In-Vivo Activated T-Cell Depletion to Prevent GVHD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for In-Vivo Activated T-Cell Depletion to Prevent GVHD (NCT00594308), a non-randomized na study. The primary outcome is Number of Patients With Acute Grade II-IV GVHD.

2. Clinical Question

3. Trial Design

The registry record describes a non-randomized, single-group study with no masking. It lists the phase as NA and reports enrollment of 10. The record status is terminated. The study began in 2007-10, and primary completion is recorded as 2008-10. The reason for termination is not reported in the registry record.

The brief summary frames the research as a comparison of basiliximab plus cyclosporine with cyclosporine alone for GVHD prevention. But the registered design and posted group information do not show a two-group comparison: the model is single-group, allocation is non-randomized, and the adverse-event information identifies a basiliximab 20 mg group. No control arm or group-specific comparative outcome is reported. The summary’s intended comparison therefore should not be read as evidence that the record contains a controlled comparison.

The intervention list includes cyclophosphamide, fludarabine, cyclosporine, mycophenolate mofetil, and basiliximab. It does not provide enough information to reconstruct the treatment schedule, or to determine each participant’s exposure to every listed drug. The study concerns prevention of GVHD following a nonmyeloablative transplant, according to the brief summary.

The primary outcome population is described as all patients who received study drug. The record does not report how many participants contributed to the primary outcome, whether any enrolled participants did not receive study drug, or whether outcome data were missing. The safety data give 10 at risk for the listed basiliximab 20 mg group, but that safety denominator should not be assumed to define the primary analysis population.

Because the design is single-group, the posted record can describe outcomes observed in that group but cannot provide a direct estimate of the difference between basiliximab plus cyclosporine and cyclosporine alone. The registry record does not report a statistical plan, a sample-size justification, or interim analyses.

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: All patient that received study drug

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 Number of Patients With Acute Grade II-IV GVHD, measured over until 30 days after stem cell transplant.

The primary endpoint is the number of patients with acute grade II-IV graft-versus-host disease (GVHD) until 30 days after stem cell transplant. It is recorded as a participant count, and the stated population is all patients who received study drug. The registry describes grading with the NMDP/CIBMTR GVHD severity scale.

According to the record, this scale assesses GVHD involvement in the skin, liver, and intestinal tract, as well as decline in activity and physical abilities. The endpoint therefore concerns the occurrence of acute GVHD within the stated follow-up period, classified at grade II-IV, rather than a continuous measurement of symptom intensity or a time-to-event estimate.

As a general statistical point, a binary event endpoint can be useful when the research question concerns whether participants experienced a defined clinical event during a specified period. A count makes the number of participants with that event explicit, while interpretation also depends on knowing the population assessed and the number with available outcome data. Here, the population is described, but the primary endpoint count and its denominator are not reported in the registry record.

The endpoint is relevant to the study’s stated prevention question because GVHD is the outcome the intervention is intended to address. However, the endpoint description alone does not establish whether the intervention changed GVHD occurrence. The record’s missing primary outcome result and lack of a reported comparator prevent that assessment.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design tell readers?

The registry identifies the model as single-group and allocation as non-randomized. In general, a single-group study can describe what happened among participants receiving the study intervention, but it does not itself show what would have happened to comparable participants receiving another treatment. A treatment comparison depends on an appropriate comparator and a method for making the groups comparable. Random allocation is one way to reduce systematic differences between groups; it is not reported for this study.

The study summary describes an intended comparison with cyclosporine alone, but the registered design and posted group information do not report that comparator group. This means the stated objective should be distinguished from the data structure available for interpretation. The record supports describing the registered study as a single-group study, not treating it as a controlled comparison.

How should the primary outcome be understood?

The primary measure is a count of participants with acute grade II-IV GVHD within the stated period, until 30 days after stem cell transplant. In general, an event count is interpreted alongside its denominator: readers need to know how many people were assessed and how many experienced the event. The record defines the intended population as all patients who received study drug, but it does not report the primary event count or the number with an observed outcome.

The outcome is based on a severity classification that considers the skin, liver, intestinal tract, and activity and physical abilities. Such a defined classification makes the outcome more specific than an unstructured report of “GVHD,” though interpretation still depends on how assessments were made and whether all participants were followed consistently. Assessment procedures beyond the scale description are not reported in the registry record.

What do confidence intervals and p-values add?

In general, a confidence interval communicates the uncertainty around an estimated quantity under a statistical model. A narrow interval indicates greater precision than a wide interval, while an interval that spans a range of clinically different possibilities may leave substantial uncertainty. A p-value measures how compatible the observed data are with a specified null hypothesis under model assumptions; it is not the probability that the null hypothesis is true and does not measure the size or importance of an effect.

Neither a primary estimate nor a confidence interval or p-value is reported for the primary outcome. No treatment comparison analysis is reported. Therefore, readers cannot use inferential statistics from this record to quantify uncertainty around a treatment difference.

Why can event counts be difficult to interpret?

Binary outcomes reduce each participant’s experience to whether the defined event occurred during the specified period. This can make an outcome straightforward to summarize, but it does not capture all variation in timing, duration, or severity beyond the chosen grade threshold. In general, the choice of threshold should be understood from the clinical definition and follow-up window; neither should be changed after seeing results without a clear rationale.

For count data, the denominator and completeness of follow-up matter. Missing outcome information can make a count misleading if participants with missing data differ from those assessed. The registry record does not report missing-data handling, follow-up completeness, or a detailed analysis population beyond the statement that the primary population includes all patients who received study drug.

What do planning calculations mean?

In general, sample-size planning illustrations describe how many participants might be needed under specified assumptions about the effect to detect, significance level, allocation, and statistical approximation. They are planning aids, not observed results and not measures of the probability that a completed study detected an effect. Any illustration based on an observed effect also depends on how that effect was estimated and can be unstable when the observed data are limited.

The registry record does not report a sample-size justification or a protocol statistical plan. It also does not report an analysis for the primary outcome from which a treatment effect could be estimated. Thus, planning assumptions should not be confused with evidence about efficacy, precision, or the power achieved by this study.

Why does over-dispersion matter in some studies?

As a general concept, over-dispersion occurs when count outcomes vary more than a statistical model assumes. If ignored, standard errors may be underestimated and confidence intervals may appear too narrow. It is relevant to certain count-data models, but this primary outcome is specified as a participant count for a binary event, and no model-based analysis is reported. The registry record does not describe an over-dispersion assessment or an analysis model.

What can the registry entries support?

The record supports a descriptive account of the study design and the safety counts it reports. It does not support an inferential claim about a difference between treatment strategies. The primary endpoint is not reported, the record lists 0 analyses, and the stated comparator is not represented as a second group in the registered design. These are limitations of the available record, not statistical results demonstrating either benefit or lack of benefit.

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("Basiliximab 20 mg")
n      <- c(10)
events <- c(10)
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  Basiliximab 20 mg  10  10  100.0  69.2  100.0  72.2  100.0  71.5  99.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 5 outcome measures and 0 analyses. It does not identify a statistical testing hierarchy, a primary-versus-secondary testing procedure beyond the outcome labels, or a method for controlling the chance of false-positive findings across multiple outcomes. Any multiplicity adjustment is not reported in the registry record.

Multiplicity is a general concern when several outcomes or several analyses are tested: considering many results can increase the chance that at least one appears notable by chance. A prespecified plan can clarify which result is primary and how secondary findings should be interpreted. The registry identifies a primary outcome and several secondary outcomes, but it does not provide a statistical analysis plan or inferential results for them.

Missing-data handling is also not reported. The primary analysis population is described as all patients who received study drug, but the record does not give the number who received study drug, the number assessed for the primary outcome, or the extent and reasons for missing measurements. It does not describe imputation, censoring, or sensitivity analyses. These omissions make it impossible to determine how incomplete follow-up, if any, affected the outcome count.

The record does not report a detailed analysis population for the secondary outcomes, exclusions after enrollment, or whether all participants contributed to each measure. It also does not report interim analyses. The listed enrollment and safety denominator do not establish the primary outcome denominator.

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

Serious events with the highest arm-level rate: gvhd (40.0%).

The safety entry for the basiliximab 20 mg group lists 10 participants at risk for serious adverse events and 4 affected. For other adverse events, it lists 10 at risk and 0 affected. These are descriptive counts in the registry record; they are not a comparison with a control group and do not establish that an event was caused by a particular drug.

GvHD appears among the top serious terms, with a reported value of 40.0%. This term listing should be read as a safety-reporting entry, not as the primary endpoint result. The primary endpoint concerns acute grade II-IV GVHD through the specified period, whereas the safety entry does not give the grade, timing, or endpoint-specific assessment details needed to equate the two measures.

The registry record does not report deaths for this group. It also does not provide event-level detail, duration, severity beyond the serious classification, or a treatment attribution for the listed adverse events. These counts describe what is recorded, not the full clinical context or a comparative safety profile.

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

The record establishes that a study was registered to examine basiliximab with cyclosporine in the context of GVHD prevention after nonmyeloablative stem cell transplantation. It specifies acute grade II-IV GVHD as the primary outcome and gives a follow-up window until 30 days after stem cell transplant. It also records a single-group, non-randomized design, enrollment of 10, and a terminated status.

It does not report the primary endpoint count. It also does not report a cyclosporine-alone group, a treatment-effect estimate, a confidence interval, or a p-value. Therefore, the record cannot establish whether adding basiliximab changed GVHD occurrence relative to cyclosporine alone. Nor can the absence of a posted primary result be interpreted as evidence that the event did not occur or that there was no treatment effect.

The safety entries provide a limited descriptive account: 4 participants had serious adverse events among 10 at risk, while 0 had other adverse events among 10 at risk. GvHD is listed as a serious term at 40.0%. These figures do not answer the comparative effectiveness question, and the record does not provide enough detail to judge event timing, attribution, or clinical course. The death count is not reported in the registry record.

In general, conclusions from a treatment study depend on a clearly defined outcome, complete assessment, and a design capable of separating treatment differences from other influences. A single-group observation cannot provide the same causal contrast as a well-conducted comparison. Here, the registered design does not match the two-treatment comparison described in the summary, and the primary outcome result is unavailable.

The most defensible reading is therefore limited: the record documents a study with a prevention objective and describes some safety counts, but it does not provide the primary result or comparative evidence needed to estimate the effect of basiliximab plus cyclosporine versus cyclosporine alone.

14. Why This Trial Matters Statistically

This record illustrates why a study’s stated objective and its registered design must be read together. The brief summary describes comparing basiliximab plus cyclosporine with cyclosporine alone, but the registered study is non-randomized and single-group. A comparison named in a summary is not a substitute for a documented comparator group with reported outcome data.

It also illustrates the difference between outcome definition and outcome evidence. The primary endpoint is described in clinical terms, including its severity scale and follow-up period. Yet the endpoint count is not reported. A precise outcome definition helps readers understand what was intended to be measured, but it cannot replace a result or indicate how precisely that result was estimated.

The safety entries reinforce the importance of keeping outcome categories distinct. Serious adverse-event counts and a serious-event term listing are relevant descriptive information, but they should not be substituted for the primary GVHD endpoint or interpreted as a treatment comparison. Clear denominators are useful, while the missing primary outcome denominator and result remain important gaps.

Finally, the record’s terminated status and absence of reported analyses make transparent reporting especially important. The reason for termination, analysis plan, missing-data handling, and primary outcome result are not reported. Statistical interpretation requires attention not only to numerical estimates but also to the design, analysis population, and completeness of the record. In this case, those features limit what can be concluded from the posted information.

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 trial-specific limitation is the mismatch between the summary’s stated comparison and the registered single-group, non-randomized design. The posted information identifies a basiliximab 20 mg group but does not report a cyclosporine-alone control group. A comparative effect cannot be estimated from the design and results described in the record.

The primary outcome count is not reported, despite a defined endpoint and stated population. The record also lists 0 analyses. No primary estimate, confidence interval, or p-value is available, and no outcome-specific denominator is reported. The enrollment figure should not be treated as the primary endpoint denominator because the endpoint population is defined as patients who received study drug and the record does not report how many did so.

The study is marked terminated, but the reason for termination and its effect on recruitment, follow-up, or outcome collection are not reported in the registry record. The record does not provide a protocol statistical plan, sample-size justification, interim-analysis information, or an account of missing data. It does not state how the listed interventions were scheduled or which listed drugs were received by each participant.

Safety reporting is limited to group-level counts and a top serious-term entry. Event timing, attribution, and clinical detail are not reported, and deaths are not reported. These omissions constrain interpretation of both safety and the relationship between the safety entries and the primary endpoint. Taken together, the available information supports a description of the registered study and selected safety counts, but not a conclusion about comparative efficacy or a complete benefit-risk assessment.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: In-Vivo Activated T-Cell Depletion to Prevent GVHD — NCT00594308.
• Registry record last updated 2014-10-06; status last verified 2014-09.
• Results first posted 2012-03-20.
• 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.

19. Record Summary

The registry record describes a terminated, non-randomized, single-group study of basiliximab with cyclosporine for GVHD prevention after nonmyeloablative stem cell transplant. Enrollment is 10; the study began in 2007-10, with primary completion recorded as 2008-10. The phase is listed as NA.

The primary outcome is the number of patients with acute grade II-IV GVHD until 30 days after transplant, among all patients who received study drug. That result is not reported in the registry record. Although the summary describes a comparison with cyclosporine alone, no control group or comparative analysis is reported.

The safety entry lists 4 participants with serious adverse events among 10 at risk and 0 with other adverse events among 10 at risk. GvHD is listed as a serious term at 40.0%. The reason for termination, deaths, missing-data handling, and statistical analysis plan are not reported.