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Is ATTAIN-1 a fair comparison of orforglipron against its comparator arm?

Asked 3 May 2025Modified 11 months agoViewed 13k times
13

The specifics, since they change the answer: ATTAIN-1 · orforglipron.

Somebody stated this to me confidently and I would like to check it before repeating it.

I would accept a well-reasoned negative answer over a poorly sourced positive one.

Is this actually true, and what is the evidence?

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VR
askedvalentina_rossi9.7k163 May 2025
4Voting to keep this open — it is more specific than it first looks. – mz_4113 6 months ago
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5 Answers

Accepted answer first, then by votes
62

Accepted answer

Fair depends on the comparator arm, and in ATTAIN-1 that means asking whether the comparator was titrated to the same ambition as the experimental one. A head-to-head that runs its comparator to a dose below the one it is licensed at is not measuring the two agents, it is measuring one agent against a handicapped version of the other. Check three things: the maximum comparator dose reached, the proportion of the comparator arm that reached it, and whether the titration schedules had the same duration. If those match, the comparison is fair on dosing and the argument moves to the endpoint. If they do not, the effect size is partly an artefact of the protocol.

The honest answer here is that the published evidence supports part of the claim and is silent on the rest, and it is worth being precise about which part is which.

Trial populations are selected. Exclusion criteria in this class routinely remove people with significant renal impairment, prior pancreatitis and unstable psychiatric illness, which is exactly the population the results are then quoted for.

Relative to absolute, worked

QuantityValueDerivation
Control-arm event rate8.0 %From the trial table, not the abstract
Hazard ratio0.80Reported
Treated event rate6.4 %8.0 × 0.80
Absolute risk reduction1.6 pp8.0 − 6.4
Number needed to treat631 ÷ 0.016
Relative risk reduction20 %1 − 0.80

The last two rows describe the same finding. Only one of them is used in headlines.

Open-label extensions are not the same evidence as the randomised phase. Once everyone knows what they are taking, the reported outcomes acquire a bias that no analysis fully removes.

The cardiovascular outcome programme in this class runs to several large randomised trials — LEADER for liraglutide, SUSTAIN-6 and SELECT for semaglutide, REWIND for dulaglutide — and they are the reason the class is discussed as more than a weight intervention.

Read the protocol and the statistical analysis plan if the result matters to you. Both are usually published alongside.

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answered · acceptedcoring_risk27k2710 May 2025
4Thank you for separating the surrogate from the outcome. That distinction gets lost constantly. – h_villanueva 10 months ago
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25

Before comparing two trials, check whether they share an endpoint definition. Frequently they do not, and the numbers then are not comparable in any sense.

Confidence intervals matter more than point estimates when two trials disagree. Two studies reporting fifteen and twenty per cent whose intervals overlap heavily have not disagreed about anything.

It helps to be literal here: a composite endpoint is only as informative as its least serious component. Where a cardiovascular composite combines death, infarction and stroke, ask which component moved, because they are not interchangeable outcomes.

Registry entries at ClinicalTrials.gov carry the pre-specified primary endpoint with a timestamp, which is the cheapest available check on whether an endpoint was changed after the data were seen.

When two sources disagree, the answer is almost always in the methods section of the one you have not read.

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answereddana_wexler11k1627 Aug 2025
17

Start with what the trial was powered for. Everything else in the publication is secondary, exploratory, or a subgroup, and those three words mean three different things.

Duration decides what can be seen. A 68-week trial can measure weight and glycaemia; it cannot measure anything whose event rate is one per cent per year without enrolling tens of thousands.

The part that matters: placebo arms in this class are not nothing. Lifestyle-intervention placebo arms in the major obesity trials commonly lose two to three per cent of body weight, so an active-arm figure quoted without its comparator overstates the drug effect by roughly that much.

Meta-analyses in this area are dominated by whichever trial contributed the most participants, so read the forest plot rather than the summary estimate.

The caveat is that trial evidence is about licensed product administered under supervision. None of it transfers automatically to research-grade material of unverified content.

If a claim cannot be traced to a named trial with a named endpoint, treat it as a claim rather than as evidence.

edited 31 Aug 2025 by Dr_Rosalind_Achebe — tightened the wording; no substantive change

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DA
answeredDr_Rosalind_Achebe69k14716 Aug 2025
14

Stated carefully, this is answerable from the published record, but only if you take the placebo arm seriously rather than reading the active arm alone.

Intention-to-treat and per-protocol analyses answer different questions. ITT asks what happens if you offer the treatment; per-protocol asks what happens if it is taken as directed. The gap between the two is a measure of how tolerable the protocol was.

Where a result is quoted from a conference abstract rather than a peer-reviewed publication, the numbers routinely move between the two. It is worth checking which one you are reading.

The short version: check the endpoint, check the comparator, check who was excluded, then look at the number.

edited 31 Aug 2025 by esben_lykke — updated for the 2026 guidance change

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EL
answeredesben_lykke84k1585 Aug 2025
Absolute risk reduction rather than relative would make this much more useful. – stopper_core 9 months ago
2Do you have a reference for the last claim? Not disputing it, just want to read it. – juliette_farnese 34 days ago
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10

The short version: the effect is real, the magnitude depends on the population, and the population is usually the part that gets dropped when a result is quoted second-hand.

Non-inferiority and superiority designs are not interchangeable. A non-inferiority result says the new agent is not meaningfully worse against a pre-specified margin — it does not say it is as good, and it certainly does not say it is better.

SELECT reported a hazard ratio of 0.80 (95% CI 0.72–0.90) for the primary composite major adverse cardiovascular event endpoint with semaglutide 2.4 mg in overweight or obese adults with established cardiovascular disease and without diabetes[1].

Quote the interval alongside the estimate and half the disagreements on this site would not start.

edited 15 Jul 2025 by coring_risk — reworded for clarity after a comment

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answeredcoring_risk27k2724 Jun 2025

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.