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 To Demonstrate Superiority of Decitabine Over Azacitidine in Subjects With Intermediate- or High-risk MDS. (NCT01011283), a randomized phase 4 study. The primary outcome is Overall Response Rate (ORR), Defined as Proportion of Patients Having Complete Response (CR) and Marrow Complete Response (mCR) After Completion of 3 Cycles of Study Drug..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01011283 |
| Phase | Phase 4 |
| Condition | Myelodysplastic Syndromes |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 26 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Eisai Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with intermediate- or high-risk myelodysplastic syndromes (MDS). The primary outcome identifies its population as the intent-to-treat population. The registry record does not give further eligibility details or explain how that analysis population was defined.
Intervention
Participants were assigned to decitabine, listed in the safety record as 20 mg/m^2. The study is described as randomized and parallel-group. Further details about administration, treatment duration, dose changes, or adherence are not reported in the registry record.
Comparator
The comparator was azacitidine, listed in the safety record as 75 mg/m^2. The registry record identifies the study as open-label, with no masking. It does not report additional details about treatment delivery or whether supportive care differed between groups.
Primary question
The stated purpose was to compare response to decitabine and azacitidine. The primary outcome was overall response rate (ORR), defined as the proportion with complete response (CR) or marrow complete response (mCR) after completion of 3 cycles of study drug, with a timeframe of 13 weeks. The registry record does not report the results or a treatment-effect estimate, so the comparative response question cannot be answered from the posted results.
3. Trial Design
This was a randomized, open-label, parallel-group phase 4 study comparing decitabine with azacitidine in people with intermediate- or high-risk MDS. The registry lists an enrollment of 26 and identifies Eisai Inc. as the sponsor. The listed start was 2009-11, the primary completion was 2011-01, and the study status is terminated. The registry record does not state why the study was terminated.
The parallel-group structure means participants were assigned to a treatment group rather than described as receiving both study drugs in sequence. Randomization is intended, in general, to reduce systematic differences between groups at the time of assignment. It does not guarantee that groups will be similar on every characteristic, particularly in a small study. The registry record does not report the randomization method, allocation concealment, stratification factors, or baseline characteristics needed to assess balance.
The study was open-label, and masking is listed as none. Participants and study personnel therefore were not masked to treatment assignment according to the registry design fields. The registry record does not describe whether outcome assessment was independently blinded. That matters because the outcome includes response categories assessed using clinical and marrow criteria; the extent to which assessment was protected from knowledge of treatment is not reported.
The listed treatment groups are decitabine 20 mg/m^2 and azacitidine 75 mg/m^2. The registry names the drugs and describes them as injections, but detailed schedules, duration, permitted co-interventions, dose modifications, and adherence are not reported in the registry record. The trial is marked terminated, but the reason, the timing of termination relative to outcome assessment, and any effect on follow-up are not reported. The record also does not describe the planned sample size or explain how enrollment related to the original design.
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 | Decitabine 20 mg/m^2 | Azacitidine 75 mg/m^2 |
|---|---|---|
| STARTED | 13 | 13 |
| COMPLETED | 2 | 2 |
| NOT COMPLETED | 11 | 11 |
Reasons for not completing this period:
| Reason | Decitabine 20 mg/m^2 | Azacitidine 75 mg/m^2 |
|---|---|---|
| Adverse Event | 4 | 2 |
| Progressive Disease | 0 | 2 |
| Terminated by Sponsor | 5 | 5 |
| Other | 2 | 2 |
Analysis population for the primary outcome, as defined in the registry: Intent to Treat Population
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 | Decitabine 20 mg/m^2 | Azacitidine 75 mg/m^2 | Total |
|---|---|---|---|---|
| Participants analysed | 13 | 13 | 26 | |
| Age, Continuous | years | 73.8 (SD 11.60) | 70.8 (SD 9.13) | 72.3 (SD 10.35) |
| Sex: Female, Male: Female | Participants | 2 | 3 | 5 |
| Sex: Female, Male: Male | Participants | 11 | 10 | 21 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 2 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 13 | 11 | 24 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): White | Participants | 13 | 12 | 25 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Response Rate (ORR), Defined as Proportion of Patients Having Complete Response (CR) and Marrow Complete Response (mCR) After Completion of 3 Cycles of Study Drug., measured over 13 Weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is overall response rate (ORR), expressed as a percentage of participants. It combines participants classified as having complete response (CR) with those classified as having marrow complete response (mCR) after completion of 3 cycles of study drug. The registry lists 13 weeks as the outcome timeframe and identifies the intent-to-treat population.
CR and mCR capture related but distinct response categories. The posted definition of CR uses bone marrow findings and peripheral blood measures. The mCR definition focuses on bone marrow findings and allows peripheral blood improvement to be noted separately. The criteria are based on the Modified International Working Group Response Criteria for Altering Natural History of Myelodysplastic Syndromes. The endpoint therefore summarizes whether participants met the specified response definition at the assessment point; it is not a measure of response duration, survival, symptom burden, or quality of life.
ORR is used in clinical research as a categorical summary of treatment response. It can make response status easier to compare across groups, but its interpretation depends on consistent assessment, complete outcome ascertainment, and a clear analysis population. The registry record does not report the number or proportion of participants meeting CR or mCR in either group, nor does it report a comparison between groups. The record separately describes ORR after completion of 6 cycles as a secondary outcome; that later assessment does not replace the primary endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record states a superiority objective: to demonstrate superiority of decitabine over azacitidine. That statement describes the study’s aim, not a demonstrated result. The primary endpoint is defined, but no primary outcome values or statistical analysis are posted. The record lists 0 analyses. Consequently, there is no reported group contrast, uncertainty interval, or test result with which to assess whether the observed data favor either treatment.
The enrollment was 26. That number describes enrollment and should not be treated as the number analyzed for the primary outcome. The registry labels the primary population as intent to treat, but does not report its composition, the number assessed at the primary endpoint, or how participants without an observed response assessment were handled. Group-specific response counts and percentages are not reported in the registry record.
Without group-level outcome estimates, the magnitude and precision of any response difference cannot be evaluated. A point estimate would describe the observed contrast, while a confidence interval would indicate the range of effects compatible with the data under the analysis assumptions. Neither is reported. The record also does not report a p-value or other inferential result. These missing quantities do not establish that the groups had identical outcomes; they mean that the posted record does not provide the response evidence needed to characterize a difference.
The study’s terminated status is relevant context, but the registry does not give the reason for termination or explain whether it affected enrollment, follow-up, or analysis. It would be inappropriate to infer that the study stopped because of efficacy, safety, recruitment, or another cause. Likewise, the available enrollment alone does not establish that the study was underpowered or that a particular result would have been detected.
The reported safety summaries are separate from the primary response comparison. They give counts of participants affected by serious and other adverse events in each treatment group, and list serious adverse event terms with percentages. These descriptive figures do not substitute for a complete safety analysis or establish a comparative safety effect. No death counts are reported. Overall, the posted record supports describing the design, endpoint definitions, and limited safety summaries, but not a conclusion about comparative response or the success of the stated superiority objective.
9. Statistical Methods Explained
Statistical methods are not reported in the registry record. The record identifies a randomized parallel-group design, an intent-to-treat primary population, and a percentage endpoint, but it does not state the planned analysis procedure, model, significance threshold, handling of missing outcomes, or approach to uncertainty. The explanations below are general statistical context; they should not be read as a description of methods used in this study.
What does randomization contribute?
General: Randomization uses a chance-based assignment process to reduce the possibility that treatment choice is systematically related to participant characteristics. Its purpose is to support a fair comparison by making treatment groups comparable on average across measured and unmeasured factors. Chance imbalance can still occur, and may be more consequential in a small study. Knowing that a trial was randomized does not reveal the precise sequence-generation method, whether assignment was concealed before enrollment, or whether the process was implemented as planned. Those details are not reported in the registry record.
How is a response percentage interpreted?
General: A response percentage is a proportion: the numerator is the number of participants meeting the response definition, and the denominator is the relevant analysis population with the outcome handled according to the study’s rules. The registry defines ORR as CR or mCR after completion of 3 cycles, but does not post the group-specific numerators or percentages. It also does not say how missing assessments, early discontinuation, or participants who did not complete the treatment period entered the denominator. Without those details and results, the response rate cannot be independently reconstructed.
General: A treatment comparison may be expressed as a difference between group response proportions or through another prespecified measure. The measure and its interpretation depend on the analysis plan. No treatment-effect estimate is posted for the primary outcome, so there is no basis for describing the size or direction of a response contrast. No unadjusted re-calculation is available from the posted primary outcome summary statistics.
What would uncertainty measures tell a reader?
General: A confidence interval conveys statistical uncertainty around an estimated effect under the model and assumptions used to calculate it. A wider interval generally indicates less precise estimation than a narrower interval. A p-value addresses how compatible the observed data are with a specified null model, conditional on the analysis assumptions; it does not measure the size or clinical importance of an effect. Neither a confidence interval nor a p-value is reported for the primary comparison. Their absence means precision and statistical evidence cannot be evaluated from the registry results.
Why does the analysis population matter?
General: An intent-to-treat analysis generally aims to retain participants in their randomized groups, regardless of treatment adherence, so that the comparison reflects assignment. The exact operational definition can vary, especially when outcome measurements are missing. Although the registry names an intent-to-treat population for the primary outcome, it does not give the analysis population’s group counts or explain how missing values and treatment discontinuation were handled. The label alone is not enough to verify the analysis.
What does the open-label design mean for interpretation?
General: When treatment assignment is known, decisions about care, reporting of symptoms, and evaluation of outcomes may be influenced by that knowledge. The extent of concern depends on the endpoint and safeguards used. This endpoint includes response categories based on specified disease criteria, but the registry record does not describe assessor masking or adjudication. It is therefore not possible to judge from the posted information whether outcome assessment was independent of treatment knowledge.
What can the adverse-event summaries establish?
General: Safety summaries may report how many participants experienced at least one event and may also classify events by type. Participant counts and event counts are not interchangeable: a participant may experience more than one event, and an event term may occur in more than one participant. The record gives affected-participant counts for serious and other adverse events by group, plus a list of serious event terms and percentages. It does not give the full event-level detail or a stated comparative safety analysis. These summaries should therefore be read descriptively, without treating the listed percentages as a complete account of event burden or as a causal comparison.
The registry’s sample-size assumptions describe a planning illustration based on an observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Such illustrations are planning calculations, not observed power and not a substitute for trial results. No sample-size justification or trial-specific statistical plan is reported in the registry record. The existence of planning assumptions does not establish what analysis was prespecified or performed.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies a primary ORR endpoint after completion of 3 cycles, with a 13-week timeframe, and a secondary ORR endpoint after completion of 6 cycles. The secondary definition also combines CR and mCR. No results are posted for either outcome, and the record lists 0 analyses. It does not report whether other outcomes or comparisons were planned beyond the measures described in the record.
When a study examines multiple outcomes, time points, subgroups, or treatment contrasts, the chance of a false-positive finding can increase if each is tested without accounting for multiplicity. General approaches can include prespecifying a hierarchy, adjusting inference, or identifying some results as exploratory. The registry record does not report whether any multiplicity strategy was planned or used. Because no analyses are posted, there is no reported inferential result to evaluate for multiplicity.
The primary population is labeled intent to treat, but the registry does not report the number analyzed, the number with an observed response, or how missing outcome data were handled. It does not say whether participants who stopped treatment early were assessed, counted as nonresponders, excluded, or handled by another rule. These details are essential because different missing-data rules can change a response proportion and the interpretation of the treatment comparison.
The study is marked terminated, but the registry does not report whether termination affected outcome collection or the analysis population. It also does not provide a protocol-level statistical analysis plan, interim-analysis information, or a sample-size justification. None of those details can be inferred from the endpoint descriptions or the posted safety counts. The missing information limits assessment of prespecification, completeness, and the robustness of any potential comparison.
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 |
|---|---|---|---|
| Decitabine 20 mg/m^2 | 7 | 13 | 53.8% |
| Azacitidine 75 mg/m^2 | 7 | 13 | 53.8% |
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 |
|---|---|
| Decitabine 20 mg/m^2 | 13 of 13 |
| Azacitidine 75 mg/m^2 | 13 of 13 |
Most frequent serious adverse event terms
| Event term | Organ system | Decitabine 20 mg/m^2 | Azacitidine 75 mg/m^2 |
|---|---|---|---|
| Pancytopenia | Blood and lymphatic system disorders | 3 of 13 | 1 of 13 |
| Febrile neutropenia | Blood and lymphatic system disorders | 2 of 13 | 2 of 13 |
| Thrombocytopenia | Cardiac disorders | 2 of 13 | 0 of 13 |
| Anemia | Blood and lymphatic system disorders | 1 of 13 | 1 of 13 |
| Pneumonia | Infections and infestations | 2 of 13 | 0 of 13 |
| Aspergillosis | Infections and infestations | 1 of 13 | 0 of 13 |
| Neutropenia sepsis | Infections and infestations | 0 of 13 | 1 of 13 |
| Diverticulitis | Infections and infestations | 0 of 13 | 1 of 13 |
| Sepsis | Infections and infestations | 1 of 13 | 0 of 13 |
| Acute respiratory failure | Respiratory, thoracic and mediastinal disorders | 1 of 13 | 0 of 13 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Decitabine 20 mg/m^2 | Azacitidine 75 mg/m^2 |
|---|---|---|---|
| Anemia | Blood and lymphatic system disorders | 7 of 13 | 5 of 13 |
| Neutropenia | Blood and lymphatic system disorders | 6 of 13 | 6 of 13 |
| Fatigue | General disorders | 5 of 13 | 7 of 13 |
| Thrombocytopenia | Blood and lymphatic system disorders | 6 of 13 | 5 of 13 |
| Nausea | Gastrointestinal disorders | 1 of 13 | 9 of 13 |
| Diarrhea | Gastrointestinal disorders | 4 of 13 | 5 of 13 |
| Vomiting | Gastrointestinal disorders | 0 of 13 | 8 of 13 |
| Leukopenia | Blood and lymphatic system disorders | 4 of 13 | 3 of 13 |
| Constipation | Gastrointestinal disorders | 3 of 13 | 3 of 13 |
| Pyrexia | General disorders | 3 of 13 | 2 of 13 |
Serious events with the highest arm-level rate: pancytopenia (23.1%), febrile neutropenia (15.4%), thrombocytopenia (15.4%), pneumonia (15.4%), anemia (7.7%).
The registry reports serious adverse events affecting 7 of 13 participants in the decitabine group and 7 of 13 participants in the azacitidine group. For other adverse events, it reports 13 of 13 participants affected in each group. These are descriptive participant counts, not a comparison adjusted for follow-up, exposure, severity, or other factors. The record does not provide a comparative statistical analysis of these figures.
The listed serious adverse event terms and percentages are pancytopenia, 23.1%; febrile neutropenia, 15.4%; thrombocytopenia, 15.4%; pneumonia, 15.4%; anemia, 7.7%; and aspergillosis, 7.7%. The registry listing does not assign these term-specific percentages to a particular treatment group, so they should not be interpreted as group-specific estimates. The record does not state whether participants could contribute more than one event term or provide event-level details such as timing, duration, or outcome.
Death counts are not reported in the registry record. The safety information is therefore limited to the posted affected-participant counts and listed serious event terms. It does not by itself establish how the treatments compare in overall safety.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, open-label comparison of decitabine and azacitidine was registered for intermediate- or high-risk MDS, with ORR after completion of 3 cycles as the primary outcome. It also establishes that the trial was terminated and that enrollment was 26. These registry entries describe the study and its registered aim; they do not show whether either treatment produced a higher response rate.
The primary result is not reported in the registry record. There are no posted response counts, proportions, treatment-effect estimates, confidence intervals, or p-values. Without those results, the size, direction, and precision of the treatment comparison are unknown from this record. The absence of a reported result should not be interpreted as evidence that there was no difference, nor as evidence that one treatment was superior.
The endpoint captures a specific response classification at a defined assessment point. It does not, by itself, show how long a response lasted, whether other clinical outcomes changed, or how participants experienced treatment. The registry’s secondary ORR outcome after completion of 6 cycles is also described without posted results. No broader clinical conclusion can be drawn from the response definitions alone.
The serious adverse event counts and listed event terms provide limited descriptive safety information. They do not constitute a full comparison of risks, and the registry does not report death counts or a statistical safety analysis. The open-label design and unreported assessment procedures are additional considerations when interpreting response classification.
Overall, the posted information is sufficient to identify the planned comparison, primary endpoint, and some adverse-event summaries. It is insufficient to determine the result of the superiority question or to judge the precision of any treatment effect. The reason for termination and the consequences for data collection and analysis are not reported in the registry record, so no explanation for the lack of posted efficacy results should be inferred.
13. Why This Trial Matters Statistically
This trial is statistically notable because its stated objective was a direct superiority comparison, while the registry record does not report the primary analysis. A well-defined objective and endpoint do not answer the research question in the absence of group results. Readers need the response counts, analysis population, treatment-effect estimate, and uncertainty to assess what the study observed.
The enrollment of 26 makes transparent reporting especially important. In general, estimates from small studies can be imprecise, and chance differences between randomized groups may remain. That general consideration is not evidence of a particular imbalance or a particular degree of uncertainty in this trial: the registry does not post baseline data, response estimates, or confidence intervals with which to assess those issues.
The endpoint also illustrates how a composite response definition can summarize more than one response category. CR and mCR are both included in the ORR definition, but the registry record does not report their separate contributions. A combined percentage may be useful for a prespecified response question, while separate category results can clarify what responses make up that summary. Those details are unavailable.
Finally, the terminated status, absence of posted outcome analyses, and limited description of missing-data handling constrain interpretation. They highlight why trial status alone cannot explain an absent result and why registry entries benefit from complete outcome reporting, analysis details, and a clear account of study completion. In this case, the study’s statistical importance lies less in a reported treatment effect than in the gap between a stated comparative objective and the results available in the registry record.
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 most important limitation for interpreting this trial is that the registry record does not report the primary response results. It lists the endpoint and analysis population but provides no group-specific ORR values or statistical comparison. The record also lists 0 analyses. As a result, the stated superiority objective cannot be evaluated using the posted efficacy information.
The study is marked terminated, but the reason for termination is not reported in the registry record. Nor does the record describe whether the termination affected enrollment, treatment exposure, outcome assessment, or follow-up. The enrollment is 26, but the numbers included in the primary analysis and with available response assessments are not reported. Enrollment should not be assumed to equal the analysis population.
The response endpoint is tied to completion of 3 cycles and a timeframe of 13 weeks. Details of assessment timing, assessor training, independent review, and handling of participants who did not complete the assessment are not reported. The record also does not report missing-data rules, protocol deviations, adherence, or treatment discontinuations. These omissions prevent assessment of how consistently response was measured and how incomplete data may have affected the outcome.
The study was open-label, with masking listed as none. Whether response assessors were masked or whether responses were adjudicated is not reported in the registry record. Randomization is stated, but the method, allocation concealment, stratification, and baseline characteristics are not reported. These design details would help readers evaluate implementation and group comparability.
Safety reporting is also limited. Serious and other adverse-event affected-participant counts are posted by group, along with serious event terms and percentages, but death counts are not reported. The record does not provide a complete account of event timing, severity, duration, exposure, or a comparative safety analysis. No protocol, detailed statistical plan, or sample-size justification is reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: To Demonstrate Superiority of Decitabine Over Azacitidine in Subjects With Intermediate- or High-risk MDS. — NCT01011283.
- Registry record last updated 2014-10-29; status last verified 2014-10.
- Results first posted 2013-09-18.
- 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 describes a randomized, open-label, parallel-group phase 4 study sponsored by Eisai Inc. It compared decitabine 20 mg/m^2 with azacitidine 75 mg/m^2 in people with intermediate- or high-risk MDS. Enrollment was 26; the listed start was 2009-11, the primary completion was 2011-01, and the status is terminated.
The primary outcome was ORR, defined using CR and mCR after completion of 3 cycles of study drug, with a 13-week timeframe and an intent-to-treat population. ORR after completion of 6 cycles was also listed as a secondary outcome. Primary response results and statistical analyses are not reported in the registry record. Safety information includes group-level participant counts for serious and other adverse events and a list of serious event terms with percentages. The reason for termination, death counts, and details of the statistical analysis are not reported.