy to reclaim the lead in the GLP-1 medication market.

REDEFINE 4 Trial Design

The REDEFINE 4 trial was a Phase 3, randomized, double-blind study comparing CagriSema — a fixed-ratio combination of semaglutide and cagrilintide — against tirzepatide (marketed as Zepbound and Mounjaro) in adults with obesity. The trial enrolled approximately 3,400 participants across multiple countries and ran for 84 weeks.

CagriSema combines two active ingredients: semaglutide (a GLP-1 receptor agonist) and cagrilintide (an amylin receptor agonist). Novo Nordisk positioned the combination as its answer to the dual GIP/GLP-1 mechanism of tirzepatide.

Results: Tirzepatide Achieved Greater Weight Reduction

The primary endpoint — percentage change in body weight from baseline at 84 weeks — showed:

Metric	CagriSema	Tirzepatide (Zepbound)
Weight loss (on-treatment)	23.0%	25.5%
Weight loss (real-world adherence)	20.2%	23.6%

The on-treatment analysis, which counts only participants who stayed on the drug for the full 84 weeks, showed tirzepatide achieving 25.5% mean weight reduction compared to CagriSema’s 23.0%. Under real-world adherence estimates — which include participants who discontinued treatment — the gap was similar: 23.6% for tirzepatide versus 20.2% for CagriSema.

The trial did not meet its primary endpoint of demonstrating non-inferiority of CagriSema to tirzepatide. Put plainly: CagriSema delivered less weight reduction than tirzepatide in this study.

Market Reaction: Novo Nordisk Shares Fell Sharply

Financial markets reacted swiftly. Novo Nordisk shares dropped 13–16% on the Copenhagen Stock Exchange following the REDEFINE 4 readout, wiping tens of billions of dollars from the company’s market capitalization. The decline reflected investor expectations that CagriSema would match or exceed tirzepatide’s performance — expectations that the data did not support.

Eli Lilly’s stock rose modestly on the same day, as the results reinforced the competitive position of Zepbound and Mounjaro.

What This Means for the Canadian Market

For Canadian consumers comparing GLP-1 medications, the REDEFINE 4 results have several practical implications:

• Tirzepatide remains the most effective option in clinical data. Zepbound and Mounjaro (both tirzepatide) continue to show the highest weight-reduction numbers in large-scale trials. However, tirzepatide products are also among the most expensive GLP-1 medications available in Canada, and no generic competition exists for tirzepatide at this time.
• Semaglutide faces generic competition; tirzepatide does not. Novo Nordisk’s semaglutide data exclusivity expired in January 2026, with nine generic manufacturers having filed with Health Canada. Tirzepatide has no near-term generic timeline, meaning its pricing will remain at branded levels for the foreseeable future.
• Novo Nordisk may accelerate lower-cost semaglutide brands. With CagriSema underperforming and generic semaglutide competition looming, Novo Nordisk faces pressure on multiple fronts. The company’s authorized lower-price semaglutide brands — Plosbrio and Poviztra — were approved by Health Canada in December 2025 and could reach pharmacies sooner as the company seeks to defend market share.
• Price comparison remains essential. With multiple semaglutide products (branded Ozempic, Wegovy, Plosbrio, Poviztra, and upcoming generics) alongside tirzepatide products (Mounjaro, Zepbound), Canadian consumers face an increasingly complex pricing landscape. Prices vary by pharmacy, province, and dosage.

CagriSema’s Regulatory Path Forward

Despite the REDEFINE 4 results, Novo Nordisk has stated it intends to proceed with regulatory submissions for CagriSema. The drug still demonstrated meaningful weight reduction — 23% on-treatment — and the broader REDEFINE clinical trial program includes additional studies evaluating CagriSema in different patient populations.

Whether CagriSema receives Health Canada approval, and at what price point it would enter the Canadian market, remains to be determined. GLP1Prices.ca will report on any regulatory developments as they occur.

This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional for questions about specific medications.