Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.

Name: Kaimen Rigor review — Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.
Item: Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.
Rating: 39
Author: Alpha1

Weitz JI, Tankó LB, Floege J, Fox KAA, Bhatt DL, Thadhani R, Hung J, Pap ÁF, Kubitza D, Winkelmayer WC, CONVERT Investigators

Paper source

Read full text (PMC)

Embed this Rigor badge

Kaimen Rigor review — 1★ (Critical), 6 critical, 2 high issues for “Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.”

Links back to this Kaimen Rigor review.

Alpha1 Editorial

This rigor review was examined and confirmed by Alpha1 Editorial · August 16, 2026

Read alongside

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.

Weitz JI, Tankó LB, Floege J, Fox KAA, Bhatt DL, Thadhani R, Hung J, Pap ÁF, Kubitza D, Winkelmayer WC, CONVERT Investigators

Read full text (PMC)

DOI

10.1038/s41591-023-02794-7

Share this Kaimen Rigor review

Post on X Share on LinkedIn Share via Email

Embed this Rigor badge

<a href="https://alpha1science.com/verify/9b24c391-4358-441f-81d1-947c5a9f9b26" target="_blank" rel="noopener">
  <img src="https://alpha1science.com/verify/9b24c391-4358-441f-81d1-947c5a9f9b26/badge" alt="Kaimen Rigor review — 1★ (Critical), 6 critical, 2 high issues for “Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.”" width="440" height="104" style="max-width:100%;height:auto" />
</a>

Every embed links back to this Kaimen Rigor review.

Record fingerprint

cb6d06e9a148d9b11aa380fccb1949f80ecc57482019c14c2e7ba5431dabad01

Verify via API

Issued Aug 16, 2026Engine 7.39.0

Alpha1 assesses methodological rigor, not the importance of the findings. See how we calibrate →

Alpha¹ by Kaimen

Fetching the latest research

Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.

Weitz JI, Tankó LB, Floege J, Fox KAA, Bhatt DL, Thadhani R, Hung J, Pap ÁF, Kubitza D, Winkelmayer WC, CONVERT Investigators

Paper source

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.

Read full text (PMC)

Embed this Rigor badge

Links back to this Kaimen Rigor review.

Alpha1 Editorial

This rigor review was examined and confirmed by Alpha1 Editorial · August 16, 2026

Kaimen Rigor review

Kaimen Rigor reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

StatisticsImpossible or misreported statistic ×6−6★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ClaimsTreatment effect not shown to be clinically meaningful−0.5★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

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

Not verified in this report

The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 3 reported means were read, and their group size is not stated where the values are printed (this source has no machine-readable table structure). These checks need the count the mean was averaged over, so none was performed.

Biggest issues6 demonstrable

01Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
84.7% does not match the reported count 199/232
“199 participants in the lower-dose osocimab group (84.7%)”
ResultsFind in source
02Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
82.9% does not match the reported count 194/224
“194 participants in the higher-dose osocimab group (82.9%)”
ResultsFind in source
03Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
87.7% does not match the reported count 206/230
“206 participants in the placebo group (87.7%)”
ResultsFind in source
04Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
75.5% does not match the reported count 178/232
“178 participants in the lower-dose osocimab group (75.5%)”
ResultsFind in source
05Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
74.4% does not match the reported count 174/224
“174 participants in the higher-dose osocimab group (74.4%)”
ResultsFind in source
06Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
74.9% does not match the reported count 176/230
“176 participants in the placebo group (74.9%)”
ResultsFind in source

2 further findings of this severity or below — every one is in the sections below, filed under its error type.

Findings by category

101ArithmeticNumerical inconsistencies 302OverreachOverstated conclusions 03AuthenticityNone found 04DisclosureNone found 05AvailabilityNone found 06Copyedit4 minor suggestions

This Kaimen Rigor review uses Kaimen 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.

The paper is a well-conducted phase 2b randomized trial with rigorous design, clear reporting of demographics, ethics, and statistical methods. The main weakness is the absence of a formal sample size calculation, which is acknowledged and typical for phase 2. Minor copyedit issues exist in tables and a potentially misleading operational expectation statement.

Both reviewers agreed on all dimensions and study type (interventional). The statistics verification component recomputed only a subset of tests (2 of 8 consistent); the remaining tests were not machine-verifiable and are not confirmed. The citation check found no retracted or unresolved references. The reproducibility check found all links live.

Numerical inconsistencies

1 finding · worst critical

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.

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed

Recomputed 2 tests: 2 consistent, 0 inconsistent; 2 via agent-written checks. 6 reported summary statistics mathematically impossible for the stated N (PERCENT).

Overstated conclusions

3 findings · worst high

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
Treatment effect not shown to be clinically meaningfulAssessed
Conclusions only partially backed by the presented evidenceAssessed

7 major claims checked against the paper's own evidence: 2 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Premise concern: surrogate not validated for clinical benefit; effect size not shown to be clinically meaningful.

Data authenticity concerns

None found

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.

Checked — nothing surfaced.

Reporting gaps

None found

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.

Checked — nothing surfaced.

Eight Dimensions8 pass

The introduction cites multiple studies on the risks of anticoagulation in kidney failure, the role of factor XI in thrombosis, and prior osocimab trials. The rationale for the trial is clearly linked to the unmet need for safer anticoagulants. Limitations of prior research (e.g., underpowered apixaban trials) are acknowledged and addressed by the trial design.

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 clear scientific premise with extensive prior work and a logical rationale for targeting factor XIa in hemodialysis patients.

Evidence

paraphrase[Introduction, paragraphs 1-3]

“Inhibitors of factor XI or its activated form, factor XIa, may be safer than the currently available anticoagulants because factor XI seems to be more important for thrombosis than for hemostasis.”

paraphrase[Introduction, last paragraph]

“To address the unmet need for safer anticoagulants for patients with end-stage kidney disease, we conducted the CONVERT trial...”

paraphrase[Discussion, paragraph 4]

“Two randomized trials comparing vitamin K antagonists with apixaban in individuals with kidney failure undergoing hemodialysis who had atrial fibrillation were able to recruit only 154 and 97 participants, respectively, and were therefore underpowered to yield definitive results.”

PASSReviewer 2· 90% conf

The paper establishes a clear scientific premise: patients on hemodialysis have high thrombotic risk but also high bleeding risk with current anticoagulants, and factor XIa inhibition may offer a safer alternative. Prior work on osocimab and factor XI is cited, and the rationale for the trial is well articulated.

Evidence

paraphrase[Introduction, paragraph 2]

“In a phase 2 dose-finding study in individuals undergoing total knee arthroplasty, a single intravenous dose of osocimab administered before surgery was superior, or after surgery was noninferior, to enoxaparin for prevention of postoperative venous thromboembolism.”

“Therefore, with limited evidence supporting the use of warfarin or direct oral anticoagulants in this patient population, there remains an unmet need for safer anticoagulants for the prevention of thromboembolic events.”

Introduction ¶1Find in source

paraphrase[Discussion, paragraph 4]

Randomization was central and covariate-adaptive, with a 2:1 ratio for each dose vs placebo. Blinding is described: double-blind, with a blinded Steering Committee and Central Adjudication Committee. Inclusion/exclusion criteria are detailed. Power analysis is not reported, but the paper explicitly states 'no formal a priori sample size calculation' and provides a rationale based on operational experience. Outlier handling is not explicitly discussed, but the analysis population (safety set) and missing-data approach are defined. Controls are appropriate (placebo). Independent replication is not applicable for a single phase 2 trial.

Sub-criteria

controlsADEQUATE

power analysisINADEQUATE

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· 90% conf

The trial design is rigorous with adequate randomization, blinding, and prespecified inclusion/exclusion criteria; however, no formal power analysis was performed.

Evidence

“Participants were centrally assigned using an interactive web-response system and covariate-adaptive randomization.”

MethodsFind in source

paraphrase[Methods, Study design and oversight]

“The Steering Committee was blinded to treatment assignment as were the members of a Central Independent Adjudication Committee...”

“There were no formal hypotheses. All analyses were descriptive and there was no formal a priori sample size calculation.”

Statistical analysisFind in source

PASSReviewer 2· 95% conf

The trial is a randomized, double-blind, placebo-controlled phase 2b study with clear inclusion/exclusion criteria, central randomization, and a pre-specified analysis population. No formal sample size calculation was performed, but this is acknowledged and typical for phase 2.

Evidence

“Participants were centrally assigned using an interactive web-response system and covariate-adaptive randomization.”

MethodsFind in source

“The Steering Committee was blinded to treatment assignment as were the members of a Central Independent Adjudication Committee, who adjudicated all deaths, suspected bleeds, and cardiovascular or thromboembolic events.”

MethodsFind in source

“There were no formal hypotheses. All analyses were descriptive and there was no formal a priori sample size calculation.”

Statistical analysisFind in source

Sex is reported for all participants (448 male, 256 female). Age, weight (BMI), and health status (comorbidities) are detailed in Table 1. Demographics include race and geographic region. Species/strain and housing are not applicable as this is a human trial.

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 well reported, including sex, age, and comorbidities.

Evidence

“704 participants (448 male, 256 female)”

AbstractFind in source

“Age, median (range) (years) | 61 (28–91) | 61 (25–90) | 60 (24–90)”

Table 1Find in source

“White, n (%) | 191 (82.3) | 185 (82.6) | 185 (80.4)”

Table 1Find in source

PASSReviewer 2· 90% conf

Demographic and clinical characteristics are well reported, including sex, age, and comorbidities. Since this is a human trial, species/strain and housing conditions are not applicable.

Evidence

“704 participants (448 male, 256 female) with kidney failure undergoing hemodialysis were randomized”

Table 1Find in source

“Age, median (range) (years) | 61 (28–91) | 61 (25–90) | 60 (24–90)”

Table 1Find in source

The paper states that an Institutional Review Board at each participating center approved the protocol and all participants provided informed consent. It also states compliance with the Declaration of Helsinki and ICH GCP. This satisfies both irb_ethics_statement and informed_consent. Regulatory compliance is explicitly stated.

Sub-criteria

iacuc statementN/A

informed consentADEQUATE

irb ethics statementADEQUATE

regulatory complianceADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Ethical approval and informed consent are adequately documented.

Evidence

“An Institutional Review Board at each participating center approved the protocol and all participants provided informed consent.”

MethodsFind in source

“This study was conducted in accordance with the consensus ethical principles derived from international guidelines including the Declaration of Helsinki and Council for International Organizations of Medical Sciences (CIOMS) International Ethical Guidelines, applicable ICH Good Clinical Practice Guidelines and all applicable laws and regulations.”

MethodsFind in source

PASSReviewer 2· 95% conf

Ethical approval and informed consent are clearly documented, with a named IRB approval and compliance with the Declaration of Helsinki and ICH GCP.

Evidence

“An Institutional Review Board at each participating center approved the protocol and all participants provided informed consent.”

MethodsFind in source

Osocimab is described as a fully human inhibitory antibody against factor XIa, with dosing regimens specified. The placebo is described as matching. Statistical software (SAS v.9.4) is identified. No other biological/chemical resources are used, so other sub-criteria are not applicable.

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The investigational product (osocimab) is adequately identified with dosing regimen; statistical software is identified.

Evidence

“The lower-dose osocimab regimen consisted of a 105 mg loading dose followed by a monthly maintenance dose of 52.5 mg, and the higher-dose regimen consisted of a 210 mg loading dose followed by a monthly maintenance dose of 105 mg.”

MethodsFind in source

“Data were analyzed using SAS base v.9.4 (SAS/STAT v.14.3).”

Statistical analysisFind in source

PASSReviewer 2· 90% conf

The investigational product (osocimab) is identified with dosing regimen and manufacturer (Bayer). The assay reagents are named (C.K. Prest, Diagnostica Stago). Software is identified (SAS v9.4).

Evidence

paraphrase[Introduction, paragraph 2]

“Osocimab is a long-acting, fully human inhibitory antibody directed against factor XIa.”

“activated partial thromboplastin times were measured using C.K. Prest—a kaolin activator (Diagnostica Stago)”

MethodsFind in source

“Data were analyzed using SAS base v.9.4 (SAS/STAT v.14.3).”

Statistical analysisFind in source

Tests are named (Cox proportional hazards, Fine-Gray, relative risk with Farrington-Manning). Exact p-values are reported for the clotting analysis. Effect sizes with 90% CIs are provided for primary outcomes. Software is identified. Data presentation includes per-group n and event rates. Mathematical plausibility checks on reported percentages and counts did not reveal inconsistencies.

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedADEQUATE

assumptions verifiedADEQUATE

mathematical plausibilityPASS

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Statistical methods are appropriate and well described; effect sizes with CIs are reported; no arithmetic errors detected.

Evidence

“Cause-specific hazard ratios were estimated with Cox proportional hazards model, subdistribution hazard ratios were estimated by Fine–Gray subdistribution hazards model.”

Statistical analysisFind in source

“lower dose versus placebo, 0.71 (95% CI, 0.54–0.93; P = 0.0085); higher dose versus placebo, 0.66 (95% CI, 0.49–0.87; P = 0.0021)”

ResultsFind in source

“Events (90% CI) per 100 patient-years | 9.7 (6.1–14.1) | 6.7 (3.7–10.3) | 10.8 (7.0–15.3)”

Table 2Find in source

PASSReviewer 2· 90% conf

Statistical methods are appropriate and well described, including Cox and Fine-Gray models, Aalen-Johansen estimators, and relative risks with CIs. The paper reports effect estimates with CIs and some p-values. No arithmetic errors were detected.

Evidence

“Cause-specific hazard ratios were estimated with Cox proportional hazards model, subdistribution hazard ratios were estimated by Fine–Gray subdistribution hazards model.”

Statistical analysisFind in source

“lower dose versus placebo, 0.71 (95% CI, 0.54–0.93; P = 0.0085); higher dose versus placebo, 0.66 (95% CI, 0.49–0.87; P = 0.0021)”

ResultsFind in source

“Events (90% CI) per 100 patient-years | 9.7 (6.1–14.1) | 6.7 (3.7–10.3) | 10.8 (7.0–15.3)”

Table 2Find in source

The data availability statement is concrete: it names the Vivli platform, describes the process (request, independent review panel, Data Use Agreement), and specifies a timeframe (within 6 months). This meets the 'reported_and_adequate' tier. Repository deposit and accession numbers are not applicable for patient-level data. Code sharing is not applicable as no bespoke code is mentioned.

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

Data availability is adequately described with a concrete access route via Vivli.

Evidence

“Interested researchers can use www.vivli.org (http://www.vivli.org) to request access to anonymized patient-level data and supporting documents from clinical studies to conduct further research that can help advance medical science or improve patient care.”

Data availabilityFind in source

PASSReviewer 2· 95% conf

A detailed data availability statement is provided, describing managed access via Vivli with conditions and timeframe. This is adequate for a clinical trial with patient-level data.

Evidence

Data availabilityFind in source

“Data will be made available within 6 months after signing the Data Use Agreement to researchers who provide a methodologically sound proposal.”

Data availabilityFind in source

The trial is registered (NCT04523220). Methods are comprehensive. Limitations are discussed (modest sample size, need for phase 3). Conclusions are appropriately cautious. Funding and competing interests are disclosed. A reporting summary is mentioned.

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineADEQUATE

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, and conclusions are proportional.

Evidence

“ClinicalTrials.gov identifier, NCT04523220”

AbstractFind in source

“Nonetheless, because of the modest sample size, additional studies are needed to assess the safety of osocimab.”

Discussion ¶5Find in source

“This study was funded by Bayer AG.”

AcknowledgementsFind in source

PASSReviewer 2· 90% conf

The trial is registered (NCT04523220), methods are detailed, limitations are discussed, conclusions are proportional, and funding/COI are disclosed. A reporting summary is mentioned.

Evidence

“ClinicalTrials.gov identifier, NCT04523220 (https://clinicaltrials.gov/study/NCT04523220)”

AbstractFind in source

“Nonetheless, because of the modest sample size, additional studies are needed to assess the safety of osocimab.”

Discussion ¶5Find in source

“This study was funded by Bayer AG.”

AcknowledgementsFind in source

Registered (1 ID: ClinicalTrials.gov). No reporting guideline cited.

Broken references and links

None found

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.

Checked — nothing surfaced.

Checked 22 references by DOI: 18 verified — 4 no DOI (shown, not verified).

3 data/code links checked; 3 live.

Copyediting

4 minor

Wording, consistency and formatting errors that need correcting before submission.

No major wording or formatting errors. 4 minor suggestions below.

4 copyedit issues flagged: mostly consistency, typo, clarity.

Kaimen Rigor Action ItemsFinal pass before journal submission

The published work is robust and well-reported; an informed reader should weigh the absence of a formal sample size calculation and the limited machine-verification of statistics. No erratum is warranted based on the identified issues, but the minor copyedit inconsistencies and the operational expectation statement could be clarified in a correction if the journal allows.

1.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 84.7% does not match the reported count 199/232
Demonstrable critical failure — blocks the verdict from passing.
2.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 82.9% does not match the reported count 194/224
Demonstrable critical failure — blocks the verdict from passing.
3.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 87.7% does not match the reported count 206/230
Demonstrable critical failure — blocks the verdict from passing.
4.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 75.5% does not match the reported count 178/232
Demonstrable critical failure — blocks the verdict from passing.
5.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 74.4% does not match the reported count 174/224
Demonstrable critical failure — blocks the verdict from passing.
6.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 74.9% does not match the reported count 176/230
Demonstrable critical failure — blocks the verdict from passing.
7.
HIGHstatistics
In the Methods, Statistical analysis section, add a formal a priori sample size calculation with effect size, alpha, and power, or explicitly state that the target sample size was based on operational feasibility rather than power.
The absence of a formal sample size calculation is a notable limitation that reviewers and readers may question.
8.
HIGHreporting
In the Methods, Statistical analysis section, clarify that the statement about 555 participants expected to complete is an operational expectation, not a formal power calculation.
The current wording could be misinterpreted as a power analysis, which the paper explicitly denies elsewhere.
9.
MEDIUMreporting
In the Methods, Statistical analysis section, explicitly describe how missing data and early discontinuations were handled in the time-to-event analyses (e.g., censoring rules).
Transparency about missing data handling strengthens the statistical reporting and addresses a common reviewer concern.
10.
MEDIUMreporting
In the Results, add the number of participants who discontinued due to adverse events in the main text or a table.
This is a key safety metric that is currently not prominently reported.
11.
MEDIUMreporting
In the Discussion, address the generalizability of the findings to older patients, given the median age of 61 years and the increasing prevalence of ESKD in older populations.
This would strengthen the discussion of the trial's applicability.
12.
MEDIUMreporting
In the main text, include a CONSORT flow diagram (or ensure the referenced figure is clearly labeled as such) to enhance reporting completeness.
A CONSORT flow diagram is a standard expectation for randomized trials and improves transparency.
13.
MEDIUMethics
In the Methods, Study design and oversight section, provide the specific IRB approval numbers or state that they are available in the supplementary appendix.
Specific approval identifiers increase transparency and verifiability of ethical oversight.
14.
MEDIUMreporting
In the Methods, clarify the role of the Data and Safety Monitoring Committee and whether any interim analyses were planned.
This is important for understanding trial oversight and potential bias.
15.
LOWcopyedit
In Table 1, Length of study row, add a space between the number and the percentage: change '89(38.7)' to '89 (38.7)'.
Consistent spacing improves table readability.
16.
LOWcopyedit
In Table 2, All-cause death row, remove the percent sign inside the parentheses for consistency: change '12 (5.2%)' to '12 (5.2)'.
Consistent formatting avoids confusion about whether the value is a count or percentage.
17.
LOWdata code
In the Data availability statement, specify the exact timeframe for data availability after approval (e.g., 'within 6 months after signing the Data Use Agreement').
A concrete timeframe improves the actionability of the data access statement.

Full text (49,537 chars)Analyzed: Aug 16, 2026

Start the discussion on JRNLClub

Community discussion on jrnlclub.com

Read alongside

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.

Weitz JI, Tankó LB, Floege J, Fox KAA, Bhatt DL, Thadhani R, Hung J, Pap ÁF, Kubitza D, Winkelmayer WC, CONVERT Investigators

Read full text (PMC)

DOI

10.1038/s41591-023-02794-7

Share this Kaimen Rigor review

Post on X Share on LinkedIn Share via Email

Embed this Rigor badge

<a href="https://alpha1science.com/verify/9b24c391-4358-441f-81d1-947c5a9f9b26" target="_blank" rel="noopener">
  <img src="https://alpha1science.com/verify/9b24c391-4358-441f-81d1-947c5a9f9b26/badge" alt="Kaimen Rigor review — 1★ (Critical), 6 critical, 2 high issues for “Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial.”" width="440" height="104" style="max-width:100%;height:auto" />
</a>

Every embed links back to this Kaimen Rigor review.

Record fingerprint

cb6d06e9a148d9b11aa380fccb1949f80ecc57482019c14c2e7ba5431dabad01

Verify via API

Issued Aug 16, 2026Engine 7.39.0

Alpha1 assesses methodological rigor, not the importance of the findings. See how we calibrate →

Kaimen Rigor review

Kaimen Rigor reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

StatisticsImpossible or misreported statistic ×6−6★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ClaimsTreatment effect not shown to be clinically meaningful−0.5★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

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

Not verified in this report

The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run: 3 reported means were read, and their group size is not stated where the values are printed (this source has no machine-readable table structure). These checks need the count the mean was averaged over, so none was performed.

Biggest issues6 demonstrable

01Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
84.7% does not match the reported count 199/232
“199 participants in the lower-dose osocimab group (84.7%)”
ResultsFind in source
02Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
82.9% does not match the reported count 194/224
“194 participants in the higher-dose osocimab group (82.9%)”
ResultsFind in source
03Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
87.7% does not match the reported count 206/230
“206 participants in the placebo group (87.7%)”
ResultsFind in source
04Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
75.5% does not match the reported count 178/232
“178 participants in the lower-dose osocimab group (75.5%)”
ResultsFind in source
05Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
74.4% does not match the reported count 174/224
“174 participants in the higher-dose osocimab group (74.4%)”
ResultsFind in source
06Printed percentage does not match its own countdemonstrable
criticalArithmeticrecomputedFull detail
74.9% does not match the reported count 176/230
“176 participants in the placebo group (74.9%)”
ResultsFind in source

2 further findings of this severity or below — every one is in the sections below, filed under its error type.

Findings by category

101ArithmeticNumerical inconsistencies 302OverreachOverstated conclusions 03AuthenticityNone found 04DisclosureNone found 05AvailabilityNone found 06Copyedit4 minor suggestions

Numerical inconsistencies

1 finding · worst critical

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed

Recomputed 2 tests: 2 consistent, 0 inconsistent; 2 via agent-written checks. 6 reported summary statistics mathematically impossible for the stated N (PERCENT).

Overstated conclusions

3 findings · worst high

Efficacy rests on an unvalidated surrogate endpointAssessed
Treatment effect not shown to be clinically meaningfulAssessed
Conclusions only partially backed by the presented evidenceAssessed

7 major claims checked against the paper's own evidence: 2 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Premise concern: surrogate not validated for clinical benefit; effect size not shown to be clinically meaningful.

Data authenticity concerns

None found

Checked — nothing surfaced.

Reporting gaps

None found

Checked — nothing surfaced.

Eight Dimensions8 pass

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 clear scientific premise with extensive prior work and a logical rationale for targeting factor XIa in hemodialysis patients.

Evidence

paraphrase[Introduction, paragraphs 1-3]

paraphrase[Introduction, last paragraph]

“To address the unmet need for safer anticoagulants for patients with end-stage kidney disease, we conducted the CONVERT trial...”

paraphrase[Discussion, paragraph 4]

PASSReviewer 2· 90% conf

Evidence

paraphrase[Introduction, paragraph 2]

Introduction ¶1Find in source

paraphrase[Discussion, paragraph 4]

Sub-criteria

controlsADEQUATE

power analysisINADEQUATE

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· 90% conf

The trial design is rigorous with adequate randomization, blinding, and prespecified inclusion/exclusion criteria; however, no formal power analysis was performed.

Evidence

“Participants were centrally assigned using an interactive web-response system and covariate-adaptive randomization.”

MethodsFind in source

paraphrase[Methods, Study design and oversight]

“The Steering Committee was blinded to treatment assignment as were the members of a Central Independent Adjudication Committee...”

“There were no formal hypotheses. All analyses were descriptive and there was no formal a priori sample size calculation.”

Statistical analysisFind in source

PASSReviewer 2· 95% conf

Evidence

“Participants were centrally assigned using an interactive web-response system and covariate-adaptive randomization.”

MethodsFind in source

“There were no formal hypotheses. All analyses were descriptive and there was no formal a priori sample size calculation.”

Statistical analysisFind in source

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 well reported, including sex, age, and comorbidities.

Evidence

“704 participants (448 male, 256 female)”

AbstractFind in source

“Age, median (range) (years) | 61 (28–91) | 61 (25–90) | 60 (24–90)”

Table 1Find in source

“White, n (%) | 191 (82.3) | 185 (82.6) | 185 (80.4)”

Table 1Find in source

PASSReviewer 2· 90% conf

Demographic and clinical characteristics are well reported, including sex, age, and comorbidities. Since this is a human trial, species/strain and housing conditions are not applicable.

Evidence

“704 participants (448 male, 256 female) with kidney failure undergoing hemodialysis were randomized”

Table 1Find in source

“Age, median (range) (years) | 61 (28–91) | 61 (25–90) | 60 (24–90)”

Table 1Find in source

Sub-criteria

iacuc statementN/A

informed consentADEQUATE

irb ethics statementADEQUATE

regulatory complianceADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Ethical approval and informed consent are adequately documented.

Evidence

“An Institutional Review Board at each participating center approved the protocol and all participants provided informed consent.”

MethodsFind in source

PASSReviewer 2· 95% conf

Ethical approval and informed consent are clearly documented, with a named IRB approval and compliance with the Declaration of Helsinki and ICH GCP.

Evidence

“An Institutional Review Board at each participating center approved the protocol and all participants provided informed consent.”

MethodsFind in source

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The investigational product (osocimab) is adequately identified with dosing regimen; statistical software is identified.

Evidence

MethodsFind in source

“Data were analyzed using SAS base v.9.4 (SAS/STAT v.14.3).”

Statistical analysisFind in source

PASSReviewer 2· 90% conf

The investigational product (osocimab) is identified with dosing regimen and manufacturer (Bayer). The assay reagents are named (C.K. Prest, Diagnostica Stago). Software is identified (SAS v9.4).

Evidence

paraphrase[Introduction, paragraph 2]

“Osocimab is a long-acting, fully human inhibitory antibody directed against factor XIa.”

“activated partial thromboplastin times were measured using C.K. Prest—a kaolin activator (Diagnostica Stago)”

MethodsFind in source

“Data were analyzed using SAS base v.9.4 (SAS/STAT v.14.3).”

Statistical analysisFind in source

Sub-criteria

tests namedADEQUATE

exact p valuesADEQUATE

effect sizes ciADEQUATE

data presentationADEQUATE

software identifiedADEQUATE

assumptions verifiedADEQUATE

mathematical plausibilityPASS

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

Statistical methods are appropriate and well described; effect sizes with CIs are reported; no arithmetic errors detected.

Evidence

“Cause-specific hazard ratios were estimated with Cox proportional hazards model, subdistribution hazard ratios were estimated by Fine–Gray subdistribution hazards model.”

Statistical analysisFind in source

“lower dose versus placebo, 0.71 (95% CI, 0.54–0.93; P = 0.0085); higher dose versus placebo, 0.66 (95% CI, 0.49–0.87; P = 0.0021)”

ResultsFind in source

“Events (90% CI) per 100 patient-years | 9.7 (6.1–14.1) | 6.7 (3.7–10.3) | 10.8 (7.0–15.3)”

Table 2Find in source

PASSReviewer 2· 90% conf

Evidence

“Cause-specific hazard ratios were estimated with Cox proportional hazards model, subdistribution hazard ratios were estimated by Fine–Gray subdistribution hazards model.”

Statistical analysisFind in source

“lower dose versus placebo, 0.71 (95% CI, 0.54–0.93; P = 0.0085); higher dose versus placebo, 0.66 (95% CI, 0.49–0.87; P = 0.0021)”

ResultsFind in source

“Events (90% CI) per 100 patient-years | 9.7 (6.1–14.1) | 6.7 (3.7–10.3) | 10.8 (7.0–15.3)”

Table 2Find in source

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

Data availability is adequately described with a concrete access route via Vivli.

Evidence

Data availabilityFind in source

PASSReviewer 2· 95% conf

A detailed data availability statement is provided, describing managed access via Vivli with conditions and timeframe. This is adequate for a clinical trial with patient-level data.

Evidence

Data availabilityFind in source

“Data will be made available within 6 months after signing the Data Use Agreement to researchers who provide a methodologically sound proposal.”

Data availabilityFind in source

Sub-criteria

funding coiADEQUATE

trial registrationADEQUATE

reporting guidelineADEQUATE

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, and conclusions are proportional.

Evidence

“ClinicalTrials.gov identifier, NCT04523220”

AbstractFind in source

“Nonetheless, because of the modest sample size, additional studies are needed to assess the safety of osocimab.”

Discussion ¶5Find in source

“This study was funded by Bayer AG.”

AcknowledgementsFind in source

PASSReviewer 2· 90% conf

The trial is registered (NCT04523220), methods are detailed, limitations are discussed, conclusions are proportional, and funding/COI are disclosed. A reporting summary is mentioned.

Evidence

“ClinicalTrials.gov identifier, NCT04523220 (https://clinicaltrials.gov/study/NCT04523220)”

AbstractFind in source

“Nonetheless, because of the modest sample size, additional studies are needed to assess the safety of osocimab.”

Discussion ¶5Find in source

“This study was funded by Bayer AG.”

AcknowledgementsFind in source

Registered (1 ID: ClinicalTrials.gov). No reporting guideline cited.

Broken references and links

None found

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.

Checked — nothing surfaced.

Checked 22 references by DOI: 18 verified — 4 no DOI (shown, not verified).

3 data/code links checked; 3 live.

Copyediting

4 minor

Wording, consistency and formatting errors that need correcting before submission.

No major wording or formatting errors. 4 minor suggestions below.

4 copyedit issues flagged: mostly consistency, typo, clarity.

Kaimen Rigor Action ItemsFinal pass before journal submission

1.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 84.7% does not match the reported count 199/232
Demonstrable critical failure — blocks the verdict from passing.
2.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 82.9% does not match the reported count 194/224
Demonstrable critical failure — blocks the verdict from passing.
3.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 87.7% does not match the reported count 206/230
Demonstrable critical failure — blocks the verdict from passing.
4.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 75.5% does not match the reported count 178/232
Demonstrable critical failure — blocks the verdict from passing.
5.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 74.4% does not match the reported count 174/224
Demonstrable critical failure — blocks the verdict from passing.
6.
CRITICALstatistics
Correct or explain the statistically impossible value: PERCENT: 74.9% does not match the reported count 176/230
Demonstrable critical failure — blocks the verdict from passing.
7.
HIGHstatistics
In the Methods, Statistical analysis section, add a formal a priori sample size calculation with effect size, alpha, and power, or explicitly state that the target sample size was based on operational feasibility rather than power.
The absence of a formal sample size calculation is a notable limitation that reviewers and readers may question.
8.
HIGHreporting
In the Methods, Statistical analysis section, clarify that the statement about 555 participants expected to complete is an operational expectation, not a formal power calculation.
The current wording could be misinterpreted as a power analysis, which the paper explicitly denies elsewhere.
9.
MEDIUMreporting
In the Methods, Statistical analysis section, explicitly describe how missing data and early discontinuations were handled in the time-to-event analyses (e.g., censoring rules).
Transparency about missing data handling strengthens the statistical reporting and addresses a common reviewer concern.
10.
MEDIUMreporting
In the Results, add the number of participants who discontinued due to adverse events in the main text or a table.
This is a key safety metric that is currently not prominently reported.
11.
MEDIUMreporting
In the Discussion, address the generalizability of the findings to older patients, given the median age of 61 years and the increasing prevalence of ESKD in older populations.
This would strengthen the discussion of the trial's applicability.
12.
MEDIUMreporting
In the main text, include a CONSORT flow diagram (or ensure the referenced figure is clearly labeled as such) to enhance reporting completeness.
A CONSORT flow diagram is a standard expectation for randomized trials and improves transparency.
13.
MEDIUMethics
In the Methods, Study design and oversight section, provide the specific IRB approval numbers or state that they are available in the supplementary appendix.
Specific approval identifiers increase transparency and verifiability of ethical oversight.
14.
MEDIUMreporting
In the Methods, clarify the role of the Data and Safety Monitoring Committee and whether any interim analyses were planned.
This is important for understanding trial oversight and potential bias.
15.
LOWcopyedit
In Table 1, Length of study row, add a space between the number and the percentage: change '89(38.7)' to '89 (38.7)'.
Consistent spacing improves table readability.
16.
LOWcopyedit
In Table 2, All-cause death row, remove the percent sign inside the parentheses for consistency: change '12 (5.2%)' to '12 (5.2)'.
Consistent formatting avoids confusion about whether the value is a count or percentage.
17.
LOWdata code
In the Data availability statement, specify the exact timeframe for data availability after approval (e.g., 'within 6 months after signing the Data Use Agreement').
A concrete timeframe improves the actionability of the data access statement.

Full text (49,537 chars)Analyzed: Aug 16, 2026