SOUL — trial digest
SOUL (N Engl J Med 2025): Does the oral formulation deliver cardiovascular benefit comparable to the injectable?
Citation and design
| Field | Value |
|---|---|
| Trial | SOUL |
| Intervention | Oral semaglutide 14 mg daily |
| Publication | N Engl J Med, 2025 (first author McGuire) |
| Design | Double-blind, placebo-controlled cardiovascular outcome trial |
| Population | Adults with type 2 diabetes and established atherosclerotic cardiovascular disease or chronic kidney disease |
This digest summarises the trial and the criticisms our journal club considered material. It is not a substitute for the paper, and where the two differ the paper is right.
The question it set out to answer
Does the oral formulation deliver cardiovascular benefit comparable to the injectable?
Stating the question before the result is a house convention. A great many arguments about this trial are actually arguments about what it was for.
What it found
Extends the cardiovascular evidence to the oral formulation, which matters because oral exposure is lower and more variable.
The practical significance is that the benefit appears to be a property of the molecule and its exposure rather than of the route.
Adherence in an oral trial with strict administration requirements is a substantive issue and worth reading carefully.
Criticisms the journal club considered material
- Administration conditions for oral semaglutide are demanding, and trial adherence is generally better than real-world adherence.
- Exposure variability means the population-average result may conceal more heterogeneity than the injectable trials.
These are criticisms of the design and of how the result is used, not of the investigators. Sessions that lose that distinction get moderated.
How it is misused
The two recurring misuses of this trial in general discussion are quoting the relative effect without the absolute one, and extending the result to a population the trial did not enrol. Both are easy to correct and both keep happening.
Where a number appears in secondary coverage without an estimand attached, assume it is whichever version is larger and check the paper.
Maintenance
Digests are reviewed when new analyses of the same trial are published, and at the review date shown above regardless. If a secondary publication changes the picture, raise it in journal club rather than editing the digest directly, so the change is discussed before it lands.
Revision history
| 2025-12-06 | n.rowntree | Reverted an unsourced change and asked the editor to re-apply it with a citation. |
| 2025-08-02 | appeals_desk | Recorded a dissent from one maintainer rather than resolving it silently. |
| 2025-07-06 | logbook_erin | Restructured into shorter sections so the outline navigation is usable. |
| 2025-04-28 | chromatogram | Added the worked example that the review thread asked for. |
| 2025-01-20 | TL4_Halvorsen | Split an overlong section in two and gave the second a proper heading. |
| 2024-09-03 | excursion_check | Initial promotion from the source topic. Structure taken from the marked solution. |
Every edit to a maintained document records its author and a note explaining the change. An edit without a note may be reverted by any wiki editor under R9, and the revert is logged. Disagreements about content belong on the source topic rather than in the revision history (R10).
Related documents
- STEP 1 — trial digestSTEP 1 (N Engl J Med 2021): Does semaglutide 2.4 mg weekly reduce body weight in adults with obesity and no diabetes?
- STEP 2 — trial digestSTEP 2 (Lancet 2021): What weight reduction does semaglutide 2.4 mg achieve in people who also have type 2 diabetes?
- STEP 3 — trial digestSTEP 3 (JAMA 2021): What does semaglutide add on top of intensive behavioural therapy?
- STEP 4 — trial digestSTEP 4 (JAMA 2021): What happens if you stop after reaching the maintenance dose?
- STEP 8 — trial digestSTEP 8 (JAMA 2022): How does weekly semaglutide compare directly with daily liraglutide?