CagriSema REDEFINE: What Novo Nordisk's Amylin Combination Actually Showed

CagriSema is Novo Nordisk's next-generation injectable weight-loss combination — cagrilintide (an amylin analog) plus semaglutide 2.4 mg (the same GLP-1 agonist already marketed as Wegovy). The hypothesis is mechanistic: amylin and GLP-1 are independent appetite-regulating gut hormones with non-overlapping receptor systems, so combining them should produce additive weight loss beyond what either alone can deliver. The REDEFINE 1 phase 3 trial in adults with overweight or obesity (no diabetes) and the REDEFINE 2 trial in adults with type 2 diabetes have both reported results [3, 4], and REDEFINE 1 has since been published in full in the New England Journal of Medicine (Davies et al., NEJM 2025). CagriSema produced the largest weight loss ever shown for an injectable combination of approved or near-approved drugs, but it missed the ~25% benchmark Novo Nordisk had previously guided investors toward, which dented the market reaction. Then, in the REDEFINE 4 head-to-head trial (topline from Novo Nordisk, February 2026), CagriSema was tested directly against tirzepatide for the first time — and missed its prespecified noninferiority objective, losing the direct comparison to tirzepatide despite delivering ~20–23% weight loss on its own. This article walks through the verified REDEFINE 1, REDEFINE 2, and REDEFINE 4 data, the mechanism, the safety profile, and what CagriSema actually represents in the evolving GLP-1 landscape.

What CagriSema actually is

Cagrilintide is a long-acting analog of amylin, a peptide hormone co-secreted with insulin from pancreatic β-cells in response to meals. Amylin slows gastric emptying, suppresses postprandial glucagon release, and signals satiety in the area postrema and other hindbrain regions — pathways that are mechanistically distinct from the GLP-1 signaling system. The phase 1b combination study (Enebo et al., Lancet 2021 [5]) and the phase 2 cagrilintide monotherapy trial (Lau et al., Lancet 2021 [6]) established the clinical signal that motivated REDEFINE.

CagriSema is a fixed-combination once-weekly subcutaneous injection delivering cagrilintide plus semaglutide 2.4 mg, titrated together over the standard ~16-week ramp.

REDEFINE 1: adults with overweight or obesity (no diabetes)

REDEFINE 1 is the pivotal phase 3 trial in the population most analogous to the existing Wegovy indication. The topline was first reported in Novo Nordisk's December 2024 Company Announcement [3] and has since been published in full in the New England Journal of Medicine (Davies et al., NEJM 2025), so the numbers below reflect a peer-reviewed manuscript rather than a press release alone. Verified design and results:

• Sample size: approximately 3,400 adults randomized
• Population: overweight or obesity with ≥1 weight-related comorbidity, no type 2 diabetes
• Arms: CagriSema, cagrilintide alone, semaglutide 2.4 mg alone, placebo
• Duration: 68 weeks
• Primary endpoint: percent change in body weight from baseline

Two important things happened in REDEFINE 1 [3]:

1. Additive benefit confirmed. CagriSema produced ~5.5 percentage points more weight loss than semaglutide alone and ~8.9 pp more than cagrilintide alone, on the full ITT analysis. Both component drugs contributed independently. The hypothesis behind the combination held up.
2. Missed the 25% target. Novo Nordisk had previously guided investors that CagriSema could plausibly hit ~25% mean weight loss. The actual mean of ~20.4% (full ITT) and ~22.7% (adherent) is meaningful but fell short of that bar, and the stock dropped sharply on the readout. The clinical relevance is that CagriSema beats semaglutide alone but does not match the tirzepatide effect size from SURMOUNT-1 (~20.9% at 72 weeks).

Novo Nordisk also reported that 40.4% of CagriSema-treated participants achieved ≥25% weight loss, and 50.7% of the CagriSema arm reached a BMI below 30 [3]. Both of these responder-rate numbers are best-in-class for an injectable.

REDEFINE 2: adults with type 2 diabetes

REDEFINE 2 evaluated CagriSema in adults with overweight or obesity AND type 2 diabetes. The trial population is important because patients with T2D consistently lose less weight on GLP-1 agonists than non-diabetic patients — the SURMOUNT-2 trial of tirzepatide showed roughly 15% weight loss at the highest dose in T2D vs the ~20% in SURMOUNT-1 non-diabetic [1]. The full REDEFINE 2 publication appeared in NEJM in 2025 [2]. Verified results:

The REDEFINE 2 effect size is smaller than REDEFINE 1, but the absolute placebo-adjusted weight loss (~10.3 pp) is consistent with what other GLP-1 agonists have produced in T2D populations and is clinically meaningful for patients managing both obesity and type 2 diabetes. The full glycemic and cardiometabolic results are in the NEJM publication [2].

REDEFINE 4: head-to-head vs tirzepatide

REDEFINE 4 is the trial that changes the story. It is the first direct phase 3 head-to-head comparison of CagriSema against tirzepatide (the active ingredient in Zepbound and Mounjaro) in adults with obesity but without type 2 diabetes, run over 68–84 weeks. Its prespecified primary objective was to show that CagriSema was noninferior to tirzepatide on percent body-weight loss. According to the topline announced by Novo Nordisk in February 2026 (REDEFINE 4 topline, Novo Nordisk, February 2026), CagriSema did not meet that noninferiority objective — it was statistically inferior to tirzepatide in the direct comparison.

The nuance matters. CagriSema still produced strong weight loss in REDEFINE 4 — roughly 20% on the treatment-regimen estimand and 23% under full adherence, numerically consistent with its REDEFINE 1 performance. But tirzepatide produced more (~23.6% and ~25.5% on the same two estimands), and the gap was large enough that CagriSema failed its noninferiority bar. In plain terms: CagriSema works, but in the only apples-to-apples trial ever run, it lost to tirzepatide rather than matching it. This retires the earlier caveat that all CagriSema-vs-tirzepatide claims were purely inferential — there is now a direct answer, and it favors tirzepatide on effect size.

Why mechanism matters

Until CagriSema, the most successful obesity drugs all targeted variations on the incretin axis: GLP-1 alone (semaglutide), GLP-1 + GIP (tirzepatide), or in development GLP-1 + GIP + glucagon (retatrutide). CagriSema is the first late-stage program to add a fundamentally different appetite-suppression mechanism — amylin signaling — to a GLP-1 backbone.

That mechanistic distinction is important because:

1. The two pathways are independent, so combining them should produce additive (not redundant) appetite suppression — and the REDEFINE 1 component-arm data confirmed this.
2. The amylin pathway has different downstream effects on glycemic control, gastric emptying, and CNS signaling than incretin pathways, which opens new questions about long-term metabolic adaptation, food-reward signaling, and the durability of weight loss.
3. Future combinations could plausibly stack amylin + GLP-1 + GIP or amylin + GLP-1 + GIP + glucagon, which would be the first “quadruple agonist” generation of obesity therapeutics.

Safety profile

Both REDEFINE trials reported a safety profile broadly consistent with the established GLP-1 class — predominantly gastrointestinal adverse events (nausea, vomiting, diarrhea, constipation), predominantly mild to moderate, predominantly resolving with continued use [3, 4]. The cagrilintide component appears to add modestly to the GI burden without introducing new categories of adverse events.

The full safety datasets are documented in the published manuscripts and the Novo regulatory submissions. As with any new injectable obesity drug, post-marketing experience and longer-term observational data will refine the rare-event picture. The standard GLP-1 class warnings (thyroid C-cell tumors, pancreatitis, gallbladder disease, retinopathy in T2D, dehydration-induced kidney injury) are expected to apply.

Where CagriSema fits in 2026

Novo Nordisk has filed a New Drug Application with the FDA for CagriSema. Timing of approval is the next major catalyst. Assuming approval, the practical positioning for CagriSema looks like this:

CagriSema is in the same weight-loss ballpark as tirzepatide and comes from a different mechanistic family, but the REDEFINE 4 head-to-head (Novo Nordisk, February 2026) showed it does not match tirzepatide's effect size in a direct comparison — CagriSema lost the noninferiority test (~20.2% vs 23.6% on the treatment-regimen estimand). So it will not displace tirzepatide as the highest-effect-size injectable. Its role is to expand the menu: a different-mechanism second option for patients who don't respond to or tolerate tirzepatide, from a company with the manufacturing scale to supply it. It also remains investigational — Novo filed an NDA (~December 2025), with an FDA decision expected around late 2026.

Open questions

1. Pricing. CagriSema launch pricing has not been announced. Novo will need to price this product competitively against tirzepatide and the newly-approved oral Foundayo.
2. Cardiovascular outcomes. A SELECT-style outcomes trial of CagriSema has not been announced. Until CagriSema accumulates its own cardiovascular outcomes evidence, Wegovy retains an edge for patients with established cardiovascular disease (see our SELECT trial deep-dive ).
3. Long-term durability. 68 weeks is the published duration. Whether the additive amylin benefit is sustained over multi-year therapy, and what happens to the weight loss after discontinuation, has not been published.
4. Direct head-to-head with tirzepatide — now answered. REDEFINE 1 and 2 did not include a tirzepatide arm, but REDEFINE 4 did. Its February 2026 topline (Novo Nordisk) showed CagriSema missing its noninferiority objective against tirzepatide (~20.2% vs 23.6% on the treatment-regimen estimand; 23.0% vs 25.5% on the efficacy estimand). The open remaining question is tolerability and real-world adherence: whether CagriSema's different (amylin-based) mechanism translates into a meaningfully different side-effect or durability profile that matters for individual patients even though it trailed on raw weight loss.

For the broader injectable GLP-1 landscape, see our tirzepatide vs semaglutide head-to-head deep-dive , the Foundayo (oral orforglipron) approval analysis , and the retatrutide triple-agonist evidence review . For the cardiovascular outcomes data on injectable semaglutide that anchors the existing standard of care, see our SELECT trial deep-dive . For pricing context across the entire GLP-1 market, see our pricing index . For trial-by-trial NCT IDs, primary completion dates, and topline results for every pipeline drug including CagriSema, see our GLP-1 Pipeline Tracker (2026) . For the chronological 2026 timeline of every approval and readout across the entire GLP-1 class, see our newest GLP-1 drugs (2026) reference .

For the parallel mechanism explainer on the dual GIP+GLP-1 agonist path (tirzepatide, sold as Mounjaro and Zepbound), see our GIP receptor explained deep dive — the GIP-receptor arm is what makes Zepbound's 20.9% SURMOUNT-1 weight loss greater than Wegovy's 14.9% STEP-1 weight loss, just as the amylin arm is what makes CagriSema's 22.7% REDEFINE 1 result greater than the single-mechanism semaglutide control.

Further reading

• Top semaglutide weight-loss studies (curated PubMed reading list)
• Top retatrutide studies