This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Natalizumab and Chronic Inflammation (NCT05177718), a na phase 4 study. The primary outcome is Effect of Natalizumab on Magnetic Resonance Imaging Measures of Blood Brain Barrier Permeability: K-trans.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05177718 |
| Phase | Phase 4 |
| Condition | Multiple Sclerosis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Vanderbilt University Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
People with multiple sclerosis. The registry describes a treatment arm of patients with multiple sclerosis, while its enrollment field reports 1 and its outcome description says analysis was not completed because only one participant completed. These entries do not establish a fully analyzed study population.
Intervention
Natalizumab, listed as a 300 MG in 15 ML injection. The arm description specifies monthly intravenous infusion at a dose of 300 mg.
Comparator
No comparator arm is reported. The study model is single group, and allocation is listed as NA; this is not a randomized comparison.
Primary question
Whether MRI K-trans measures of blood-brain-barrier permeability change between baseline and post-treatment scans at month 3 and month 12. The registry does not report an analyzed change or an estimate of its precision.
The broader study description concerns whether natalizumab can restore blood-brain-barrier integrity and repair subtle barrier leakages. That description states the research aim; it is not evidence that either effect occurred. A secondary outcome concerns MRI Pool Saturation Ratio (PSR), a measure of myelin integrity. The registry lists 3 outcome measures, but it does not provide results for the primary or secondary measures.
The clinical question is therefore an intended within-group MRI assessment, rather than a comparison of natalizumab with another treatment or with no treatment. Without analyzed MRI values, the direction and size of any change cannot be determined from the registry record.
3. Trial Design
The study is listed as phase 4 and uses a single-group model. Allocation is recorded as NA, and masking is listed as none. These features mean that the record does not describe a randomized, masked comparison between treatment groups. A control group and a like-for-like contrast are not reported.
Natalizumab is the listed intervention. The treatment-arm description says that patients with multiple sclerosis received monthly intravenous infusions at a dose of 300 mg. The enrollment field reports 1, whereas that arm description refers to 30 patients. The outcome description also says that only one participant completed (each arm), despite the record describing a single-group study. These entries are not reconciled in the registry record, so they should not be treated as a coherent account of the number planned, enrolled, or analyzed.
The study start is recorded as 2022-09-16, and primary completion as 2023-04-05. The status is terminated. The primary outcome timeframe is 12 months, with planned comparisons of K-trans between baseline and scans at month 3 and month 12. The record does not explain the reason for termination or how the stated timeframe relates to the dates recorded.
The registry does not report a protocol-level rationale for the design, a sample-size justification, or a statistical analysis plan. Since only one group is described and outcome analysis was not completed, the record cannot support a treatment-versus-control effect estimate.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Treatment Single Arm |
|---|---|
| STARTED | 1 |
| COMPLETED | 0 |
| NOT COMPLETED | 1 |
Analysis population for the primary outcome, as defined in the registry: Data analysis was not completed because only one participant completed (each arm) and disclosing data could violate privacy interests.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Treatment Single Arm |
|---|---|---|
| Participants analysed | 1 | |
| Age, Customized: 46 | years | 1 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Effect of Natalizumab on Magnetic Resonance Imaging Measures of Blood Brain Barrier Permeability: K-trans, measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is an MRI measure called K-trans, identified as a measure of blood-brain-barrier permeability. The registry describes assessing changes from baseline (pre-treatment) to post-treatment scans at month 3 and month 12. Its stated timeframe is 12 months. No unit or statistical parameter is reported.
General explanation: An endpoint is a defined measurement used to address a study question. K-trans is used in this study as an imaging measure related to movement across the blood-brain barrier. A comparison of measurements over time can describe whether the imaging measure changed within the observed group. That change alone does not establish that treatment caused it, particularly when there is no control group to help distinguish treatment effects from changes over time, measurement variability, or other influences.
The registry does not report the baseline or follow-up K-trans values, the calculated change, or an uncertainty interval. It also does not describe how scans were processed or how a change would be summarized statistically. A secondary outcome is PSR, identified as an MRI measure of myelin integrity, but no result for that measure is reported either.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The main statistical fact is that the primary outcome analysis was not completed. The registry says this was because only one participant completed (each arm) and disclosing data could violate privacy interests. Consequently, there is no posted K-trans estimate, no reported change from baseline, and no measure of uncertainty such as a confidence interval. The absence of an estimate means the direction, magnitude, and precision of any MRI change cannot be evaluated from the registry results.
The study is described as single group, with no comparator and no masking. A within-group change, if it had been reported, would describe measurements over time in the treated group. Without a control group, it could not by itself separate a treatment-associated change from other explanations. In this record, even such a change estimate is not available.
The enrollment field reports 1, while the treatment description refers to 30 patients and the primary outcome text says only one participant completed (each arm). The record does not reconcile these statements. The completion statement should not be taken as proof of an analyzable group comparison: the design is listed as single group, and the registry reports zero analyses. The intended number, actual enrollment, and number of completed scans are not fully clarified.
For the same reason, the safety counts have limited scope. The record lists one person at risk for serious adverse events and zero with a serious adverse event; it lists one at risk for other adverse events and zero with another adverse event, and reports zero deaths. Those are registry counts, not comparative estimates. The record does not report event definitions, attribution, or a comparator against which to judge differences.
Overall, the posted record documents a study objective and a planned MRI outcome, alongside a terminated status and an uncompleted outcome analysis. It does not provide evidence that K-trans or PSR changed, nor does it provide a precise estimate of any treatment effect. It also cannot establish the absence of effects: lack of analyzed outcome data is not equivalent to a finding of no change.
9. Statistical Methods Explained
What does a within-group change measure?
General explanation: In a single-group study, measurements made before and after treatment can be compared within the same group. Such a comparison describes how the measured outcome varies over time among participants with recorded measurements. It does not provide the counterfactual comparison that a control group could offer: what might have happened over the same period without the study treatment. Changes can also reflect natural variation, other care, measurement procedures, or selective availability of follow-up data.
For this study, the primary outcome description specifies K-trans at baseline and at month 3 and month 12 after treatment. This defines the intended measurement schedule, but the registry does not report the observations or an analysis of change. The schedule alone cannot establish whether change occurred.
Why does precision matter?
General explanation: An estimate describes the observed effect, while a confidence interval describes uncertainty around that estimate under the assumptions of the analysis. A narrow interval generally indicates more precision than a wide interval. With very sparse outcome data, estimates may be unstable or impossible to calculate meaningfully. This record reports no K-trans estimate and no confidence interval, so the precision of any change cannot be assessed.
What does the registry say about the analysis?
The record lists zero analyses. It states that data analysis was not completed because only one participant completed (each arm) and disclosing data could violate privacy interests. No analysis model, covariate adjustment, handling of repeated measurements, or statistical test is reported in the registry record. Those details should not be inferred from the planned MRI timepoints.
General explanation: Repeated measurements from the same participant are related, rather than independent observations. An analysis of change over time should account for that structure when the available data permit it. The registry does not state whether such a model was planned or used, and it reports no outcome analysis from which to assess the method.
What can a planning calculation tell a reader?
The registry describes sample-size illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the target effect is a stated fraction of the observed effect. It also distinguishes participant-per-arm calculations from total-event calculations for time-to-event outcomes. These are described as planning illustrations, not as the trial's own design.
General explanation: A sample-size calculation estimates the data volume a future study might need under specified assumptions. It is not an analysis of the current study and does not show that an effect was observed. A calculation based on an observed effect is only as informative as that effect estimate and its underlying data. The registry does not report an analyzed K-trans effect, and it does not report the trial's own sample-size justification. Thus, the planning assumptions do not fill the gap left by the absent outcome analysis.
Why is over-dispersion relevant in general?
General explanation: Over-dispersion occurs when count data vary more than a statistical model expects. Ignoring it can make uncertainty look smaller than it is. This is a general issue for some count outcomes, but the primary endpoint is an MRI measure, and the registry does not report an analysis that would allow a model-adequacy assessment. No claim about over-dispersion in this study is supported by the record.
In short, the registry identifies the intended endpoint, schedule, and broad planning assumptions, but it does not report the numerical outcome data or a completed statistical analysis. No recalculated effect estimate can be drawn from the posted record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 3 outcome measures. The primary measure is K-trans for blood-brain-barrier permeability, and a secondary measure is PSR for myelin integrity. The descriptions of the other outcome measures are not reported in the registry record. No results are reported for the listed MRI outcomes.
When a study evaluates multiple outcomes or timepoints, the chance of obtaining at least one apparently notable result can be affected by how many comparisons are made. General explanation: A prespecified multiplicity strategy can help define how evidence should be interpreted across multiple outcomes or tests. The registry record does not report whether an adjustment strategy was planned. Because no outcome analyses were completed, there are no reported statistical tests or multiplicity-adjusted results to interpret.
The record does not describe methods for handling missing measurements, incomplete scans, or participants who did not complete follow-up. It states that data analysis was not completed because only one participant completed (each arm) and disclosing data could violate privacy interests. It does not specify whether missingness affected this decision, how many planned scans were unavailable, or how any missing observations would have been handled.
The registry also does not define an analysis population, such as which participants or scans would be included in a primary analysis. The enrollment field, arm description, and completion statement are not fully consistent, and the record does not resolve that inconsistency. Without a stated analysis population and completed outcome data, the results cannot be generalized beyond the information explicitly recorded.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Treatment Single Arm | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment Single Arm | 0 of 1 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment Single Arm | 0 of 1 |
The registry reports zero participants with a serious adverse event among one at risk, zero participants with another adverse event among one at risk, and zero deaths. These are the reported group counts. The record lists no serious adverse-event terms.
These counts should be read as descriptive safety reporting, not as evidence from a comparative safety analysis. The study is listed as a single group, and no comparator is reported. The registry does not provide event definitions, severity details beyond the serious-event grouping, attribution to treatment, or the period over which events were collected. It also does not explain how the privacy concern affected the amount of safety information disclosed.
A reported count of zero means that the registry lists no event in that category for the reported group; it does not establish that an event is impossible or that risk is absent. The small amount of reported participant information and the absence of detailed safety methods limit how much can be concluded. No broader safety conclusion can be drawn from these counts alone.
12. What the Result Does, and Does Not, Mean
This record documents a study of natalizumab and MRI measures in multiple sclerosis, with a primary focus on K-trans as a measure of blood-brain-barrier permeability. It specifies an intended comparison between baseline and scans at month 3 and month 12, and names PSR as a secondary MRI measure of myelin integrity. The registry status is terminated.
What the result does mean is limited: the registry reports that the primary outcome analysis was not completed because only one participant completed (each arm) and disclosure could violate privacy interests. It therefore provides no numerical estimate of K-trans change, no uncertainty interval, and no analyzed secondary outcome result. No treatment effect can be estimated from these posted outcome data.
What it does not mean is that there was no change. An unreported or uncompleted analysis cannot distinguish no effect from an effect that could not be estimated or disclosed. Nor can the study establish that any observed change would be caused by treatment, because no comparator is reported. The stated research aim should not be mistaken for a finding.
The differences among the enrollment field, arm description, and completion wording remain unresolved in the registry record. That uncertainty further limits interpretation of who was enrolled and what follow-up information was available. The safety counts are also descriptive and do not establish comparative risks.
Accordingly, the record is most useful for understanding the study's intended question, design, outcome schedule, and reporting limitations. It does not support a conclusion about the size, direction, or precision of a treatment-associated MRI effect.
13. Why This Trial Matters Statistically
This study illustrates why a registered research question and an analyzable result are different things. The record identifies an imaging endpoint, a treatment schedule, and planned follow-up measurements, but it does not report the primary outcome analysis. Without an effect estimate and its uncertainty, readers cannot evaluate the magnitude or precision of change.
The single-group design also matters to interpretation. Measurements over time can describe what happened in the group with available data, but a treatment effect is a causal comparison. Without a control group, other explanations for change cannot be separated in the same way as in a comparative design. In this record, the outcome analysis was not completed, so even a descriptive change is unavailable.
There is also a practical reporting lesson in the mismatch between enrollment, arm-description, and completion entries. Clear distinctions among planned enrollment, actual enrollment, completed follow-up, and the analysis population are important for judging what evidence a study can provide. The registry does not resolve those details.
Finally, privacy protection can constrain reporting when very little participant information is available. The registry explicitly cites privacy interests as part of the reason data were not disclosed. That context helps explain why results may be absent, but it does not substitute for an estimate or make the missing analysis interpretable. Statistically, the record is informative about the limits of the available evidence rather than about the treatment effect.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation is the absence of a completed primary outcome analysis. The registry provides no K-trans values, change estimate, confidence interval, or statistical test. It also reports no results for PSR or the other listed outcome measures. This prevents assessment of both effect size and precision.
The study is single group, with allocation listed as NA and masking as none. No comparator is reported, so any within-group change would not by itself establish a causal treatment effect. The record also does not report an analysis model, a statistical analysis plan, or a sample-size justification.
Enrollment is reported as 1, while the treatment-arm description refers to 30 patients. The outcome text says that only one participant completed (each arm), although the design is described as single group. The registry does not reconcile these statements or clarify the number with completed MRI measurements. The reason for termination is not reported in the registry record.
Other limitations include the absence of reported methods for missing data, definition of the analysis population, image-processing procedures, multiplicity handling, and detailed adverse-event ascertainment. These omissions mean that neither outcome analyses nor safety counts can be evaluated against a fuller protocol description.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Natalizumab and Chronic Inflammation — NCT05177718.
- Registry record last updated 2024-04-18; status last verified 2024-04.
- Results first posted 2024-04-18.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT05177718 is a phase 4, single-group study of natalizumab in multiple sclerosis. The intervention description specifies monthly intravenous infusions at a dose of 300 mg. The primary outcome is K-trans, an MRI measure related to blood-brain-barrier permeability, assessed from baseline to month 3 and month 12. PSR, an MRI measure of myelin integrity, is listed as a secondary outcome.
The registry records the study as terminated and reports that the primary analysis was not completed because only one participant completed (each arm) and disclosing data could violate privacy interests. No primary or secondary outcome estimates are reported. Enrollment, treatment-arm, and completion entries are not fully consistent. Safety counts list zero serious adverse events, zero other adverse events, and zero deaths in the reported group.