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 Clofarabine Plus Low-Dose Cytarabine Induction and Decitabine Consolidation in Frontline Acute Myeloid Leukemia (AML) and High-Risk Myelodysplastic Syndrome (MDS) (NCT00778375), a na phase 2 study. The primary outcome is Number of Participants With Complete Remission [Complete Response (CR), Complete Response With Platelet Recover (CRp) or Complete Response With Incomplete Marrow Recovery (CRi)].
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00778375 |
| Phase | Phase 2 |
| Condition | Acute Myeloid Leukemia, Myelodysplastic Syndrome |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 122 |
| Arms in the primary outcome | n/a |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Adults aged 60 years or older with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) were the intended population. The registry record reports 122 enrolled participants and describes 119 treated participants in the primary outcome information.
Intervention
The regimen began with clofarabine plus low-dose cytarabine induction. The registered treatment sequence then describes consolidation with clofarabine plus low-dose cytarabine alternating with decitabine. The treatment goal described in the record was to study disease control and safety.
Comparator
No separate comparator group is described. The study is registered as single-group, with allocation marked NA and masking listed as none. Its results therefore cannot provide a randomized, like-for-like comparison with another treatment.
Primary question
The primary outcome was the number of participants achieving complete remission, including CR, CRp or CRi, assessed after two 10-day induction cycles and through an additional re-induction cycle, up to 40 days. The registry record does not report the number who achieved this outcome.
3. Trial Design
This was a phase 2, single-group study sponsored by M.D. Anderson Cancer Center. The registry lists the study as completed, with a start date of 2008-10 and primary completion in 2015-01. Enrollment was 122. The primary outcome description refers to 119 treated participants, and notes that one participant was not evaluable for response.
The treatment was intended for patients aged 60 years or older with AML or high-risk MDS. The registered sequence was clofarabine plus low-dose cytarabine induction, followed by consolidation in which clofarabine plus low-dose cytarabine alternated with decitabine. The listed regimen describes clofarabine 20 mg/m^2 by intravenous infusion daily for 5 days; cytarabine 20 mg subcutaneously twice daily for 10 days, administered 3 to 6 hours following the start of clofarabine infusions; and decitabine 20 mg/m^2 by infusion daily for 5 days.
There was no randomized allocation, masking was listed as none, and no concurrent control arm is described. The registry record does not report a statistical design justification, a planned sample size, or a detailed analysis plan. The secondary outcomes listed were event-free survival and overall response rate, with response categories CR, CRp/CRi and PR. Their results 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 | Clofarabine + Cytarabine + Decitabine |
|---|---|
| STARTED | 122 |
| COMPLETED | 119 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Clofarabine + Cytarabine + Decitabine |
|---|---|
| Ineligible | 3 |
Analysis population for the primary outcome, as defined in the registry: One participant of 119 treated was not evaluable for outcome.
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 | Clofarabine + Cytarabine + Decitabine |
|---|---|---|
| Participants analysed | 122 | |
| Age, Continuous | years | 68 (60 to 81) |
| Sex: Female, Male: Female | Participants | 44 |
| Sex: Female, Male: Male | Participants | 78 |
| Region of Enrollment: United States | participants | 122 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Complete Remission [Complete Response (CR), Complete Response With Platelet Recover (CRp) or Complete Response With Incomplete Marrow Recovery (CRi)], measured over Beginning assessment following two 10-day induction cycles through an additional re-induction cycle, up to 40 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counted participants with complete remission, defined in the outcome title as CR, CRp or CRi. The registry description says responses followed IWG criteria (2003), and defines the CR rate as the number of participants with CR out of the total treated participants. CR requires disappearance of clinical and/or radiologic evidence of disease, a normal bone marrow differential with < 5% blasts, neutrophil count > 1.0 times 10^9/L and platelet count > 100 times 10^9/L. CRi is described as meeting the CR criteria without normal blood counts. The registry record does not explain CRp further.
The response assessment began following two 10-day induction cycles and continued through an additional re-induction cycle, up to 40 days. Bone marrow aspirate and/or biopsy was scheduled starting on day 21 (+/- 7 days) of therapy. A remission endpoint is a binary outcome at the participant level: each participant either meets the specified response definition or does not. It is useful for describing the frequency of a defined response in the treated group. It does not, by itself, establish how the outcome compares with another treatment, and the registry record does not report the observed remission count or rate.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a single-group phase 2 treatment study and identifies complete remission, including CR, CRp or CRi, as its primary outcome. However, it does not report the primary outcome result. No remission count, rate, confidence interval or inferential test is available in the registry record. Consequently, the posted information cannot quantify the observed remission frequency or its precision.
The record reports that 119 participants were treated and that one of them was not evaluable for response. It also says that 22 participants required re-induction. These details help describe assessment and treatment exposure, but they do not supply the remission result. The registry's endpoint definition uses the total treated participants for the CR rate; the record does not state a separate response analysis population or explain how the non-evaluable participant was handled in a reported estimate.
The study has no separate comparator group. Its single-group design can describe outcomes among participants who received the regimen, but it cannot separate treatment effects from other explanations for observed outcomes, such as participant characteristics, disease course or care outside the study. No causal comparison with an alternative regimen is available from this design.
General statistical interpretation: a confidence interval expresses the uncertainty around an estimate. For a binary outcome such as remission, its width depends in part on the number of participants with evaluable outcome information. Without a reported estimate or interval, the precision of the primary result cannot be assessed. A p-value, if one were reported, would address compatibility with a specified statistical null model; it would not measure the size or clinical importance of an effect. No primary-outcome p-value or test result is reported in the registry record.
The listed secondary outcomes are event-free survival and overall response rate, but no results for them are included in the record. The safety information reports affected-participant counts and selected serious adverse event terms. Those counts describe reported events in the study group; without a comparator and fuller follow-up detail, they do not establish comparative safety.
9. Statistical Methods Explained
The registry identifies the primary outcome as a count of participants meeting a remission definition. For statistical purposes, this is a binary participant-level outcome: each participant is classified according to whether the specified response criteria were met. A count can be converted to a proportion when the analysis denominator is defined, but no observed primary count or proportion is reported in the registry record. The endpoint description defines CR rate using the total treated participants and notes one participant of 119 treated was not evaluable. It does not provide a reported estimate or explain how that participant was treated in an analysis.
What does a confidence interval contribute?
General explanation: an estimate based on a group of participants is subject to sampling variability. A confidence interval gives a range of values compatible with the data under a statistical procedure and its assumptions. It is not a guarantee that the true value lies within the interval. For a binary outcome, uncertainty is influenced by the number of participants and by how many meet the outcome definition. A narrower interval generally indicates greater precision. Since the registry record has no remission estimate or interval, precision cannot be evaluated for the primary outcome.
What can a single-group study estimate?
The registered design has one treatment group, no randomized allocation and no masking. Such a study can report the outcomes observed among participants who received the regimen. It does not create a concurrent counterfactual group—that is, a comparable group showing what would have occurred under another treatment. As a result, an outcome rate in this group alone cannot be interpreted as the difference attributable to treatment. Participant selection, disease characteristics, follow-up and other factors may also shape observed outcomes. The registry record does not report an adjusted comparative analysis.
How should the response definition be read?
The endpoint combines CR, CRp and CRi in its title, while the description provides specific criteria for CR and CRi. It refers to IWG criteria (2003), specifies blood-count and marrow criteria for CR, and defines CRi as meeting the CR criteria without normal blood counts. It does not provide a separate CRp definition. These categories are not interchangeable in their clinical criteria, even though the primary outcome title groups them. The record also specifies marrow assessment beginning on day 21 (+/- 7 days) of therapy, with the outcome timeframe extending through an additional re-induction cycle, up to 40 days. That assessment window matters when interpreting who could be counted as a responder.
What do the planning assumptions represent?
The registry's planning illustration uses a two-sided significance level of 0.05, equal allocation between two hypothetical arms and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Time-to-event planning illustrations use a total number of events; other illustrations use participants per arm. These are planning assumptions, not evidence that the actual study had two arms. The registered trial is single-group, and the record does not report that these assumptions were the trial's design or sample-size justification. Planning sample sizes are not observed power, and they do not add outcome information to the study.
Why does variability matter?
General explanation: statistical models make assumptions about the variability and distribution of outcomes. Over-dispersion means that observed variation is greater than a model expects; if ignored, uncertainty can be understated. For a simple binary count, the key issues include the outcome definition, denominator, participant evaluability and whether observations can reasonably be treated as independent. The registry record does not describe an over-dispersion assessment or a model-based primary analysis, so no such method should be attributed to this study.
The record lists event-free survival and overall response rate as secondary outcomes, but does not provide analysis methods or results for them. It also does not report a statistical analysis plan, interim analyses, handling of multiple outcomes, or a missing-data strategy. Those omissions limit assessment of how analyses were chosen and how uncertainty was handled.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome and two secondary outcomes: event-free survival and overall response rate. The overall response rate categories are listed as CR, CRp/CRi and PR. The record does not report whether statistical testing was planned for these outcomes, whether tests were adjusted for multiple comparisons, or which outcome would guide any formal conclusion. A multiplicity strategy is not reported in the registry record.
Multiplicity matters when several outcomes or analyses are tested: the chance of at least one apparently unusual result can increase as the number of tests grows. General explanation: adjustment methods or a prespecified hierarchy can help control that issue, but the record does not say whether either approach was used. There are no reported outcome analyses from which to assess multiplicity in practice.
For missing outcome information, the primary outcome description states that one participant of 119 treated was not evaluable for response. It also says 22 participants required re-induction. The record does not report why the response assessment was not evaluable, how the participant was handled in an analysis, or whether other primary outcome data were missing. It does not specify an imputation method or sensitivity analysis. The outcome description defines the CR rate using total treated participants, but a result and its denominator are not reported.
The registry does not describe separate intention-to-treat, per-protocol or other analysis populations. The treated count is stated, but the record does not clarify whether all enrolled participants received treatment or how enrollment and treatment populations related beyond the counts reported. Without these details, the analysis population and missing-data assumptions cannot be fully assessed.
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 |
|---|---|---|---|
| Clofarabine + Cytarabine + Decitabine | 12 | 119 | 10.1% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Clofarabine + Cytarabine + Decitabine | 67 of 119 |
Most frequent serious adverse event terms
| Event term | Organ system | Clofarabine + Cytarabine + Decitabine |
|---|---|---|
| Bone marrow hypocellular | Blood and lymphatic system disorders | 7 of 119 |
| Infection | Infections and infestations | 5 of 119 |
| Sudden death | General disorders | 2 of 119 |
| Death | General disorders | 2 of 119 |
| Disease Progression | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 119 |
| Hemorrhage/Bleeding | Blood and lymphatic system disorders | 1 of 119 |
| Pneumonia | Infections and infestations | 1 of 119 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Clofarabine + Cytarabine + Decitabine |
|---|---|---|
| Febrile neutropenia | Blood and lymphatic system disorders | 31 of 119 |
| Infection | Infections and infestations | 26 of 119 |
| Fever | General disorders | 7 of 119 |
| Renal failure | Renal and urinary disorders | 6 of 119 |
| Bilirubin increased | Investigations | 4 of 119 |
| Pneumonia | Respiratory, thoracic and mediastinal disorders | 4 of 119 |
| Alanine aminotransferase increased | Investigations | 3 of 119 |
| Hemorrhage/Bleeding (Other) | Blood and lymphatic system disorders | 3 of 119 |
| Pain (Other) | General disorders | 3 of 119 |
| Rash desquamating | Skin and subcutaneous tissue disorders | 3 of 119 |
Serious events with the highest arm-level rate: bone marrow hypocellular (5.9%), infection (4.2%), sudden death (1.7%), death (1.7%), disease progression (0.8%).
The registry reports 119 participants at risk for the listed safety summaries. It records 12 participants affected by serious adverse events and 67 affected by other adverse events. These are participant counts, not measures of comparative risk. The record lists bone marrow hypocellular at 5.9%, infection at 4.2%, sudden death at 1.7%, death at 1.7%, disease progression at 0.8%, and hemorrhage/bleeding at 0.8% among the serious adverse event terms.
These percentages describe the listed terms as reported in the registry. The record does not give event-level detail, timing, duration, severity grading beyond the serious-event classification, or attribution to treatment. The listed terms should not be added together: a participant could have more than one event, and the record does not state whether categories overlap. It also does not report a separate death count in the safety summary. The presence of death-related terms in the list is not a substitute for that count.
General explanation: serious adverse event summaries indicate events meeting a seriousness classification; they are distinct from a complete account of all treatment-emergent symptoms or laboratory changes. Because there is no control group, these figures describe what was recorded in the treated group and do not establish whether an event was more or less frequent than under another treatment.
12. What the Result Does, and Does Not, Mean
The registry record documents a phase 2, single-group study of clofarabine plus low-dose cytarabine induction followed by consolidation involving clofarabine plus low-dose cytarabine alternating with decitabine. It identifies a remission outcome and provides the response criteria, assessment window, treatment details and selected safety counts. It does not report the primary remission result, secondary outcome results, or a comparative treatment analysis.
Therefore, the posted information cannot show how many participants achieved CR, CRp or CRi, how precise a response estimate would be, or how outcomes compared with another approach. The fact that 22 participants required re-induction describes treatment during the study; it is not itself a response result. Likewise, enrollment and treated-participant counts describe study size and exposure, not efficacy.
The safety counts and serious-event terms provide a limited description of reported events among treated participants. They do not show whether the regimen caused an event or how its safety compares with another regimen. Interpretation is further limited by the lack of reported event details, a comparator group and a complete analysis description.
General explanation: a clinical study's result is not the same as a treatment recommendation. Findings from a single group are most directly informative about outcomes observed in that group under the study's conditions. They cannot by themselves establish a causal treatment effect or predict an individual participant's outcome. The registry record also does not report enough statistical detail to assess the uncertainty around a primary outcome estimate, because no such estimate is included.
The appropriate conclusion is bounded by the available record: the study was completed, the planned primary outcome concerned remission, and selected safety counts were posted. Whether the primary remission objective was met is not reported in the registry record.
13. Why This Trial Matters Statistically
This study illustrates why a clearly defined endpoint and a reported result are both necessary for statistical interpretation. The record specifies remission categories, blood-count and marrow criteria, a response assessment period, and a treated-participant count. Yet without the observed number meeting the endpoint, readers cannot estimate the response frequency or its precision. A detailed endpoint definition alone does not answer the clinical question.
The design is also important. A single-group phase 2 study can describe outcomes in a treated population, but it lacks a concurrent randomized comparison. This distinction limits the type of inference: a response count would characterize the group, but would not establish how much the regimen changed outcomes relative to another option. The registry's planning assumptions involving equal allocation between two arms are illustrations, not a description of the registered design.
The safety summary demonstrates a separate statistical concern. Counts of participants affected and percentages for selected serious-event terms convey some information, but overlapping events, absent event-level detail and lack of a comparator constrain interpretation. Safety summaries should be read as descriptive records of events, not direct estimates of comparative treatment effects.
Finally, the record's missing analysis details matter. No statistical analysis plan, multiplicity approach, missing-data strategy or reported outcome analysis is included. These omissions make it difficult to evaluate how endpoint data would have been handled or how uncertain conclusions might be. Taken together, the record supports careful description of design and reported safety counts, but not a quantitative assessment of the primary remission outcome.
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 primary limitation is that the registry record does not report the primary remission result. Although the endpoint and assessment period are described, there is no reported count of participants achieving CR, CRp or CRi, no rate and no precision estimate. The listed secondary outcomes also have no results in the record.
The study is registered as single-group, without randomized allocation or masking, and has no separate comparator arm. Any outcome description would therefore lack a randomized concurrent comparison. The registry record does not report a statistical analysis plan, a sample-size justification, interim analyses, an approach to multiplicity, or a missing-data strategy. It does not explain how the one participant described as not evaluable for response was handled, and it does not describe analysis populations beyond the reported enrollment and treated counts.
The endpoint title includes CR, CRp and CRi, but the description gives explicit definitions for CR and CRi and does not explain CRp separately. The response timeframe includes assessment following two 10-day induction cycles through an additional re-induction cycle, up to 40 days; the record says 22 participants required re-induction but does not report their response outcomes.
Safety reporting is also limited. The record gives counts of participants affected and selected serious adverse event terms, but no detailed event chronology, treatment attribution or comparative safety estimates. The record does not report a separate death count in the safety summary. These limitations restrict both clinical interpretation and statistical assessment.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Clofarabine Plus Low-Dose Cytarabine Induction and Decitabine Consolidation in Frontline Acute Myeloid Leukemia (AML) and High-Risk Myelodysplastic Syndrome (MDS) — NCT00778375.
- Registry record last updated 2016-07-14; status last verified 2016-06.
- Results first posted 2016-02-26.
- 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 describes a completed phase 2, single-group study sponsored by M.D. Anderson Cancer Center, with enrollment of 122 and a start date of 2008-10. Primary completion was 2015-01. The intended population was adults aged 60 years or older with AML or high-risk MDS.
The regimen used clofarabine plus low-dose cytarabine for induction, followed by consolidation involving clofarabine plus low-dose cytarabine alternating with decitabine. The primary outcome was the number of participants achieving CR, CRp or CRi, assessed through an additional re-induction cycle, up to 40 days. The primary remission result and the listed secondary outcome results are not reported in the registry record.
The outcome information refers to 119 treated participants, with one not evaluable for response; 22 participants required re-induction. Safety summaries list 12 participants affected by serious adverse events and 67 affected by other adverse events. The record does not include a comparator group or sufficient statistical analysis details for comparative interpretation.