Cagrilintide and CagriSema Research Guide

CagriSema has moved from early combination studies into multiple phase 3 programs, an FDA application, and a head-to-head result that did not meet its prespecified primary endpoint. That creates a difficult evidence environment: a result can be statistically impressive within an arm while still failing the trial’s formal comparison, and an application under review can be mistaken for an approval.

This guide separates molecular identity, receptor pharmacology, trial design, numerical results, and regulatory status. It also marks the boundary between Novo Nordisk’s investigational fixed-dose medicine and separately supplied research reagents. Status statements are current through July 22, 2026 and must be rechecked against official records before deployment.

What is the difference between cagrilintide and CagriSema?

Cagrilintide, also developed under the name AM833, is a long-acting analogue of the pancreatic hormone amylin. Semaglutide is a GLP-1 receptor agonist with its own molecular identity and approved pharmaceutical formulations. CagriSema is not one molecule. It is Novo Nordisk’s investigational fixed-dose combination of cagrilintide 2.4 mg and semaglutide 2.4 mg in the development program discussed here, so it does not have a single peptide sequence, formula, molecular mass, or CAS number.

The distinction matters for every downstream claim. A cagrilintide paper can support a statement about cagrilintide under the studied conditions. A semaglutide paper remains semaglutide evidence. A CagriSema result describes the fixed-dose clinical program and cannot automatically be assigned to either component alone.

Component reagent identity

Each active substance carries its own registry identity; the combination carries none. The values below are chemical-registry data taken from the PubChem records and their linked CAS numbers. They identify isolated substances and are not clinical evidence.

How was cagrilintide designed, and which receptors does it engage?

Amylin is co-secreted with insulin by pancreatic beta cells and participates in nutrient-related signaling. Amylin receptors are not a single standalone receptor protein. They are receptor complexes formed by a calcitonin receptor core associated with a receptor-activity-modifying protein, producing recognized AMY receptor subtypes. Hay and colleagues described this molecular composition and pharmacology, while Lutz reviewed the experimental history that established amylin as a satiety signal (PMID 15494035; PMID 35183619).

Kruse and colleagues reported the medicinal-chemistry development of cagrilintide as a long-acting amylin analogue (PMID 34288673). Its extended-action design includes lipidation and sequence changes intended to support pharmacokinetic durability while retaining amylin-receptor agonism. Those design features are part of cagrilintide’s identity; they should not be reduced to a generic description such as “modified amylin.”

Structural work published by Cao and colleagues in 2025 examined cagrilintide binding to calcitonin and amylin receptor complexes (PMID 40204768). It provides receptor-level context, not a clinical efficacy claim. Receptor engagement, exposure, and an outcome measured in a clinical trial remain separate evidence layers.

Why combine amylin-receptor and GLP-1-receptor signaling?

The scientific rationale is complementary pathway recruitment. Cagrilintide engages amylin-receptor systems; semaglutide engages the GLP-1 receptor. These systems can converge on appetite and metabolic endpoints through partly distinct peripheral and central circuits. Complementarity supports testing the combination, but it does not prove a strictly additive or synergistic response in every model, endpoint, or population.

The first human combination publication by Enebo and colleagues evaluated concomitant multiple doses of cagrilintide with semaglutide in a randomized phase 1b trial (PMID 33894838). That study was designed around safety, tolerability, pharmacokinetics, and pharmacodynamics. Frias and colleagues then reported a phase 2 active-controlled trial in adults with type 2 diabetes (PMID 37364590). These studies established a development path; they did not create an approval or establish use outside their protocols.

How is the clinical evidence program organized?

The evidence is easier to interpret when grouped by purpose. Cagrilintide monotherapy dose-finding tested the amylin analogue on its own. Early combination trials studied whether concomitant administration could be advanced. REDEFINE focused on overweight and obesity populations, while REIMAGINE focused on type 2 diabetes across different background-therapy settings. REDEFINE 3 is a separate cardiovascular-outcomes question and had no completed outcome result in the July 22 review.

What did the REDEFINE trials report?

REDEFINE 1 and REDEFINE 2

REDEFINE 1 evaluated coadministered cagrilintide and semaglutide in adults with overweight or obesity. Garvey and colleagues reported a mean body-weight change of -20.4% under the treatment-policy estimand and -22.7% under the trial-product estimand at 68 weeks, compared with -3.0% and -2.3% for placebo, respectively (PMID 40544433). The two percentages answer different questions and should never be presented as interchangeable.

REDEFINE 2 evaluated adults with overweight or obesity and type 2 diabetes. Davies and colleagues reported -13.7% under the treatment-policy estimand and -15.7% under the trial-product estimand, compared with -3.4% and -3.1% for placebo (PMID 40544432). Comparing the headline percentage from REDEFINE 1 directly with REDEFINE 2 without the population context would erase an important design difference.

REDEFINE 4: a large within-arm change and a failed primary endpoint

Novo Nordisk announced headline REDEFINE 4 results on February 23, 2026. The open-label 84-week trial randomized 809 participants and compared CagriSema 2.4 mg/2.4 mg with tirzepatide 15 mg. Under the efficacy estimand, the announcement reported -23.0% for CagriSema and -25.5% for tirzepatide; under the treatment-regimen estimand, it reported -20.2% and -23.6%.

The prespecified primary objective was to show non-inferiority to tirzepatide. That endpoint was not met. The scientifically accurate headline therefore contains both facts: CagriSema produced a large mean within-arm change, and the trial did not establish the required non-inferiority comparison. The developer announcement is a primary issuer source for headline results, but a full peer-reviewed report remains preferable for detailed methods and subgroup interpretation.

REDEFINE 5 and REDEFINE 3

REDEFINE 5 added an East Asian active-comparator study versus semaglutide, reported by Yamauchi and colleagues in 2026 (PMID 42009015). REDEFINE 3, NCT05669755, is an event-driven cardiovascular-outcomes trial with an actual enrollment of 7,101 shown in the registry snapshot reviewed for this update. Its active, not-recruiting status and estimated completion timing are not evidence of cardiovascular benefit or harm.

What did REIMAGINE 1-3 add?

REIMAGINE extends the program across type 2 diabetes settings. On June 7, 2026, Novo Nordisk reported that all three trials met their primary HbA1c endpoints and confirmatory body-weight endpoints. The simultaneous publications cover diet-and-exercise background therapy, metformin with or without an SGLT2 inhibitor, and add-on use with basal insulin.

REIMAGINE 1 was a 40-week placebo-controlled trial in 189 adults. Under the efficacy estimand, the 2.4 mg/2.4 mg arm was reported at -1.8 percentage points for HbA1c and -13.8% for body weight, compared with -0.1 percentage points and -1.4% for pooled placebo. The peer-reviewed reports are indexed as Aroda et al. for REIMAGINE 1 (PMID 42251860), Buse et al. for REIMAGINE 2 (PMID 42251859), and Rosenstock et al. for REIMAGINE 3 (PMID 42251856).

These are diabetes-program results, not a basis for selecting a personal treatment or converting clinical doses into a research protocol. Background therapy, rescue medication, discontinuation handling, follow-up, and endpoint hierarchy define the result. Readers looking for the broader compound landscape can compare this evidence lane with the site’s next-generation GLP-1 research guide and the separate semaglutide research guide.

How should CagriSema trial numbers be read?

A complete result names the randomized arm, comparator, population, time point, endpoint, estimand, and statistical verdict. Removing any of those elements can turn a precise result into a misleading marketing number.

• Treatment-policy or treatment-regimen estimand: estimates the randomized-arm difference while accounting for specified intercurrent events such as discontinuation or additional therapy under the trial’s plan.
• Trial-product or efficacy estimand: estimates an idealized question tied to continued assigned treatment and defined handling of other interventions.
• Within-arm change: describes what happened in one group; it does not establish superiority or non-inferiority by itself.
• Between-arm comparison: addresses the randomized comparison and requires its confidence interval and prespecified margin.
• Primary endpoint: carries the formal trial verdict. Secondary and exploratory results add context but do not overwrite a failed primary endpoint.

What do the trials show about safety, and what remains uncertain?

Across the published program, gastrointestinal events are prominent, as expected for the mechanisms and populations studied. The phase 1b study reported gastrointestinal disorders as a substantial portion of adverse events, and the pivotal trials documented nausea, constipation, vomiting, and discontinuations in their protocol-defined populations. These findings belong to the investigational pharmaceutical program; they are not a safety specification for a research reagent.

Several limitations matter. Most major compound-specific trials were sponsored by Novo Nordisk, so independent replication and longer follow-up remain important. Trial populations, eligibility criteria, titration procedures, adherence, and supportive care can differ from other settings. REDEFINE 4 headline results came first through a company announcement. REDEFINE 3 had not produced an outcomes result in the review window. An FDA review also evaluates manufacturing, controls, labeling, and benefit-risk evidence not reducible to a journal article.

No clinical publication establishes that combining separately obtained research reagents reproduces the tested exposure, device performance, formulation stability, impurity profile, or safety of the investigational fixed-dose product. Clinical trial data should never be used to create a self-directed dosing or mixing instruction.

Is CagriSema approved?

Investigational as of July 22, 2026

Novo Nordisk announced a United States New Drug Application submission on December 18, 2025 for once-weekly CagriSema 2.4 mg/2.4 mg for chronic weight management. The developer later stated that an FDA decision was anticipated in late 2026. A filed NDA means the application entered FDA review; it is not a marketing approval.

The July 14, 2026 European Medicines Agency page located during this update records a decision concerning modification of an agreed paediatric investigation plan for cagrilintide and semaglutide. Its underlying decision date is May 15, 2025. A PIP decision concerns paediatric development planning and is not an EU marketing authorization.

The same-day public-record review found no public FDA or EMA marketing approval for CagriSema as of July 22, 2026. Because this status can change, the deployment reviewer must repeat the search rather than treating this paragraph as permanently current.

What is the boundary between the clinical product and research reagents?

Cagrilintide and semaglutide can be studied as separate chemical entities in appropriately designed in-vitro and preclinical work. That does not make a mixture of research reagents equivalent to CagriSema. The investigational medicine includes a specified ratio, formulation, container-closure and delivery system, manufacturing process, release specifications, stability program, clinical protocol, and regulatory dossier.

Analytical evidence must also remain method-specific. HPLC can characterize a chromatographic purity profile under a stated method, while mass spectrometry can test consistency with an expected mass model. Neither method alone establishes pharmaceutical equivalence, clinical performance, sterility, dose accuracy, or device function. The broader distinction is explained in Research Grade vs Pharmaceutical Grade.

Frequently asked questions

References and official status sources

1. Hay DL, et al. Amylin receptors: molecular composition and pharmacology. Biochem Soc Trans. 2004;32(Pt 5):865-7. PMID: PMID 15494035.
2. Kruse T, et al. Development of Cagrilintide, a Long-Acting Amylin Analogue. J Med Chem. 2021;64(15):11183-11194. PMID: PMID 34288673.
3. Lau DCW, 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. Lancet. 2021;398(10317):2160-2172. PMID: PMID 34798060.
4. Enebo LB, et al. Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide 2·4 mg for weight management: a randomised, controlled, phase 1b trial. Lancet. 2021;397(10286):1736-1748. PMID: PMID 33894838.
5. Lutz TA. Creating the amylin story. Appetite. 2022;172:105965. PMID: PMID 35183619.
6. Frias JP, 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. Lancet. 2023;402(10403):720-730. PMID: PMID 37364590.
7. Cao J, et al. Structural and dynamic features of cagrilintide binding to calcitonin and amylin receptors. Nat Commun. 2025;16(1):3389. PMID: PMID 40204768.
8. Garvey WT, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2025;393(7):635-647. PMID: PMID 40544433.
9. Davies MJ, et al. Cagrilintide-Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes. N Engl J Med. 2025;393(7):648-659. PMID: PMID 40544432.
10. Yamauchi T, et al. Efficacy and safety of co-administered cagrilintide and semaglutide versus semaglutide alone in adults with overweight or obesity with or without type 2 diabetes in Japan and Taiwan (REDEFINE 5): a multicentre, randomised, active-controlled, phase 3a trial. Lancet Diabetes Endocrinol. 2026;14(6):450-462. PMID: PMID 42009015.
11. Aroda VR, et al. Efficacy and safety of once-weekly cagrilintide-semaglutide (CagriSema) in adults with type 2 diabetes inadequately controlled on diet and exercise (REIMAGINE 1): a randomised, double-blind, placebo-controlled, phase 3a study. Lancet Diabetes Endocrinol. 2026;14(8):649-661. PMID: PMID 42251860.
12. Buse JB, et al. Cagrilintide-semaglutide (CagriSema) versus semaglutide or cagrilintide in people with type 2 diabetes (REIMAGINE 2): a double-blind, randomised, controlled, phase 3 study. Lancet Diabetes Endocrinol. 2026;14(8):662-677. PMID: PMID 42251859. A published correction exists for this record and could not be retrieved at the July 2026 freeze; no numeric figure on this page is attributed to it.
13. Rosenstock J, et al. Cagrilintide-semaglutide (CagriSema) as an add-on to basal insulin in adults with type 2 diabetes (REIMAGINE 3): a randomised, double-blind, placebo-controlled, multicentre, phase 3 study. Lancet. 2026;408(10549):38-51. PMID: PMID 42251856.
14. Novo Nordisk. FDA NDA submission announcement. December 18, 2025.
15. Novo Nordisk. REDEFINE 4 headline results. February 23, 2026.
16. Novo Nordisk. REIMAGINE 1-3 results announcement. June 7, 2026.
17. ClinicalTrials.gov. REDEFINE 3, NCT05669755. Accessed July 22, 2026.
18. ClinicalTrials.gov. REDEFINE 4, NCT06131437. Accessed July 22, 2026.
19. European Medicines Agency. Cagrilintide/semaglutide paediatric investigation plan decision record. First published July 14, 2026.