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 T-Reg Cell Kinetics, Stem Cell Transplant, REGALE (NCT00578539), a na na study. The primary outcome is Median Percentage of Treg Cells at 1 Year Post Transplant.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00578539 |
| Phase | NA |
| Condition | Leukemia, Hodgkin Lymphoma, Non Hodgkin Lymphoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 24 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Baylor College of Medicine |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with blood-related disorders, including leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, and myeloproliferative disorders. The registry summary describes patients without a perfect-match sibling donor, for whom a best-matched related or unrelated donor could be considered. The record states that 24 patients enrolled; 13 had Treg values at 1 year and were included in the primary endpoint analysis.
Intervention
The study evaluates stem cell transplantation in a treatment program that lists ARA C, cyclophosphamide, MESNA, total body irradiation, Campath-1h, and stem cell infusion. The summary describes preparatory treatment before transplantation. The available intervention description does not give a complete account of the regimen, so its full sequence and details are not reported in the registry record.
Comparator
There is no separate comparator group in the posted design. The study is classified as single-group, and allocation is listed as NA. The registry record therefore does not describe a randomized or concurrent control comparison. A comparison with another treatment plan or population is not reported in the registry record.
Primary question
The primary endpoint asks for the median percentage of Treg cells among total CD4+ cells at 1 year after transplant. Its stated purpose is to define the biologic recovery and behavior of T regulatory cells after transplantation. The registry identifies 13 analyzed participants, but the median and its inter-quartile range are not reported in the registry record. Consequently, the endpoint’s observed level and variability cannot be described from the posted results.
3. Trial Design
This is a single-group study sponsored by Baylor College of Medicine. Its title concerns T-regulatory cell kinetics in patients receiving alemtuzamb and undergoing stem cell transplantation from mismatched-related, matched, or one-antigen-mismatched-unrelated donors. The registry lists the study phase as NA, allocation as NA, and masking as none. It is not a randomized comparison, and the registry does not identify a control arm.
The study enrolled 24 participants. The listed conditions are leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, and myeloproliferative disorders. The brief summary describes transplantation using donor stem cells, with donor matching dependent on availability. It also describes preparatory treatment before the transplant. Listed interventions include ARA C, cyclophosphamide, MESNA, total body irradiation, Campath-1h, and stem cell infusion. The arm description is incomplete in the registry record, so further treatment details are not reported in the registry record.
The study start is recorded as 2007-10, and primary completion as 2013-05. Its status is terminated. The registry does not state why the study was terminated, and the reason is not reported in the registry record.
The primary outcome is the median percentage of Treg cells at 1 year post transplant, expressed as a percentage of total CD4+ cells. Although 24 participants enrolled, only 13 were included in this analysis because they had Treg values at 1 year. The outcome is described as a biologic assessment, not as a comparison of clinical outcomes between treatment groups. No statistical analysis results are listed. The registry does not report a protocol rationale for the enrollment target, a sample-size justification, or further details of the analysis plan.
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 | Stem Cell Transplant |
|---|---|
| STARTED | 24 |
| COMPLETED | 24 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Only 13 of the 24 patients enrolled were included in this analysis as only 13 patients have Treg values at 1 year.
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.
Population: A total of 24 patients were enrolled on the study and all of them received the conditioning treatment and the transplant.
| Characteristic | Unit | Stem Cell Transplant |
|---|---|---|
| Participants analysed | 24 | |
| Age, Continuous | years | 10.0 (SD 4.9) |
| Age, Categorical: <=18 years | Participants | 23 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 7 |
| Sex: Female, Male: Male | Participants | 17 |
| Region of Enrollment: United States | participants | 24 |
6. Primary Endpoint
The registry lists the primary outcome as Median Percentage of Treg Cells at 1 Year Post Transplant, measured over 1 year.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | percentage of total CD4+ cells |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the median percentage of Treg cells at 1 year after transplantation, measured as a percentage of total CD4+ cells. The registry describes its purpose as defining the biologic recovery and behavior of T regulatory cells in patients undergoing the specified transplant protocol. The endpoint therefore characterizes a cell population at a stated follow-up time; it is not itself a direct measure of disease control, survival, or comparative treatment effect.
General statistical context: a median describes the middle of an ordered set of observations. It can summarize a distribution without requiring the values to follow a symmetric, bell-shaped pattern. The inter-quartile range describes the span from the lower to upper quartile, giving information about the distribution’s central spread. These summaries can be useful when values are skewed or when a typical value is more informative than an arithmetic average.
The endpoint analysis included 13 of the 24 enrolled participants because only 13 had Treg values at 1 year. The median and inter-quartile range themselves are not reported in the registry record. Accordingly, the posted information identifies what the endpoint was intended to measure and who contributed data, but not the observed endpoint value or its spread.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a biologic endpoint after stem cell transplantation: the median percentage of Treg cells among total CD4+ cells at 1 year. It reports that 13 participants had values at that time and were included in the analysis. However, the numerical median and inter-quartile range are not reported in the registry record. There is therefore no posted endpoint estimate to interpret for magnitude, direction, or precision.
The study enrolled 24 participants, but the endpoint analysis used a smaller group of 13. The record attributes this to availability of Treg values at 1 year. It does not explain why the remaining enrolled participants lacked such values, whether their lack of values was related to clinical status, or whether any methods were used to address missing observations. Those details are not reported in the registry record. General statistical context: an analysis limited to participants with observed follow-up values can describe that observed subset, but its representativeness of all enrolled participants depends on why observations are missing. The registry does not give enough information to assess that issue.
This is a single-group study, with no separate control group and no randomized allocation. Its endpoint can describe Treg levels among the analyzed participants, but the posted design does not support a direct estimate of how those levels compare with another treatment or with an untreated group. Changes over time also cannot be assessed from the stated endpoint alone, because the registry record does not report a baseline Treg value or repeated measurements for the endpoint.
The study status is terminated. That status does not explain why the study ended, and the reason is not reported in the registry record. It should not be treated as evidence about the endpoint or about the effects of transplantation. Likewise, the registry lists an outcome measure but reports zero analyses. No statistical test, confidence interval, or uncertainty estimate for the primary endpoint is reported in the registry record.
General statistical context: a confidence interval, when reported, gives a range of estimates compatible with the data and the analysis assumptions; it communicates uncertainty as well as the estimate’s location. Without a reported endpoint value or interval, the precision of the primary result cannot be evaluated. The enrollment and analysis counts alone do not establish the size or precision of an observed Treg percentage. The record supports a description of the intended biological question and the subset analyzed, but not a numerical conclusion about the endpoint.
The safety entries are separate from the primary biologic outcome. They report counts of participants with serious and other adverse events and frequencies for selected serious-event terms. Those entries do not supply the missing Treg endpoint result, and the endpoint information does not resolve safety questions. Each type of result requires its own interpretation.
9. Statistical Methods Explained
The primary outcome is specified as a median, with an inter-quartile range, at 1 year after transplant. The measurement unit is percentage of total CD4+ cells. The registry describes the scientific aim as defining T regulatory cell recovery and behavior in transplant recipients. This endpoint is a summary of a biologic measurement at a particular follow-up point, rather than a between-group treatment contrast.
What does the median describe?
General statistical explanation: after observations are ordered from lowest to highest, the median is the central value. It is a measure of location that is less affected by extreme observations than a mean. The inter-quartile range covers the middle half of a distribution and describes its central spread. Reporting both gives a sense of the typical value and how dispersed values are among the analyzed participants. The registry specifies these summary measures, but does not report their observed values.
What can a single-group analysis establish?
The registry classifies the design as single-group, with allocation listed as NA and no masking. There is no separate control group described. General statistical explanation: a single-group summary can characterize observations in the group studied, but it cannot by itself separate the influence of the intervention from other influences or establish what would have happened under a different treatment. It also does not provide a randomized treatment contrast. Since the primary endpoint is reported only at 1 year, and no baseline value is described for it, the posted information does not establish a change from baseline.
How should the analysis population be understood?
The record says 24 participants enrolled, while 13 participants had Treg values at 1 year and were included in the endpoint analysis. The distinction matters: the endpoint summary, if reported, would describe the participants with observed values, rather than automatically describing all enrolled participants. General statistical explanation: when follow-up values are missing, the implications depend on the reasons for missingness and on any analysis methods used. The registry does not describe those reasons or methods, so their effects on interpretation cannot be assessed.
What uncertainty information is available?
The registry identifies a median and inter-quartile range as the endpoint summaries but does not give either value. It also lists zero analyses. No confidence interval, test statistic, p-value, or other inferential result for the endpoint is reported in the registry record. General statistical explanation: an estimate describes the observed result, while an uncertainty measure indicates how much imprecision is compatible with the data and method. Neither can be recovered from the enrollment count alone, and no such value should be inferred from the information posted.
What do the planning assumptions mean?
The registry’s planning description refers to an illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined relative to an observed effect. It distinguishes total events for time-to-event illustrations from participants per arm for other illustrations. These assumptions do not describe the actual single-group design, which has no two-arm allocation. The registry does not report the trial’s own sample-size justification, and no numerical planning illustration is reported in the registry record.
General statistical explanation: a sample-size calculation is conditional on its design assumptions, target effect, variability assumptions, and chosen error rate. A calculation framed around two equally allocated arms cannot be read as the enrollment plan for a single-group study. Planning counts are not observed power, and they do not establish what the study actually achieved. The registry does not report an analysis of power based on the completed study.
What can be concluded from the methods record?
The stated endpoint and analysis subset are identifiable, but details needed to reconstruct the statistical analysis are limited. The registry does not report a fuller statistical plan, how the inter-quartile range was calculated, how missing values were handled, or whether any adjustment or subgroup analysis was conducted. Interim analyses are not reported in the registry record. These absences mean that the endpoint’s numerical result and the analytical choices behind it cannot be evaluated from the posted record alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and zero analyses. The primary outcome is the median percentage of Treg cells at 1 year post transplant. The record does not report a family of hypothesis tests, a testing hierarchy, or a multiplicity adjustment. Whether the protocol specified multiple outcomes or analyses beyond those listed is not reported in the registry record.
The primary endpoint analysis included 13 participants, while 24 participants enrolled. The registry explains that only 13 had Treg values at 1 year. It does not report reasons that values were unavailable for the others, whether missingness was anticipated, or whether imputation or sensitivity analyses were used. Those details are not reported in the registry record. General statistical context: missing-data methods rely on assumptions about why observations are missing; without information about the missingness process and the method used, readers cannot assess how robust a complete-observation summary might be.
The registry does not describe the full analysis population beyond the 13 participants with 1-year Treg values. It does not state whether all enrolled participants were included in any other outcome analyses. A protocol-defined analysis population, an intention-to-treat approach, or a per-protocol approach is not reported in the registry record.
Interim analyses, stopping rules, and a detailed statistical analysis plan are also not reported in the registry record. The study status is terminated, but no reason for termination is given. The absence of these details limits assessment of analysis choices and selective reporting; it does not establish that any particular practice was or was not used.
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 |
|---|---|---|---|
| Stem Cell Transplant | 17 | 24 | 70.8% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Stem Cell Transplant | 13 of 24 |
Most frequent serious adverse event terms
| Event term | Organ system | Stem Cell Transplant |
|---|---|---|
| Infection with Grade 3 or 4 neutrophils - Blood | Infections and infestations | 3 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Bladder (urinary) | Infections and infestations | 3 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Blood | Infections and infestations | 3 of 24 |
| Renal failure | Renal and urinary disorders | 3 of 24 |
| Pericardial effusion (non-malignant) | Cardiac disorders | 2 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Abdomen NOS | Infections and infestations | 2 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Catheter-related | Infections and infestations | 2 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Upper aerodigestive NOS | Infections and infestations | 2 of 24 |
| Infection with normal ANC or Grade 1 or 2 neutrophils - Upper airway NOS | Infections and infestations | 2 of 24 |
| AST, SGOT | Metabolism and nutrition disorders | 2 of 24 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Stem Cell Transplant |
|---|---|---|
| Mucositis/stomatitis (clinical exam) | Gastrointestinal disorders | 4 of 24 |
| Nausea | Gastrointestinal disorders | 3 of 24 |
| Vomiting | Gastrointestinal disorders | 3 of 24 |
| Hypotension | Cardiac disorders | 2 of 24 |
| PTT | Vascular disorders | 2 of 24 |
| Diarrhea | Gastrointestinal disorders | 2 of 24 |
| Infection - Other: CMV viremia | Infections and infestations | 2 of 24 |
| Infection with Grade 3 or 4 neutrophils - Blood | Infections and infestations | 2 of 24 |
| AST, SGOT | Metabolism and nutrition disorders | 2 of 24 |
| Renal failure | Renal and urinary disorders | 2 of 24 |
Serious events with the highest arm-level rate: infection with grade 3 or 4 neutrophils - blood (12.5%), infection with normal anc or grade 1 or 2 neutrophils - bladder (urinary) (12.5%), infection with normal anc or grade 1 or 2 neutrophils - blood (12.5%), renal failure (12.5%), pericardial effusion (non-malignant) (8.3%).
The safety record lists one group, titled Stem Cell Transplant, with 24 participants at risk for serious adverse events and 24 at risk for other adverse events. It records 17 participants affected by serious adverse events and 13 affected by other adverse events. These are group-level participant counts; they do not describe the severity, timing, duration, or outcome of every event.
Selected serious adverse-event terms are listed with frequencies. The listed entries include three infection terms, each recorded as 12.5%, renal failure at 12.5%, pericardial effusion (non-malignant) at 8.3%, and infection with normal ANC or Grade 1 or 2 neutrophils in the abdomen at 8.3%. The registry record does not provide further detail in these entries about event timing or individual clinical courses.
General statistical context: participants may experience more than one event or more than one event type, so term frequencies should not be added to estimate a total number of affected participants. The listed terms are not a comparison against a control group. The deaths field is not populated; deaths are not reported in the registry record. That is different from a statement that no deaths occurred.
12. What the Result Does, and Does Not, Mean
The posted record establishes that this study was designed to examine T-regulatory cell measurements after stem cell transplantation and that its primary endpoint was the median percentage of Treg cells among total CD4+ cells at 1 year. It also establishes that 13 participants with values at that time were included in the endpoint analysis, out of 24 participants enrolled. These details describe the question and analysis population, not the endpoint’s numerical result.
The median and inter-quartile range are not reported in the registry record. Therefore, the posted information does not establish the observed Treg percentage, its spread, or the precision of the estimate. It does not show whether values rose, fell, or remained stable, since a baseline measure and longitudinal results are not reported in the registry record.
The study has a single-group design and no separate control arm. As a result, the record does not provide a direct comparison with another transplant approach or treatment. The endpoint is biological and should not be interpreted as a direct clinical outcome. No conclusion about disease control, survival, or comparative benefit can be drawn from the endpoint description alone.
The safety record separately reports participants affected by serious and other adverse events, as well as selected serious-event terms. It does not provide a controlled comparison of safety outcomes. The deaths field is unpopulated, so deaths are not reported in the registry record; this does not establish that none occurred.
The study’s terminated status is recorded, but its reason is not reported in the registry record. No causal explanation for termination or interpretation of the missing endpoint result can be inferred from the status alone. Overall, the registry supports a description of the intended biologic assessment, its available analysis population, and selected safety entries. It does not provide the primary endpoint estimate or comparative evidence.
13. Why This Trial Matters Statistically
This study is statistically notable because the question is framed around a biologic measure rather than a comparison of clinical outcomes between treatment groups. The primary endpoint asks for the median percentage of Treg cells among total CD4+ cells at 1 year. That focus makes the distinction between describing a biological observation and estimating a comparative treatment effect especially important.
The record also makes the analysis population visible: 24 participants enrolled, and 13 with Treg values at 1 year were included in the endpoint analysis. That distinction is essential when judging who the endpoint summary would represent. Because the median and inter-quartile range are not reported, the available record cannot show the measured level or the variability among those analyzed. Because the reasons for unavailable values are not reported, the possible effect of missing follow-up on interpretation also remains uncertain.
The single-group design illustrates a basic limit of descriptive evidence. A summary can characterize the observed group, but without a control group it cannot isolate the intervention’s effect relative to an alternative. The registry’s planning description refers to a two-arm illustration, while the actual study is single-group. Keeping planning assumptions separate from the completed study design avoids treating an illustrative calculation as the study’s actual allocation or as observed power.
Finally, the record distinguishes the biological endpoint from safety reporting. Counts of participants with adverse events and selected event-term frequencies describe another part of the study, but they cannot substitute for the unreported Treg result. Together, these features show why interpretation depends not only on the endpoint definition, but also on the reported estimate, analysis population, missing-data information, and design.
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 that the primary endpoint’s median and inter-quartile range are not reported in the registry record. Although the outcome and time point are specified, the posted record does not give a numerical result or uncertainty estimate. The listed analysis count is zero.
The endpoint analysis included 13 of the 24 participants enrolled. The registry attributes this to the availability of 1-year Treg values, but does not explain why values were unavailable for the others, or describe any approach to missing data. The representativeness of the analyzed subset cannot therefore be assessed from the record.
The single-group design has no separate comparator. It can support description of the analyzed participants, but does not provide a randomized comparison or a direct estimate against another treatment approach. A baseline Treg result or other repeated measurements are not reported in the registry record, so change over time cannot be evaluated from the stated primary endpoint.
The registry does not report the reason the study was terminated, the trial’s sample-size justification, interim analyses, or a detailed statistical analysis plan. The arm description is incomplete, and the full regimen details are not reported in the registry record. These limitations constrain interpretation of both study conduct and the analysis.
Safety entries include participant counts and selected serious-event frequencies, but the record does not provide further detail on timing or clinical course in those entries. The deaths field is unpopulated, so deaths are not reported in the registry record. These limitations should be kept distinct from the missing primary endpoint result.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: T-Reg Cell Kinetics, Stem Cell Transplant, REGALE — NCT00578539.
- Registry record last updated 2016-04-22; status last verified 2016-03.
- Results first posted 2014-09-08.
- 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
NCT00578539 is a terminated, single-group study sponsored by Baylor College of Medicine. It enrolled 24 participants and lists leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, and myeloproliferative disorders among its conditions. The study start is recorded as 2007-10, with primary completion at 2013-05.
The primary endpoint is the median percentage of Treg cells among total CD4+ cells at 1 year after transplant. The registry reports that 13 participants had values at 1 year and were included in the analysis. The endpoint median and inter-quartile range are not reported in the registry record.
The design has no comparator group. The registry lists serious adverse events in 17 of 24 participants at risk and other adverse events in 13 of 24 at risk. A reason for termination, deaths, and a detailed statistical analysis plan are not reported in the registry record.