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 Chemotherapy and a Donor Natural Killer Cell Infusion in Treating Patients With Relapsed or Persistent Leukemia or Myelodysplastic Syndrome After a Donor Stem Cell Transplant (NCT00526292), a na phase 2 study. The primary outcome is Treatment Efficacy as Defined by Complete or Partial Remission.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00526292 |
| Phase | Phase 2 |
| Condition | Leukemia, Myelodysplastic Syndromes |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Memorial Sloan Kettering Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with relapsed or persistent leukemia or myelodysplastic syndrome after a donor stem cell transplant. The trial description focuses on relapse or persistence after an allogeneic stem cell transplant; further eligibility details are not reported in the registry record.
Intervention
Salvage chemotherapy followed by infusion of natural killer (NK) cells from a related donor who shares half of the patient’s HLA proteins. The listed interventions include NK cell therapy, cyclophosphamide, and fludarabine.
Comparator
There is no concurrent comparison group in this single-group study. Allocation is recorded as not applicable, so the trial does not provide a randomized comparison with another treatment or with no treatment.
Primary question
What number of participants have a complete or partial remission at 3 Months following treatment? The endpoint is listed, but the observed remission count and associated statistical analysis are not reported in the registry record.
The clinical question concerns a treatment sequence rather than the NK cell infusion in isolation: the registry describes chemotherapy followed by cells collected from a related donor and purified before infusion. The study sought to assess treatment efficacy and effects on blood cancer and bone marrow function. The registered primary endpoint is treatment efficacy defined by complete or partial remission, expressed as a count of participants at the stated follow-up.
Because the study has a single group, its results cannot directly establish how outcomes compare with an alternative treatment. Any observed remission would describe outcomes among participants treated in this study, not the difference attributable to NK cells or chemotherapy. Other features of care, participant characteristics, and the underlying disease could also matter to observed outcomes. The registry record does not report an observed remission count, so the primary question cannot be answered from the outcome information available in the record.
3. Trial Design
This is a Phase II, single-group study sponsored by Memorial Sloan Kettering Cancer Center. The registry lists enrollment as 12 and the study status as completed. The recorded start is 2007-08, and primary completion is recorded as 2015-07. Masking is listed as none, and allocation is listed as not applicable. These design features describe a non-randomized study without a concurrent control group.
The treatment regimen combined salvage chemotherapy with an infusion of natural killer cells from an HLA-haploidentical related donor. The brief description says the donor shares half of the patient’s HLA proteins and that the cells are collected from the donor and purified. Cyclophosphamide and fludarabine are among the listed interventions, alongside natural killer cell therapy. The registry’s arm description identifies the regimen as NK cells with salvage chemotherapy, but does not provide a complete description of eligibility or all treatment procedures.
The primary endpoint is a binary clinical outcome summarized as a number of participants: complete or partial remission at 3 Months following treatment. The registry lists one outcome measure, but no analyses are listed. The actual remission count and any accompanying estimate of uncertainty are not reported in the registry record.
A single-group design can describe what happened among participants who received the regimen, but it does not isolate the effect of a particular component or support a direct comparison against another strategy. The absence of masking is also part of the recorded design; the registry does not explain how outcome assessment was conducted. Details about protocol deviations, analysis populations, follow-up completeness, and the statistical analysis plan 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 | HLA Haploidentical Natural Killer Cell Infusion |
|---|---|
| STARTED | 6 |
| COMPLETED | 6 |
| NOT COMPLETED | 0 |
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 | HLA Haploidentical Natural Killer Cell Infusion |
|---|---|---|
| Participants analysed | 6 | |
| Age, Categorical: <=18 years | Participants | 3 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Treatment Efficacy as Defined by Complete or Partial Remission, measured over 3 Months following treatment.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is treatment efficacy defined as complete or partial remission, measured as the number of participants who meet either remission category at 3 Months following treatment. This combines complete and partial remission into one registered outcome. The registry does not specify further response criteria or describe how remission was assessed.
A remission endpoint is used to summarize whether disease has met a defined response state after treatment. Combining complete and partial remission can capture more than one degree of response, but it also means the registered endpoint does not distinguish those categories in its title. The registry record does not report separate counts for complete and partial remission, nor does it give the overall count meeting the combined endpoint.
As a binary outcome, each participant would ordinarily be classified as meeting or not meeting the endpoint, provided the relevant assessment is available. This is a general explanation of binary outcomes, not a description of the unreported analysis. The endpoint’s stated follow-up provides a time point for assessment, but details about the timing window, handling of missing assessments, and any confirmation requirements are not reported in the registry record.
The primary endpoint therefore identifies what the study intended to measure, but the endpoint definition alone does not establish the observed result. Without a reported remission count or statistical analysis, the extent and precision of any observed response cannot be evaluated from the registry information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically focused question and a defined primary endpoint, but does not report the primary outcome result. Although the endpoint is complete or partial remission at 3 Months following treatment, the record does not give the number of participants who met that definition. It also lists no analyses. Consequently, there is no reported efficacy estimate or measure of its precision to interpret.
The study is recorded as a completed Phase II trial with a single group and enrollment of 12. Completion and enrollment describe the conduct of the study; they do not themselves indicate whether the treatment sequence was associated with remission. The record’s lack of an outcome analysis should not be read as a zero remission count, nor as evidence that no outcome was collected. The result is simply not reported in the registry record.
Even if a response count were available, a single-group design would limit causal interpretation. Without a concurrent comparator, an observed outcome could not be directly contrasted with outcomes under another treatment. The design also cannot separate the contribution of the chemotherapy from that of the donor NK cell infusion. These are limits of the comparison structure, not evidence for or against either component.
Precision is also not assessable from the information reported. A confidence interval, in general, expresses the uncertainty around an estimated outcome; a narrower interval indicates greater precision under the method used. No interval or other uncertainty estimate for the primary endpoint is reported. The record likewise does not report a p-value or an inferential test for remission. Without those results, it is not possible to judge how compatible the data are with a range of possible response rates.
The registry does list serious adverse event information. It reports 4 affected participants among 6 at risk for serious events, and 6 affected among 6 at risk for other events. It also lists death not associated with a CTCAE term—disease progression NOS at 50.0% and febrile neutropenia at 16.7% among the serious-event terms. These figures concern the reported safety categories, not the unreported remission endpoint. The death count itself is not reported.
Planning calculations, when presented as illustrations based on observed effects, should not be mistaken for evidence of efficacy or for observed power. The registry’s stated illustration assumptions include equal allocation between two arms, although the trial itself is recorded as single-group. Such planning estimates do not supply the missing endpoint result and do not turn this study into a controlled comparison.
In practical statistical terms, the record supports describing the design, intended outcome, and selected adverse event figures. It does not support a conclusion about the magnitude, direction, or precision of the primary efficacy result. Any stronger interpretation would require outcome results and analysis details not reported in the registry record.
9. Statistical Methods Explained
What does a single-group design estimate?
In a single-group study, the direct statistical description is the outcome observed among participants who received the study regimen. For a binary endpoint such as complete or partial remission, the basic result can be reported as a count of participants meeting the endpoint, often alongside the number assessed. This is a general description of how binary outcomes are summarized. The registry record gives the endpoint and enrollment, but does not report the remission count, the number assessed for remission, or an analysis population.
A treatment comparison asks a different question: whether outcomes differ between treatment strategies. Random allocation can help make groups comparable on average, while a concurrent control group provides an outcome benchmark under another strategy. Neither is part of the recorded design: the study is single-group, and allocation is not applicable. As a result, any outcome observed in the study would be descriptive of this treated group rather than a randomized estimate of a treatment contrast.
How should a binary endpoint be read?
A binary endpoint assigns each eligible assessment to a category such as remission or no remission. The registered primary outcome combines complete and partial remission and is measured at 3 Months following treatment. Counts are straightforward to understand, but interpreting them also requires knowing the denominator: the number of participants who were eligible for the assessment and whose outcome was known. That denominator and the handling of unavailable assessments are not reported in the registry record.
For a binary outcome, uncertainty can be expressed with a confidence interval around an estimated proportion. In general, a confidence interval reflects the range of values reasonably compatible with the data under its statistical assumptions. It is not a guarantee that the true value lies within the interval, and it does not resolve the limits of a non-randomized design. No confidence interval for the remission outcome is reported, so its statistical precision cannot be assessed.
What do the analysis entries establish?
The registry lists one outcome measure and zero analyses. This means the record identifies an endpoint but does not include a listed statistical analysis for it. The registry does not report a remission estimate, a p-value, an interval, or details of any adjustment. The absence of an analysis entry is not proof that no analysis was conducted outside the registry; it means that such an analysis is not reported in the registry record.
For clinical outcomes, an analysis plan may define how endpoint status is assessed, which participants are included, how missing observations are handled, and whether estimates are adjusted for other variables. Those choices can affect the result and its interpretation. The registry record does not report these details. They should therefore not be inferred from the endpoint title or from the fact that the study is Phase II.
What do the planning illustrations mean?
The planning illustrations are described as calculations based on the observed effect, with two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. They are described as showing the participants per arm for 80% power or other stated planning targets, with the effect to detect expressed as a fraction of the observed effect. Such calculations address a hypothetical future design under specified assumptions. They are not observed outcomes and are not observed power.
There is an important design distinction: this trial is recorded as single-group, whereas the stated planning assumptions use equal allocation between two arms. A future two-arm planning illustration is not a direct description of how this study was conducted. Because no remission result is reported, the observed effect underlying the illustration is not available in the registry record for independent interpretation. The illustration also cannot replace a control group or resolve uncertainty about confounding.
For time-to-event outcomes, the stated planning convention uses a total number of events; other planning figures are expressed as participants per arm. The registered primary endpoint is a count for a binary remission outcome, not a time-to-event outcome. These conventions describe how the planning calculations are framed, not how the primary endpoint was analyzed.
Why do analysis assumptions matter?
Statistical methods depend on the outcome type, design, and data completeness. For example, a binary endpoint calls for methods that reflect whether each participant meets a defined event criterion, while time-to-event methods account for event timing and censoring. These are general distinctions. The registry does not report the method used to analyze remission, so no specific model or test can be attributed to this trial.
Over-dispersion is a general issue in models for count data: variability can exceed what a simple model assumes, potentially making standard errors too small if the model is not adapted. It is not possible to say whether over-dispersion is relevant to the remission endpoint from the information reported; the registered endpoint is a participant count for a binary outcome, and no model is described. More broadly, model assumptions and analysis choices should be evaluated from the analysis plan and results, neither of which is reported in sufficient detail in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies one primary outcome measure: treatment efficacy defined by complete or partial remission at 3 Months following treatment. It lists zero analyses. No multiplicity adjustment, hierarchy of outcomes, or testing strategy is reported in the registry record. Multiplicity is a general concern when several outcomes or statistical tests are assessed, because repeated testing can increase the chance of a false-positive finding if results are interpreted without accounting for that repetition. The available record does not establish whether additional analyses were conducted or how they were handled.
The registry record does not report the remission count, the number assessed for the endpoint, or the number with missing endpoint status. It does not describe whether participants with unavailable assessments were excluded, classified in a particular way, or addressed using an imputation method. These omissions prevent assessment of how missing data might affect the endpoint estimate. The absence of a reported missing-data method should not be interpreted as evidence that there were no missing outcomes.
Analysis populations are also not described. The record does not state whether the primary analysis included all enrolled participants, only those who received the intended treatment, or another defined group. Nor does it report exclusions or protocol deviations relevant to analysis. These are important details because the population included in an analysis determines what the resulting estimate describes.
Accordingly, neither the handling of multiplicity nor the robustness of the primary endpoint to missing data or analysis-population choices can be evaluated from the registry record. No assumptions about these procedures should be substituted for the unreported methods.
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 |
|---|---|---|---|
| HLA Haploidentical Natural Killer Cell Infusion | 4 | 6 | 66.7% |
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 |
|---|---|
| HLA Haploidentical Natural Killer Cell Infusion | 6 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | HLA Haploidentical Natural Killer Cell Infusion |
|---|---|---|
| Death not associated with CTCAE term-Disease progression NOS | General disorders | 3 of 6 |
| Febrile neutropenia | General disorders | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | HLA Haploidentical Natural Killer Cell Infusion |
|---|---|---|
| Leukocytes (total WBC) | Blood and lymphatic system disorders | 6 of 6 |
| Lymphopenia | Blood and lymphatic system disorders | 6 of 6 |
| Neutrophils/granulocytes (ANC/AGC) | Blood and lymphatic system disorders | 6 of 6 |
| Platelets | Blood and lymphatic system disorders | 6 of 6 |
| Hemoglobin | Blood and lymphatic system disorders | 5 of 6 |
| Magnesium, high (hypermagnesemia) | Metabolism and nutrition disorders | 2 of 6 |
| Phosphate, low (hypophosphatemia) | Metabolism and nutrition disorders | 2 of 6 |
| Glucose, high (hyperglycemia) | Metabolism and nutrition disorders | 1 of 6 |
| Potassium, high (hyperkalemia) | Metabolism and nutrition disorders | 1 of 6 |
| Potassium, low (hypokalemia) | Metabolism and nutrition disorders | 1 of 6 |
Serious events with the highest arm-level rate: death not associated with ctcae term-disease progression nos (50.0%), febrile neutropenia (16.7%).
The registry reports serious-event information for the HLA Haploidentical Natural Killer Cell Infusion group. It lists 6 at risk and 4 affected for serious events, and 6 at risk and 6 affected for other events. These are separate reported categories; they should be read using their own listed at-risk and affected figures rather than combined into a new total.
The leading serious-event terms listed are death not associated with a CTCAE term—disease progression NOS at 50.0%, and febrile neutropenia at 16.7%. These percentages are reported as event-term figures. The registry does not provide enough detail to establish whether participants could contribute to more than one term, how recurrent events were counted, or the precise time at risk for each term. The number of deaths is not reported in the record.
Adverse event figures describe events recorded during the study and are not measures of treatment efficacy. They also do not, on their own, establish that an event was caused by the regimen. The single-group design provides no concurrent comparison for judging how event occurrence differs under another strategy. These figures should therefore be interpreted as the registry’s reported safety information, with the stated categories and denominators, rather than as comparative risk estimates.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed Phase II single-group trial evaluated salvage chemotherapy followed by infusion of donor NK cells for patients with relapsed or persistent leukemia or myelodysplastic syndrome after a donor stem cell transplant. It identifies complete or partial remission at 3 Months following treatment as the primary endpoint. It also reports selected serious adverse event information. These details describe the research question and some aspects of the study’s conduct.
The record does not report the observed remission count or a statistical analysis of that endpoint. It therefore cannot show the magnitude or precision of the remission outcome. This absence does not mean that the endpoint was zero, nor does it demonstrate that the regimen had no effect. It means the efficacy result is not available in the registry record for interpretation.
The design also does not provide a randomized comparison with another treatment. Even with an outcome estimate, a single-group study would not establish the difference between this regimen and an alternative. It would not separate the effects of chemotherapy from those of the NK cell infusion, either. Such limits concern what the design can identify, rather than the biological plausibility of the treatment or the clinical value of the research question.
The adverse event figures add descriptive safety information, but they do not resolve the missing efficacy result or provide a comparative safety assessment. The record does not report a death count or details sufficient to determine attribution. Overall, the registry supports a description of the intended endpoint, design, and listed event counts, but not a conclusion about treatment benefit, lack of benefit, or comparative safety.
13. Why This Trial Matters Statistically
This trial addresses a difficult clinical setting described in the registry: blood cancer that has relapsed or persisted after a donor stem cell transplant. The study’s question combines salvage chemotherapy with donor NK cell infusion, and the endpoint focuses on remission at a defined follow-up. From a statistical perspective, the case illustrates why a clearly named endpoint and a completed study are not enough to interpret efficacy when the outcome estimate and analysis are not reported.
It also shows how design determines the scope of a conclusion. A single-group study can document outcomes among treated participants, but without a concurrent comparator it cannot directly estimate a treatment contrast. This matters especially for a regimen with multiple components: observed outcomes would not, by themselves, isolate the contribution of chemotherapy, cell infusion, or other influences on disease course.
The registry’s adverse event information illustrates the importance of reading counts with their stated denominators and categories. Serious-event and other-event figures are reported separately, while specific event terms are given as percentages. These descriptions should not be converted into a broader comparative safety claim when the design has no control group and the record does not report event attribution details.
Finally, the record shows why registry entries and statistical results answer different questions. The design and endpoint identify what researchers intended to study. The missing outcome analysis leaves the central efficacy question unresolved in the registry record. Planning illustrations, where used, can inform future study design under stated assumptions, but are not substitutes for observed outcomes or a controlled comparison.
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.
Several trial-specific limitations follow directly from the registry information. The study is single-group, with allocation listed as not applicable and masking listed as none. There is no concurrent comparator in the recorded design. Any observed outcomes would therefore be descriptive, and the design cannot directly estimate a difference versus another treatment. It also cannot separate the effects of salvage chemotherapy from those of the NK cell infusion.
The registry record identifies the primary remission endpoint but does not report its result or analysis. It lists one outcome measure and zero analyses. Without the remission count, an uncertainty estimate, and analysis details, neither the size nor the precision of the primary outcome can be assessed. Missing-data handling, analysis populations, response-assessment procedures, and outcome adjudication are not reported in the registry record.
The intervention is a treatment sequence involving chemotherapy and donor cells. The record names NK cell therapy, cyclophosphamide, and fludarabine, but does not fully describe all treatment procedures or eligibility criteria in the available arm description. This limits how fully the study population and regimen can be characterized from the registry entry alone.
Safety interpretation is also constrained. The record gives serious and other event counts and selected serious-event terms, but does not report a death count or enough detail about event attribution, recurrence, and time at risk to support broader inference. These limitations do not establish that outcomes were unfavorable or that the study was poorly conducted; they describe what cannot be evaluated from the information reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Chemotherapy and a Donor Natural Killer Cell Infusion in Treating Patients With Relapsed or Persistent Leukemia or Myelodysplastic Syndrome After a Donor Stem Cell Transplant — NCT00526292.
- Registry record last updated 2016-02-12; status last verified 2016-01.
- Results first posted 2016-02-12.
- 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
NCT00526292 is a completed Phase II, single-group study sponsored by Memorial Sloan Kettering Cancer Center. The registry records enrollment of 12, a start date of 2007-08, and primary completion in 2015-07. The study examined salvage chemotherapy followed by infusion of donor natural killer cells for relapsed or persistent leukemia or myelodysplastic syndrome after a donor stem cell transplant.
The primary endpoint is the number of participants with complete or partial remission at 3 Months following treatment. The registry lists one outcome measure and zero analyses, and does not report the remission result or its statistical precision. Serious adverse event information includes 4 affected among 6 at risk; other events include 6 affected among 6 at risk. Listed serious-event terms include death not associated with a CTCAE term—disease progression NOS at 50.0%, and febrile neutropenia at 16.7%. The death count is not reported.