Is 0.16 percentage points of HbA1c clinically meaningful?

It is small. Thresholds for meaningful change are debated and depend on baseline and context, but 0.16 is well below what is usually treated as clinically important, and below what adding most first-line agents achieves. The trial establishes that the difference is real; how much it matters is a separate judgement.

Why is the cagrilintide-alone arm so small?

152 participants, against 603 and 605 for the arms in the primary comparison. Allocation follows the questions a trial is powered for, and cagrilintide monotherapy is not one of them - that arm exists to characterise the component rather than to support a comparison.

Which estimand was used?

The efficacy estimand for the primary endpoint here, whereas REDEFINE 1 and REDEFINE 2 reported the treatment-policy estimand. That difference matters when placing figures side by side, and it is a reason not to compare numbers across the two programmes without checking.

Does this mean CagriSema is better than semaglutide?

On HbA1c in this population, by this margin, yes and by a small amount. Neither trial answers the broader question a reader usually means, and CagriSema is not licensed anywhere so no clinical comparison is available to anyone in practice.

Research & Regulatory News

Superior to Semaglutide, by 0.16 Percentage Points

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-243 cited sources

REIMAGINE 2 (NCT06065540) randomised 2,713 adults who had type 2 diabetes across six arms, including arms receiving each of the two components alone. Its primary endpoint was HbA1c change against semaglutide 2.4 mg, and the combination beat that comparator by 0.16 percentage points.

Key facts

Registration: NCT06065540
Registered acronym: REIMAGINE 2
Primary comparator: Semaglutide 2.4 mg, not placebo
Primary endpoint: Change in HbA1c at week 68
Randomisation ratio: 8:8:2:8:8:1:1
Randomised: 2,713, from 3,593 screened
Key arm sizes: 603 combination vs 605 semaglutide 2.4 mg
Primary result: -1.91 vs -1.75 percentage points
Estimated difference: -0.16 points (95% CI -0.27 to -0.05), p=0.0035

Why this trial is structurally different

Almost every registration trial in this field uses placebo as its primary comparator, because that is what demonstrates efficacy for a regulator. REIMAGINE 2 did not. Its registered primary endpoint is the change in glycated haemoglobin from baseline to week 68 with cagrilintide-semaglutide 2.4 mg of each versus semaglutide 2.4 mg - an active comparator, and specifically one of the combination's own components. That is the question a fixed-dose combination most needs to answer and most often avoids, and this trial put it first.

The design

Randomised, double-blind, placebo-controlled and active-controlled, in 30 countries. Participants aged 18 or over with inadequately controlled type 2 diabetes - HbA1c 7.0 to 10.5% - receiving metformin with or without an SGLT2 inhibitor, and a BMI of 25 or more, were randomised 8:8:2:8:8:1:1 to cagrilintide-semaglutide 2.4 mg each, semaglutide 2.4 mg, cagrilintide 2.4 mg, cagrilintide-semaglutide 1.0 mg each, semaglutide 1.0 mg, or corresponding placebo, for 68 weeks. From 3,593 screened, 2,713 were randomised: 603, 605, 152, 595, 609 and 149 respectively. 95.7% completed the study and 87.6% were on treatment at week 68.

The result, and the number that matters

Mean baseline HbA1c was 8.2%. On the primary endpoint, using the efficacy estimand, HbA1c fell by 1.91 percentage points with the combination and 1.75 percentage points with semaglutide 2.4 mg alone. The estimated treatment difference was -0.16 percentage points, with a 95% confidence interval of -0.27 to -0.05 and a p-value of 0.0035. The authors' interpretation is that the combination was superior to semaglutide for reducing HbA1c and that the findings support the added benefit of the combination for glycaemic control. All of that is accurate. The added benefit is 0.16 percentage points of HbA1c.

Significant and small are different findings

A p-value of 0.0035 says the difference is unlikely to be chance. It says nothing about whether the difference is large. With 603 and 605 participants per arm and a tightly measured endpoint, a trial of this size can detect differences well below the size that would change anything for a person, and that is exactly what has happened here: the confidence interval runs from 0.27 to 0.05 percentage points, so even the most favourable end of the plausible range is a fraction of what a first-line agent achieves. Reporting this as superiority is correct. Reporting it without the effect size leaves a reader with an impression the data do not support.

What this result is and is not about

It is about glycaemic control. HbA1c was the primary endpoint of this trial, and weight was not. The combination's advantage over semaglutide on body weight is a separate question with a separate answer that this endpoint does not address, and it would be an error to conclude from 0.16 HbA1c points that the amylin component contributes little overall. What can be said is narrower and still useful: on the endpoint this trial was designed and powered to test, adding 2.4 mg of cagrilintide to semaglutide produced a statistically robust and clinically modest improvement, at a cost of adverse events in 86.9% of that arm against 81.2% on semaglutide alone.

Why it belongs beside REDEFINE 1

REDEFINE 1 allocated 21 parts to the combination and 3 to each monotherapy, so its component comparisons carry 302 participants each and are not primary endpoints. REIMAGINE 2 allocated 8 parts to the combination and 8 to semaglutide, so the head-to-head carries 603 against 605 and is the primary endpoint. Two trials in the same programme, taking opposite approaches to the same question. Read together they are a good illustration of how much a randomisation ratio determines what a trial can conclude. CagriSema is not licensed anywhere; semaglutide is a licensed prescription medicine that research material is not an alternative to.

Quick reference

Arm	Randomised	Role
Cagrilintide-semaglutide 2.4/2.4	603	Test arm, primary comparison
Semaglutide 2.4 mg	605	Primary comparator
Cagrilintide 2.4 mg	152	Second component alone
Cagrilintide-semaglutide 1.0/1.0	595	Lower dose combination
Semaglutide 1.0 mg	609	Lower dose comparator
Placebo (pooled)	149	Assay sensitivity

Extended research context

The Research & Regulatory News deep dive

Deep dive: why 2026 was the year the incretin field split in two

For a decade every meaningful GLP-1 medicine was a peptide, and every one of them was injected. 2026 broke that pattern in both directions at once. In August the MHRA authorised orforglipron, a small molecule with no peptide bonds that works as an ordinary daily tablet. Three months earlier, retatrutide's TRIUMPH-1 reported a 28.3% mean weight reduction — the largest figure yet from a single molecule, and achievable only with a peptide capable of engaging three receptors at once. The field is not converging on one answer; it is separating into a convenience track and a magnitude track, and those tracks have different chemistry.

Deep dive: what a marketing authorisation actually means

An authorisation is granted to a specific product, in a specific formulation, for a specific indication, by a specific regulator. It is not a statement about a compound class and it does not transfer. Orforglipron being licensed in the UK tells you nothing about the legal or regulatory status of any other incretin, and nothing at all about compounds that remain investigational. Authorisation is also separate from funding: a licensed medicine is not automatically available on the NHS, which requires a further NICE appraisal.

Deep dive: reading trial results without being misled

Headline percentages are the least transferable part of a trial. A figure is only meaningful alongside its population, its duration, its comparator and its dropout rate. TRIUMPH-1's 28.3% came from an 80-week study in a relatively uncomplicated obesity population; TRIUMPH-3's 22.6% came from adults with severe obesity and established cardiovascular disease, and the gap between those two numbers is mostly population, not potency. Discontinuation rates deserve the same attention as efficacy: 11.3% of the TRIUMPH-1 12 mg arm stopped due to adverse events against 4.9% on placebo, and that figure is routinely dropped from summaries.

Research applications

▸Tracking regulatory status of investigational incretin compounds
▸Understanding the difference between authorisation, NICE appraisal and NHS availability
▸Comparing peptide and non-peptide receptor agonist pharmacology
▸Interpreting Phase 3 topline releases before peer-reviewed publication
▸Verifying trial identity against ClinicalTrials.gov registrations

Handling checklist

✓Check the compound named in a trial registration matches the compound being discussed
✓Confirm the NCT identifier resolves to the acronym being cited
✓Read topline press releases as preliminary until peer-reviewed publication
✓Separate the trial population from the headline percentage before comparing studies
✓Treat authorisation in one jurisdiction as saying nothing about status in another

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Treating a positive Phase 3 as approval

Fix: Filing begins a review that commonly takes a year or more and can end in a request for more data.

✗ Comparing weight-reduction percentages across different trials

Fix: Population, duration and comparator differ; the numbers are not interchangeable.

✗ Assuming one incretin's approval legitimises another compound

Fix: Authorisations are product-specific and do not transfer between compounds.

✗ Citing a TRIUMPH number without checking the NCT identifier

Fix: Verify against ClinicalTrials.gov — the numbering has been widely misreported.

✗ Reading research material as an alternative to a licensed medicine

Fix: Research material is supplied for laboratory use only and is not a substitute for anything prescribed.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

Is 0.16 percentage points of HbA1c clinically meaningful?: It is small. Thresholds for meaningful change are debated and depend on baseline and context, but 0.16 is well below what is usually treated as clinically important, and below what adding most first-line agents achieves. The trial establishes that the difference is real; how much it matters is a separate judgement.
Why is the cagrilintide-alone arm so small?: 152 participants, against 603 and 605 for the arms in the primary comparison. Allocation follows the questions a trial is powered for, and cagrilintide monotherapy is not one of them - that arm exists to characterise the component rather than to support a comparison.
Which estimand was used?: The efficacy estimand for the primary endpoint here, whereas REDEFINE 1 and REDEFINE 2 reported the treatment-policy estimand. That difference matters when placing figures side by side, and it is a reason not to compare numbers across the two programmes without checking.
Does this mean CagriSema is better than semaglutide?: On HbA1c in this population, by this margin, yes and by a small amount. Neither trial answers the broader question a reader usually means, and CagriSema is not licensed anywhere so no clinical comparison is available to anyone in practice.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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