Effects of Ocrelizumab on B-cell Tolerance Defect in Relapsing Multiple Sclerosis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Ocrelizumab on B-cell Tolerance Defect in Relapsing Multiple Sclerosis (NCT04261790), a na phase 4 study. The primary outcome is Change in Peripheral B-cell Tolerance Checkpoints in People With MS Before and After Ocrelizumab Therapy..

2. Clinical Question

The biological question concerns peripheral B-cell tolerance checkpoints: processes associated with limiting autoreactive B cells. The planned assessment used antibodies produced by isolated B cells to determine the frequencies, expressed as percentages, of polyreactive and anti-nuclear clones. It covered new emigrant/transitional B cells and mature naive B cells.

The registry describes a hypothesis about how ocrelizumab treatment might relate to these checkpoints in relapsing multiple sclerosis. That hypothesis is not itself an outcome. The primary endpoint data were not collected: the registry states that antibodies from the immune cells could not be cloned for analysis. As a result, the record cannot answer whether the measured frequencies changed over the planned observation period.

This is a before-and-after question within one group, not a comparison of ocrelizumab with another treatment or with no treatment. The record therefore does not provide a concurrent control for separating treatment-associated changes from time-related changes or other influences.

3. Trial Design

This was a Phase 4, open-label, single-group study sponsored by Johns Hopkins University. The registry lists an enrollment of 10 and a condition of relapsing-remitting multiple sclerosis. The study began on 2020-08-01, had a primary completion date of 2024-10-31, and is marked completed.

Participants were assigned no randomized or otherwise described allocation: the allocation entry is NA. The masking entry is none, so the study was open-label. There was no like-for-like control arm. The registry describes all participants as receiving ocrelizumab, rather than being assigned to distinct study arms.

The intervention description says participants would receive two courses of ocrelizumab (Ocrevus) for one year, then stop medication and be monitored for return of disease activity. Participants experiencing a return of disease activity could go back on medication. The registry does not report further details of the course schedule or monitoring visits.

The primary outcome timeframe is baseline and 18-24 months. The endpoint was intended to track frequencies of specified B-cell clones using antibodies from isolated B cells. Secondary outcomes listed in the record include return of disease activity, change in disability assessed by the Expanded Disability Status Scale, and change in quality of life assessed by the Neuro-QoL Fatigue T-score. Results for those secondary outcomes are not reported in the registry record.

The record does not report the rationale for the enrollment target, a statistical analysis plan, or the intended analysis model. It also does not report a separate comparator or a protocol-defined approach for interpreting results after medication was stopped. These omissions limit what can be inferred about the planned statistical evaluation beyond the stated single-group, before-and-after outcome.

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

Analysis population for the primary outcome, as defined in the registry: Data were not collected. None of the antibodies from the immune cells were able to cloned for analysis and no data were collected from the lab samples.

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.

6. Primary Endpoint

The registry lists the primary outcome as Change in Peripheral B-cell Tolerance Checkpoints in People With MS Before and After Ocrelizumab Therapy., measured over Baseline and 18-24 months.

The primary endpoint was the change in peripheral B-cell tolerance checkpoints in people with multiple sclerosis before and after ocrelizumab therapy. The planned measurement was based on antibodies produced by isolated B cells. Investigators intended to determine the frequencies, expressed as percentages, of polyreactive and anti-nuclear clones among new emigrant/transitional and mature naive B cells. The stated timeframe was baseline and 18-24 months.

These measurements were intended to characterize selected features of the B-cell population relevant to the study’s tolerance question. Looking at the frequencies of defined clone types can describe how the measured cell population is composed at each assessment. A within-participant comparison can, in principle, assess whether those measurements differ over time. This is a general description of the endpoint’s statistical purpose, not a claim that a change was observed.

The registry explicitly states that the primary outcome data were not collected. Antibodies from the immune cells could not be cloned for analysis, and no data were collected from the lab samples. Consequently, there is no reported baseline value, follow-up value, change estimate, or measure of uncertainty for this endpoint. The record cannot establish whether the planned frequencies increased, decreased, or stayed similar.

The use of a laboratory measurement does not by itself establish a clinical effect. The endpoint concerns cellular measurements, while the registry separately lists clinical outcomes such as disease activity, disability, and fatigue-related quality of life. Results for those other outcomes are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The design is a single-group before-and-after study. In general, this design measures participants at more than one time and describes changes within the same group. For a numeric endpoint, a paired analysis can account for the fact that two measurements from one person are related. That is a general statistical principle; the registry does not report a planned paired method or another analysis model for this study.

What a change estimate would represent

For the primary endpoint, the planned quantities were frequencies expressed as percentages of specified B-cell clone types at baseline and 18-24 months. If those measurements had been available, a change estimate could describe the within-participant difference between the assessments, or a group-level summary of those differences. The choice of summary and model affects the exact interpretation. The registry does not report which summary or model was intended.

A confidence interval is a way to express the precision of an estimate: it gives a range of values compatible with the data and the method used, under the method’s assumptions. Its width depends on factors such as the amount and variability of observed data. No confidence interval can be interpreted for this primary endpoint because the registry says the laboratory data were not collected. No p-value or other primary endpoint test result is reported either.

Why the single-group structure matters

A within-group change is not the same as a treatment-versus-control effect. In a randomized comparison, the concurrent control group can help account for changes that might have occurred over time without the intervention. This study has no separate comparison group, and its allocation is recorded as NA. Even if before-and-after values were available, observed changes would not by themselves isolate the effect of ocrelizumab from other influences. In this case, there are no primary endpoint values to describe such changes.

Open-label status means the study was not masked. Masking can matter when outcomes involve judgment or when awareness of treatment could influence behavior, reporting, or assessment. The planned primary outcome was a laboratory measurement, but the registry does not describe safeguards, laboratory blinding, or other analysis procedures. Those details are not reported in the registry record.

Precision, variability, and model choice

Statistical methods should reflect the form of the outcome and its variability. Frequencies are proportions, and measured proportions can vary with the number of cells examined and the distribution of cell types. A method designed for normally distributed measurements may not describe all proportion data well. More generally, over-dispersion occurs when variability exceeds what a chosen probability model expects; ignoring it can make uncertainty estimates too small. These are general considerations, not a description of the analysis performed in this study. The registry does not report the number of cells assessed, the observed variation, or a model for these measurements.

Repeated observations may also be correlated within each participant. A method that treats those observations as independent can misstate precision. A paired or repeated-measures approach can account for within-person structure, but the appropriate approach depends on the actual data and protocol. Neither an analysis plan nor a fitted model is reported in the registry record, and no primary data were available for such an analysis.

Sample size and planning

The registry lists enrollment of 10. It does not report a sample-size justification, target effect, or assumptions used to choose that enrollment. In general, sample-size planning depends on the outcome’s variability, the effect the study aims to detect, the statistical method, and the desired precision or error rates. These considerations cannot be reconstructed from the enrollment number alone.

A planning calculation based on an observed effect is not the same as a study’s original design justification. Nor is a planning sample size an observed measure of power. For this study’s primary endpoint, no observed effect is available because the laboratory outcome data were not collected. The registry record therefore does not support an effect-based interpretation of planning calculations for that endpoint.

What can be analyzed from this record

The posted outcome information supports describing the trial structure, the planned endpoint, the stated reason primary data were unavailable, and the reported adverse-event counts. It does not support estimating a B-cell frequency, a change from baseline, a treatment effect, or precision for the primary outcome. General statistical methods explain what could be done with suitable data; they do not substitute for measurements that were not obtained.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures, including the primary B-cell endpoint and secondary outcomes concerning return of disease activity, disability assessed by the Expanded Disability Status Scale, and quality of life assessed by the Neuro-QoL Fatigue T-score. It also records 0 analyses. The registry does not report a multiplicity strategy for interpreting several outcomes or several comparisons. In general, examining multiple outcomes can increase the chance of finding an apparently notable result by chance; prespecified testing plans or adjusted procedures can address that concern. No such plan is reported.

The key missingness issue for the primary endpoint is explicitly described: antibodies from immune cells could not be cloned for analysis, and no data were collected from the lab samples. This is not a reported set of partially observed primary measurements with some participant values missing. The endpoint data were not collected, so neither a complete-case analysis nor an imputation procedure can produce an observed primary outcome estimate from the registry record.

The record does not report whether participants had missing data for the listed secondary outcomes, how many contributed to any analysis, or how missing secondary measurements were handled. Results for those outcomes are not reported in the registry record. The number enrolled should not be treated as the analysis denominator for any outcome without reported participant-level outcome data.

Analysis populations are not reported in the registry record. There is no stated intention-to-treat, per-protocol, or safety population definition in the information available. The record also does not describe exclusions, withdrawals, or a method for handling participants who might have restarted medication after disease activity returned. These details would affect interpretation of any longitudinal outcome analysis, but they cannot be inferred from the intervention description.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists 10 participants at risk for serious adverse events and 0 affected. It lists 10 participants at risk for events in the other adverse-event category and 7 affected. Deaths are listed as 0. These are counts of participants, not a measure of event timing or duration.

The serious adverse-event count means that no serious adverse events are recorded among the 10 participants at risk in this registry summary. It does not establish that no such events could occur, and it does not describe how long participants were observed. The registry does not report serious adverse-event terms in the listed top-term field. Details of the other adverse events, including their specific terms, severity, timing, and whether events were considered related to treatment, are not reported in the registry record.

The 7 participants in the other adverse-event category should be read as a count in that category, separate from the serious adverse-event count. The registry does not provide enough detail to characterize those events further. These safety counts describe the recorded experience in this small enrolled group; they do not answer the primary question about B-cell tolerance checkpoints.

12. What the Result Does, and Does Not, Mean

The result that can be stated most directly is that the registry reports no collected data for the primary B-cell endpoint. The intended assessment was a change in the frequencies of polyreactive and anti-nuclear clones in specified B-cell populations from baseline to 18-24 months. Because the antibodies could not be cloned for analysis, there is no reported change estimate to interpret.

This does not mean that the study measured no change. It means that the registry explicitly says the laboratory measurements were not obtained. A lack of an estimate is not evidence that the true change was zero, nor does it establish that the biological hypothesis was supported. The direction and size of any change remain unknown in the registry record.

The study also does not provide a controlled estimate of the effect of ocrelizumab. It was open-label and single-group, with no separate comparison group. The study’s planned before-and-after endpoint could have described changes over time within the group, but such a comparison would not by itself establish what would have happened without treatment. In this case, the primary measurements are unavailable as well.

The registry’s discussion of a proposed biological explanation is a rationale for studying the question, not a finding from this trial. Similarly, the intervention description and secondary outcome names indicate what was planned or monitored; they do not establish results. Results for the listed secondary outcomes are not reported in the registry record.

The safety counts should be interpreted narrowly: 0 serious adverse events among 10 at risk, 7 participants with an event in the other category among 10 at risk, and 0 deaths. Those counts do not resolve the primary biological question and should not be generalized beyond the participants and observation reported.

In statistical terms, the record offers no estimate of the primary effect and therefore no precision assessment for that endpoint. It is not possible to determine whether an estimated effect was small, large, or uncertain, because no effect was estimated. The study’s completed status does not change this limitation: completion status describes the trial record, while the primary result remains unavailable.

13. Why This Trial Matters Statistically

This study illustrates an important distinction between a clearly stated research question and an answerable statistical result. The protocol description defines a specific laboratory question: whether selected peripheral B-cell clone frequencies differ between baseline and 18-24 months. But the registry states that the antibodies needed for analysis could not be cloned, leaving the primary outcome without data.

For biostatisticians and clinical researchers, this is a reminder that an endpoint’s operational measurement is as important as its biological rationale. A planned measure depends on successful collection, processing, and analysis of the material required to produce it. When the measurement cannot be completed, standard tools for estimating change, uncertainty, and association cannot recover the absent outcome.

The trial also demonstrates why design and measurement limitations should be separated. The single-group, open-label design would have restricted causal interpretation even if the planned pre-post data had been available. The laboratory failure creates a more fundamental limitation: there is no observed primary outcome to describe, regardless of the design’s capacity for causal inference.

Finally, the record distinguishes enrollment and completion from analytic evidence. Ten participants were enrolled and the study is marked completed, but these registry entries do not imply that the primary endpoint was successfully measured. Reporting the reason for unavailable data is useful because it prevents an absent result from being mistaken for a null change. It also identifies where the evidentiary chain stopped: before the planned primary statistical analysis could be performed.

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 most direct limitation is the absence of primary endpoint data. The registry states that antibodies from immune cells could not be cloned for analysis, so no laboratory measurements were collected. This prevents estimation of the planned B-cell frequency changes and makes it impossible to assess their precision.

The study enrolled 10 participants and had no separate comparison group. With a single group, any observed before-and-after pattern would not provide a direct treatment-versus-control contrast. The open-label design is another feature relevant to interpretation, while the registry does not report whether laboratory or outcome assessors were masked.

The intervention description includes stopping medication after two courses for one year, monitoring for return of disease activity, and the possibility of going back on medication if disease activity returned. The registry does not report how such treatment changes would be incorporated into analyses or how long each participant was followed. Those details could matter for interpreting longitudinal clinical outcomes.

Although the record lists 8 outcome measures, it reports 0 analyses. The secondary outcomes are named, but their results, analysis populations, and missing-data handling are not reported in the registry record. The registry also does not report the statistical analysis plan, a sample-size justification, or a multiplicity strategy. These omissions limit interpretation of the broader outcome set, in addition to the primary endpoint data failure.

Finally, the safety summary provides participant counts but not event terms or timing. The listed counts are useful as descriptive registry information, but the absence of further detail limits characterization of the events and the period over which they were observed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Effects of Ocrelizumab on B-cell Tolerance Defect in Relapsing Multiple Sclerosis — NCT04261790.
• Registry record last updated 2025-02-17; status last verified 2025-01.
• Results first posted 2025-02-17.
• 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.

18. Record Summary

NCT04261790 is a completed Phase 4, open-label, single-group study sponsored by Johns Hopkins University. It enrolled 10 people with relapsing multiple sclerosis. The intervention description specifies two courses of ocrelizumab for one year, followed by stopping medication and monitoring for return of disease activity, with the possibility of resuming medication if activity returned.

The primary endpoint was intended to assess changes in frequencies of selected polyreactive and anti-nuclear B-cell clones from baseline to 18-24 months. The registry states that antibodies from immune cells could not be cloned for analysis and no primary laboratory data were collected. It lists 8 outcome measures and 0 analyses; secondary outcome results are not reported in the registry record.

The safety summary lists 0 serious adverse events among 10 at risk, 7 participants with events in the other adverse-event category among 10 at risk, and 0 deaths. The record does not report a comparator group, a statistical analysis plan, or a sample-size justification.