CagriSema: The First GLP-1 + Amylin Combo for Obesity
Phase 3 REDEFINE 1 data show CagriSema delivers 22.7% weight loss in non-diabetic adults — and an FDA decision is expected in 2026. Here's what the science actually says.
Medically Reviewed
Reviewed by Dr. James Chen, MD, PhD, FACE on April 28, 2026
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For the better part of three years, the obesity-pharmacology conversation has been dominated by a single question: how do you push weight loss past the ceiling that monotherapy GLP-1s and even tirzepatide hit somewhere between 15% and 22%? Novo Nordisk's answer is CagriSema — a once-weekly fixed-dose combination of semaglutide 2.4 mg (a GLP-1 receptor agonist) and cagrilintide 2.4 mg (a long-acting amylin analogue). The thesis is biologically clean: target two distinct satiety pathways at the same time, and you should get more weight loss than either drug alone. The Phase 3 REDEFINE program, published in the New England Journal of Medicine in mid-2025, has now tested that thesis in over 5,000 adults.
Evidence: "The estimated mean percent change in body weight from baseline to week 68 was −20.4% with cagrilintide–semaglutide as compared with −3.0% with placebo (estimated difference, −17.3 percentage points; 95% CI, −18.1 to −16.6; P<0.001)." — Garvey WT, et al. New England Journal of Medicine. 2025. DOI: 10.1056/NEJMoa2502081
Novo Nordisk submitted the New Drug Application to the FDA on December 18, 2025. Under the standard 10-month review window, a decision is anticipated around October 2026 — making CagriSema the first GLP-1/amylin co-formulation likely to reach the U.S. market.
How CagriSema Works: Two Satiety Systems, One Injection
GLP-1 receptor agonists like semaglutide act primarily through the brainstem and hypothalamus to slow gastric emptying, reduce hedonic food reward, and increase post-meal satiety. They are powerful — but they leave the amylin axis untouched.
Amylin is a pancreatic hormone co-secreted with insulin from beta cells in response to a meal. It binds to amylin receptor complexes (AMY1R and AMY3R) in the area postrema and hypothalamus to suppress glucagon, slow gastric emptying, and signal meal-time fullness. Cagrilintide is a long-acting, lipidated amylin analogue engineered for once-weekly dosing — and it produces weight loss through brain amylin receptors that GLP-1 drugs do not engage.
Evidence: "The body weight–lowering effects of cagrilintide depend on amylin receptors AMY1R and AMY3R, with primary action in the area postrema and arcuate nucleus of the hypothalamus." — Lutz TA, et al. eBioMedicine. 2025. DOI: 10.1016/j.ebiom.2025.105800
The pharmacological argument for combining the two is that the satiety circuits are complementary rather than redundant. GLP-1 dampens reward-driven eating; amylin gates meal-termination signals. In animal models and Phase 2 human data, the combination produced additive — and possibly synergistic — appetite suppression that monotherapy could not match.
How CagriSema differs from existing dual-action drugs
| Drug | Mechanism | Dosing | Phase 3 weight loss |
|---|---|---|---|
| Semaglutide 2.4 mg (Wegovy) | GLP-1 only | Weekly SC | ~15% at 68 wks |
| Tirzepatide 15 mg (Zepbound) | GLP-1 + GIP dual agonist | Weekly SC | ~21% at 72 wks |
| Retatrutide 12 mg | GLP-1 + GIP + glucagon triple | Weekly SC | ~24% at 48 wks (Ph 2) |
| CagriSema 2.4/2.4 mg | GLP-1 + amylin co-formulation | Weekly SC | ~22.7% at 68 wks |
CagriSema is mechanistically distinct from tirzepatide and retatrutide — those drugs combine multiple incretin pathways inside a single peptide, while CagriSema co-administers two structurally separate molecules in one pen. This matters for two reasons: titration of each component can theoretically be uncoupled in future generations, and the safety footprint of amylin agonism (well-characterized from pramlintide) differs from GIP or glucagon agonism.
REDEFINE 1: The Headline Trial in Non-Diabetic Obesity
REDEFINE 1 was a 68-week, multinational, double-blind, placebo-controlled and active-controlled Phase 3a trial that enrolled 3,417 adults with a BMI ≥ 30, or BMI ≥ 27 with at least one obesity-related complication. Critically, all participants had no type 2 diabetes — this was a pure obesity population. They were randomized to:
- CagriSema 2.4/2.4 mg (n = 2,108)
- Semaglutide 2.4 mg alone (n = 302)
- Cagrilintide 2.4 mg alone (n = 302)
- Placebo (n = 705)
All groups received standardized lifestyle intervention. The primary endpoint was percent change in body weight from baseline to week 68.
The numbers that matter
CagriSema produced 22.7% mean weight loss in the treatment-policy estimand (representing the average effect across all randomized patients, including those who discontinued) and 20.4% in the trial-product estimand (representing the effect if patients adhered to the regimen as randomized). Both are clinically meaningful and statistically significant versus all comparators.
Other clinically important findings:
- 60% of CagriSema participants achieved ≥20% weight loss (vs. 5% on placebo)
- 23% achieved ≥30% weight loss — a threshold previously seen only with bariatric surgery
- 91.9% achieved ≥5% weight loss vs. 31.5% on placebo
- 88% of participants with prediabetes returned to normoglycemia
- Significant improvements in waist circumference, systolic blood pressure, and lipid panel
Notably, CagriSema beat both monotherapy arms, validating the additive design hypothesis — semaglutide alone produced approximately 16% weight loss in this study, and cagrilintide alone produced approximately 12%. The combination was meaningfully greater than the sum of either.
REDEFINE 2: Adults With Type 2 Diabetes
REDEFINE 2 ran in parallel across 12 countries and enrolled 1,206 adults with a BMI ≥ 27, type 2 diabetes, and HbA1c between 7% and 10%. Participants received either CagriSema or placebo plus lifestyle intervention for 68 weeks.
Evidence: "The estimated mean change in body weight from baseline to week 68 was −13.7% in the cagrilintide–semaglutide group and −3.4% in the placebo group, and 73.5% of participants in the cagrilintide–semaglutide group reached a glycated hemoglobin level of 6.5% or less, compared with 15.9% in the placebo group." — Davies MJ, et al. New England Journal of Medicine. 2025. DOI: 10.1056/NEJMoa2502082
The 13.7% weight loss in T2D patients is consistent with a recurring pattern across the GLP-1 class: people with diabetes lose roughly 30–40% less weight on the same drug than people without diabetes, likely because of insulin's anti-lipolytic effects and altered fuel partitioning. Even so, the glycemic data are striking — nearly three quarters of CagriSema-treated patients achieved an HbA1c at or below the prediabetic threshold, raising the question of type 2 diabetes remission as a realistic endpoint with this combination.
Why CagriSema didn't hit Novo's 25% target
When Novo Nordisk first projected CagriSema outcomes to investors, the internal expectation was 25% mean weight loss. The actual 22.7% figure triggered a temporary stock-price decline in late 2024 when topline data first surfaced, despite the result being objectively superior to every approved obesity drug. Two factors explain the gap. First, REDEFINE 1's trial-product estimand was diluted by participants who could not tolerate the maximum dose and remained on lower titrations. Second, the trial was powered against placebo and active comparators — not against an arbitrary effect-size benchmark. By the standards of clinical efficacy, 22.7% with statistically robust comparator superiority is a regulatory win.
Safety Profile: Amylin Adds GI Burden, Not Novel Risks
The dominant safety story is gastrointestinal — predictable, given that both components delay gastric emptying and act on brainstem nausea pathways.
Evidence: "Adverse events leading to discontinuation occurred in 4.6% of participants in the cagrilintide–semaglutide group and 3.0% in the placebo group; gastrointestinal events were the most common, reported by 79.6% and 39.9% of participants respectively." — Garvey WT, et al. New England Journal of Medicine. 2025. DOI: 10.1056/NEJMoa2502081
Key observations from the pooled REDEFINE safety data:
- Nausea, vomiting, diarrhea, constipation — most common, mostly mild-to-moderate, transient, concentrated during dose escalation
- Discontinuation rate of 4.6% — roughly comparable to semaglutide monotherapy in STEP trials
- No increase in pancreatitis, gallbladder events, or thyroid signal versus expectations from GLP-1 monotherapy
- No new cardiovascular safety signals — though cardiovascular outcome trial data are still pending
- Injection site reactions modestly higher than monotherapy, consistent with co-formulated peptides
The safety profile is the safety profile of two drugs we already understand stacked on top of each other. There are no novel mechanism-related red flags — a meaningful contrast with first-in-class molecules like retatrutide, where glucagon-receptor agonism introduces hepatic and glycemic considerations that amylin does not.
Who should not take CagriSema
The contraindications expected on the FDA label will mirror semaglutide's existing label:
- Personal or family history of medullary thyroid carcinoma
- Multiple endocrine neoplasia syndrome type 2
- Pregnancy or active attempts to conceive
- History of severe gastrointestinal disease, including gastroparesis
- Hypersensitivity to either active component
Patients currently on semaglutide who would switch to CagriSema should not stack the drugs — total semaglutide exposure must remain at 2.4 mg weekly.
What CagriSema Means for the Market
If the FDA approves CagriSema in late 2026, the obesity-pharmacology landscape will fragment into roughly four tiers of weight-loss efficacy: ~5–10% (older agents like phentermine or Contrave), ~12–17% (semaglutide, liraglutide, oral orforglipron), ~20–23% (tirzepatide, CagriSema), and ~24%+ (retatrutide, pending Phase 3). Within the 20%+ tier, CagriSema's differentiation will come from three things:
- A safety profile rooted in two well-characterized mechanisms rather than novel polypharmacology
- Potential pricing leverage — Novo Nordisk holds both component patents and can co-formulate without licensing
- Theoretical durability — amylin agonism may attenuate the appetite-rebound seen when patients discontinue GLP-1s, though this remains an open research question relevant to anyone tracking weight regain after GLP-1s
Two-year extension data from REDEFINE 1 are expected in late 2026 and will be the most informative dataset on weight-loss durability. A dedicated cardiovascular outcomes trial (REDEFINE 3) is enrolling patients with established cardiovascular disease and obesity, with topline results not anticipated before 2028.
Key Takeaways
- CagriSema is a once-weekly fixed-dose combination of semaglutide 2.4 mg (GLP-1 agonist) and cagrilintide 2.4 mg (long-acting amylin analogue), engineered to engage two complementary satiety pathways
- REDEFINE 1 demonstrated 22.7% mean weight loss at 68 weeks in adults with obesity and no diabetes — superior to either monotherapy and to placebo
- REDEFINE 2 produced 13.7% weight loss and 73.5% achievement of HbA1c ≤6.5% in adults with type 2 diabetes
- Safety burden is gastrointestinal, mostly transient, with a 4.6% discontinuation rate and no novel mechanism-related signals
- FDA decision expected approximately October 2026, following December 2025 NDA submission
- CagriSema sits in the same efficacy tier as tirzepatide (~20–23%) but reaches it through a mechanistically distinct route
The next 18 months will determine whether CagriSema becomes a first-line option, a second-line escalation after tirzepatide, or something in between. What is no longer in doubt is that adding amylin agonism to GLP-1 therapy produces clinically meaningful additional weight loss — a finding that will likely shape obesity drug development for the rest of the decade.
References
- Garvey WT, Birkenfeld AL, Dicker D, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2025;393(4):301–315. DOI: 10.1056/NEJMoa2502081
- Davies MJ, Aronne LJ, Bajaj HS, et al. Cagrilintide–Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes. New England Journal of Medicine. 2025;393(4):316–328. DOI: 10.1056/NEJMoa2502082
- Lutz TA, Coester B, Whiting L, et al. Cagrilintide lowers bodyweight through brain amylin receptors 1 and 3. eBioMedicine. 2025;118:105800. DOI: 10.1016/j.ebiom.2025.105800
- Lau DCW, Erichsen L, Francisco AM, et al. Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. The Lancet. 2021;398(10317):2160–2172. DOI: 10.1016/S0140-6736(21)01751-7
- Frias JP, Deenadayalan S, Erichsen L, et al. Efficacy and safety of co-administered once-weekly cagrilintide 2·4 mg with once-weekly semaglutide 2·4 mg in type 2 diabetes: a multicentre, randomised, double-blind, active-controlled, phase 2 trial. The Lancet. 2023;402(10403):720–730. DOI: 10.1016/S0140-6736(23)01163-7
- Kruse Hansen T, Lehrskov LL, Astrup A. A Long-Acting Amylin Analog for the Treatment of Obesity. Obesity Reviews. 2023;24(5):e13548. DOI: 10.1111/obr.13548
Last updated: 2026-04-28 Medical review: Dr. James Chen, MD, PhD, FACE
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Written By
Dr. Sarah Mitchell
Medical Director, MD, FACP
Dr. Sarah Mitchell is a board-certified internist specializing in metabolic medicine and weight management. With over 15 years of clinical experience, she has helped thousands of patients achieve sustainable weight loss through evidence-based approaches.
Medical Reviewer
Dr. James Chen
Endocrinologist, MD, PhD, FACE
Dr. James Chen is a fellowship-trained endocrinologist with expertise in diabetes, metabolism, and hormone-related weight disorders. His research on GLP-1 receptor agonists has been published in leading medical journals.
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