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 Study of Azacitidine to Evaluate Safety and Effectiveness for Chinese Patients With Higher Risk Myelodysplastic Syndrome (NCT01599325), a na phase 2 study. The primary outcome is Percentage of Participants With a Hematologic Response Based on the International Working Group (IWG) Criteria for Myelodysplastic Syndrome (MDS) and Programmatically Assessed by the Sponsor Using Clinically Relevant Data..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01599325 |
| Phase | Phase 2 |
| Condition | Myelodysplastic Syndrome (MDS) |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 72 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Celgene |
| Results posted | Yes |
2. Clinical Question
Population
Adults in China with higher-risk myelodysplastic syndromes were the intended study population. The primary endpoint population is described as the intent-to-treat group, including all participants enrolled in the study. The registry record lists 72 participants as enrolled.
Intervention
Participants received subcutaneous azacitidine at 75 mg/m^2/day for 7 days every 28 days. Treatment was planned to continue until disease progression, adverse events, withdrawal of consent, death, loss to follow-up, or protocol violation.
Comparator
There was no comparator arm: the study is recorded as single-group, with no allocation and no masking. The observed outcomes therefore describe participants treated in this study; they do not provide a randomized comparison with another treatment or with no treatment.
Primary question
The primary question was what percentage of enrolled participants had a hematologic response, assessed using the International Working Group criteria for myelodysplastic syndromes and sponsor-programmed clinical data. The response definition includes complete response, partial response, and stable disease. The registry record describes assessment timing but does not report the observed percentage or confidence interval.
3. Trial Design
This was a phase 2, open-label, single-arm study of subcutaneous azacitidine in adult Chinese participants with higher-risk myelodysplastic syndromes. The registry record gives an enrollment of 72 and labels the study completed. It lists Celgene as the sponsor. Allocation is recorded as not applicable, consistent with the single-group design, and masking is recorded as none.
Azacitidine was administered at 75 mg/m^2/day subcutaneously for 7 days every 28 days. The arm description states that treatment could continue until disease progression, adverse events, withdrawal of consent from further treatment, withdrawal of consent, death, loss to follow-up, or protocol violation. These are the stated stopping conditions; the registry record does not provide participant-level treatment duration or explain how often each stopping condition occurred.
The study start date is 2012-07-24, and the primary completion date is 2015-01-29. The primary endpoint description says response was initially assessed at the end of cycle 6, then every 4 cycles, with the stated timeframe extending up to 29 January 2015 and 894 days. The record does not provide a randomized control group or a contemporaneous comparator. Any interpretation of outcomes must therefore focus on the treated group and avoid attributing differences to treatment relative to an alternative.
The registry lists 18 outcome measures, including the primary hematologic-response measure and secondary measures concerning transfusions, infections, overall survival, treatment-emergent adverse events, and azacitidine pharmacokinetics. The record does not provide a detailed statistical analysis plan, a sample-size justification, or a description of planned interim analyses.
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.
Primary Parent Phase
| Stage | Azacitidine |
|---|---|
| STARTED | 72 |
| Intent to Treat (ITT) Population | 72 |
| Pharmacokinetic (PK) Population | 12 |
| COMPLETED | 15 |
| NOT COMPLETED | 57 |
Reasons for not completing this period:
| Reason | Azacitidine |
|---|---|
| Adverse Event | 5 |
| Disease Progression | 7 |
| Withdrawal by Subject | 20 |
| Death | 13 |
| Protocol Violation | 1 |
| Lack of Therapeutic Effect | 9 |
| Other | 2 |
Extension Phase
| Stage | Azacitidine |
|---|---|
| STARTED | 15 |
| COMPLETED | 0 |
| NOT COMPLETED | 15 |
Reasons for not completing this period:
| Reason | Azacitidine |
|---|---|
| Study Closure | 1 |
| Stopped to Receive Stem Cell Transplant | 1 |
| Lack of Therapeutic Effect | 4 |
| Disease Progression | 1 |
| Withdrawal by Subject | 8 |
Analysis population for the primary outcome, as defined in the registry: Intent to Treat (ITT) includes all participants who were enrolled into the study.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: ITT includes all participants who had been screened and enrolled into the study.
| Characteristic | Unit | Azacitidine |
|---|---|---|
| Participants analysed | 72 | |
| Age, Continuous | years | 54.3 (SD 11.78) |
| Sex: Female, Male: Female | Participants | 34 |
| Sex: Female, Male: Male | Participants | 38 |
| International Prognostic Scoring System (IPSS) Risk Classification: Low (0) | Participants | 0 |
| International Prognostic Scoring System (IPSS) Risk Classification: Intermediate 1 (0.5-1.0) | Participants | 0 |
| International Prognostic Scoring System (IPSS) Risk Classification: Intermediate 2 (1.5-2.0) | Participants | 47 |
| International Prognostic Scoring System (IPSS) Risk Classification: High (>=2.5) | Participants | 25 |
| French-American-British classification (FAB): RAEB=Refractory anemia with excess blasts | Participants | 63 |
| French-American-British classification (FAB): RAEB in transformation | Participants | 8 |
| French-American-British classification (FAB): Modified CMML=Chronic myelomonocytic leukemia | Participants | 1 |
| MDS World Health Organization (WHO) Classification: RAEB-1=Refractory anemia with excess blasts | Participants | 14 |
| MDS World Health Organization (WHO) Classification: RAEB -2 with MPD=Myeloproliferative disease | Participants | 50 |
| MDS World Health Organization (WHO) Classification: Acute Myelogenous Leukemia (AML) | Participants | 7 |
| MDS World Health Organization (WHO) Classification: CMML | Participants | 1 |
| MDS World Health Organization (WHO) Classification: MDS and myeloproliferative disease (MPD) | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With a Hematologic Response Based on the International Working Group (IWG) Criteria for Myelodysplastic Syndrome (MDS) and Programmatically Assessed by the Sponsor Using Clinically Relevant Data., measured over Response initially assessed at end of cycle 6, then every 4 cycles; Up to 29 January 2015; 894 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with a hematologic response, assessed using International Working Group criteria for myelodysplastic syndromes and programmatically evaluated by the sponsor using clinically relevant data. The stated response category includes complete response, partial response, and stable disease. These categories combine changes in marrow and peripheral blood findings with evidence about disease progression or stability; they are not interchangeable clinical states.
The registry definition specifies complete response using marrow findings and peripheral blood values sustained for at least 2 months. Partial response requires specified marrow improvement relative to pretreatment, alongside peripheral blood criteria. Stable disease is defined as failure to achieve partial response without evidence of progression for at least 2 months. The record also describes failure, relapse, disease progression, and transformation to acute myelogenous leukemia, which help distinguish response from worsening or loss of response.
A percentage endpoint expresses how common the defined response was in the stated analysis population. The registry identifies that population as intent to treat, including all enrolled participants. Such an endpoint can describe the frequency of a response under the study’s assessment rules, but its meaning depends on consistent evaluation and complete outcome classification. The registry record does not report the observed response percentage or its 95% confidence interval. It therefore does not allow readers to quantify the primary endpoint from the registry information alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The available record establishes the study setting and the intended primary outcome, but it does not give the observed primary response percentage or its 95% confidence interval. Without those values, the magnitude and precision of the primary endpoint cannot be described. The response definition is available, as is the timing of assessments, but an endpoint definition is not a result.
The study is single-arm and open-label. Its primary outcome can describe the proportion of enrolled participants classified as having complete response, partial response, or stable disease under the stated criteria. It cannot, on its own, estimate how that proportion differs from what would have occurred under another treatment or without treatment. The registry record lists no like-for-like control group, and the posted findings should not be read as a randomized treatment comparison.
Precision would ordinarily be assessed using the confidence interval around a response percentage. A confidence interval communicates the range of values compatible with the observed data under the statistical method used; it does not remove limitations in study design or endpoint assessment. Here, the endpoint is listed as having a 95% confidence interval, but the interval itself is not reported in the registry record. No conclusion about precision can be drawn from the interval label alone.
The record lists an enrollment of 72 and identifies the primary population as intent to treat. That provides context for the study’s planned endpoint population, but does not supply the number with an evaluable response, the number classified in each response category, or how missing assessments were handled. The registry record does not report these details. It also does not give the sponsor’s numerical primary analysis result, so the endpoint cannot be reconstructed from the information recorded.
Safety information is reported separately. In the parent-phase group, the record lists 38 participants with serious adverse events and 13 deaths; it also lists serious-event terms with percentages. These figures describe recorded events in the study group and do not establish that azacitidine caused each event. The extension-phase figures are for a separate extension group and should not be merged with or treated as a controlled comparison against the parent phase.
Overall, the registry record supports a description of design, treatment, endpoint definitions, and selected safety counts. It does not provide enough primary efficacy information to characterize the observed response rate, and the single-arm design does not support a comparative treatment-effect estimate.
9. Statistical Methods Explained
The primary endpoint is a percentage: the fraction of participants classified as having the specified hematologic response, expressed as a percentage. The response classification combines complete response, partial response, and stable disease under the stated International Working Group criteria. The registry record says the sponsor programmatically assessed the endpoint using clinically relevant data. It does not describe the programming rules, data checks, adjudication process, or handling of ambiguous assessments.
What does a confidence interval add?
A confidence interval is a statistical expression of uncertainty around an estimate. For a percentage, it helps distinguish a relatively precise estimate from one that is compatible with a wider range of underlying response frequencies. It does not mean that the true value has a specified probability of lying within that particular interval. The registry identifies a 95% confidence interval for the primary measure, but does not report its limits or the method used to construct it. Consequently, neither the estimate nor its precision can be assessed from the registry record.
Why does the single-arm design matter?
In a single-arm study, outcomes are observed among participants who receive the study intervention, without a randomized comparator group. The resulting estimate is descriptive of the study population and its follow-up. It does not separate the influence of treatment from other explanations, such as participant characteristics, disease course, supportive care, assessment practices, or changes over time. Those considerations are general features of interpreting uncontrolled studies, not claims about what occurred in this particular study. The record lists allocation as not applicable and masking as none.
Open-label means that masking is not part of the recorded design. For outcomes that require clinical judgment or interpretation of clinical data, knowledge of treatment can be relevant to assessment. The registry states that the sponsor programmatically assessed the response using clinically relevant data, but does not explain how open-label assessment was managed or whether response classification received independent review. That process is not reported in the registry record.
How should the response criteria be read?
The endpoint groups complete response, partial response, and stable disease. The stated definitions refer to marrow findings, peripheral blood values, duration, and progression. A combined response percentage can be useful as a summary, but it conceals the distribution across its component categories unless those results are reported separately. The registry record does not give category-specific counts or percentages. Its definitions also include failure, relapse, progression, and transformation, but do not report how many participants met those outcomes.
Timing matters because response can change during follow-up. The registry describes an initial assessment at the end of cycle 6, followed by assessment every 4 cycles, with a timeframe up to 29 January 2015 and 894 days. This defines the stated assessment schedule and timeframe, but does not tell readers how many assessments each participant completed, whether all participants had the same follow-up, or how a participant’s response was summarized across assessments. Those details are not reported in the registry record.
What can safety percentages tell readers?
A percentage for an adverse-event term describes its frequency under the registry’s reporting convention. Interpretation depends on the population and observation period used as the denominator, and whether events are counted by participant or by occurrence. The record lists percentages for serious-event terms and reports group-level counts, but does not give the event-term counts or explain the denominator and coding conventions for each percentage. Those term percentages should therefore be read as reported, not reverse-engineered into counts.
General statistical practice distinguishes an adverse event occurring during a study from an event shown to have been caused by the intervention. A registry count alone does not establish causality. Safety comparisons also require comparable groups and observation conditions; this record describes a single-arm parent phase and an extension phase, not a randomized safety comparison.
What is not described about the analysis?
The registry lists 18 outcome measures and zero analyses. It does not report the statistical analysis plan, the confidence-interval procedure, adjustment for covariates, rules for censoring or missing data, or multiplicity handling. These omissions mean that readers cannot determine from the registry record which planned analysis choices were made or whether results were prespecified. General explanations of confidence intervals and design limitations do not fill in those study-specific details.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 18 outcome measures, spanning response, transfusions, infections, overall survival, adverse events, and pharmacokinetics. When a study examines multiple outcomes, there can be multiple opportunities to identify a result that appears notable by chance. Whether and how to address that issue depends on the prespecified analysis strategy, the hierarchy of outcomes, and the intended interpretation. The registry record does not report a multiplicity procedure or clarify whether any secondary outcomes were designated as confirmatory.
The record lists zero analyses. It does not provide a statistical analysis plan or enough detail to establish which analyses were prespecified, whether any analyses were exploratory, or whether interim analyses were conducted. These points are not reported in the registry record and should not be inferred from the number or types of listed outcomes.
The primary population is described as intent to treat and includes all enrolled participants. That definition identifies the intended population, but does not explain how missing response assessments, withdrawal, or incomplete follow-up were handled in the endpoint calculation. The registry record does not report the number of participants with missing primary outcome data, the assumptions used for missing values, or any sensitivity analyses. It also does not state whether participants without an observed response were counted in a particular category.
For outcomes such as overall survival, statistical handling can depend on follow-up and censoring rules; the registry lists Kaplan-Meier estimates among the secondary outcomes but does not provide those rules or results in the record. For the primary response percentage, the absence of missing-data methods and the numerical result limits interpretation of both the estimate and its uncertainty.
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 |
|---|---|---|---|
| Azacitidine - Parent Phase | 38 | 72 | 52.8% |
| Azacitdine - Extension Phase | 5 | 15 | 33.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Azacitidine - Parent Phase | 13 of 72 |
| Azacitdine - Extension Phase | 0 of 15 |
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 |
|---|---|
| Azacitidine - Parent Phase | 72 of 72 |
| Azacitdine - Extension Phase | 14 of 15 |
Most frequent serious adverse event terms
| Event term | Organ system | Azacitidine - Parent Phase | Azacitdine - Extension Phase |
|---|---|---|---|
| Pneumonia | Infections and infestations | 11 of 72 | 1 of 15 |
| Febrile neutropenia | Blood and lymphatic system disorders | 5 of 72 | 0 of 15 |
| Thrombocytopenia | Blood and lymphatic system disorders | 4 of 72 | 1 of 15 |
| Agranulocytosis | Blood and lymphatic system disorders | 4 of 72 | 0 of 15 |
| Lung infection | Infections and infestations | 2 of 72 | 2 of 15 |
| Upper respiratory tract infection | Infections and infestations | 4 of 72 | 0 of 15 |
| Anaemia | Blood and lymphatic system disorders | 1 of 72 | 2 of 15 |
| Cardiac failure | Cardiac disorders | 2 of 72 | 1 of 15 |
| Mouth haemorrhage | Gastrointestinal disorders | 3 of 72 | 0 of 15 |
| Pyrexia | General disorders | 3 of 72 | 0 of 15 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Azacitidine - Parent Phase | Azacitdine - Extension Phase |
|---|---|---|---|
| Thrombocytopenia | Blood and lymphatic system disorders | 52 of 72 | 10 of 15 |
| Leukopenia | Blood and lymphatic system disorders | 48 of 72 | 10 of 15 |
| Neutropenia | Blood and lymphatic system disorders | 48 of 72 | 6 of 15 |
| Anaemia | Blood and lymphatic system disorders | 38 of 72 | 6 of 15 |
| Upper respiratory tract infection | Infections and infestations | 27 of 72 | 1 of 15 |
| Constipation | Gastrointestinal disorders | 22 of 72 | 1 of 15 |
| Pyrexia | General disorders | 21 of 72 | 2 of 15 |
| Nausea | Gastrointestinal disorders | 19 of 72 | 3 of 15 |
| Pneumonia | Infections and infestations | 19 of 72 | 1 of 15 |
| Diarrhoea | Gastrointestinal disorders | 15 of 72 | 3 of 15 |
Serious events with the highest arm-level rate: pneumonia (15.3%), anaemia (13.3%), lung infection (13.3%), febrile neutropenia (6.9%), cardiac failure (6.7%).
For the parent phase, the registry lists 72 participants at risk for serious adverse events and 38 affected; it also lists 72 at risk and 72 affected for the other adverse-event field. The record reports 13 deaths for this group. These are registry counts, and the record does not provide further detail about timing, cause, seriousness criteria, or attribution for each death or event.
For the extension phase, the registry lists 15 participants at risk for serious adverse events and 5 affected; it lists 15 at risk and 14 affected for the other adverse-event field, and 0 deaths. This extension group is not a randomized control group. Its figures should not be interpreted as a direct comparison with the parent-phase figures: the record does not establish comparable follow-up, eligibility, or observation conditions between the groups.
The listed serious-event terms include pneumonia (15.3%), anaemia (13.3%), lung infection (13.3%), febrile neutropenia (6.9%), cardiac failure (6.7%), and thrombocytopenia (6.7%). The registry does not report the corresponding term counts or explain the denominator used for each percentage. These figures describe reported serious-event terms; they do not establish that the events were caused by azacitidine. The registry record does not give enough information to assess event timing, recurrence, or individual clinical circumstances.
12. What the Result Does, and Does Not, Mean
The registry record describes a study of azacitidine in adult Chinese participants with higher-risk myelodysplastic syndromes, using an open-label, single-arm phase 2 design. It specifies a dose and schedule, describes the primary hematologic-response definition, and lists selected safety counts and serious-event percentages. These details clarify what the study set out to observe and how the primary response was defined.
The record does not report the numerical primary response percentage or its 95% confidence interval. It therefore does not allow readers to assess the observed frequency of response or its statistical precision from the registry record. A listed endpoint and a stated confidence-interval type cannot substitute for the missing estimate and interval.
Even if a response percentage is available elsewhere, the design would remain uncontrolled. A single-arm response estimate describes the studied participants under the study’s treatment and assessment conditions; it does not show how outcomes would compare with another treatment. Differences between treated participants and a hypothetical or external group cannot be interpreted as a randomized treatment effect.
The safety figures also require careful interpretation. They identify reported counts and percentages but do not establish causation, and the extension-phase data are not a like-for-like control comparison. The registry record does not explain event-term denominators or provide participant-level timing and attribution details.
Accordingly, the record supports a description of design, treatment, endpoint criteria, and selected reported safety information. It does not support a quantitative conclusion about the primary response result, a precise estimate of its uncertainty, or a comparative claim about benefit or harm.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of how a clinical question is shaped by its design and endpoint definition. The record specifies a target population, treatment schedule, response criteria, assessment timing, and intent-to-treat population. Those details are necessary for understanding what a reported response percentage would represent.
The single-arm design also makes the limits of descriptive endpoints especially clear. A response percentage can summarize outcomes among participants receiving the intervention, but it cannot establish a contrast with a concurrent randomized control group when none is recorded. The open-label design and sponsor-programmed assessment are relevant context; the registry does not describe whether independent review or other assessment safeguards were used.
The response endpoint combines complete response, partial response, and stable disease. This illustrates an important statistical reading issue: a composite category can simplify reporting while bringing together states defined by different clinical findings. Component results would help readers understand what contributed to an overall response classification, but the registry record does not report those component counts.
Finally, statistical interpretation depends on results as well as design. Although the primary endpoint is associated with a 95% confidence interval, the registry record does not report the estimate or interval. Without them, the result’s magnitude and precision cannot be evaluated. The record therefore illustrates why endpoint definitions, population rules, analysis methods, and numerical findings all matter when assessing a clinical study.
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 for interpreting efficacy is that the registry record does not report the primary response percentage or its 95% confidence interval. It also does not provide category-specific response results, missing-outcome counts, or details of how response assessments were summarized over time. The endpoint definition and assessment schedule are described, but these do not provide the observed result.
The single-arm, open-label design has no randomized comparator. It supports description of outcomes in the treated study group but does not support a controlled estimate of the treatment’s effect relative to another option. The record does not describe masking or independent review of the sponsor-programmed response assessment beyond stating that masking was none and that clinically relevant data were used.
Several analysis details are not reported in the registry record, including the statistical analysis plan, confidence-interval method, multiplicity handling, missing-data approach, and any interim analyses. The listed intent-to-treat population includes all enrolled participants, but the record does not say how participants without an observed assessment were handled. The record also lists 18 outcome measures and zero analyses, without explaining the analysis status of each outcome.
Safety interpretation is limited by the absence of event-level detail, term-specific counts, denominator explanations for the listed percentages, and attribution information. The parent and extension groups are not a randomized comparison, and the record does not establish comparable follow-up between them. These limitations constrain interpretation of both event frequency and differences between phases.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of Azacitidine to Evaluate Safety and Effectiveness for Chinese Patients With Higher Risk Myelodysplastic Syndrome — NCT01599325.
- Registry record last updated 2019-03-19; status last verified 2019-03.
- Results first posted 2016-02-29.
- 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, open-label, single-arm phase 2 study of subcutaneous azacitidine in adult Chinese participants with higher-risk myelodysplastic syndromes. Enrollment is listed as 72. Treatment was specified as 75 mg/m^2/day for 7 days every 28 days, with continuation until listed stopping conditions. The primary outcome was the percentage with a hematologic response under International Working Group criteria, assessed initially at the end of cycle 6 and then every 4 cycles.
The record identifies an intent-to-treat population and a 95% confidence interval for the primary endpoint, but does not report the response percentage or interval. It lists 18 outcome measures and zero analyses. Safety information includes parent-phase and extension-phase counts, deaths, and selected serious-event percentages. These data are descriptive and do not constitute a randomized comparison. The registry record does not report the statistical analysis plan, missing-data methods, multiplicity handling, or detailed event attribution.