Vidaza to Restore Hormone Thx Prostate: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vidaza to Restore Hormone Thx Prostate (NCT00384839), a na phase 2 study. The primary outcome is Percentage of Patients With PSA Doubling Time >=3 Months..

2. Clinical Question

The study’s stated purpose was to assess whether Vidaza could convert hormone-refractory prostate cancer to a hormone-responsive state. The registry describes assessment through the proportion of patients reaching the specified PSA doubling-time threshold. This is a biomarker-based question: it concerns the timing of change in prostate-specific antigen (PSA), rather than a direct comparison of survival or tumor response between treatment groups.

The registry also lists PSA response rate, objective response rate by RECIST, progression-free survival, 1-year overall survival, and changes in fetal hemoglobin over time as secondary outcomes. Their results are not reported in the registry record. The record does not report a comparator against which to judge what would have happened without azacitidine, so the clinical question is descriptive of outcomes in the treated group rather than a randomized estimate of treatment effect.

3. Trial Design

This was a phase II, single-group study of azacitidine for injectable suspension, also called Vidaza in the registry. The listed condition was prostate cancer, and the stated objective concerned hormone-refractory prostate cancer. The study was not masked, and its allocation field is NA. There is no separate control arm described in the registry record.

Enrollment is recorded as 36. The study status is COMPLETED. The recorded start was 2006-04, and primary completion was 2009-11. US Oncology Research is named as the sponsor. These administrative details describe the trial record but do not establish how many participants completed treatment, contributed data to the primary endpoint, or were included in each secondary analysis.

The primary outcome is the percentage of patients with a PSA doubling time of at least 3 months. Its specified timeframe is until progression or up to a maximum of 12 cycles, and its population is identified as evaluable. The record does not define the evaluable population, describe the treatment schedule, or report actual follow-up duration for individual participants. Those details are not reported in the registry record.

The registry lists six outcome measures and names five secondary outcomes: PSA response rate; objective response rate by RECIST; progression-free survival; 1-year overall survival; and changes in fetal hemoglobin with time. The record does not include analysis results for these outcomes. The study’s single-group design means the reported observations, if available, would describe participants receiving azacitidine; they would not form a like-for-like randomized comparison with an untreated or alternative-treatment group.

The registry record does not report a statistical analysis plan, sample-size justification, interim analyses, masking procedures beyond NONE, or further details of allocation. No additional design assumptions should be inferred from the phase label or the stated objectives.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Evaluable 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.

Population: ITT Population

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Patients With PSA Doubling Time >=3 Months., measured over Until progression or up to a maximum of 12 cycles.

The primary endpoint is the percentage of evaluable patients whose documented PSA doubling time is at least 3 months. PSA doubling time describes the interval over which a measured PSA level doubles. In this study, the endpoint turns that continuous timing measure into a threshold-based outcome: each evaluable patient is classified according to whether the specified interval is reached. The registry’s timeframe is until progression or up to a maximum of 12 cycles.

As a general statistical point, a proportion is a way to summarize how often a defined event or threshold occurs in a particular population. It can provide a compact description of a biomarker-related outcome, but the result depends on the endpoint definition, the population included, and the completeness and timing of measurements. The registry identifies the primary population as evaluable but does not define the criteria for evaluation or report the number of evaluable participants.

The registry describes the endpoint as a percentage and specifies a 95% confidence interval as its dispersion measure. A confidence interval conveys uncertainty around an estimated quantity; it is not a guarantee that the true value lies within the particular interval. The endpoint estimate and its confidence interval are not reported in the registry record, so neither the observed proportion nor its precision can be assessed from the posted results.

The endpoint was used to assess the study’s stated question about hormonal responsiveness. It is not itself a direct comparison of treatment groups, and the registry does not report a concurrent control group. Nor should this PSA-based measure be treated as interchangeable with the listed secondary outcomes, such as objective response or survival.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary endpoint summarize?

The primary outcome is a threshold-based proportion: the percentage of evaluable patients whose documented PSA doubling time reached at least 3 months. The endpoint is not reported as a mean change in PSA or as a comparison between treatment groups. Each participant’s status relative to the threshold contributes to the proportion, according to the endpoint definition. The registry specifies a 95% confidence interval as the uncertainty measure, but neither the estimate nor the interval is reported in the registry record.

General statistical explanation: a confidence interval is a range of values compatible with the observed data under the method used to construct it. Its width reflects both the amount of information and the variability in the data. It should be read alongside the point estimate and the population analyzed. Since those endpoint results and the evaluable count are missing from the registry record, the interval’s width and the precision of the primary estimate cannot be evaluated.

Why does the analysis population matter?

The primary outcome identifies the evaluable population, but the registry record does not explain what makes a participant evaluable. For a biomarker endpoint, the availability and timing of measurements can affect whether the outcome can be classified. General statistical explanation: excluding participants without sufficient measurements can change the population represented by an estimate, especially if missingness is related to disease status, follow-up, or treatment. The record does not report the number excluded, reasons for missing measurements, or a missing-data strategy, so their implications cannot be assessed.

The enrollment count is 36, while the safety group lists 34 at risk. Those figures refer to different recorded quantities; the record does not explain the difference. They should not be substituted for one another when interpreting an endpoint or safety percentage. The number analyzed for the primary endpoint is not reported in the registry record.

What can be inferred from the design?

The study is listed as single-group, with no masking and allocation recorded as NA. General statistical explanation: a single-group study can describe outcomes among participants receiving the intervention, but it lacks a concurrent randomized group to estimate what would have happened under another treatment or without the intervention. Changes over time may reflect several influences, and a within-group observation does not by itself identify which influence caused a change. The registry record does not describe a comparator or a randomized treatment contrast.

Non-masking can matter when outcomes or their assessment involve judgment or participant reporting. The primary endpoint is based on PSA measurements, but the registry record does not describe measurement procedures, assessor roles, or safeguards against assessment bias. No conclusion about the practical influence of masking can be drawn from the record alone.

How should the listed outcomes be treated?

The registry names PSA response rate, objective response rate by RECIST, progression-free survival, 1-year overall survival, and changes in fetal hemoglobin with time as secondary outcomes. It also records six outcome measures. Results and analytic details for those outcomes are not reported in the registry record. General statistical explanation: distinct outcomes can capture different aspects of disease and can have different measurement scales and time structures. A response proportion, a time-to-event outcome, and a longitudinal biomarker outcome are not interchangeable, so one cannot infer the missing results of one from another.

When multiple outcomes are examined, the chance of at least one apparently noteworthy result can increase if many statistical tests are conducted. General statistical explanation: multiplicity is the issue of interpreting several tests or estimates together. The registry record does not report a multiplicity adjustment, a testing hierarchy, or which outcomes were formally tested. It is therefore not possible to determine how multiple outcomes were handled or how any statistical claims were prioritized.

What is known about the analysis plan?

The registry record does not report the statistical analysis plan, the method used to calculate the primary confidence interval, the handling of censoring or missing observations, or any interim analyses. It also does not report a sample-size justification. These omissions prevent a detailed assessment of whether the planned analyses matched the endpoint structure and how departures from a plan, if any, were handled.

General statistical explanation: over-dispersion occurs when observed variability in count or proportion data exceeds what a simple model assumes. If a statistical method assumes less variability than the data contain, uncertainty can be understated. Whether this issue is relevant depends on the data and model. The registry record does not report a model for the primary endpoint, so over-dispersion cannot be assessed as a trial-specific concern.

The record contains no reported analysis results for the primary endpoint, and the number of analyses is recorded as zero. That entry does not provide enough detail to determine whether analyses were conducted but not posted, or whether no analyses were registered in that field. It should not be used to infer that the study collected no outcome data. The primary outcome result remains not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and several secondary outcomes, but it does not report a statistical analysis plan, a hierarchy for testing outcomes, or a method for controlling multiplicity. General statistical explanation: when multiple hypotheses are tested, the probability of encountering at least one result that appears statistically noteworthy can rise. Adjustments or a prespecified testing order can address this issue, but the registry record does not say whether either approach was used. No conclusion about multiplicity control can be drawn.

The primary endpoint identifies an evaluable population. The registry does not define eligibility for that population, report its size, or state how patients without adequate PSA measurements were handled. It does not report missing-data methods, reasons for missing data, or sensitivity analyses. These details are important because the proportion reaching a threshold can depend on which participants have classifiable outcomes. The primary result and its confidence interval are not reported in the registry record.

The record also does not describe analysis populations for the secondary outcomes, the number of participants contributing to each, or how incomplete follow-up was handled for time-to-event outcomes. General statistical explanation: time-to-event analyses often account for participants whose event has not been observed by the end of their follow-up, but the registry record does not specify whether or how such methods were applied in this study.

Enrollment is recorded as 36, and the safety group lists 34 at risk. The record does not explain this difference or link it to the evaluable population. The number of participants analyzed for any efficacy outcome is not reported in the registry record. These absences limit assessment of missingness and analysis-set selection; they do not establish that data were missing or that a particular handling method was used.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: nausea (2.9%), vomiting (2.9%).

The registry lists one participant with a serious adverse event among 34 at risk in the Vidaza group. It lists 31 participants affected by other adverse events among 34 at risk. These counts describe the safety group as recorded; they do not establish how many distinct event episodes occurred or whether an individual experienced more than one event. The record does not explain why the safety denominator differs from the enrollment count of 36.

Nausea and vomiting are each listed among the top serious adverse-event terms at 2.9%. These percentages are reported as such in the registry record. The record does not provide the full serious-event listing or further details about event timing, severity grading, relationship to treatment, or outcome. Deaths are not reported in the registry record.

General statistical explanation: adverse-event counts are descriptive and need context, including the population monitored, duration of observation, event definitions, and whether participants can contribute multiple events. A single-group safety summary does not provide a randomized comparison of risks. The posted counts therefore describe reported events in the recorded group; they do not establish comparative safety or causation.

12. What the Result Does, and Does Not, Mean

The registry record describes a completed phase II, single-group study of azacitidine in prostate cancer and identifies a primary PSA doubling-time endpoint. It does not report the primary endpoint result, its confidence interval, or the number of evaluable participants. As a result, the central outcome cannot be quantified or interpreted for magnitude and precision from the registry information. The absence of a posted result should not be read as a null finding.

The record also names secondary outcomes but does not report their results. It therefore does not establish what was observed for PSA response, RECIST objective response, progression-free survival, 1-year overall survival, or fetal hemoglobin over time. Nor does it provide enough analysis detail to assess missing data, multiplicity, or the statistical methods used for those outcomes.

General statistical interpretation: even a clearly estimated change within a treated group would not, by itself, establish that the intervention caused that change. A control group helps distinguish treatment effects from other influences over time. This study is listed as single-group and has no separate comparator, so the registry design does not support a randomized between-group estimate.

The safety summary reports one serious adverse event affected among 34 at risk and other adverse events affecting 31 among 34 at risk. Nausea and vomiting are listed as serious-event terms at 2.9% each. These figures are useful as descriptive registry entries, but the record does not provide comparative safety data, detailed event narratives, or death counts.

In sum, the record allows a description of the study question, design, and limited safety counts, but not a conclusion about efficacy or comparative benefit. The stated aim of assessing hormonal responsiveness is an objective, not a reported result. A clinical interpretation would require the missing endpoint results and fuller information about analysis populations and methods.

13. Why This Trial Matters Statistically

This trial illustrates the distinction between a clearly stated research question and a result that can be statistically interpreted. The registry defines a threshold-based primary outcome, a population, and a follow-up window. Yet the primary estimate, confidence interval, and evaluable sample size are not reported in the registry record. Without those elements, readers cannot assess either the observed proportion or the uncertainty around it.

The single-group design also makes the comparison question important. Outcomes among participants receiving azacitidine can describe what was observed in that group, but there is no separate randomized group in this record to support a controlled treatment contrast. General statistical explanation: random allocation helps balance known and unknown factors between groups on average, while an uncontrolled before-and-after or single-group pattern may also reflect changes unrelated to the intervention.

The endpoint itself offers a useful example of how a continuous biological measure can be converted to a threshold outcome. Such a definition can be clinically interpretable, but its interpretation depends on clear measurement rules, participant inclusion criteria, and transparent reporting of the estimate and its uncertainty. The registry record does not report the operational definition of evaluability, the relevant measurement details, or the endpoint result.

Finally, the safety entries show why denominators and outcome definitions matter. Enrollment is 36, while 34 are listed at risk for the safety group, and the record does not explain the difference. The reported event counts should be read as descriptive rather than comparative. Together, these features make the study a useful case for distinguishing design, planned outcomes, posted results, and the limits of what a registry record can establish.

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 consequential limitation for interpretation is that the primary endpoint result is not reported in the registry record. The estimate, 95% confidence interval, and evaluable sample size are unavailable, so the magnitude and precision of the principal outcome cannot be judged. The results of the named secondary outcomes are also not reported.

The study is single-group, with allocation listed as NA and no masking. The record therefore does not describe a randomized control comparison. Any within-group changes, if documented elsewhere, would not alone isolate the effect of azacitidine from other influences. This interpretation is limited to the design recorded; the registry does not provide further details about concurrent care or measurement procedures.

The primary population is described as evaluable, but the record does not define that term or say how many participants qualified. Enrollment is 36, while the safety group lists 34 at risk, and the reason for that difference is not reported. The registry also does not describe missing-data handling, endpoint-specific analysis populations, follow-up completeness, or methods for censoring.

Other trial-specific information needed to assess analysis choices is not reported in the registry record, including the statistical analysis plan, sample-size justification, interim analyses, and multiplicity handling. The record gives limited safety information: event counts and the named serious terms, but not detailed event characteristics or death counts. These gaps constrain interpretation and should not be filled by assumptions about the protocol or analyses.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Vidaza to Restore Hormone Thx Prostate — NCT00384839.
• Registry record last updated 2018-10-25; status last verified 2018-09.
• Results first posted 2018-10-25.
• 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.

18. Record Summary

NCT00384839 is a completed phase II, single-group study of azacitidine for injectable suspension, identified as Vidaza, in prostate cancer. US Oncology Research is listed as sponsor. Enrollment is recorded as 36; the start is recorded as 2006-04 and primary completion as 2009-11.

The primary outcome is the percentage of evaluable patients with a PSA doubling time of at least 3 months, measured until progression or up to a maximum of 12 cycles. Its result and confidence interval are not reported in the registry record. The record lists secondary outcomes covering PSA response, RECIST objective response, progression-free survival, 1-year overall survival, and fetal hemoglobin changes, but does not report their results.

The safety group lists one serious adverse event affected and 31 affected by other adverse events among 34 at risk. Nausea and vomiting are each listed among the top serious terms at 2.9%. Deaths are not reported in the registry record. The single-group design does not provide a randomized comparator for interpreting treatment effects.