Idarubicin, Cytarabine, and Pravastatin Sodium in Treating Patients With Acute Myeloid Leukemia or Myelodysplastic Syndromes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Idarubicin, Cytarabine, and Pravastatin Sodium in Treating Patients With Acute Myeloid Leukemia or Myelodysplastic Syndromes (NCT01831232), a na na study. The primary outcome is Number of Participants With Good Complete Remission (CR).

2. Clinical Question

3. Trial Design

This was a completed, single-group study sponsored by Fred Hutchinson Cancer Center. The registry lists a planned enrollment of 24 and records the trial as open-label, with masking listed as none. Allocation is listed as NA; there is no parallel control group for a treatment comparison. The registry lists phase as NA.

The study concerned treatment of newly diagnosed acute myeloid leukemia or myelodysplastic syndromes with pravastatin sodium, idarubicin, and cytarabine. The treatment description specifies pravastatin sodium PO QD on days 1-8, idarubicin IV over 10-15 minutes on days 4-6, and cytarabine IV continuously on days 4-7. Courses repeated every 28-56 days for up to 4 courses in the absence of disease progression or unacceptable toxicity. Laboratory biomarker analysis is also listed as an intervention.

The registry lists a start date of 2013-05, primary completion of 2015-02, and status of completed. The primary endpoint was good CR, assessed at 35 days. Secondary outcomes listed include progression-free survival, overall survival, biomarker-positive participants with clinical responses, and rates of CR, CR with incomplete blood count recovery, and partial remission. The registry record does not report the observed primary endpoint result or analyses for these outcomes.

The primary endpoint description says that a Bayesian design intended to monitor efficacy and toxicity simultaneously would be used. The registry record does not report the details of that design, such as its decision rules or priors. It also does not report a statistical analysis plan. With a single treatment group, the study can describe outcomes among participants who received the regimen, but it cannot establish a randomized treatment contrast.

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

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Good Complete Remission (CR), measured over 35 days.

The primary endpoint is the number of participants with good complete remission at 35 days. It is a count endpoint: it concerns how many participants met the specified response definition, rather than the time until an event or a continuous measurement.

Good CR combines conventional remission criteria with a requirement concerning MRD. The conventional criteria listed are an absolute neutrophil count > 1,000/uL, a platelet count > 100,000/uL, and marrow with <5% morphologic blasts. In addition, marrow MRD, detected by 10-color flow cytometry or conventional cytogenetic evaluation, had to be absent, and the specified blood counts had to be obtained. This definition is more specific than a remission definition based only on marrow morphology and blood counts.

Response endpoints are used to describe whether participants meet a prespecified clinical state after treatment. Here, the MRD requirement makes the endpoint reflect both conventional remission criteria and the absence of detectable residual disease by the listed methods. The registry record does not report the observed number meeting this definition, the analysis population used, or uncertainty around the result. The endpoint’s clinical meaning can be described from its definition, but its observed frequency cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a count endpoint represent?

The primary outcome is the count of participants meeting the good CR definition at 35 days. A count describes how many endpoint events occurred in the assessed group. To interpret a count as a response frequency, readers also need the relevant denominator: the number of participants assessed for that endpoint. The registry record does not report the primary outcome count or its analysis denominator. The planned enrollment of 24 is not a substitute for either value.

What does the single-group design allow?

In a single-group study, outcomes can be described among participants receiving the regimen. There is no concurrent control arm to estimate what would have happened under an alternative treatment. A within-group response count may be clinically descriptive, but it does not by itself isolate the treatment’s effect from other factors. Random allocation and a suitable comparator are often used to strengthen causal comparisons; neither is recorded as part of this study. This is a general design principle, not a claim about an unreported analysis.

What is a confidence interval?

In general, a confidence interval expresses statistical uncertainty around an estimated quantity, such as a response proportion. A narrower interval indicates greater precision under the assumptions of the method; a wider interval indicates less precision. No confidence interval for the primary endpoint is reported in the registry record, and no result is available from which to assess its precision.

What does the Bayesian design statement mean?

The endpoint description states that a Bayesian design intended to monitor efficacy and toxicity simultaneously would be used. In general, Bayesian methods combine a probability model for the data with prior information to characterize uncertainty and support decisions. A monitoring design may specify how accumulating outcomes affect decisions about continuing or stopping a study. The registry record does not report the model, priors, decision thresholds, monitoring schedule, or whether any interim decisions occurred. Those details cannot be inferred from the statement that the design was Bayesian.

How should sample-size illustrations be read?

Any sample-size estimates associated with the posted material are planning illustrations based on the stated assumptions, not observed power. The assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. Time-to-event planning is described in terms of total events; other planning is described as participants per arm. These are general planning conventions, not evidence that this single-group study used a two-arm design or that its protocol used those assumptions. The registry record does not report the trial’s sample-size justification. Planning illustrations cannot establish the probability that the completed study detected an effect.

Why does over-dispersion matter?

In general, over-dispersion occurs when observed variability in count data is greater than a model assumes. A model that does not account for over-dispersion can underestimate uncertainty and make results appear more precise than they are. Whether over-dispersion is relevant depends on the outcome model and the data. The registry record does not report an analysis model for the primary count endpoint, so no claim can be made about whether over-dispersion was assessed or how it affected an estimate.

What can be said about reported analyses?

The registry record reports zero analyses. It gives the primary endpoint definition and a design description, but does not report a primary effect estimate, its uncertainty, or a statistical test. It also does not report analysis-population rules or methods for handling missing endpoint data. These absences limit statistical interpretation: the design description explains what the investigators intended to study, while an analysis result would be needed to characterize the observed endpoint and its uncertainty.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Treatment (Pravastatin Sodium, Idarubicin, and Cyt")
n      <- c(24)
events <- c(12)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Treatment (Pravastatin Sodium, Idarubicin, and Cyt  24  12  50.0  29.1  70.9  31.4  68.6  31.3  68.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures, including the primary good CR endpoint and secondary outcomes covering progression-free survival, overall survival, biomarker-positive participants with clinical responses, and remission categories. When a study examines multiple outcomes, the chance of finding an apparently noteworthy result across the set can differ from the chance associated with a single prespecified test. General approaches to multiplicity include prespecifying a primary outcome, adjusting testing or interpretation, or treating secondary analyses as exploratory. The registry record does not report a multiplicity procedure or explain how the listed outcomes were prioritized beyond identifying the primary endpoint.

The record describes a Bayesian design intended to monitor efficacy and toxicity simultaneously, but does not report the monitoring rules or how decisions were made. It also reports zero analyses. No result is posted for the primary endpoint or the listed secondary outcomes, so it is not possible to assess whether multiplicity affected any reported inference.

Missing-data handling is not reported in the registry record. The record does not state how many participants had an evaluable 35-day assessment, how missing response assessments were classified, or whether an analysis used all enrolled participants or another population. These details matter because an endpoint count needs a clearly defined analysis population and denominator. The planned enrollment of 24 cannot establish how many had outcome data available.

The registry record also does not report exclusions, withdrawals, or a missing-data sensitivity analysis. No assumptions about the reasons for missing observations or their likely effect on the endpoint can therefore be made. Without an analysis population, denominator, and missing-data strategy, the primary outcome cannot be independently interpreted or its robustness assessed.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: multi organ failure secondary to sepsis (8.3%).

For the treatment group, the registry lists 24 participants at risk for serious adverse events and 2 affected. For other adverse events, it lists 24 at risk and 24 affected. It also lists 6 deaths. The serious adverse event summary identifies multi organ failure secondary to sepsis at 8.3% among the top serious terms.

These figures are descriptive registry entries, not a comparison with another treatment. The labels distinguish serious adverse events from other adverse events, but the summaries do not explain the full event definitions, the observation period for each category, or whether the same participant could contribute to more than one category. The counts should not be added together: their overlap is not reported, and deaths may also relate to events included in other categories.

The listed serious term does not establish that all serious events had that term, nor does it describe the timing or attribution of the events. The registry record does not report a complete event-level account or a comparison that would support estimating relative safety. These figures describe what is recorded for this group; they do not establish a causal explanation for an event or a comparative safety effect.

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

The registry record describes a study of pravastatin sodium, idarubicin, and cytarabine for newly diagnosed acute myeloid leukemia or myelodysplastic syndromes. It identifies a single treatment group, an open-label design, and a primary endpoint of good CR at 35 days. The endpoint definition requires conventional remission criteria, absence of marrow MRD by the listed detection approaches, and the specified blood counts. The record also gives the treatment schedule and selected adverse-event counts.

What the record does not establish is the observed primary endpoint result. It does not report how many participants met the good CR definition, the endpoint denominator, or an estimate of uncertainty. The registry record therefore cannot answer how frequently good CR occurred in the study group or how precise such an estimate would be. No conclusion about the treatment’s efficacy should be drawn from the endpoint definition alone.

The design also does not provide a randomized comparison. Even if a within-group response result were reported, that result alone would not show how outcomes compare with another regimen or distinguish treatment effects from other influences. The registry record does not report a treatment contrast.

The safety counts provide descriptive information for the treated group, but they do not quantify comparative risk or establish causation. Details about event timing, attribution, overlap, and the relationship between deaths and adverse events are not reported in the registry record.

In short, the record documents what was planned and selected safety information, while leaving the primary efficacy result and important analysis details unreported. The most defensible interpretation is limited to those documented design features and counts.

14. Why This Trial Matters Statistically

This study raises a statistical distinction between a clearly defined endpoint and a reported endpoint result. The registry defines good CR in detail, combining conventional remission criteria with absence of marrow MRD. That precision helps explain what investigators intended to count. But without the observed count, denominator, and uncertainty estimate, the definition cannot tell readers how often the endpoint occurred or how precise the result would be.

The single-group design is also important for interpretation. Descriptive outcomes can be useful for characterizing participants who received a regimen, but they do not provide the same evidence as a randomized comparison. Without a comparator, a treatment-associated outcome cannot be separated from other influences using a direct between-group contrast. This limits causal interpretation regardless of how carefully the endpoint is defined.

The record’s statement about Bayesian monitoring illustrates another useful distinction: naming a statistical framework is not the same as reporting its implementation. Model choices, priors, monitoring criteria, and analysis results are not reported. Without them, readers cannot evaluate how the intended monitoring design would have affected decisions or estimates.

Finally, the registry lists several outcomes and selected safety counts but does not report analyses. The record therefore demonstrates why design information, outcome definitions, analysis details, and observed results each have separate roles. A registry entry can clarify the intended question while still leaving the main statistical result unavailable for interpretation.

15. 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 this trial is that the primary outcome result is not reported in the registry record. Although good CR at 35 days is defined, the record does not give the observed count, the number assessed, or an uncertainty estimate. The planned enrollment of 24 does not supply those missing endpoint details.

The study is single-group and open-label, with no comparator arm recorded. This limits the ability to interpret any within-group outcome as a comparative treatment effect. The registry record does not provide a randomized contrast against another regimen or a control condition.

Several details of the statistical plan are not reported in the registry record. The endpoint description mentions a Bayesian design intended to monitor efficacy and toxicity, but does not specify its model, priors, decision rules, or monitoring results. The registry reports zero analyses. It also does not report a sample-size justification, analysis populations, missing-data methods, or a multiplicity procedure.

The safety summaries give selected counts, but do not report event timing, attribution, overlap among categories, or full event-level detail. The top serious-term entry is not a complete description of serious adverse events. The registry record also does not clarify the relationship between the reported deaths and adverse-event categories.

These limitations concern what can be concluded from the registry record; they do not establish that unreported analyses or details were absent from other study materials.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Idarubicin, Cytarabine, and Pravastatin Sodium in Treating Patients With Acute Myeloid Leukemia or Myelodysplastic Syndromes — NCT01831232.
• Registry record last updated 2017-11-17; status last verified 2017-10.
• Results first posted 2017-11-17.
• 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.

19. Record Summary

NCT01831232 is recorded as a completed, open-label, single-group study sponsored by Fred Hutchinson Cancer Center. The planned enrollment was 24, and the registry lists a start date of 2013-05 and primary completion of 2015-02. The study examined pravastatin sodium, idarubicin, and cytarabine for newly diagnosed acute myeloid leukemia or myelodysplastic syndromes.

The primary endpoint was the number of participants with good CR at 35 days, defined using conventional remission criteria plus absence of marrow MRD. The registry record does not report the observed primary endpoint result and reports zero analyses. Safety entries list 2 participants with serious adverse events, 24 with other adverse events, and 6 deaths; multi organ failure secondary to sepsis is listed as a top serious term at 8.3%. These safety figures are descriptive and do not provide a comparison with another treatment.