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 Safety and Efficacy of Donor T-lymphocytes Depleted ex Vivo of Host Alloreactive T-cells (ATIR) in Patients With a Hematologic Malignancy Who Received a Hematopoietic Stem Cell Transplantation From a Haploidentical Donor (NCT01794299), a na phase 2 study. The primary outcome is Transplant-related Mortality (TRM).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01794299 |
| Phase | Phase 2 |
| Condition | Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Myelodysplastic Syndrome |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 31 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Kiadis Pharma |
| Results posted | Yes |
2. Clinical Question
Population
Participants had a hematologic malignancy and received a CD34-selected hematopoietic stem cell transplant from a haploidentical donor. The listed conditions are acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome. The registry record reports enrollment of 31 participants but does not report further eligibility details or the characteristics of the participants included in each analysis.
Intervention
The intervention was ATIR, described as donor T-lymphocytes depleted ex vivo of host alloreactive T-cells. It was infused following a T-cell-depleted stem cell graft from a related haploidentical donor. The registry record identifies ATIR as the biological intervention; details of its administration are not reported in the registry record.
Comparator
The study is listed as single-group, with no masking and no randomized allocation. The registry record does not identify a control group or a like-for-like comparator. Consequently, the posted study design does not provide a randomized comparison of ATIR against another treatment or against no ATIR.
Primary question
The primary endpoint is transplant-related mortality, estimated at 6 months post HSCT using the Kaplan-Meier method. The study purpose also refers to safety, reducing transplant-related mortality, and improving overall survival. The central statistical question is what the observed transplant-related mortality estimate and its uncertainty were in the ATIR group. The registry record does not report the estimate, confidence interval, or primary analysis result, so the magnitude and precision of that outcome cannot be assessed from the posted results.
3. Trial Design
This is a completed Phase 2 study with enrollment of 31 participants. Its official title describes an exploratory, open-label, multicenter study of ATIR in people with a hematologic malignancy who received a CD34-selected hematopoietic stem cell transplant from a haploidentical donor. The registry record lists a single-group model, no masking, and allocation as not applicable. The listed conditions are acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome.
The study began in 2013-03 and reached primary completion in 2016-06; its status is recorded as completed. The intervention is ATIR, donor T-lymphocytes depleted ex vivo of host alloreactive T-cells. The brief summary describes its intended evaluation following a T-cell-depleted stem cell graft from a related haploidentical donor. Details such as the treatment schedule, eligibility criteria, and follow-up procedures are not reported in the registry record.
A single-group study can describe outcomes among participants who receive the intervention, but it does not by itself separate an intervention-associated effect from other influences on outcomes. Because the study has no randomized comparator, differences from historical or external populations cannot be interpreted as a randomized treatment contrast. The registry record does not report any comparator group or adjusted comparative analysis. Its exploratory designation also does not supply a statistical design plan: the protocol's sample-size justification, planned interim analyses, and detailed statistical analysis plan are not reported in the registry record.
The primary endpoint is transplant-related mortality at 6 months post HSCT, estimated with Kaplan-Meier methods. Secondary outcomes listed in the record include immune reconstitution, relapse-related mortality, overall survival, progression-free survival, participants with viral, fungal, and bacterial infections, and participants with graft versus host disease. The record lists seven outcome measures, but the outcome estimates and analyses are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | ATIR |
|---|---|
| STARTED | 31 |
| COMPLETED | 9 |
| NOT COMPLETED | 22 |
Reasons for not completing this period:
| Reason | ATIR |
|---|---|
| ATIR manufacturing not possible | 1 |
| Death | 14 |
| Graft failure | 1 |
| ATIR batch rejected | 2 |
| Relapse | 2 |
| Discontinued from active follow-up | 1 |
| Relapse and rejection of ATIR batch | 1 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | ATIR |
|---|---|---|
| Participants analysed | 23 | |
| Age, Continuous | years | 34 (20 to 60) |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 10 |
| Race and Ethnicity Not Collected | Participants | — |
| Human leukocyte antigen (HLA)-match n (%): 3/6 | Participants | 16 |
| Human leukocyte antigen (HLA)-match n (%): 4/6 | Participants | 6 |
| Human leukocyte antigen (HLA)-match n (%): 5/6 | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Transplant-related Mortality (TRM), measured over At 6 months post HSCT.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Kaplan-Meier estimates (%) |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is transplant-related mortality (TRM), expressed as a Kaplan-Meier estimate (%) at 6 months post HSCT. The registry definition classifies TRM as death due to causes other than disease relapse or progression, while excluding causes unrelated to the transplantation procedure, such as accident or suicide. This definition is intended to distinguish mortality attributed to the transplant context from deaths associated with relapse, progression, or unrelated causes.
Time-to-event methods are used when the timing of an event matters and participants may have different lengths of follow-up. In general, the Kaplan-Meier method estimates the probability of remaining free of the event over time while accounting for censored observations, such as participants whose event status is not observed through the full follow-up period. It can therefore provide an estimate at a prespecified time point without requiring every participant to have the event or complete follow-up at that time. This is a general explanation of the method, not a claim about the trial's follow-up completeness.
TRM is relevant to the stated study purpose because the brief summary focuses on transplant-related mortality and overall survival after transplantation. The estimate's interpretation depends on the stated event definition, the follow-up data, and the handling of competing events. The registry record does not report the 6-month estimate, its 95% confidence interval, the event count, or the analysis population. Therefore, the endpoint's observed magnitude and precision cannot be described from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed, exploratory Phase 2 study of ATIR in participants with hematologic malignancies after haploidentical stem cell transplantation. Enrollment was 31, and the design is single-group and open-label, with no masking and no randomized allocation. Those details define what can be learned from the record: outcomes could be described for the treated group, but the design does not establish a randomized contrast with another group.
The primary endpoint is transplant-related mortality at 6 months post HSCT. Although the endpoint and its Kaplan-Meier estimation method are identified, the primary estimate and its 95% confidence interval are not reported in the registry record. The event count and the number of participants contributing to the estimate are also not reported in the registry record. As a result, the posted information does not establish the observed TRM level or how precisely it was estimated. The study's stated aim is not itself an outcome result.
Secondary outcomes include immune reconstitution, relapse-related mortality, overall survival, progression-free survival, infections, and graft versus host disease. Listing these outcomes indicates what was intended to be assessed, but does not reveal their observed values. The record lists seven outcome measures and no analysis entries. Outcome-specific estimates, uncertainty intervals, and statistical tests are not reported in the registry record. No conclusion about the direction or size of an outcome can be drawn solely from its appearance in the outcome list.
The safety information identifies 23 participants at risk in the ATIR group for serious adverse events and 3 affected; the corresponding other adverse event counts are 23 at risk and 4 affected. The record also lists acute graft versus host disease, chronic graft versus host disease, and autoimmune haemolytic anaemia among the leading serious terms, each at 4.3%. These are descriptive safety figures. The record does not report whether an event was judged related to ATIR, how events were defined or collected, or whether the same participant could contribute to more than one term. The deaths field is not populated.
In general, a confidence interval describes statistical uncertainty around an estimate under the analysis assumptions; it does not address limitations such as a lack of a comparator or incomplete outcome reporting. Here the interval itself is not reported, so precision cannot be judged. Likewise, the sample-size illustrations based on an observed effect are planning exercises, not observed power and not a substitute for the missing primary result. They do not show that the trial detected an effect. The registry record does not report the protocol's own sample-size justification or analysis plan.
Overall, the record gives useful design and endpoint definitions, along with limited safety counts, but it does not provide the numerical efficacy results needed to assess the primary or secondary outcomes. It supports a description of the study's structure and what was measured, not a claim that ATIR reduced mortality, improved survival, or changed another clinical outcome.
9. Statistical Methods Explained
The statistical methods named in the record are most specific for the primary endpoint: TRM is reported as a Kaplan-Meier estimate (%) at 6 months post HSCT, with a 95% confidence interval. The outcome description explains how TRM is defined. Other details needed to reproduce or fully evaluate the analysis are not reported in the registry record. The methods below explain the named concepts in general and distinguish them from details that are absent from the record.
What does a Kaplan-Meier estimate describe?
In general, Kaplan-Meier analysis estimates the probability of remaining free of a specified event as time passes. For this trial, the specified event is death meeting the registry definition of TRM. The estimate at 6 months post HSCT is the estimated event-free experience up to that time expressed as a mortality estimate. The method can use information from participants who have different follow-up durations, rather than treating everyone without a recorded event as if they had complete follow-up.
A participant is censored when their event status is no longer observed during the relevant follow-up, for example because observation ends before the event occurs. In general, Kaplan-Meier estimation relies on assumptions about censoring, including that censoring does not systematically conceal a different event risk among those remaining under observation. The registry record does not report censoring counts, follow-up duration distributions, or whether the assumptions were assessed. It therefore is not possible to evaluate those features of the primary analysis from the record.
What does the confidence interval add?
A confidence interval gives a range of values compatible with the observed data under the statistical model and its assumptions. The registry specifies a 95% confidence interval for the primary estimate, but does not report the interval's endpoints. Without the estimate and interval, neither the observed TRM level nor its precision can be assessed. In general, an interval is not a guarantee that the true value lies within its particular endpoints, and it does not remove uncertainty caused by design limitations or missing information.
The endpoint is a time-to-event outcome. Such outcomes depend on both whether events occur and when they occur. A percentage at a stated time point is not interchangeable with a simple proportion unless follow-up and analysis support that interpretation. The registry explicitly identifies the Kaplan-Meier method, so the reported endpoint is intended as a time-based estimate rather than merely a raw event count divided by enrollment. The event count, time-to-event data, and analysis population are not reported in the registry record.
How should the single-group design affect interpretation?
In general, an estimate from a single group describes outcomes observed within that group. Without a concurrent randomized comparator, there is no trial-based estimate of how outcomes would have differed under another treatment assignment. Clinical characteristics, transplant procedures, follow-up, and other influences can contribute to outcomes; the record does not provide a design that isolates the intervention's effect from those influences. This limitation remains even if an estimate is precise. Precision describes statistical uncertainty under the model, whereas causal attribution depends on the design and assumptions.
The study is described as exploratory and open-label. Open-label means masking is absent according to the registry design fields. In general, awareness of treatment can affect reporting, observation, or management, depending on the outcome and study procedures. The record does not describe outcome adjudication or other steps that might address such influences, so no further claim about their presence or control is warranted.
What are the planning illustrations?
The planning assumptions describe illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. For time-to-event outcomes, the stated method concerns the total number of events using Schoenfeld; for other outcomes, it concerns participants per arm. These are planning calculations, not observed outcomes and not the trial's own stated design justification. The registry record does not report that the trial used those assumptions to choose its enrollment target.
In general, a planning calculation asks what sample size might be needed to detect a specified effect under stated assumptions. Its output depends on the assumed effect, allocation, significance level, analysis method, and other design choices. An illustration based on an observed effect is not observed power and does not show that the study was adequately powered. It also does not supply missing efficacy estimates. The actual numeric planning outputs are not described in the registry record.
The record's assumptions refer to detecting stated fractions of an observed effect. Such scenarios explore how planning requirements may change when the target effect differs from the effect used as a reference. These are hypothetical planning contrasts, not evidence that any such effect occurred. The registry record does not report the protocol's sample-size justification, target effect, or a prospective power calculation.
What cannot be evaluated from the record?
The record lists seven outcome measures but no analysis entries. The primary estimate and interval, outcome-specific event counts, missing-data handling, analysis populations, covariate adjustments, and detailed model specifications are not reported in the registry record. Nor are interim analyses or a complete statistical analysis plan. These omissions matter because estimates can depend on the population analyzed, event definitions, censoring, and analytic choices. Statistical methods identified in the record can be explained, but unreported procedures should not be inferred.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists a primary endpoint and several secondary outcomes, but does not report a detailed statistical analysis plan or any analysis entries. The primary endpoint is TRM at 6 months post HSCT. Listed secondary outcomes include immune reconstitution, relapse-related mortality, overall survival, progression-free survival, infections, and graft versus host disease. With multiple outcomes, there can be multiple opportunities to observe apparently noteworthy findings. In general, multiplicity refers to the interpretive and statistical issue created by making several comparisons or tests; methods such as prespecifying a hierarchy or adjusting significance thresholds may address it. The registry record does not report whether any multiplicity strategy was planned or used.
Missing-data handling is also not reported in the registry record. For a time-to-event analysis, participants may have incomplete follow-up or be censored, but the record does not report how many were censored, why follow-up ended, or how missing information was treated. It does not report missingness for the secondary outcomes either. In general, missing data can affect interpretation when the probability or pattern of missingness relates to outcome status.
The analysis populations are not reported in the registry record. Enrollment is reported as 31, but the record does not specify how many participants were included in the primary or secondary analyses, whether participants who did not receive ATIR were included, or how exclusions were handled. These details are necessary to understand the denominator underlying each estimate. The record also does not report interim analyses, adjusted analyses, or the protocol's statistical plan. Therefore, it is not possible to determine whether the listed outcomes were analyzed according to a prespecified hierarchy or which analysis population underlies any numerical result.
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 |
|---|---|---|---|
| ATIR | 3 | 23 | 13.0% |
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 |
|---|---|
| ATIR | 4 of 23 |
Most frequent serious adverse event terms
| Event term | Organ system | ATIR |
|---|---|---|
| acute graft versus host disease (aGVHD) | Immune system disorders | 1 of 23 |
| chronic graft versus host disease (cGVHD) | Immune system disorders | 1 of 23 |
| Autoimmune haemolytic anaemia | Blood and lymphatic system disorders | 1 of 23 |
Most frequent non-serious adverse event terms
| Event term | Organ system | ATIR |
|---|---|---|
| aGVHD | Immune system disorders | 4 of 23 |
Serious events with the highest arm-level rate: acute graft versus host disease (agvhd) (4.3%), chronic graft versus host disease (cgvhd) (4.3%), autoimmune haemolytic anaemia (4.3%).
The registry's safety record lists 23 participants at risk for serious adverse events in the ATIR group, of whom 3 were affected. For other adverse events, it lists 23 at risk and 4 affected. These are reported counts, not estimates of comparative risk: the study is single-group and no control group is identified. The record's deaths field is not populated, so it does not report a death count in this safety entry.
The leading serious adverse event terms listed are acute graft versus host disease (aGVHD) at 4.3%, chronic graft versus host disease (cGVHD) at 4.3%, and Autoimmune haemolytic anaemia at 4.3%. These term-level percentages should be read as registry-reported descriptive figures. The record does not explain whether participants could appear under more than one term, how the percentages were calculated, or whether events were considered related to ATIR. They should not be added together or treated as a count of distinct participants.
In general, serious adverse event counts describe events meeting a seriousness definition, while other adverse event counts may cover a different category. The registry entry does not give further definitions, collection methods, or follow-up duration for these figures. They describe what was recorded in the safety fields, but cannot establish whether ATIR caused an event or how its safety compares with an alternative.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed, exploratory Phase 2 study enrolled 31 participants and evaluated ATIR in a single-group, open-label design after haploidentical stem cell transplantation. It identifies TRM at 6 months post HSCT as the primary endpoint and specifies Kaplan-Meier estimation with a 95% confidence interval. These details describe the study question and its planned outcome measure; they are not the numerical findings.
The primary TRM estimate and confidence interval are not reported in the registry record. Nor are the outcome estimates for the listed secondary measures. As a result, the posted information cannot show the observed mortality level, the uncertainty around that estimate, or whether any secondary outcome changed in the study group. The stated purpose of assessing safety, reducing TRM, and improving overall survival must not be mistaken for evidence that those goals were achieved.
Even if outcome estimates were available, the single-group design would limit causal conclusions. In general, observed outcomes in a treated group may reflect factors beyond the intervention, and without a concurrent randomized control group the study cannot establish what would have happened to comparable participants under another treatment. A confidence interval, if reported, would describe statistical precision under its assumptions, not resolve this design limitation.
The safety entry reports affected-participant counts and several serious-event terms, but does not provide comparative safety data or attribution to ATIR. It also does not provide enough detail to determine overlap among event terms. Those figures therefore support a descriptive account of recorded events only.
The appropriate interpretation is bounded: the registry record documents the study's design, intended outcomes, and limited safety counts, while leaving the primary numerical result and much of the analysis detail unreported. It does not establish that ATIR reduced transplant-related mortality, improved survival, or altered any other outcome. It also does not establish the opposite. The efficacy result is not assessable from the registry information described.
13. Why This Trial Matters Statistically
This study raises statistical questions that are common in transplant research: how to define mortality related to a procedure, how to estimate outcomes over time when follow-up may differ, and how to interpret results from an exploratory study without a randomized comparator. The registry record names TRM as the primary endpoint and defines the event in relation to relapse, progression, and causes unrelated to transplantation. Clearly stating such an event definition matters because different classifications can produce different endpoint counts and interpretations.
The Kaplan-Meier method is appropriate to the stated time-to-event form of the endpoint in general, but interpretation still depends on follow-up, censoring, and event ascertainment. The registry identifies the method and a 6-month time point, yet does not report the estimate, interval, event count, or censoring information. This makes the distinction between a defined analysis and an assessable result especially important.
The single-group design also illustrates that statistical precision and causal strength are different issues. A single-group estimate can describe outcomes among participants, but a precise estimate alone cannot establish what outcomes would have been under a different treatment. The registry record reports no randomized comparison. Its exploratory context and the absence of posted outcome estimates mean that the information supports discussion of design and measurement rather than an efficacy conclusion.
Finally, the listed secondary outcomes and safety counts show why transparent analysis details matter. Multiplicity, analysis populations, missing data, and event attribution can shape how results should be read. Those details are not reported in the registry record. The trial therefore matters statistically as an example of the need to distinguish a study's objective and methods from the numerical evidence required to evaluate its outcomes.
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 central limitation of the registry record is that it does not report the primary endpoint result. Although the TRM definition, 6-month time point, Kaplan-Meier method, and 95% confidence interval are specified, the estimate and interval are absent. Event counts, censoring information, and the primary analysis population are also not reported in the registry record. This prevents assessment of both the magnitude and precision of the primary outcome.
The single-group design, with allocation listed as not applicable and no masking, does not provide a randomized control comparison. The registry record does not identify a concurrent comparator. Accordingly, outcomes in the ATIR group cannot by themselves establish the effect of ATIR relative to another approach. The study is described as exploratory, and details of eligibility, treatment administration, follow-up, and outcome adjudication are not reported in the registry record.
Although seven outcome measures are listed, their numerical results and analysis entries are not reported. The registry does not describe the statistical plan, sample-size justification, interim analyses, multiplicity handling, missing-data methods, or analysis populations. This makes it difficult to assess how outcomes were selected, whether planned methods were followed, and what participants contributed to each analysis.
Safety information is limited to reported at-risk and affected counts and selected serious adverse event terms. The record does not report event attribution, detailed definitions, participant overlap across terms, collection procedures, or the deaths count. Consequently, the safety fields are descriptive and do not support a comparison or causal interpretation. The absence of these details should not be read as evidence that events did not occur; the relevant information is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy of Donor T-lymphocytes Depleted ex Vivo of Host Alloreactive T-cells (ATIR) in Patients With a Hematologic Malignancy Who Received a Hematopoietic Stem Cell Transplantation From a Haploidentical Donor — NCT01794299.
- Registry record last updated 2021-04-12; status last verified 2021-03.
- Results first posted 2021-01-12.
- 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
The registry record identifies NCT01794299 as a completed Phase 2, exploratory, open-label, multicenter study of ATIR after CD34-selected haploidentical hematopoietic stem cell transplantation in people with hematologic malignancies. Enrollment was 31. The listed conditions are acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome. The study began in 2013-03 and reached primary completion in 2016-06.
The design is single-group, with no masking and allocation listed as not applicable. The primary endpoint is transplant-related mortality at 6 months post HSCT, estimated using Kaplan-Meier methods with a 95% confidence interval. Secondary outcomes include immune reconstitution, relapse-related mortality, overall survival, progression-free survival, infections, and graft versus host disease.
The registry record does not report the primary estimate, its confidence interval, or secondary outcome results. Safety entries list 23 participants at risk and 3 affected for serious adverse events, and 23 at risk and 4 affected for other adverse events. Selected serious terms are reported at 4.3% each. Detailed analysis methods, analysis populations, missing-data handling, and comparative results are not reported in the registry record.