T-Cell Depletion, Donor Hematopoietic Stem Cell Transplant (HSCT), and T-Cell Infusions in Treating Patients With Hematologic Cancer or Other Diseases: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for T-Cell Depletion, Donor Hematopoietic Stem Cell Transplant (HSCT), and T-Cell Infusions in Treating Patients With Hematologic Cancer or Other Diseases (NCT00589602), a na phase 2 study. The primary outcome is Treatment-related Mortality (TRM).

2. Clinical Question

The registry describes a feasibility study, not a randomized comparison. Its central statistical question is therefore whether the observed treatment-related mortality met the stated criteria in the treated group, rather than whether outcomes differed from a concurrent control. The reported enrollment was 13, while the primary endpoint population is defined as patients who received treatment. The number who received treatment is not reported in the registry record, so enrollment alone cannot establish the endpoint denominator.

3. Trial Design

This was a phase II feasibility study of T-cell depletion in allogeneic unrelated bone marrow transplantation followed by delayed T-cell infusions. The registry lists the design as single-group, with allocation not applicable and no masking. The intervention description includes transplantation and lymphocyte therapy, as well as total-body irradiation. The arm is named T-Cell Depletion Transplant. The brief summary gives the rationale for removing donor T cells before transplant and administering donor T cells after transplant, but it does not provide a complete account of the treatment schedule or the procedures received by each participant.

Reported enrollment was 13. The study started in 2004-01, and primary completion was recorded in 2009-08. Its status is listed as terminated. The reason for termination, whether recruitment reached a planned target, and whether the study ended according to its intended schedule are not reported in the registry record. The sponsor is The Cleveland Clinic.

The primary endpoint was treatment-related mortality, measured as the number of participants and assessed 180 days after transplant. The primary endpoint description states criteria of 55% or greater for an unacceptable result and 33% or less for an effective result. These are stated decision thresholds, not a reported outcome. The registry also names secondary outcomes concerning acute graft versus host disease, duration of absolute neutropenia, ability to receive T-cell add backs, and relapse-free survival. Definitions, timeframes, and numerical results for these secondary outcomes are not reported in the registry record.

Because there is no concurrent control group, the study design does not provide a direct treatment-group contrast. Any interpretation must focus on what was observed in the treated group and the uncertainty around that observation. The registry lists 0 analyses, and it does not report a statistical analysis plan, an interim analysis plan, or a sample-size justification for the trial.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Patients that received treatment

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 Treatment-related Mortality (TRM), measured over 180 days after transplant.

The primary endpoint is treatment-related mortality, expressed as the number of participants who experienced it. Its assessment timeframe is 180 days after transplant, and the endpoint population is described as patients who received treatment. The registry’s description identifies graft failure and severe graft versus host disease as important contributors to treatment-related mortality in the setting discussed. The endpoint therefore captures a serious outcome in the context of the transplant regimen, rather than measuring a laboratory value or a symptom score.

The registry states in advance that treatment-related mortality at 55% or greater would make the regimen unacceptable, while a result at 33% or less would be considered effective. These cutoffs give context to how the study intended to judge the endpoint. They do not show that either criterion was met. The observed number of participants with treatment-related mortality, its denominator, and any uncertainty interval are not reported in the registry record.

Using a defined timeframe helps make the outcome’s observation period explicit: events outside the stated 180-day period are not what this primary endpoint describes. However, further details about endpoint adjudication, cause-of-death classification, and handling of participants whose outcome status was unknown are not reported in the registry record. Without the observed endpoint data and the number treated, the stated criteria cannot be evaluated from the registry entry.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

A single-group study observes participants receiving the study regimen without a concurrent treatment group serving as a control. As a general statistical matter, this design can describe event counts and proportions in the observed group. It cannot directly separate the effects of the regimen from other influences on outcomes, because there is no concurrent contrast. Here, the registry lists the model as single-group, allocation as not applicable, and masking as none. These design labels describe the structure; they do not provide an outcome analysis.

What does a count endpoint tell us?

The primary endpoint is recorded as a number of participants experiencing treatment-related mortality within 180 days after transplant. A count describes how many endpoint events were observed, but interpretation also depends on the population included in the count. To understand a proportion, the denominator must be known as well. The registry defines the primary population as patients who received treatment, but the number treated and the primary event count are not reported in the registry record. The enrollment figure of 13 does not by itself establish either the treated population or the endpoint denominator.

Counts and proportions are also distinct from estimates of precision. A confidence interval is a statistical range used to express uncertainty around an estimated quantity. In general, intervals tend to be wider when information is limited and narrower when information is more precise. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be assessed from the posted primary outcome information.

How should the endpoint thresholds be understood?

The endpoint description states that treatment-related mortality at 55% or greater would be considered unacceptable and at 33% or less would be considered effective. These cutoffs are rules or criteria stated in the registry description. They are not statistical tests, and the record does not give a primary result to compare with them. It also does not report how a result between those criteria would be interpreted, whether uncertainty intervals would affect the decision, or whether a formal decision rule was specified elsewhere.

In general, an observed proportion near a threshold may be uncertain, especially when the number of observations is limited. A point estimate alone does not show how much the underlying rate could vary. This is why counts, denominators, and uncertainty measures matter together. For this study, the endpoint count and denominator are not reported in the registry record, so the stated thresholds cannot be assessed statistically from the available entry.

What does the trial’s analysis information establish?

The registry lists 0 analyses. This means that the entry does not provide a reported statistical analysis result for the endpoints in the record. A prespecified analysis plan can describe how outcomes are to be summarized, what populations are included, and how missing observations are handled. Such a plan is not reported in the registry record. The information also does not report whether analyses were adjusted, whether any interim analyses were planned or conducted, or whether hypothesis tests were used.

The record includes a description of planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions describe a planning exercise, not the single-group trial’s reported allocation. The effect to detect is described as a stated fraction of the observed effect. The record also distinguishes total event counts for time-to-event planning from participants per arm for other planning. No numerical planning results are reported in the registry record, and these illustrations should not be read as observed power or as evidence about the trial’s outcome.

Why can over-dispersion matter?

As a general concept, over-dispersion occurs when observed variability in count data exceeds what a simple statistical model assumes. If it is ignored, standard errors and uncertainty intervals may be too small, making results appear more precise than they are. Whether over-dispersion is relevant depends on the outcome and analysis model. The registry does not report a count-model analysis or a plan to assess over-dispersion, so no conclusion about its use or impact can be drawn for this trial.

How do safety summaries differ from an endpoint analysis?

The safety listing gives participants at risk and affected for serious and other events, plus selected serious-event terms and percentages. These summaries describe safety reporting, but they do not automatically define the primary outcome. The primary endpoint is treatment-related mortality at a stated timeframe; the safety terms include death-related categories, but the registry does not explain how the event summaries map to the primary endpoint or how their denominators were set. A general distinction is that a safety summary may count participants affected by one or more events, while an endpoint analysis may use a specific definition and observation window. The record does not provide enough detail to reconcile them.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("T-Cell Depletion Transplant")
n      <- c(12)
events <- c(8)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  T-Cell Depletion Transplant  12  8  66.7  34.9  90.1  39.1  86.2  38.6  86.1

11. Multiplicity, Missing Data and Analysis Populations

The registry names the primary treatment-related mortality endpoint and lists secondary outcomes concerning acute graft versus host disease, duration of absolute neutropenia, ability to receive T-cell add backs, and relapse-free survival. It does not report results for those outcomes, and it does not describe a statistical plan for testing or prioritizing them. In general, examining multiple outcomes can increase the chance of finding an apparently unusual result by chance if each is tested separately. Methods such as prespecifying a primary outcome or adjusting for multiple comparisons can address that concern, but use of any such method is not reported in the registry record.

The record lists 0 analyses. It does not report whether any endpoints were analyzed but not posted, whether secondary outcomes were exploratory, or how multiplicity would have been handled. The registry lists five outcome measures, while the named secondary outcomes are not accompanied by results or full analysis details. The status of any additional outcome measure is not reported in the registry record.

Missing-data handling is also not reported in the registry record. The primary endpoint population is described as patients who received treatment, but the number treated is not given. The record does not describe participant flow, missing endpoint status, censoring, exclusions, or how deaths and follow-up losses were handled in analyses. These omissions limit assessment of the analysis population and the extent to which the reported safety summaries cover all participants at risk.

No statistical analysis plan, interim analysis plan, or approach to missing outcomes is reported in the registry record. These details should not be inferred from the trial phase, the stated endpoint thresholds, or the planning assumptions.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death by relapse (33.3%), death from acute gvhd (25.0%), death due to respiratory failure (8.3%), death due to infection (8.3%).

The safety listing reports that 9 participants were affected by serious events among 12 at risk in the T-Cell Depletion Transplant group. It also reports other events affecting 12 participants among 12 at risk. These are participant counts in separate event categories. They do not indicate how many events each participant experienced, and the record does not explain whether participants could appear in more than one category.

The listed serious-event terms are Death by Relapse at 33.3%, Death from Acute GVHD at 25.0%, Death due to respiratory failure at 8.3%, and Death due to Infection at 8.3%. These percentages are reproduced as listed; the denominator and classification rules for each term are not reported in the registry record. They should not be added together or treated as mutually exclusive causes. The record does not establish how these terms correspond to the primary treatment-related mortality endpoint, which is defined for 180 days after transplant.

The number of deaths field is not populated. The event terms alone do not resolve that missing value or provide the primary endpoint count. The safety summaries describe reported events in this treatment group, but without a concurrent comparator they do not estimate a comparative safety effect.

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

The registry record establishes that the study was designed to examine a T-cell-depletion transplant approach followed by delayed T-cell infusions in patients with hematologic cancer or other diseases. It identifies treatment-related mortality within 180 days after transplant as the primary endpoint and gives criteria for judging the result. It also records enrollment, the study’s single-group design, and selected safety summaries. These details describe the question and the available reporting, but they do not provide the primary outcome result.

The record does not report the primary treatment-related mortality count or its denominator. It therefore cannot show whether the observed endpoint met the stated criterion of 55% or greater for an unacceptable result or 33% or less for an effective result. Nor does it report an uncertainty interval or an inferential analysis for that endpoint. A conclusion about the endpoint’s level or precision cannot be drawn from the registry entry.

The serious and other event summaries provide a limited view of safety reporting. The listed participant counts and serious-event terms do not supply a full account of event timing, severity grading, attribution, overlap, or relationship to the primary endpoint. The registry does not report the reason the study was terminated. That status should not be interpreted as evidence for or against the regimen.

The design also limits what can be concluded. A single-group study does not compare outcomes directly with a concurrent control group, so it cannot establish a comparative treatment effect. The record does not report enough information about participant flow, endpoint assessment, missing data, or statistical methods to resolve these limitations. Accordingly, the registry supports a description of the study design and the posted safety summaries, but not a conclusion that the regimen did or did not achieve its intended clinical or statistical goals.

14. Why This Trial Matters Statistically

This study illustrates why a clearly named endpoint and an observed endpoint result are both needed for interpretation. The registry specifies treatment-related mortality within 180 days after transplant and gives criteria of 55% or greater and 33% or less. Those details help define the intended question. However, without the number of endpoint events and the number of treated participants contributing to the endpoint, the stated criteria cannot be evaluated.

The entry also highlights the distinction between enrollment and an analysis population. Enrollment is reported as 13, while the primary population is defined as patients who received treatment. The size of that treated population is not reported in the registry record. The safety listing has its own at-risk figure of 12, but the record does not establish that this is the primary endpoint denominator. Keeping these populations distinct is essential when reading event counts and proportions.

The single-group design makes the study a description of outcomes under the studied approach, rather than a controlled comparison. This matters statistically because an observed event frequency does not by itself tell how outcomes would compare under another regimen. Uncertainty estimates, complete outcome reporting, and a clear analysis population would further help readers judge the strength of the evidence, but these are not reported for the primary endpoint.

Finally, the record shows how registry status and outcome evidence answer different questions. The study is marked terminated, but the reason is not reported. The status cannot explain the trial’s results or establish why it ended. Together, these features make the entry useful for identifying the design, endpoint, and reporting gaps while leaving the main endpoint question unresolved.

15. 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 reported primary endpoint result. The registry gives the endpoint definition and its stated criteria, but not the number of participants experiencing treatment-related mortality or the denominator used. Although enrollment is reported as 13, the primary endpoint population is patients who received treatment, and the number treated is not reported in the registry record. The safety listing’s at-risk figure does not resolve this because the registry does not state that it is the primary endpoint denominator.

The single-group design has no concurrent control group. It can describe outcomes in the treated group, but the record cannot support a like-for-like comparison with another treatment. Masking is listed as none. The registry does not report details about endpoint adjudication, participant flow, missing outcome data, or methods for censoring or follow-up.

Although several secondary outcomes are named, their results and full definitions are not reported in the registry record. The record lists 0 analyses and does not provide a statistical analysis plan, a multiplicity approach, or an interim analysis plan. It also does not provide an uncertainty interval for the primary endpoint. Thus, the precision of any primary endpoint estimate cannot be assessed.

The safety information is limited to participant counts and selected serious-event terms. The record does not describe overlap among categories, the denominator for the term-specific percentages, or how these terms relate to the primary treatment-related mortality definition. The reason for termination is not reported in the registry record, so it cannot be inferred from the status alone.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: T-Cell Depletion, Donor Hematopoietic Stem Cell Transplant (HSCT), and T-Cell Infusions in Treating Patients With Hematologic Cancer or Other Diseases — NCT00589602.
• Registry record last updated 2017-05-30; status last verified 2017-04.
• Results first posted 2017-05-30.
• 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.

19. Record Summary

The registry describes a phase II, single-group feasibility study of T-cell depletion in allogeneic unrelated bone marrow transplantation followed by delayed T-cell infusions. Enrollment was 13, the study started in 2004-01, primary completion was 2009-08, and status is listed as terminated. The primary endpoint was treatment-related mortality among patients who received treatment, assessed 180 days after transplant.

The endpoint description states criteria of 55% or greater for an unacceptable result and 33% or less for an effective result. The primary endpoint result, its denominator, and its uncertainty are not reported in the registry record. Safety summaries list 9 participants with serious events among 12 at risk and 12 with other events among 12 at risk, along with selected serious-event terms. The entry lists 0 analyses. It does not report the reason for termination, a statistical analysis plan, or results for the named secondary outcomes.