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 Belimumab for Prevention of Chronic Graft-versus-Host Disease Following Allogeneic Hematopoietic Cell Transplantation (NCT03207958), a na phase 1 study. The primary outcome is Safety and Tolerability of Belimumab as Prophylaxis of Chronic GvHD in Subjects Following alloHCT as Measured by Number of Participants Who Experience Each Adverse Event.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03207958 |
| Phase | Phase 1 |
| Condition | Graft Vs Host Disease, Graft-versus-host-disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Washington University School of Medicine |
| Results posted | Yes |
2. Clinical Question
The study asks whether belimumab can be given as prophylaxis after allogeneic hematopoietic cell transplantation (alloHCT), with the principal focus on safety and tolerability and a secondary interest in preliminary efficacy. The registry describes this as a pilot and feasibility study. Its rationale is based on the role of B cells and BAFF signaling in the development of chronic graft-versus-host disease (GvHD); that rationale explains the question but is not itself evidence of a treatment effect.
Population
Subjects meeting eligibility criteria after alloHCT. The registry enrollment is 10. The specific eligibility criteria are not reported in the registry record.
Intervention
Intravenous belimumab, starting between Day +30 and Day +80 after alloHCT. The planned course is 3 doses every 2 weeks, followed by 4 monthly doses, for a total of 7 doses over 6 months.
Comparator
There is no control group in this single-group study. Allocation is listed as NA, and masking as none, so the record does not describe a randomized or blinded comparison.
Primary question
How many participants experience each adverse event during treatment and through 30 days after treatment ends, with adverse events graded according to CTCAE v4.03?
The registry also lists chronic and acute GvHD, overall survival, relapse, corticosteroid requirements, and alternative treatment modalities among the secondary outcomes. Results for those outcomes are not reported in the registry record, so the principal question that can be assessed from the posted counts is safety reporting, not comparative prevention of GvHD.
3. Trial Design
This is a Phase 1, single-group pilot study sponsored by Washington University School of Medicine. The registry lists an enrollment of 10 and a completed status. The study start date is 2018-05-16, and the primary completion date is 2022-06-04. These dates describe the registry record; they do not by themselves establish when each participant began or finished treatment.
Participants meeting eligibility criteria were to start belimumab between Day +30 and Day +80 after alloHCT. The planned intravenous regimen consisted of 3 doses at 2-week intervals, followed by 4 doses at monthly intervals. The total planned course was 7 doses over 6 months. The eligibility criteria and the number of participants who completed all planned doses are not reported in the registry record.
The design has one belimumab group and no concurrent control arm. Allocation is recorded as NA, the model as single group, and masking as none. Consequently, the results cannot provide a like-for-like comparison with usual care or another treatment. Changes in clinical status over time cannot be separated from the effects of transplantation, other care, or the natural course of illness using this design alone.
The primary outcome concerns the number of participants who experience each adverse event. Its observation period runs from treatment start through 30 days after treatment completion. The listed median follow-up is 205 days, with a full range of 56-229 days. The registry also lists 11 outcome measures overall, including secondary clinical outcomes, but reports 0 analyses. Detailed analysis procedures and results for the secondary outcomes are not reported in the registry record.
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 | Belimumab |
|---|---|
| STARTED | 10 |
| COMPLETED | 8 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Belimumab |
|---|---|
| Adverse Event | 1 |
| Relapsed lymphoma | 1 |
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 | Belimumab |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | years | 55.5 (32 to 69) |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 10 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 10 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Safety and Tolerability of Belimumab as Prophylaxis of Chronic GvHD in Subjects Following alloHCT as Measured by Number of Participants Who Experience Each Adverse Event, measured over From start of treatment through 30 days following the completion of treatment (median length of follow-up 205 days, full range 56-229 days).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is safety and tolerability, measured as the number of participants who experience each adverse event. This participant-count approach describes how many people were affected by each reported event; it is not a measure of the total number of event episodes. The record states that events were graded according to CTCAE v4.03 and observed from treatment start through 30 days following treatment completion. Median follow-up was 205 days, with a full range of 56-229 days.
The registry’s collection rules matter when interpreting the counts. Adverse events below CTCAE grade 3 were not collected unless they met the definition of a serious adverse event. Events not designated as being of special interest were also not collected unless they met that serious-event condition. Special-interest adverse events were to be recorded regardless of grade, including events thought to be related to chronic GvHD. The protocol’s list of special-interest events is not reported in the registry record.
Safety and tolerability are appropriate concerns for a Phase 1 pilot because the study is assessing the experience of participants receiving the regimen. However, the endpoint does not on its own establish whether belimumab prevents chronic GvHD. The registry’s primary outcome title refers to each adverse event, but the posted summary does not provide a complete event-by-event account or a comparative safety estimate.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted adverse-event summary lists 10 participants at risk in the belimumab group. It records 1 participant affected by a serious adverse event and 5 participants affected by other adverse events. The listed top serious-event terms are Diarrhea and Confusion, each shown as 10.0%. The record also lists 2 deaths. These are descriptive counts; the registry information does not establish whether any event or death was caused by belimumab.
The serious-event and other-event counts should not be added together. The record does not say whether the categories overlap, and the count of participants affected is not necessarily a count of event episodes. Nor should the two listed serious-event terms be interpreted as a complete list of all serious events. The posted summary identifies them as the top terms, but fuller event-level detail is not reported in the registry record.
The outcome observation period begins with treatment and continues through 30 days after treatment ends. Median follow-up is 205 days, with a full range of 56-229 days. The adverse-event collection rules exclude some lower-grade events, subject to exceptions for serious and special-interest events. Thus, the recorded counts do not represent every symptom or health event that may have occurred during follow-up.
This single-group study has no concurrent control group, so the counts cannot quantify how event experience differs from that under another treatment or no belimumab. The registry reports 0 analyses, and it does not provide confidence intervals, hypothesis tests, or adjusted estimates for these counts. The precision of any underlying event frequency therefore cannot be assessed from an inferential analysis in the record.
The study’s broader clinical question concerns chronic GvHD prevention, but results for chronic GvHD incidence or severity, acute GvHD, survival, relapse, corticosteroid requirements, and alternative treatment modalities are not reported in the registry record. The stated hypothesis and biological rationale are not outcome findings. On the posted information, the supportable interpretation is limited to the listed safety counts and the study’s design; no comparative efficacy conclusion follows.
9. Statistical Methods Explained
The registry describes a single-group study and reports 0 analyses. This means the posted information includes descriptive safety counts, but no reported statistical comparison or model-based estimate. General statistical explanations below clarify what those methods could contribute; they are not claims that the registry used them.
What does a participant count represent?
The primary outcome is expressed as the number of participants who experience each adverse event. A participant count answers how many people were affected, rather than how many separate episodes occurred. If one participant experienced repeated episodes of the same event, a participant-level count would not necessarily distinguish those episodes. The registry does not provide episode-level details, so the posted counts should be read at the participant level.
Counts are direct and easy to interpret, especially in a pilot study. They do not, by themselves, describe uncertainty with the same detail as an estimate accompanied by a confidence interval. A confidence interval is a range of values compatible with the observed data under a specified statistical method. General statistical principle: intervals are especially useful when sample sizes are small because a point estimate alone can give a misleading impression of precision. No confidence intervals are reported for the adverse-event counts in the registry record.
Why does the single-group design matter?
With one treatment group and no control group, the observed counts describe participants who received belimumab under the study conditions. They do not estimate the difference between belimumab and a comparator. General statistical principle: a concurrent comparison can help distinguish treatment-associated outcomes from outcomes that might also occur because of the underlying condition, transplantation, other care, or time. Without that comparison, causal attribution is not supported by the design alone.
Allocation is listed as NA, the model is single group, and masking is none. There is therefore no randomized allocation between treatment arms described in the record. The registry does not report a protocol for controlling other sources of variation or a statistical adjustment intended to address them. Those details are not reported in the registry record.
How should event ascertainment be considered?
The primary outcome is limited by its collection rules. Events below CTCAE grade 3 were generally not collected unless they met the serious-adverse-event definition. Events not identified as special-interest events were also subject to that grade threshold, while special-interest events were recorded regardless of grade. As a result, the recorded counts reflect the specified monitoring and reporting rules rather than an unrestricted inventory of every health event.
General statistical principle: incomplete or selective ascertainment can affect estimates of event frequency. The direction and size of that effect cannot be inferred without knowing which events were not collected and how they were distributed. The registry provides the broad collection rules, but the full special-interest list and participant-level event data are not reported in the registry record.
What can the listed analysis information establish?
The registry lists 11 outcome measures and 0 analyses. Secondary outcomes include chronic and acute GvHD incidence and severity, overall survival, relapse rate, corticosteroid requirements for chronic GvHD, and alternative treatment modalities for chronic GvHD. The record does not report analysis populations, statistical models, endpoint-specific denominators beyond the safety group at risk, or inferential results for these outcomes. Their methods and findings are therefore not available for statistical evaluation from this record.
When many outcomes are examined, the chance of at least one apparently notable result can rise if each is tested separately. General statistical principle: multiplicity procedures can control that risk, but they depend on a prespecified testing strategy and the intended interpretation of the outcomes. The registry does not report a multiplicity adjustment or a testing hierarchy. With 0 analyses reported, no claim about how multiplicity was handled can be made.
What do the sample-size assumptions mean?
The registry includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. For time-to-event outcomes, the illustration refers to a total number of events; for other outcomes, it refers to participants per arm. These are planning assumptions, not a description of the single-group study’s observed results. No calculated planning values are reported in the registry record.
General statistical principle: a sample-size illustration estimates the scale of a future study under its assumptions. It is not observed power, and it does not show that a treatment effect exists. If the assumed effect is based on an unstable estimate from a small pilot, planning estimates can be uncertain. The registry record does not report a sample-size justification for the pilot, nor does it report enough outcome estimates to evaluate such a justification.
Overall, the posted information supports descriptive reading of the listed adverse-event counts and the stated observation rules. More detailed inference would require analysis methods and outcome data that are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 11 outcome measures, spanning safety, chronic and acute GvHD, survival, relapse, corticosteroid requirements, and alternative treatment modalities. It reports 0 analyses. A multiplicity plan, such as a hierarchy of outcomes or an adjustment for multiple statistical tests, is not reported in the registry record. Without reported analyses and a stated testing strategy, it is not possible to determine whether multiplicity was considered or how any result across outcomes should be interpreted.
Missing-data handling is not reported in the registry record. The record does not state how missing outcome observations, incomplete follow-up, or withdrawal from treatment were handled in analyses. It also does not describe an analysis population, such as whether all enrolled participants or only participants who received treatment were included in each outcome calculation. These omissions do not establish that data were missing; they mean that the registry information does not describe how missingness or analysis inclusion was addressed.
The safety endpoint has defined collection rules: some lower-grade events were not collected unless they met the serious-event definition, and special-interest events were recorded regardless of grade. That is an ascertainment rule, not a general missing-data method. The count of participants affected by an event should therefore be interpreted in light of those rules, not as a complete count of every possible adverse event. The record does not provide event-level data or outcome-specific denominators for the secondary endpoints.
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 |
|---|---|---|---|
| Belimumab | 1 | 10 | 10.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Belimumab | 2 of 10 |
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 |
|---|---|
| Belimumab | 5 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | Belimumab |
|---|---|---|
| Diarrhea | Gastrointestinal disorders | 1 of 10 |
| Confusion | Psychiatric disorders | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Belimumab |
|---|---|---|
| Lymphocyte count decreased | Investigations | 3 of 10 |
| Eye pain | Eye disorders | 1 of 10 |
| Facial pain | General disorders | 1 of 10 |
| Alanine aminotransferase increased | Investigations | 1 of 10 |
| Alkaline phosphatase increased | Investigations | 1 of 10 |
| Aspartate aminotransferase increased | Investigations | 1 of 10 |
| Platelet count decreased | Investigations | 1 of 10 |
| Hyponatremia | Metabolism and nutrition disorders | 1 of 10 |
| Rash maculo-papular | Skin and subcutaneous tissue disorders | 1 of 10 |
Serious events with the highest arm-level rate: diarrhea (10.0%), confusion (10.0%).
The belimumab group has 10 participants listed at risk. The safety summary reports 1 participant affected by a serious adverse event and 5 affected by other adverse events. It lists Diarrhea and Confusion as the top serious-event terms, each at 10.0%, and lists 2 deaths. These figures are reported counts and terms; they do not establish that belimumab caused any event or death.
The serious-event and other-event participant counts should not be summed: the registry does not state whether the groups overlap. The top serious-event terms are not necessarily a complete listing of all serious events. The record also does not provide enough detail to determine the relationship between the listed deaths and the adverse events or treatment.
Collection was not comprehensive for all grades: events below CTCAE grade 3 were generally excluded unless serious, while special-interest events were recorded regardless of grade. Thus, the counts describe events captured under the registry’s stated rules. They are not a full inventory of all health events during follow-up, and without a comparator they cannot show whether the observed counts differ from those under another approach.
12. What the Result Does, and Does Not, Mean
The record establishes that this Phase 1 pilot evaluated belimumab in a single group after alloHCT and that its primary outcome was safety and tolerability measured through participant-level adverse-event counts. The posted safety summary includes a group at risk of 10, 1 participant affected by a serious adverse event, 5 affected by other adverse events, two listed top serious-event terms at 10.0% each, and 2 deaths. The observation period and event-collection rules help define what those counts represent.
Those findings do not establish whether belimumab prevents chronic GvHD, changes its severity, or affects acute GvHD, survival, relapse, corticosteroid use, or alternative treatment needs. Although these outcomes appear in the registry, their results are not reported in the registry record. The study’s biological rationale and central hypothesis describe why the investigators pursued the question; they are not evidence that the hypothesized effect occurred.
The design also limits causal interpretation. With no concurrent comparator, the observed events cannot be contrasted with what might have happened under another treatment or without belimumab. The record reports no inferential analyses or confidence intervals for the safety counts. It therefore does not quantify uncertainty through a statistical comparison, and it does not support a claim that an event rate is higher or lower than an alternative.
General statistical principle: a pilot can provide descriptive experience and inform the design of later studies, but small descriptive datasets can yield imprecise estimates. The registry does not report a sample-size justification or comparative outcome estimates. The appropriate reading is therefore narrow: the posted information describes the safety counts collected under this study’s rules, while efficacy and comparative safety conclusions remain unavailable from the reported results.
13. Why This Trial Matters Statistically
This study is statistically important as an example of how design determines the reach of a result. A single-group pilot can describe events observed among participants receiving a planned regimen, but it cannot provide the same comparative evidence as a controlled design. The absence of a comparator is especially relevant when outcomes may also arise in the context of alloHCT or other care.
The primary endpoint is a count of participants experiencing each adverse event, while the collection rules exclude some lower-grade events and treat special-interest events differently. That distinction illustrates why a number must be interpreted alongside its ascertainment definition. Counts are not interchangeable with event episodes, and a list of top terms is not necessarily a full account of all events.
The registry also lists multiple clinical outcomes but reports 0 analyses. This makes the boundary between planned questions and demonstrated results important: a listed outcome is not a reported finding. Likewise, a biological rationale and a central hypothesis explain the study’s motivation but do not substitute for outcome estimates or a comparator.
Finally, planning assumptions and sample-size illustrations have a different role from observed study results. They concern hypothetical future designs and depend on stated assumptions; they are not evidence of treatment effect or observed power. This distinction helps readers separate feasibility and safety description from confirmatory comparative inference. In this record, the available information supports a careful descriptive account, while broader conclusions await reported outcome analyses.
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 main limitation is the single-group design. Because no concurrent control arm is reported, the adverse-event counts cannot be compared directly with another treatment or with no belimumab. The registry lists allocation as NA and masking as none; it does not describe a randomized or blinded comparison. As a result, the record cannot establish that the observed events were caused by the intervention or that clinical outcomes differ from an alternative.
The registry enrollment is 10, which makes the safety findings a small pilot description rather than a broad estimate of event experience. No confidence intervals or inferential analyses are reported for the posted counts. The serious-event and other-event categories may overlap, and the record does not provide participant-level event details. The top serious-event terms do not establish a complete event inventory.
Event ascertainment was selective by design: lower-grade events were generally excluded unless serious, and special-interest events were recorded regardless of grade. The list of special-interest events is not reported in the registry record. The resulting counts should not be interpreted as capturing every health event during the observation period.
Results for the listed GvHD, survival, relapse, corticosteroid, and alternative-treatment outcomes are not reported in the registry record. Analysis populations, missing-data methods, multiplicity procedures, and a sample-size justification are also not reported. The record therefore leaves important questions about the precision, completeness, and analysis of outcomes unresolved.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Belimumab for Prevention of Chronic Graft-versus-Host Disease Following Allogeneic Hematopoietic Cell Transplantation — NCT03207958.
- Registry record last updated 2026-04-20; status last verified 2026-04.
- Results first posted 2026-04-20.
- 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
NCT03207958 is a completed Phase 1, single-group pilot of belimumab for prevention of chronic GvHD after alloHCT. Washington University School of Medicine is listed as sponsor. The registry records enrollment of 10, a study start date of 2018-05-16, and a primary completion date of 2022-06-04.
The planned regimen began between Day +30 and Day +80 after transplantation and consisted of 7 intravenous doses over 6 months. The primary outcome assessed the number of participants experiencing each adverse event from treatment start through 30 days after treatment completion. The listed median follow-up was 205 days, with a full range of 56-229 days.
The safety summary lists 1 participant with a serious adverse event, 5 with other adverse events, Diarrhea and Confusion as top serious-event terms at 10.0% each, and 2 deaths. The registry reports 0 analyses. Results for the listed secondary clinical outcomes and further analysis details are not reported in the registry record.