Rigor Reviewed

Rigor-Reviewed Manuscript

Bimagrumab plus semaglutide alone or in combination for the treatment of obesity: a randomized phase 2 trial.

Name: Αlpha¹ Rigor Record — Bimagrumab plus semaglutide alone or in combination for the treatment of obesity: a randomized phase 2 trial.
Item: Bimagrumab plus semaglutide alone or in combination for the treatment of obesity: a randomized phase 2 trial.
Rating: 96
Author: Αlpha¹

Heymsfield SB, Aronne LJ, Montgomery P, Klickstein LB, Coleman LA, Dole K, Mindeholm L, Spruill S, Li X, Attie KM, BELIEVE trial investigators

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Αlpha¹ Rigor Review — 2.5★ (Weak), 0 critical, 5 high issues for “Bimagrumab plus semaglutide alone or in combination for the treatment of obesity: a randomized phase 2 trial.”

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Αlpha¹ Editorial

This rigor review was examined and confirmed by Αlpha¹ Editorial · August 15, 2026

Αlpha¹ Rigor Review

Rigor Reviewed

2.5 / 5

Weak — serious problems found

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

IntegrityIntegrity concern ×3−1.5★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ReportingEthical approvals partially met−0.25★
CitationsUnresolved reference−0.25★

Model-reported confidence: highReviewer agreement: highEngine: 7.39.0Source: full text

Problems surfaced5 types

Numerical inconsistencies1

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Internal contradictions in the reported numbersAssessed

Overstated conclusions1

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Efficacy rests on an unvalidated surrogate endpointAssessed

Data authenticity concerns1

An adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.

Other integrity concernAssessed

Reporting gaps1

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Ethics/consent reporting incompleteAssessed

Broken references and links1

References checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.

References not resolvable to a published paperRecomputed

This Αlpha¹ Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

This is a well-designed and transparently reported phase 2 randomized trial. The main methodological strength is the rigorous design with pre-specified analyses and comprehensive reporting. The primary weakness is the absence of an explicit ethics approval and informed consent statement, which is a fixable reporting gap.

Both reviewers agreed on all dimensions; no divergence to reconcile. The study type is interventional (randomized controlled trial). Non-applicable sub-criteria (e.g., animal housing, cell line authentication) were excluded from scoring. The statistics verification covered only a subset of reported tests; the absence of detected errors does not confirm overall statistical correctness.

3 major claims checked against the paper's own evidence: all adequately supported.

Premise concern: surrogate not validated for clinical benefit.

Recomputed 2 tests: 2 consistent, 0 inconsistent; 2 via agent-written checks.

3 integrity concerns flagged (0 high).

Reporting

Eight Dimensions7 pass · 1 warn

The introduction cites prior work on bimagrumab's mechanism (ActRII inhibition), a prior phase 2 study in obesity and type 2 diabetes, and preclinical combination studies with incretins. It also acknowledges the need to preserve lean mass during weight loss, providing a clear rationale for the combination. Limitations of prior research are implicitly addressed by the trial design (e.g., combining drugs to enhance efficacy while preserving lean mass).

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper establishes a strong scientific premise by citing prior research on bimagrumab's mechanism, preclinical combination data, and a prior phase 2 study, and logically links this to the trial's objectives.

Evidence

paraphrase[Introduction, paragraph 2]

“In a phase 2, 48-week study in adults with obesity and type 2 diabetes, treatment with bimagrumab significantly reduced total body fat mass, VAT and intrahepatic fat while increasing lean mass and lowering glycated hemoglobin (HbA1c).”

paraphrase[Introduction, paragraph 3]

“In preclinical animal models with diet-induced obesity, combining bimagrumab with incretins such as semaglutide or tirzepatide resulted in enhanced fat loss and preservation of muscle mass.”

direct quote[Introduction, paragraph 4]

“In the present trial (BELIEVE), we evaluated the efficacy and safety of intravenous bimagrumab and open-label subcutaneous semaglutide, alone or in combination, in adults with obesity.”

View in source

PASSReviewer 2· 90% conf

Evidence

paraphrase[Introduction, paragraph 2]

paraphrase[Introduction, paragraph 3]

“In preclinical animal models with diet-induced obesity, combining bimagrumab with incretins such as semaglutide or tirzepatide resulted in enhanced fat loss and preservation of muscle mass.”

direct quote[Introduction, paragraph 4]

“In the present trial (BELIEVE), we evaluated the efficacy and safety of intravenous bimagrumab and open-label subcutaneous semaglutide, alone or in combination, in adults with obesity.”

View in source

Randomization method is described (centralized web-based interactive response system) with stratification by sex. The unit of randomization is the participant. Blinding is described: double-blind for bimagrumab/placebo, but open-label for semaglutide due to commercial prefilled pens; this is stated. Power analysis is reported (80% power, effect size 5%, SD 8%, dropout 20%). Inclusion/exclusion criteria are extensive and pre-specified. Outlier handling is addressed via pre-specified estimands and multiple imputation for missing data. Controls are the placebo group. Independent replication is not applicable for a single pivotal trial.

Sub-criteria

controlsADEQUATE

power analysisADEQUATE

blinding levelsADEQUATE

outlier handlingADEQUATE

randomization unitADEQUATE

inclusion exclusionADEQUATE

randomization methodADEQUATE

replicate distinctionN/A

independent replicationN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

The trial design is rigorous: randomized, double-blind (for bimagrumab), with a pre-specified sample size, stratification, and clear inclusion/exclusion criteria. Blinding is partially open-label for semaglutide, which is disclosed and justified.

Evidence

paraphrase[Methods, Randomization]

“Participants were randomly assigned (1:1:1:1:1:1:1:1:1 ratio) to one of the following nine treatment groups using a centralized web-based interactive response system... Randomization was stratified by sex across the treatment groups.”

paraphrase[Methods, Procedures]

“The participant, investigator and sponsor were blinded to bimagrumab dose or placebo−bimagrumab until database lock... The trial used commercially available semaglutide in prefilled pen injectors, which precluded the possibility of blinding. Thus, open-label semaglutide was self-administered subcutaneously once weekly.”

paraphrase[Methods, Statistical analysis]

“The planned sample size of 495 participants was estimated to provide over 80% statistical power to detect a difference between any active treatment group and placebo with respect to the primary endpoint using a two-sided t-test with significance level of 0.05. This assumed a minimum treatment effect of 5% weight reduction at week 48 with a standard deviation of 8% and a dropout rate of 20%.”

PASSReviewer 2· 95% conf

The trial design is rigorous: randomized, double-blind (for bimagrumab), placebo-controlled, with a pre-specified sample size calculation, stratification, and clear inclusion/exclusion criteria.

Evidence

paraphrase[Methods, Randomization]

paraphrase[Methods, Procedures]

paraphrase[Methods, Statistical analysis]

Sex is reported (57.4% female). Age, weight, BMI, waist circumference, and various metabolic parameters are reported in Table 1. Demographics include race/ethnicity. Species/strain and housing conditions are not applicable for a human trial. Health status is captured via inclusion/exclusion criteria and baseline characteristics.

Sub-criteria

demographicsADEQUATE

sex reportedADEQUATE

sex justifiedN/A

age weight healthADEQUATE

housing conditionsN/A

species strain sourceN/A

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Demographic and clinical characteristics are thoroughly reported, including sex, age, weight, BMI, and comorbidities. Since both sexes are enrolled, sex justification is not applicable.

Evidence

direct quote[Results, Baseline demographics]

“most participants were female (57.4%) and White (75.1%)”

View in source

paraphrase[Results, Baseline demographics]

“Mean values for the trial were as follows: age 47.5 years, body weight 107.5 kg, body mass index (BMI) 37.3 kg m−2”

PASSReviewer 2· 90% conf

Demographic and clinical characteristics are comprehensively reported, including sex, age, race, BMI, and comorbidities; sex is reported and both sexes are enrolled, so no single-sex justification is needed.

Evidence

paraphrase[Table 1]

“Female sex, n (%) | 32 (57.1) | ... | 291 (57.4)”

paraphrase[Table 1]

“Age, years | 47.8 (14.6) | ... | 47.5 (12.1)”

The paper describes a clinical trial with human participants, so ethics approval and informed consent are required. However, no explicit statement of IRB approval or informed consent is found in the provided text. The trial is registered (NCT05616013), which implies some ethical oversight, but the specific approval statement is missing. Regulatory compliance is not explicitly stated either.

Sub-criteria

iacuc statementN/A

informed consentNOT REPORTED

irb ethics statementNOT REPORTED

regulatory complianceNOT REPORTED

Per reviewer (2) — the votes behind the verdict

WARNReviewer 1· 80% conf

The paper does not explicitly state ethics approval by a named IRB/ethics committee or describe informed consent, despite involving human participants. This is a reporting gap.

Evidence

absence[Full text]

No ethics approval statement is found.

absence[Full text]

No informed consent statement is found.

WARNReviewer 2· 80% conf

The paper does not explicitly state that an ethics committee approved the trial or that informed consent was obtained, despite involving human participants; this is a reporting gap.

Evidence

absence[Full text]

No ethics approval statement is present.

absence[Full text]

No informed consent statement is present.

Bimagrumab is described as a monoclonal antibody targeting ActRII, and semaglutide is commercially available; both are named with doses and administration routes. The paper does not provide manufacturer/catalog numbers for the drugs, but for a clinical trial, the investigational product is adequately identified by name and dose. Software for statistical analysis is not explicitly named, but the statistical methods are described. No antibodies, cell lines, or other reagents are used.

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedINADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 85% conf

The investigational products (bimagrumab and semaglutide) are identified with doses and regimens, and the statistical software is implied. No other key biological/chemical resources are used.

Evidence

paraphrase[Abstract]

“bimagrumab (10 mg kg−1 or 30 mg kg−1 intravenously every 12 weeks), semaglutide (1.0 mg or 2.4 mg subcutaneously once a week)”

absence[Methods, Statistical analysis]

Statistical software is not explicitly named.

PASSReviewer 2· 85% conf

The investigational products (bimagrumab and semaglutide) are identified with doses and regimens; the software used for statistical analysis is not explicitly named, but this is a minor gap.

Evidence

paraphrase[Abstract and Methods]

“bimagrumab (10 mg kg−1 or 30 mg kg−1 intravenously every 12 weeks), semaglutide (1.0 mg or 2.4 mg subcutaneously once a week)”

absence[Methods, Statistical analysis]

Statistical software is not identified.

Tests are named (two-sided t-tests, ANCOVA, MMRM, logistic regression). Assumptions are handled via pre-specified models and estimands. Exact p-values are reported for many comparisons (e.g., p=0.133, p<0.001). Effect sizes with 95% CIs are provided for the primary endpoint. Statistical software is not explicitly identified, but the methods are described. Data presentation includes LSM changes with SEs and CIs. Mathematical plausibility checks: the reported percentages and counts appear consistent; no obvious arithmetic errors were detected.

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedINADEQUATE

assumptions verifiedADEQUATE

mathematical plausibilityPASS

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Statistical methods are thoroughly described, including ANCOVA, MMRM, multiple imputation, and estimands. P-values are reported exactly for many comparisons, and effect sizes with CIs are provided. No arithmetic inconsistencies were found.

Evidence

direct quote[Methods, Statistical analysis]

“Continuous endpoints were analyzed using the analysis of covariance (ANCOVA) model, and categorical endpoints were analyzed by logistic regression.”

View in source

direct quote[Table 2]

“−2.7 (−6.2 to 0.8) p = 0.133”

View in source

paraphrase[Table 2]

“LSM difference from placebo (95% CI): −5.9 (−9.5 to −2.4) p < 0.001”

PASSReviewer 2· 90% conf

Statistical methods are well-described: tests are named, effect sizes with CIs are reported, and the analysis uses appropriate models (ANCOVA, MMRM) with multiple imputation; p-values are reported as thresholds, which is acceptable for a large trial.

Evidence

direct quote[Methods, Statistical analysis]

“Continuous endpoints were analyzed using the analysis of covariance (ANCOVA) model, and categorical endpoints were analyzed by logistic regression.”

View in source

paraphrase[Table 2]

“LSM difference from placebo (95% CI) | – | −2.7 (−6.2 to 0.8) p = 0.133 | ...”

paraphrase[Table 2]

“p < 0.001”

The data availability statement is concrete: it names Vivli as the platform, specifies the timeframe (6 months after approval), and describes the review process. This meets the standard for managed access to patient-level data. Source data for figures are provided as supplementary files. No custom code is mentioned, so code sharing is not applicable.

Sub-criteria

code sharingN/A

accession numbersN/A

repository depositN/A

data availability statementADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

A detailed data availability statement is provided, describing managed access via Vivli with conditions and timeframe. Source data for figures are included as supplementary. No custom code is mentioned.

Evidence

paraphrase[Data availability]

“Eli Lilly and Company provides access to all individual participant data collected during the trial, after anonymization... Data are available upon reasonable request 6 months after the indication studied has been approved... Access is provided after a proposal has been approved by an independent review committee... For details on submitting a request, see the instructions provided at https://vivli.org/”

PASSReviewer 2· 90% conf

A detailed data availability statement is provided, describing managed access via Vivli with conditions and timeframe; source data for figures are included as supplementary.

Evidence

paraphrase[Data availability]

Trial registration is provided (NCT05616013). Methods are comprehensive. Limitations are discussed (e.g., open-label semaglutide, no multiplicity adjustment). Conclusions are proportional to the results. Funding and competing interests are disclosed. A reporting guideline is not explicitly referenced, but the paper includes a CONSORT flow diagram and follows standard reporting.

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineINADEQUATE

methods completenessADEQUATE

all outcomes reportedADEQUATE

limitations discussedADEQUATE

conclusions proportionalADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The trial is registered, methods are detailed, limitations are discussed, conclusions are proportional, and funding/COI are disclosed. A reporting guideline is not explicitly mentioned, but the paper follows CONSORT-like structure.

Evidence

direct quote[Abstract]

“ClinicalTrials.gov identifier: NCT05616013”

View in source

direct quote[Discussion]

“No multiplicity adjustments were made; therefore, these results should not be used to infer definitive treatment effects.”

View in source

direct quote[Competing interests]

“Eli Lilly and Company funded the study and all support for the manuscript.”

View in source

PASSReviewer 2· 90% conf

The trial is registered, methods are detailed, limitations are discussed, conclusions are proportional, and funding/COI are disclosed; a reporting guideline is not explicitly mentioned.

Evidence

direct quote[Abstract]

“ClinicalTrials.gov identifier: NCT05616013”

View in source

direct quote[Discussion]

“No multiplicity adjustments were made; therefore, these results should not be used to infer definitive treatment effects.”

View in source

direct quote[Competing interests]

“Eli Lilly and Company funded the study and all support for the manuscript.”

View in source

3 copyedit issues flagged: mostly consistency, clarity, other.

Checked 33 references by DOI: 2 verified — 1 DOI unresolved, 30 no DOI (shown, not verified).

Reproducibility

1 data/code link checked; 1 live.

Registered (2 IDs: ClinicalTrials.gov). No reporting guideline cited.

Αlpha¹ Rigor Action ItemsFinal pass before journal submission

The published work is robust overall, but readers should weigh the missing explicit ethics approval statement and the open-label semaglutide design. An erratum or clarification adding the ethics approval details would strengthen the record. The copyedit issues are minor and do not affect scientific validity.

1.
HIGHethics
Add an explicit ethics approval statement in the Methods, naming the IRB/ethics committee and protocol number, and state that informed consent was obtained from all participants.
The paper currently lacks any explicit ethics approval or informed consent statement, which is a required reporting element for a human trial.
2.
HIGHreporting
Add a statement of regulatory compliance (e.g., Declaration of Helsinki, ICH-GCP) in the Methods.
Regulatory compliance is not explicitly stated, and adding it would strengthen the ethics reporting.
3.
HIGHstatistics
Identify the statistical software used (e.g., SAS version) in the Statistical analysis section.
The statistical software is not named, which is a minor but easily fixable reporting gap.
4.
HIGHreporting
Mention adherence to a reporting guideline (e.g., CONSORT) in the Methods or Reporting Summary.
The paper does not explicitly reference a reporting guideline, though it follows standard reporting.
5.
HIGHother
Verify or correct the reference 'E9(R1) Statistical Principles for Clinical Trials: Addendum: Estimands and Sensitivity Analysis in Clinical Trials' (DOI 10.1016/s2213-8587(24) which could not be found in the registry.
A reference that cannot be found in any registry may be fabricated or have an incorrect DOI; it should be verified or corrected.
6.
MEDIUMstatistics
Consider reporting exact p-values (e.g., p=0.133) instead of thresholds where possible, though this is acceptable for large trials.
Exact p-values improve transparency and allow readers to assess evidence more precisely.
7.
MEDIUMcopyedit
Fix the inconsistent p-value formatting in Table 2, Appendicular lean mass row: change 'p < .001' to 'p < 0.001'.
Consistent formatting of p-values improves readability and professionalism.
8.
MEDIUMcopyedit
Specify the magnitude of weight reduction in the abstract for clarity.
The abstract currently states 'substantial reductions' without a number, which is less informative.
9.
MEDIUMcopyedit
Fix the orphaned phrase 'are provided with this paper.' in the Data availability section.
The sentence ends abruptly and should be integrated into the surrounding text.
10.
MEDIUMreporting
Clarify the blinding of the data monitoring committee and whether they were unblinded, as this is not explicitly stated.
This detail is relevant for assessing potential bias in trial oversight.
11.
MEDIUMreporting
In the Discussion, explicitly address the potential bias from open-label semaglutide and its impact on the results.
The open-label design is disclosed but its potential bias is not fully discussed.
12.
LOWreporting
Provide a CONSORT checklist as supplementary material to enhance transparency.
A checklist would help readers verify that all CONSORT items are reported.

Full text (91,507 chars · analyzed ~82%, head + tail)Analyzed: Aug 15, 2026

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