Imatinib Mesylate in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia Who Have Received Chemotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Imatinib Mesylate in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia Who Have Received Chemotherapy (NCT00509093), a na phase 2 study. The primary outcome is Median Progression-free Survival (PFS) for Patients Less Than 60 Years of Age.

2. Clinical Question

This is a study of an outcome after a treatment sequence, not a direct comparison of imatinib with another maintenance strategy. The record describes the study as phase 2 and states that the aim was to study imatinib mesylate in people with newly diagnosed acute myeloid leukemia who had received chemotherapy. Its scope is narrower than all people with acute myeloid leukemia: the official title specifies c-kit positive disease, and the primary outcome is limited to those less than 60 years old. The record does not report a separate comparative question or an estimated difference between groups. Consequently, the clinical question that can be described is whether progression-free survival was observed in this treated group, not whether it differed from a control group.

3. Trial Design

The registry describes NCT00509093 as a phase 2, single-group study with enrollment of 32 participants. Allocation is listed as not applicable, and masking as none. These details indicate that the record does not describe randomized assignment or a masked comparison. There is one listed treatment arm, Imatinib Mesylate; no comparator arm is given.

The intervention was imatinib mesylate used as maintenance therapy after induction and consolidation chemotherapy. The registry also lists gene expression analysis, mutation analysis, polymerase chain reaction, flow cytometry and biopsy. Their presence in the intervention list does not establish how often they were performed or how their results were used. Those operational details are not reported in the registry record.

Case Comprehensive Cancer Center is listed as the sponsor. The recorded start is 2008-10, primary completion is 2014-05-09, and status is completed. These dates describe the registry entry; they do not provide a detailed account of recruitment, follow-up or the timing of individual assessments.

The primary outcome concerns median progression-free survival for participants less than 60 years of age, with a timeframe of up to 5 years from the end of treatment. The actual number of enrolled participants meeting this age criterion, their follow-up distribution and the outcome estimate are not reported in the registry record. The record lists toxicity as a secondary outcome, but does not report a detailed safety-analysis plan. Sample-size justification, stopping rules, interim analyses, and the statistical analysis plan are not reported in the registry record. Without a control group, outcomes describe the participants in the study and cannot estimate a controlled difference between treatment strategies.

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: All participants less than 60 years of age

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 Median Progression-free Survival (PFS) for Patients Less Than 60 Years of Age, measured over up to 5 years from the End of Treatment.

The primary endpoint is median progression-free survival (PFS), measured in months among participants less than 60 years of age. The registry defines the interval as beginning on the date of complete response and ending at relapse or death. Its description also defines progression using events including progression to accelerated phase or blast crisis, death, loss of complete hematologic response or major cytogenetic response, or increasing white blood cell count despite appropriate therapeutic management in patients who had not achieved complete hematologic response. This is the definition as recorded; additional operational details are not reported in the registry record.

Time-to-event endpoints are generally useful when the timing of an event matters and participants may have different lengths of follow-up. A median gives a central point in the event-time distribution, while the inter-quartile range describes the middle spread of observed event times. These summaries do not, by themselves, describe every participant's course or establish a comparison with an alternative treatment. Their interpretation also depends on the number of participants followed, event information and handling of incomplete follow-up.

The registry states a timeframe of up to 5 years from the end of treatment. However, it does not report the median PFS, its inter-quartile range, the number of participants contributing to this outcome, or the number of events. The endpoint definition is recorded, but its numerical result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a median PFS describe?

Progression-free survival is a time-to-event outcome. Each participant's time begins at the origin specified by the endpoint—in this study, the date of complete response—and ends when an event meeting the registry definition occurs. The median is the point in the estimated distribution at which half the observed event-time experience lies on either side, subject to the method used to account for participants whose event time is not observed. It is a summary of timing, not a count of people who benefit and not a comparison with an untreated or alternative-treatment group.

In general, time-to-event analysis can retain information from participants who have not experienced the event by the time their observation ends. Such observations are commonly described as censored. This approach relies on assumptions about why observation ended and whether that process is related to event risk. The registry record does not report how censoring was defined or handled, whether a survival-curve estimator was used, or how the median was calculated. Those details should not be inferred from the endpoint label alone.

Why does the event definition matter?

The registry's PFS definition includes relapse or death and describes several disease-related events that qualify as progression. A composite endpoint combines different event types into one time-to-first-event measure. This can make an endpoint clinically and statistically useful when more than one event represents worsening, but the combined summary does not reveal which component occurred. Component-specific counts and analyses would be needed to distinguish the event types; those results are not reported in the registry record.

The description includes different criteria depending on whether a participant achieved complete hematologic response. It also names accelerated phase, blast crisis, loss of specified responses and increasing white blood cell count. Those definitions should be understood as the registry's stated criteria. The record does not provide a separate adjudication process or further rules for applying them.

What does the inter-quartile range add?

In general, the inter-quartile range describes the span between the lower and upper quartiles of a distribution. For event times, it gives information about the spread of the middle portion of observed times, complementing the median. A narrow or wide range is not, by itself, a measure of statistical significance, and the inter-quartile range is not a confidence interval for the median. The registry identifies the inter-quartile range as the dispersion measure but does not report its value or the median value.

Precision is often assessed with a confidence interval. A confidence interval conveys uncertainty around an estimate under a specified procedure and assumptions. It is distinct from a range describing participant event times. No confidence interval for the primary endpoint is reported in the registry record. The record also does not report an estimated hazard ratio. In general, a hazard ratio compares event rates over time between groups; it requires a defined comparison and should not be treated as a direct summary of the median. Here, no control group is listed.

How should the design affect statistical interpretation?

The study is recorded as single-group, with allocation not applicable and no masking. In a single-group study, descriptive outcome estimates can characterize what happened in the enrolled group, subject to follow-up and missing-data limitations. A comparison with another group is not built into this design. Differences from outcomes in other settings would be vulnerable to differences in eligibility, disease features, treatment sequence, follow-up and outcome assessment. The registry record does not report a comparative analysis that addresses these concerns.

The primary outcome population is participants less than 60 years of age, whereas enrollment of 32 refers to the study as a whole. These quantities are not interchangeable. The age-specific count and the number included in the endpoint analysis are not reported in the registry record. Statistical precision depends on the information available for the endpoint, including events and follow-up, not only total enrollment.

What do the planning assumptions mean?

A planning illustration is not an observed treatment effect and does not indicate the probability that a study detected an effect. The record describes planning assumptions based on an observed effect, a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation, with the target effect expressed as a fraction of the observed effect. For time-to-event illustrations, the stated quantity is total events. These are planning conventions, not evidence that the actual trial used a two-arm design: the registry describes this trial as single-group. Such calculations are not observed power and do not replace the trial's own design justification, which is not reported in the registry record.

More generally, statistical power is a property of a design under specified assumptions, not a measure of whether a particular result is true. A planning calculation depends on the assumed effect, variability or event rate, significance threshold and allocation. If those assumptions do not match the study setting, the resulting illustration may not reflect the study's actual information. The registry does not report a sample-size justification or detailed statistical analysis plan, so no claim about the rationale for enrollment or the analysis actually used is warranted.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 6 outcome measures and identifies toxicity as a secondary outcome. It does not describe the full set of outcome definitions in enough detail to establish how many statistical hypotheses were tested, how outcomes were ordered, or whether any adjustment for multiple testing was planned. The number of listed outcomes alone does not establish that each was tested or that any particular multiplicity procedure was used. Multiplicity handling is not reported in the registry record.

In general, evaluating many outcomes or several analyses can increase the chance of finding an apparently unusual result by chance if each is interpreted without regard to the others. Methods such as prespecifying a primary outcome, controlling a family-wise error rate, or using a false-discovery approach can address different multiplicity goals. Which approach is appropriate depends on the scientific question and analysis plan. No such approach is reported for this study, so the registry entries do not support a claim that multiplicity was controlled—or that it was ignored in the complete study analysis.

The record reports 0 analyses. This means it does not provide analysis results in the registry entry; it does not establish that no analyses were conducted outside the entry. The primary outcome population is all participants less than 60 years of age, but the number in that population and the number included in an analysis are not reported.

Missing-data methods are also not reported in the registry record. It does not say how incomplete follow-up, missing outcome measurements, withdrawal or other loss of observation was handled. In general, missingness can affect a time-to-event estimate when it is related to the chance or timing of an event. The record does not report whether imputation, censoring rules, sensitivity analyses or other methods were used. The analysis populations, including any safety or intention-to-treat population definitions, are not reported in the registry record.

11. 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: neutropenia (3.1%), hypotension (3.1%), pericardial effusion (non-malignant) (3.1%), urticaria (hives, welts, wheals) (3.1%), diarrhea (3.1%).

The registry lists 32 participants at risk for serious adverse events and 5 affected. It separately lists 32 at risk for other adverse events and 30 affected. These are participant counts in the registry's adverse-event summary; the record does not provide a detailed account of event timing, duration, severity grading beyond the categories shown, or whether events were considered related to imatinib.

The serious-event terms listed include neutropenia, hypotension, pericardial effusion (non-malignant), urticaria (hives, welts, wheals), diarrhea and infection with unknown ANC - Blood. Each term is shown with a value of 3.1%. The record does not clarify whether participants could contribute to more than one term, so the term entries should not be added together or interpreted as mutually exclusive categories. Nor should those percentages be used to infer additional counts.

The record also lists 20 deaths. It does not report their timing, causes, relationship to treatment or whether each occurred during a specified safety follow-up period. A recorded death count is not, by itself, evidence that treatment caused the deaths, and it cannot be compared with another strategy without an appropriate control group. These safety figures are descriptive registry entries, not a causal estimate.

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

The registry record establishes that a phase 2 single-group study enrolled 32 participants and evaluated imatinib mesylate as maintenance therapy after chemotherapy in newly diagnosed acute myeloid leukemia. It specifies a primary PFS outcome for participants less than 60 years old, provides an event definition and names the intended timeframe. Those details clarify the question the study set out to address.

However, the record does not report the primary outcome's median or inter-quartile range, the age-specific analysis population, event counts or a confidence interval. It therefore does not quantify the observed PFS outcome or its precision. The record also contains no sponsor-reported hazard ratio. No comparative effect can be inferred from an endpoint definition or from the sample-size planning assumptions.

Because there is no listed control arm, the registry results cannot establish how outcomes would differ under another maintenance strategy. Even a reported outcome in the treated group would be descriptive unless paired with a suitable comparison and analysis. A single-group study may contribute information about outcomes and safety in its enrolled participants, but it cannot by itself isolate the effect of treatment from other influences.

The safety summary reports affected-participant counts and selected serious-event terms, as well as deaths. It does not report attribution or timing. These entries describe events recorded in the registry; they do not establish that imatinib caused an event or death, nor do they provide a comparative safety estimate.

In general, interpretation of a clinical trial requires attention to the population, design, outcome definition, follow-up, analysis and uncertainty. The registry record contains some of these elements, but does not report key numerical efficacy results or enough analytical detail to assess missingness and precision. The defensible conclusion is limited: the record describes the study question and selected safety counts, while the magnitude and precision of the primary outcome and comparative effects are not reported in the registry record.

13. Why This Trial Matters Statistically

This study illustrates why trial design and registry results must be read together. The primary endpoint is a time-to-event measure, but the study is recorded as single-group. That combination permits a descriptive account of progression-free survival in the treated group if the result is reported; it does not create a controlled estimate of treatment effect. The distinction between an outcome and a treatment contrast is fundamental to clinical-trial interpretation.

The population definition also matters. Enrollment is reported for the full study, while the primary endpoint applies only to participants less than 60 years of age. Without an age-specific denominator and endpoint estimate, the total enrollment cannot be used to judge how much information supports that outcome. This is a practical reminder that overall enrollment and analysis-population size are different quantities.

Endpoint construction matters as well. The registry defines PFS using several types of progression events and death. Such a composite can summarize time to a clinically relevant event, but a single summary does not identify which event types drove the outcome. A complete statistical account would need to make the event definition, follow-up, analysis method and uncertainty clear. Several of these details are not reported in the registry record.

Finally, absence of numerical efficacy results is consequential. Without the median, inter-quartile range, confidence interval or analysis population, readers cannot assess the observed PFS distribution or its precision. The safety counts likewise require context about attribution and timing, which is not reported. These limitations do not negate the value of carefully defined registry entries; they show why design details and complete reporting are both needed for a sound statistical interpretation.

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 immediate limitation is that the registry record does not report the primary outcome estimate. The median PFS and inter-quartile range are absent, as are a confidence interval, event count and number of participants contributing to the age-restricted endpoint. The record therefore does not allow readers to evaluate either the outcome's magnitude or its precision.

The outcome is defined for participants less than 60 years of age, but the age-specific denominator is not reported. Although total enrollment is 32, that number does not identify how many participants met the endpoint population criterion or were included in an analysis. Follow-up completeness and loss to follow-up are also not reported.

The study is single-group and has no listed comparator. The design cannot provide a randomized estimate of how outcomes would differ under another maintenance approach. Allocation is not applicable and masking is none; the registry does not provide further details about outcome assessment or the analysis process.

The event definition combines multiple progression events and death. The registry does not report component-specific results or additional procedures for confirming events. It also does not report the method used to estimate the time-to-event distribution, how censoring was handled, or how missing data were addressed. A detailed statistical analysis plan, sample-size justification and interim-analysis information are not reported in the registry record.

The safety record gives counts for participants affected and selected serious-event terms, but does not report event attribution, timing or a comparator. The 20 recorded deaths likewise lack reported cause and relationship to treatment. These gaps limit causal interpretation of safety as well as efficacy. Results from this registry entry should therefore be read as incomplete descriptive reporting rather than a full statistical account of the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Imatinib Mesylate in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia Who Have Received Chemotherapy — NCT00509093.
• Registry record last updated 2020-03-17; status last verified 2020-03.
• Results first posted 2020-03-04.
• 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

NCT00509093 is recorded as a completed phase 2, single-group study sponsored by Case Comprehensive Cancer Center, with enrollment of 32. It evaluated imatinib mesylate as maintenance therapy after induction and consolidation chemotherapy in newly diagnosed c-kit positive acute myeloid leukemia. The recorded start is 2008-10, and primary completion is 2014-05-09.

The primary outcome is median progression-free survival in months for participants less than 60 years of age, measured from complete response to relapse or death under the registry's progression definition. Its median and inter-quartile range are not reported in the registry record. The entry lists toxicity as a secondary outcome, 5 participants affected by serious adverse events, 30 affected by other adverse events and 20 deaths. Event attribution and timing are not reported. With no listed comparator and no numerical primary outcome result, the record does not provide a comparative treatment-effect estimate.