CagriSema (Cagrilintide + Semaglutide): What the REDEFINE Trials Reveal
A new class of obesity treatment is on the horizon. CagriSema, the combination of cagrilintide and semaglutide developed by Novo Nordisk, has generated enormous interest after delivering over 20% average weight loss in Phase 3 clinical trials.
What Is CagriSema?
CagriSema is a fixed-dose, once-weekly subcutaneous injection combining two active ingredients: Semaglutide 2.4 mg (a GLP-1 receptor agonist, the same ingredient in Wegovy) and Cagrilintide 2.4 mg (a long-acting amylin analog). The pairing exploits two complementary appetite-suppressing pathways simultaneously.
How Does Cagrilintide Work? The Amylin Pathway
Amylin is released from the pancreas alongside insulin in response to meals. It signals satiety, slows gastric emptying, and suppresses postprandial glucagon secretion. In people with obesity and type 2 diabetes, amylin signaling is often impaired. Cagrilintide restores and amplifies this signal via once-weekly dosing achieved through fatty acid conjugation.
An earlier amylin analog, pramlintide (Symlin), required three daily injections and achieved modest results. Cagrilintide long half-life makes it practical as a co-formulation.
The GLP-1 + Amylin Synergy
GLP-1 receptor agonists like semaglutide suppress appetite primarily through hypothalamic and brainstem pathways. Amylin analogs act through overlapping but distinct brain circuits. When combined, preclinical models and early human data suggest a synergistic effect: patients lose more weight than either drug contributes alone.
This dual-pathway concept mirrors tirzepatide (Zepbound), which targets GLP-1 and GIP receptors. But CagriSema uses an entirely different second pathway — amylin rather than GIP — potentially benefiting patients who respond differently to incretin-only therapy.
REDEFINE Trials: The Phase 3 Evidence
Novo Nordisk conducted two pivotal Phase 3 trials simultaneously published in the New England Journal of Medicine at the 85th Scientific Sessions of the American Diabetes Association in June 2025.
REDEFINE 1 (Without Type 2 Diabetes)
3,417 adults with overweight or obesity were randomized to CagriSema, semaglutide alone, cagrilintide alone, or placebo.
Mean weight loss at week 68:
- CagriSema: −20.4%
- Semaglutide alone: −14.9%
- Cagrilintide alone: −11.5%
- Placebo: −3.0%
60% of CagriSema participants achieved ≥20% weight loss; 23% lost 30% or more. CagriSema also significantly improved blood pressure, waist circumference, lipids, and glycemic control. Among participants with prediabetes, 88% returned to normoglycemia.
REDEFINE 2 (With Type 2 Diabetes)
1,206 adults with overweight/obesity and type 2 diabetes were enrolled.
Mean weight loss at week 68:
- CagriSema: −13.7%
- Placebo: −3.4%
Glycemic outcomes were remarkable: 73.5% of CagriSema participants achieved HbA1c ≤6.5% versus just 15.9% on placebo.
CagriSema vs. Tirzepatide: The Head-to-Head
In a Phase 3 head-to-head trial completed in early 2026, tirzepatide 15 mg produced approximately 25.5% weight loss versus 23.0% for CagriSema at 84 weeks — a statistically significant difference favoring tirzepatide. The margin is narrower than initial headlines suggested, and CagriSema still substantially outperforms semaglutide monotherapy.
| Drug | Mechanism | Avg. Weight Loss |
|---|---|---|
| Semaglutide 2.4 mg (Wegovy) | GLP-1 | ~15–16% |
| CagriSema 2.4/2.4 mg | GLP-1 + Amylin | ~20–23% |
| Tirzepatide 15 mg (Zepbound) | GLP-1 + GIP | ~22–25% |
Dosing Schedule
CagriSema uses a gradual once-weekly escalation protocol:
- Starting dose: 0.25 mg once weekly (weeks 1–4)
- Escalation: Increased every 4 weeks
- Maintenance: 2.4 mg/2.4 mg once weekly (reached around week 16)
Side Effects and Safety
From REDEFINE trial data, gastrointestinal effects are the most common adverse events:
- Nausea: 40–45%
- Diarrhea: 25–30%
- Vomiting: 20–25%
- Constipation: ~20%
Overall, 72.5% of CagriSema participants reported GI adverse events (vs. 34.4% placebo). Most were transient and mild to moderate, peaking during dose escalation. Notably, the amylin component does not appear to substantially increase the GI burden beyond semaglutide alone — encouraging news for tolerability.
FDA Approval Timeline
On December 18, 2025, Novo Nordisk filed a New Drug Application (NDA) with the FDA — making CagriSema the first injectable GLP-1 + amylin combination to seek U.S. approval.
- NDA filed: December 2025
- Standard FDA review: ~12 months
- Projected approval window: Late 2026 to early 2027
No breakthrough therapy designation has been confirmed, and no formal PDUFA date has been set as of April 2026. Regarding compounding: without FDA approval or drug shortage status, compounding access to CagriSema remains very limited. Consult a licensed physician and only use PCAB-accredited or 503B-licensed pharmacies for any peptide or GLP-1 therapy.
Looking Ahead: Amylin Enters the Mainstream
CagriSema signals a broader revival of amylin-based medicine. Novo Nordisk is also advancing amycretin — a single molecule activating both GLP-1 and amylin receptors — into Phase 3 trials. If amylin consistently amplifies GLP-1 weight loss, it may reshape obesity pharmacotherapy well beyond the current co-injection format.
Bottom Line
CagriSema represents a genuine leap forward in obesity treatment. By combining semaglutide with cagrilintide, it achieved over 20% mean weight loss in Phase 3 — far beyond what either drug achieves alone. While tirzepatide holds a narrow performance edge, CagriSema offers a distinct mechanism that may suit patients who respond differently or tolerate it better. With an FDA decision expected by late 2026, CagriSema is one of the most important obesity drugs to watch.