Retatrutide vs CagriSema: Comparing Triple-Agonist and GLP-1/Amylin Trial Data
TL;DR: CagriSema missed non-inferiority vs tirzepatide in REDEFINE-4 (Feb 2026); retatrutide's TRIUMPH-1 reports larger losses.
What Is CagriSema and How Does It Differ From Retatrutide?
CagriSema is Novo Nordisk's investigational once-weekly subcutaneous injection combining cagrilintide 2.4mg, a long-acting amylin-receptor agonist, with semaglutide 2.4mg, the GLP-1 receptor agonist already marketed as Wegovy and Ozempic.[1] That design is structurally different from retatrutide, Eli Lilly's single-molecule triple agonist, which is engineered to activate the GLP-1, GIP and glucagon receptors from one peptide backbone. CagriSema is instead a fixed-dose combination of two separate active substances, one of which (semaglutide) already carries an established regulatory and safety record from its individual approvals.
The amylin pathway CagriSema adds is mechanistically distinct from the GIP and glucagon pathways retatrutide targets: amylin is a pancreatic hormone co-secreted with insulin that acts on satiety and gastric-emptying circuitry in the brainstem, giving Novo Nordisk's programme an independent route to the same broad research question — whether pairing GLP-1 agonism with a second metabolic receptor improves on semaglutide alone — that retatrutide, survodutide and other pipeline agonists are also testing from different mechanistic angles.[2] Neither compound is approved for human use in any jurisdiction; CagriSema has a pending FDA New Drug Application, and retatrutide remains in late-stage clinical development with no filing yet submitted.
What Did REDEFINE-1 and REDEFINE-2 Report?
Design: 3,417 adults with obesity or overweight and at least one weight-related comorbidity, without type 2 diabetes, were randomised to once-weekly CagriSema 2.4mg/2.4mg, its individual components, or placebo, over 68 weeks. Result at 68 weeks: mean body-weight loss of 22.7% under the in-trial (treatment-adherent) estimand versus 2.3% on placebo, or 20.4% versus 3.0% under the treatment-policy estimand; 91.9% of CagriSema-treated participants achieved at least 5% weight loss versus 31.5% on placebo.[1]
Source: PMID 40544433; N Engl J Med, DOI 10.1056/NEJMoa2502081
Design: 1,206 adults with type 2 diabetes and obesity or overweight were randomised to once-weekly CagriSema 2.4mg/2.4mg or placebo over 68 weeks. Result at 68 weeks: mean body-weight loss of 15.7% versus 3.1% on placebo, alongside an HbA1c reduction of 2.0 percentage points versus 0.1 on placebo; 80.7% of CagriSema-treated participants reached HbA1c ≤6.5% versus 12.2% on placebo.[3]
Source: PMID 40544432; N Engl J Med, DOI 10.1056/NEJMoa2502082; ClinicalTrials.gov NCT05394519
These two trials formed the primary evidence base for Novo Nordisk's FDA filing, submitted on 18 December 2025.[4]
What Did the REDEFINE-4 Head-to-Head Trial Against Tirzepatide Show?
Design: 809 adults with obesity and at least one weight-related comorbidity were randomised to once-weekly CagriSema 2.4mg/2.4mg or Eli Lilly's tirzepatide 15mg (marketed as Zepbound), over 84 weeks — the first published Phase 3 trial to test CagriSema directly against an approved competitor rather than placebo. Result at 84 weeks: CagriSema produced 23.0% mean weight loss versus 25.5% for tirzepatide under the efficacy (treatment-adherent) estimand. CagriSema did not meet its pre-specified non-inferiority endpoint against tirzepatide. Both arms reported gastrointestinal adverse events consistent with the GLP-1 receptor agonist class, with no new safety signal identified.[5]
Source: Novo Nordisk company announcement, 23 Feb 2026; trade-press reporting (Patient Care Online, HCPLive, Endocrinology Advisor)
The comparator matters here: tirzepatide is Eli Lilly's already-approved GLP-1/GIP dual agonist — the company's prior-generation drug, and the direct predecessor to retatrutide's own triple-receptor mechanism. A newly announced Novo Nordisk combination product falling short of Lilly's older dual agonist is a materially different research signal than falling short of retatrutide itself, which has separately outperformed tirzepatide's own headline Phase 3 figures in Lilly's TRIUMPH programme.[6]
How Do CagriSema and Retatrutide's Trial Data Compare Side by Side?
| Compound & dose | Trial (phase) | n | Duration | Reported result |
|---|---|---|---|---|
| CagriSema 2.4/2.4mg | REDEFINE-1 obesity (Phase 3) | 3,417 | 68 wks | −22.7% weight vs 2.3% placebo |
| CagriSema 2.4/2.4mg | REDEFINE-2, T2D + obesity (Phase 3) | 1,206 | 68 wks | −15.7% weight; A1C −2.0pp |
| CagriSema 2.4/2.4mg | REDEFINE-4 vs tirzepatide (Phase 3) | 809 | 84 wks | −23.0% (missed non-inf. vs −25.5%) |
| Retatrutide 12mg | TRIUMPH-1 obesity (Phase 3) | 2,339 | 80 wks | −28.3% weight (up to −30.3% at 104 wks) |
| Retatrutide | TRIUMPH-2, T2D + obesity (Phase 3) | 1,152 | 80 wks | up to −20.8% weight; A1C −1.6pp |
Figures are as reported in each publication, at different durations, populations and estimands. This table is for contextual research reference only and, aside from REDEFINE-4's direct comparison to tirzepatide, is not a head-to-head clinical comparison.
In matched settings — obesity without diabetes, and type 2 diabetes with obesity — retatrutide's published TRIUMPH figures are larger than CagriSema's REDEFINE figures in both the treatment-adherent and treatment-policy estimands. Trial design differs enough to caution against reading too much into the gap: REDEFINE-1 ran 68 weeks against 80 for TRIUMPH-1, and REDEFINE-2's diabetes population and TRIUMPH-2's diabetes-plus-obesity population were not enrolled under identical criteria. What REDEFINE-4 adds is more direct: it is an actual head-to-head trial, not a cross-trial comparison, and CagriSema still came up short against Lilly's older dual-agonist drug.
Why Does the Combination-vs-Single-Molecule Design Matter for Incretin Research?
Two validated actives vs one engineered molecule
CagriSema pairs a marketed drug (semaglutide) with a novel amylin-receptor partner (cagrilintide) — a lower-risk development strategy that leans on semaglutide's existing safety record. Retatrutide instead is a fully novel single peptide built to hit three receptors at once, a harder engineering problem with a potentially larger reward if the multi-receptor hypothesis holds.
REDEFINE-4 is evidence, not proof, against combination strategies
One 84-week head-to-head trial showing CagriSema behind tirzepatide doesn't settle whether combination or single-molecule multi-agonism is the better research path — but it is a data point against the assumption that combining two approved-class mechanisms automatically outperforms a single engineered multi-receptor molecule.
An existing component doesn't guarantee a faster review
Despite building on semaglutide's established profile, CagriSema's FDA application is undergoing standard, not priority, review — a reminder that regulators evaluate the fixed-dose combination as its own new entity, with its own timeline, regardless of how well-characterised one ingredient already is.
What's Next in CagriSema's Regulatory Timeline?
Novo Nordisk filed CagriSema's New Drug Application with the FDA on 18 December 2025, based on the REDEFINE-1 and REDEFINE-2 pivotal data.[4] The filing is undergoing standard (not priority) review, and as of this writing neither the FDA nor Novo Nordisk has publicly confirmed a PDUFA action date or scheduled an advisory committee meeting; company guidance points to a decision in the fourth quarter of 2026. Separately, Novo Nordisk has begun REDEFINE-11, testing a higher-dose cagrilintide component (2.4mg/7.2mg semaglutide/cagrilintide), with dosing due to start in the second half of 2026 and data expected in the first half of 2027.
That timeline sits alongside, but does not overlap with, retatrutide's own regulatory path. Eli Lilly confirmed on 23 July 2026 that retatrutide's Biologics License Application target has moved to Q1 2027, later than earlier guidance, citing additional manufacturing and quality-control (CMC) data rather than any change in trial results — see our separate coverage of the retatrutide filing delay.
What Should UK Researchers Take From This?
CagriSema is an unapproved, patent-protected Novo Nordisk investigational combination product confined to registered clinical trials and a pending FDA application. It is not available for purchase, compounding, or research use from any lawful source, and Velox Peptides does not supply it or its cagrilintide component. Its published data is presented here purely as third-party scientific context for researchers tracking the wider incretin-receptor field that retatrutide research sits within.
That does not change retatrutide's own regulatory position. It remains an unlicensed investigational medicine, with a Q1 2027 BLA filing target in the US and no confirmed MHRA timeline. Velox Peptides supplies retatrutide strictly as an HPLC-verified in vitro research reagent, with batch-specific certificates of analysis, and makes no therapeutic or weight-loss claims for it.
Retatrutide is supplied as a research reagent only. It is not a medicine and has not been evaluated by the MHRA or FDA for use in our products. Not for human or veterinary use. CagriSema, cagrilintide and semaglutide are not Velox Peptides products and are not available for sale. See our Research Use Policy and MHRA Statement.
References
- Garvey WT, Blüher M, Osorto Contreras CK, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2025. PMID: 40544433. DOI: 10.1056/NEJMoa2502081. pubmed.ncbi.nlm.nih.gov
- Müller TD, Finan B, Bloom SR, et al. Glucagon-like peptide 1 (GLP-1). Mol Metab. 2019;30:72–130. PMID: 30120083. pubmed.ncbi.nlm.nih.gov
- Davies MJ, Bajaj HS, Broholm C, et al. Cagrilintide-Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes. N Engl J Med. 2025;393:648-659. PMID: 40544432. DOI: 10.1056/NEJMoa2502082. pubmed.ncbi.nlm.nih.gov
- Novo Nordisk. Novo Nordisk files for FDA approval of CagriSema, the first once-weekly combination of GLP‑1 and amylin analogues for weight management. Press release, 18 December 2025. prnewswire.com
- Novo Nordisk. CagriSema versus tirzepatide head-to-head Phase 3 trial (REDEFINE-4), topline results. Company announcement, 23 February 2026, ClinicalTrials.gov NCT06131437. novonordisk.com
- Eli Lilly and Company. Lilly's triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial (TRIUMPH-1). Press release, 21 May 2026. PR Newswire
- Eli Lilly and Company. Lilly's triple agonist, retatrutide, successful in two additional Phase 3 obesity trials, delivering significant improvements in weight and A1C (TRIUMPH-2, TRIUMPH-3). Press release, 23 July 2026. PR Newswire
Frequently Asked Questions
What is CagriSema?
CagriSema is Novo Nordisk's investigational once-weekly subcutaneous injection combining cagrilintide 2.4mg, a long-acting amylin-receptor agonist, with semaglutide 2.4mg, the GLP-1 receptor agonist already marketed as Wegovy and Ozempic. It is a fixed-dose two-molecule combination product, unlike retatrutide, which is a single engineered molecule activating the GLP-1, GIP and glucagon receptors at once. CagriSema is not approved for human use in any jurisdiction.
What did REDEFINE-1 and REDEFINE-2 show?
REDEFINE-1 (Garvey et al, New England Journal of Medicine, 2025; n=3,417 adults with obesity or overweight without diabetes) reported 22.7% mean weight loss at 68 weeks versus 2.3% on placebo. REDEFINE-2 (Davies, Bajaj et al, NEJM 2025;393:648-659; n=1,206 adults with type 2 diabetes and obesity or overweight) reported 15.7% weight loss versus 3.1% on placebo, plus an HbA1c reduction of 2.0 percentage points versus 0.1 on placebo.
How did CagriSema perform against tirzepatide in REDEFINE-4?
REDEFINE-4, an 84-week open-label Phase 3 trial in 809 adults with obesity, compared CagriSema 2.4mg/2.4mg directly against Eli Lilly's tirzepatide 15mg (Zepbound). Topline results announced 23 February 2026 showed CagriSema achieved 23.0% weight loss versus 25.5% for tirzepatide, missing its pre-specified non-inferiority endpoint.
How does CagriSema compare with retatrutide's trial data?
Across matched trial settings, retatrutide's Phase 3 TRIUMPH programme reports larger weight-loss figures than CagriSema's REDEFINE programme: TRIUMPH-1 reported 28.3% at 80 weeks (up to 30.3% at 104 weeks) versus REDEFINE-1's 22.7% at 68 weeks, and TRIUMPH-2 reported up to 20.8% in a type 2 diabetes and obesity population versus REDEFINE-2's 15.7%. The trials differ in duration, dosing regimen and population, so this is contextual comparison rather than a head-to-head study.
Is CagriSema available as a research reagent?
No. CagriSema is an unapproved, patent-protected Novo Nordisk investigational combination product with a pending FDA New Drug Application. It is not available for purchase, compounding, or research use from any lawful source, and Velox Peptides does not supply it or its cagrilintide component.
Is retatrutide available as a research reagent?
Yes. Velox Peptides supplies retatrutide as an HPLC-verified (≥99% purity) lyophilised research reagent for in vitro laboratory research only. It is not licensed as a medicine, is not evaluated by the MHRA or FDA, and is not intended for human or veterinary use.