Zevalin-Containing Nonmyeloablative Conditioning for Stem Cell Transplantation (SCT): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Zevalin-Containing Nonmyeloablative Conditioning for Stem Cell Transplantation (SCT) (NCT01490723), a na phase 2 study. The primary outcome is Treatment-Related Mortality (TRM).

2. Clinical Question

The central statistical question is therefore descriptive: what outcomes and adverse events were recorded among participants receiving this regimen in this single-group study? Without a comparator, any observed outcomes describe this study group; they do not estimate a treatment difference against another approach. The registry lists Overall Survival as a secondary outcome, but an outcome value and analysis are not reported in the registry record. The posted information also does not establish how treatment-related mortality was defined or attributed. That distinction matters when interpreting a count of participants without treatment-related mortality: the endpoint is specifically framed around treatment-related mortality, not simply all deaths or all-cause survival.

3. Trial Design

This is a phase 2, completed, single-group study sponsored by M.D. Anderson Cancer Center. The registry lists enrollment as 20. Allocation is recorded as NA and masking as none. These design entries, together with the single-group model, indicate that the posted record does not describe a randomized, masked comparison between treatment arms. The registry itself cautions that this is not a like-for-like control comparison.

The regimen centers on dose-intense Yttrium-90 ibritumomab tiuxetan as part of non-myeloablative conditioning before allogeneic stem cell transplantation. The study summary describes the combination of rituximab, bendamustine, and fludarabine, followed by transplantation. It distinguishes the Yttrium-90 form, intended to deliver a radioactive particle to lymphoma cells, from the Indium-111 form, used with imaging to assess drug movement and retention. These are descriptions of the study rationale in the registry, not findings about how the regimen performed.

The listed intervention record includes Rituximab, 111In Ibritumomab, Planar Scintigraphy Imaging, 90Y IbritumomabTiuxetan, Fludarabine, Bendamustine, Thymoglobulin, and Tacrolimus. The available arm description begins with a day-by-day schedule but is incomplete in the registry entries used; a full protocol schedule is not reported in the registry record. The exact eligibility criteria, treatment modifications, transplant procedures, and follow-up schedule beyond the endpoint timeframe are also not reported.

The study began in 2013-01, has a primary completion date of 2019-04-24, and is listed as completed. These registry dates give context for the study record but do not, by themselves, provide evidence about outcome quality or completeness. The record lists two outcome measures and identifies Overall Survival as a secondary outcome. It reports zero analyses, so the posted material does not supply the statistical results needed to assess the primary or secondary outcome estimates. Sample-size illustrations elsewhere on the page should be understood as planning exercises rather than as evidence that the trial was designed or powered in a particular way.

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

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 100 days.

The primary endpoint is Treatment-Related Mortality (TRM), expressed in the registry as the number of participants without treatment-related mortality at day 100. In this wording, the outcome is a participant count at a specified time point. The registry does not provide the observed count or proportion, a confidence interval, or an analysis of the endpoint. It also does not report the operational definition of treatment-related mortality, the process for deciding whether a death was treatment-related, or the handling of participants whose status at day 100 was unknown.

General statistical context: a time-specific mortality endpoint can summarize a safety outcome at a defined follow-up point. The fixed timeframe makes clear when the status is being assessed, but interpretation still depends on the event definition, follow-up completeness, and analysis population. Here, the description is specifically about being without treatment-related mortality; it should not be silently substituted with all-cause survival or a count of all deaths.

The registry lists Overall Survival as a secondary outcome, but its result and detailed measurement description are not reported in the registry record. Although the adverse-event summary lists six deaths in the study group, it does not state whether those deaths were treatment-related or whether they occurred by day 100. That death count therefore cannot be used to reconstruct the primary endpoint. The key endpoint information available is its label, its participant-count unit, and its day 100 timeframe; an observed endpoint result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical context: a study design determines which comparisons its data can support. In a single-group study, outcomes are observed in a group receiving the study regimen, without a concurrent control group in the registry design. Such results can describe what happened in that group. They do not, on their own, estimate how outcomes would have differed under another regimen. The registry explicitly identifies this record as not being a randomized comparison.

What does a participant-count endpoint tell us?

The primary outcome is stated as the number of participants without treatment-related mortality at day 100. A count is an absolute description of participants meeting the endpoint definition. A count alone is not an estimate of comparative effect, and its interpretation depends on the number included in the analysis and on how outcome status was determined. The registry lists enrollment of 20 but does not report the observed primary count or the number included in its endpoint analysis. It also does not report how missing day 100 status, early withdrawal, or other incomplete follow-up was handled.

General statistical context: when an endpoint is measured at a fixed follow-up point, the time point is part of the definition. A count at day 100 is not interchangeable with a count over the entire study, and treatment-related mortality is not interchangeable with death from any cause. The posted description does not supply the criteria for attributing a death to treatment. The separate adverse-event listing of six deaths therefore cannot be treated as the day 100 TRM result.

How should uncertainty be assessed?

General statistical context: a confidence interval expresses the range of values compatible with an estimate under a specified statistical model and procedure. It conveys precision as well as the observed estimate. The registry information does not include a primary-endpoint estimate or confidence interval, so precision for the endpoint cannot be assessed from the posted results. There are no posted analyses in the registry record. A reader should not infer a result or its precision from enrollment alone.

For safety, the registry lists participants at risk and participants affected for serious and other adverse events, along with selected serious-event terms and percentages. These data provide a descriptive summary. The record does not give an adjusted model, comparative analysis, or uncertainty interval for those summaries. It also does not explain whether multiple event terms can occur in one participant. General statistical context: adverse-event categories often need not be mutually exclusive, so category percentages should not automatically be added or interpreted as separate sets of people. The record does not clarify this point for these terms.

What do the planning illustrations represent?

The sample-size assumptions describe a planning illustration, not the trial’s own design justification. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. For time-to-event tables, the stated quantity is total events using the Schoenfeld approach; other tables give participants per arm. These assumptions describe hypothetical planning comparisons and do not turn the actual single-group study into a two-arm trial.

General statistical context: a sample-size calculation depends on its assumed effect, error rate, allocation, outcome type, and analysis method. A planning illustration answers a conditional question about what sample size would be needed under those assumptions. It is not a finding about the trial and does not show the probability that the study detected an effect. In particular, sample-size calculations are not observed power. The registry does not report the trial’s own sample-size justification, and that justification should not be inferred from the illustration.

The record also does not report whether there were interim analyses, a prespecified statistical analysis plan, or a model for any endpoint. Those details are not reported in the registry record. General statistical context: choices such as endpoint definitions, analysis populations, handling of incomplete data, and multiplicity procedures can affect how estimates should be interpreted. Without those details and without posted results, the reader cannot verify how the planned analyses were carried out.

The phrase “recalculated” on a page can refer to a simple unadjusted calculation from posted summary statistics, rather than the sponsor’s original analysis. There is no posted endpoint analysis to reproduce or compare in that way. If a discrepancy is identified between a sponsor analysis and a simple recalculation, the sponsor’s own analysis takes precedence. The registry record in this case reports zero analyses, so the available statistical interpretation should not go beyond the descriptive design and safety information.

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("Yttrium-90 Ibritumomab + Chemo")
n      <- c(20)
events <- c(18)
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  Yttrium-90 Ibritumomab + Chemo  20  18  90.0  68.3  98.8  69.9  97.2  69.6  97.0

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary outcome, Treatment-Related Mortality at day 100, and lists Overall Survival as a secondary outcome. It reports two outcome measures and zero analyses. No outcome results or statistical tests are reported in the registry record. A multiplicity procedure, such as a rule for interpreting several outcomes or comparisons together, is not reported in the registry record. It would therefore be inappropriate to claim that a particular adjustment was applied or that any statistical significance threshold was prespecified for the posted outcomes.

General statistical context: multiplicity arises when several outcomes, time points, or comparisons are tested. Without a stated approach, the chance of a misleading positive result across multiple tests can be difficult to assess. Here, the absence of reported analyses means there are no posted p-values or inferential results for which to evaluate multiplicity handling. The fact that the registry names a primary and secondary outcome does not establish what analysis hierarchy or testing procedure was used.

Missing-data methods and analysis populations are also not reported in the registry record. The record does not say how participants with incomplete follow-up were handled for the day 100 endpoint, whether all enrolled participants were included in each analysis, or how outcomes after discontinuation were treated. These omissions matter because a participant-count endpoint requires a defined denominator and a way to handle unknown status. The listed enrollment of 20 should not automatically be assumed to be the analysis population for every endpoint.

The registry also does not report an interim-analysis plan, a statistical analysis plan, or a sample-size justification for the trial. These items are distinct from the planning illustrations, which are described as hypothetical two-arm sample-size calculations. Any claims about missing-data handling, interim monitoring, multiplicity control, or the trial’s original analysis population would go beyond what is reported.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: infections and infestations (40.0%), febrile neutropenia (40.0%), rash maculo-papular (20.0%), sepsis (5.0%), thromboembolic (5.0%).

The registry adverse-event summary lists one study group, with 20 participants at risk for serious adverse events and 12 affected. For other adverse events, it lists 20 at risk and 18 affected. It also lists six deaths. These figures are descriptive summaries; they are not a comparison with another group. The registry does not state whether the listed deaths were treatment-related or whether they occurred by day 100.

The serious-event terms listed include Infections and Infestations (40.0%), Febrile neutropenia (40.0%), Rash maculo-papular (20.0%), Sepsis (5.0%), Thromboembolic (5.0%), and Acute kidney injury (5.0%). The values are percentages as recorded. The available information does not provide corresponding participant counts for each term, identify the denominator used for each percentage, or explain whether participants could be represented in multiple terms. Do not sum these categories or treat them as non-overlapping groups on the basis of the record.

General statistical context: adverse-event summaries describe events observed and recorded during the study, but interpretation depends on definitions, observation periods, and attribution rules. Those details are not fully. These safety figures do not establish that the regimen caused every listed event, and they cannot be used to infer a comparative risk without a comparator. They also do not substitute for the primary endpoint result, which is not reported in the registry record.

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

The record documents a completed phase 2, single-group study with enrollment of 20 and a primary endpoint focused on participants without treatment-related mortality at day 100. It also provides a descriptive adverse-event summary, including counts for serious and other adverse events, selected serious-event percentages, and six deaths. These registry entries describe the study and the posted safety information; they do not provide an outcome analysis of the primary endpoint.

The record does not report the day 100 TRM result, an Overall Survival result, or analyses of lymphoma control. It therefore cannot establish the observed frequency of the primary endpoint, the precision of an outcome estimate, or a relationship between the regimen and any outcome. The death count cannot be assumed to represent treatment-related mortality: the record does not identify cause, attribution, or timing for those deaths. Similarly, listed adverse events do not by themselves show that the regimen caused the events.

The single-group design is central to interpretation. Without a concurrent comparator, the study’s observed events cannot be contrasted with outcomes under another treatment in this trial. General statistical context: even a clearly measured outcome in a single group does not alone determine what would have occurred under an alternative approach. The registry’s caution that the arms are not a like-for-like control comparison reinforces that no randomized treatment contrast is available.

The registry lists the study as completed, but completion status is not the same as a complete outcome report. It identifies Overall Survival as a secondary outcome and reports two outcome measures, yet the posted record includes zero analyses. The most supportable reading is therefore limited: the record describes the study design and supplies selected safety summaries, while key efficacy and primary-endpoint results are not reported in the registry record.

Nothing in this interpretation is a recommendation about care. It is a statement about the evidence visible in the registry: a single-group study, descriptive adverse-event data, and no posted analysis of the named primary and secondary outcomes. The distinction between an outcome being named and an outcome being reported is especially important when judging what the study’s posted results can establish.

14. Why This Trial Matters Statistically

This trial matters statistically because its design and reporting illustrate the difference between an outcome question and an answer to that question. The registry names a specific primary endpoint—participants without treatment-related mortality at day 100—and identifies Overall Survival as a secondary outcome. Yet it reports zero analyses, and the outcome values are not reported in the registry record. A reader can identify what the study set out to measure but cannot assess the posted outcome estimate or its precision.

The single-group design also illustrates why study structure constrains interpretation. The study combines a specialized conditioning approach with allogeneic stem cell transplantation, but no concurrent control group is described. Any observed outcomes would be descriptive for this study group rather than a randomized estimate of a difference between treatments. That distinction remains important even when safety information is available, because event counts without a comparator do not quantify relative risk.

The adverse-event summary shows another statistical issue: counts, percentages, event terms, and deaths represent different kinds of information. The registry lists participants affected by serious and other adverse events, percentages for selected serious-event terms, and a death count. The record does not explain the term-specific denominators or whether categories overlap, and it does not connect deaths to the primary endpoint. Clear interpretation requires keeping these measures separate rather than combining them into a single outcome claim.

Finally, the sample-size material is a planning illustration, not evidence about the actual trial’s design rationale or observed power. The registry does not report the original sample-size justification or the outcome analyses that would be needed to interpret a treatment effect. Together, these features make the study useful for discussing how design, endpoint definition, and reporting completeness shape the limits of statistical conclusions.

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.

Several limitations are specific to the information available for this study. The primary endpoint is defined as a participant count without treatment-related mortality at day 100, but its observed value is not reported in the registry record. The record also does not provide the criteria for defining or attributing treatment-related mortality, nor does it describe how an unknown day 100 status would be handled. The six deaths in the adverse-event summary cannot fill this gap because their timing and relationship to treatment are not stated.

The study is listed as single-group, with allocation NA and masking none. There is no concurrent comparator described, so posted observations cannot provide a randomized treatment contrast. The registry cautions that this is not a like-for-like control comparison. The enrollment is listed as 20, and the adverse-event group lists 20 at risk; however, the analysis population for the primary endpoint and secondary outcome is not reported.

The registry names Overall Survival as a secondary outcome but does not provide its result or detailed analysis. It reports zero analyses. Statistical methods for the primary and secondary outcomes, confidence intervals, missing-data handling, analysis populations, multiplicity procedures, and interim analyses are not reported in the registry record. Nor is the trial’s own sample-size justification reported.

The adverse-event summary is limited to the categories and figures shown. The registry does not clarify the denominator behind each serious-event percentage, whether the categories overlap, or the full observation period for those events. The arm description is incomplete, so full regimen details and protocol procedures are not established by this record. These limitations restrict both the interpretation of safety summaries and the strength of any conclusion about efficacy or comparative outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Zevalin-Containing Nonmyeloablative Conditioning for Stem Cell Transplantation (SCT) — NCT01490723.
• Registry record last updated 2020-05-05; status last verified 2020-04.
• Results first posted 2020-05-05.
• 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

This completed phase 2 study, sponsored by M.D. Anderson Cancer Center, evaluates Zevalin-containing non-myeloablative conditioning before allogeneic stem cell transplantation in B-cell malignancies. The registry lists leukemia and lymphoma as conditions, enrollment of 20, a single-group model, allocation NA, and no masking. The study began in 2013-01 and has a primary completion date of 2019-04-24.

The primary outcome is Treatment-Related Mortality, defined in the record as the number of participants without treatment-related mortality at day 100. Overall Survival is listed as a secondary outcome. The registry reports zero analyses and does not report results for either outcome. Its adverse-event summary lists 12 participants affected by serious adverse events, 18 affected by other adverse events, six deaths, and selected serious-event terms with percentages.

The design supports descriptive reporting of the study group, not a randomized comparison. Key details about outcome analyses, missing data, analysis populations, and treatment-related mortality attribution are not reported in the registry record.