Combination Chemotherapy With or Without Monoclonal Antibody Therapy in Treating Patients With AML Leukemia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Combination Chemotherapy With or Without Monoclonal Antibody Therapy in Treating Patients With AML Leukemia (NCT00049517), a randomized phase 3 study. The primary outcome is Overall Survival (Induction Phase).

2. Clinical Question

3. Trial Design

This was a phase III randomized, parallel-group trial with no masking, listed as completed. The registry identifies the sponsor as the Eastern Cooperative Oncology Group. The recorded start date is 2002-12-19, and primary completion is listed as 2009-03. Enrollment is recorded as 657.

The posted primary endpoint is Overall Survival (Induction Phase). Its analysis population is all randomized patients, described as intention-to-treat. For this endpoint, the registry presents two groups: Standard Daunorubicin, with 330 participants, and High-dose Daunorubicin, with 327 participants. These are the endpoint group counts, and the record does not establish from these figures alone how every participant proceeded through later treatment stages.

The trial title and arm descriptions indicate that treatment involved chemotherapy and, depending on treatment pathway, gemtuzumab ozogamicin and transplantation. The record lists autologous and allogeneic hematopoietic cell transplantation. It also describes consolidation or transplant as risk-allocated. Therefore, the primary endpoint’s two-group presentation should not be read as a complete account of every treatment decision or subsequent treatment received.

The registry describes randomization and a parallel model, but the allocation ratio, randomization procedures, stratification factors, and masking rationale are not reported in the registry record. The protocol’s detailed statistical plan and the rationale for the planned enrollment are not reported in the registry record. No assumption about those design features can be made from the endpoint summaries.

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.

Induction

Reasons for not completing this period:

Conditioning/Transplant

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All randomized patients are included in the analysis (intention-to-treat).

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 Overall Survival (Induction Phase), measured over Assessed during the first 4 months, then at least every three months for 2 years. then every six months until 5 years after study entry and every 12 months thereafter..

Overall survival is the time from randomization in the induction phase to death. The registry specifies assessment during the first 4 months, then at least every three months for 2 years, then every six months until 5 years after study entry, and every 12 months thereafter. It reports this endpoint as a median time in months with a 95% confidence interval.

As a general statistical concept, overall survival is a time-to-event endpoint: it represents how long participants remain alive after a defined starting point. It is useful because it has a clear event definition and incorporates deaths over follow-up, rather than measuring only an intermediate response. The median is the time by which half of the relevant survival distribution has experienced the event, as estimated by the study’s method.

The statistical method used to estimate the survival distribution and the median is not reported in the registry record. The endpoint definition and follow-up schedule are reported, but the record does not provide detailed information about censoring rules, handling of incomplete follow-up, or the method used to construct the confidence intervals.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports a median time-to-event outcome with a 95% confidence interval for each of the two displayed daunorubicin groups. The endpoint is overall survival during the induction phase, defined as time from randomization in that phase to death. The registry does not report a sponsor-estimated hazard ratio or a between-group p-value for this endpoint. Accordingly, the available result is a pair of group-level summaries, not a reported estimate of the relative treatment effect.

What does a median survival time describe?

As a general statistical explanation, a median time-to-event estimate is the point at which the estimated proportion still free of the event reaches one half. For overall survival, the event is death. The median summarizes the central point of the estimated survival distribution; it does not say that every participant lived for that duration, nor does it describe the full pattern of survival over time. Participants may have different follow-up lengths, and some may not have had the event by the end of observation.

The registry’s reported medians are 15.7 months for Standard Daunorubicin and 23.7 months for High-dose Daunorubicin. Their respective 95% confidence intervals are 12.7 to 19.0 months and 19.0 to 31.7 months. A median from one group cannot on its own establish how the groups compare over the full follow-up period. For example, a direct contrast may use a time-to-event model or another prespecified procedure; which procedure was used for formal inference is not reported in the registry record.

How should the confidence intervals be read?

As a general statistical explanation, a confidence interval expresses sampling uncertainty around an estimate under a particular method and its assumptions. The intervals posted are for each group’s median, not for a contrast between medians or for a hazard ratio. A formal comparison requires an estimate of the contrast and its uncertainty, or a reported test. Neither is included in the registry record for this primary endpoint.

The methods used to estimate the survival curves, locate the medians, and calculate their confidence intervals are not reported in the registry record. In general, time-to-event analyses account for participants who have not experienced the event by the time their observation ends through censoring. The registry’s endpoint description does not specify the censoring rules or how incomplete follow-up was handled, so those details should not be assumed.

What does intention-to-treat mean?

The registry says that all randomized patients are included in the primary analysis and labels this intention-to-treat. In general, intention-to-treat analysis retains participants in their randomized group for analysis, whether or not they complete the assigned treatment. This approach aims to preserve the comparison created by randomization. The record does not describe deviations from assigned treatment, crossovers, or the handling of participants with missing outcome information.

The endpoint group counts are 330 for Standard Daunorubicin and 327 for High-dose Daunorubicin. The registry enrollment is 657. These figures are presented as recorded; no additional totals or derived quantities are needed to interpret the medians. The record does not state whether the endpoint counts reflect any exclusions from the full randomized population or how those counts relate to later transplant pathways.

What can planning calculations establish?

As a general statistical explanation, sample-size planning calculations describe the size of a future study under chosen assumptions about the effect to detect, statistical significance level, allocation, and analysis method. They are planning illustrations, not observed trial findings, and they do not indicate the probability that a particular result is true. The stated planning framework uses a two-sided significance level of 0.05, equal allocation, a normal approximation, and fractions of the observed effect. For time-to-event calculations, the stated convention is a total number of events; for other outcomes, it is participants per arm.

Those assumptions do not identify the trial’s original sample-size justification. The protocol’s planning assumptions, target effect, anticipated event rate, and sample-size rationale are not reported in the registry record. No planning result is interpreted as observed power. A specific planning value cannot be discussed unless it is reported in the registry record.

Finally, no recalculated unadjusted treatment comparison is presented for this median time endpoint. The registry’s own analysis would take precedence if a recalculation differed, but the record does not report a hazard ratio or another sponsor-level contrast for this endpoint. The available statistical interpretation therefore remains descriptive and limited to the posted group medians and confidence intervals.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists Overall Survival (Induction Phase) as the primary outcome and Overall Survival (Consolidation Phase) as a secondary outcome. It also records three outcome measures, but the other outcome details are not fully described in the registry record for this analysis. A plan for controlling multiplicity across outcomes, treatment comparisons, or interim looks is not reported in the registry record. The number of analyses recorded is zero; that does not establish whether interim analyses were planned or performed.

The primary analysis population is described as all randomized patients, analyzed by intention to treat. This identifies the intended population for the reported endpoint, but it does not explain how missing or incomplete survival information was handled. The registry’s follow-up schedule is stated, while censoring rules, loss-to-follow-up procedures, and missing-data methods are not reported in the registry record.

The registry does not provide participant flow through the endpoint analysis, counts of deaths or censored observations, or a detailed accounting of exclusions. It also does not report a per-protocol population or sensitivity analyses for missing data. Consequently, the available material does not allow an assessment of whether missing information could have affected the group summaries or a treatment contrast.

These absences should be treated as limits of the registry record rather than evidence that a particular method was or was not used. No statistical plan, interim-monitoring approach, or multiplicity adjustment should be inferred without a report in the registry record.

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: leukopenia (99.4%), thrombocytopenia (98.8%), neutropenia (97.3%), anemia (78.4%), transfusion platelets (63.4%).

The registry lists serious adverse event groups for Standard Daunorubicin (Induction Therapy) and High Dose Daunorubicin (Induction Therapy). The serious-event fields report 328 at risk and 328 affected in the standard group, and 325 at risk and 325 affected in the high-dose group. The deaths fields are not populated, so deaths in these groups are not reported in the registry record.

The registry also lists other adverse events: 319 affected among 328 at risk in the standard group, and 318 affected among 325 at risk in the high-dose group. These are counts, not percentages calculated. The record does not explain in the available information how adverse events were selected for reporting, how repeated events were counted, or whether the reported figures represent participants with at least one event.

Listed serious adverse-event terms include Leukopenia at 99.4%, Thrombocytopenia at 98.8%, Neutropenia at 97.3%, Anemia at 78.4%, Transfusion platelets at 63.4%, and Transfusion: PRBCS at 60.1%. The record does not provide an arm-specific breakdown for these listed percentages in the information, so they should not be attributed to one treatment group or used to compare groups.

These safety figures describe registry reporting and are not, by themselves, a complete comparative safety analysis. Event definitions, severity grading details, timing, and statistical comparisons are not reported in the registry record.

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

The result describes the registry’s reported overall-survival medians during the induction phase: 15.7 months in the Standard Daunorubicin group and 23.7 months in the High-dose Daunorubicin group. The associated 95% confidence intervals are 12.7 to 19.0 months and 19.0 to 31.7 months, respectively. The record defines the endpoint as time from randomization in the induction phase to death and identifies an intention-to-treat population.

These data do not, on their own, establish the magnitude of a treatment effect. The two medians are not a direct estimate of the difference between assigned strategies, and their confidence intervals are not an interval for that contrast. A sponsor-reported hazard ratio, formal test, or confidence interval for the comparison is not reported in the registry record. The results therefore do not support a statement about statistical significance based on the posted summaries alone.

The record also does not provide enough information to assess the full survival pattern, numbers of deaths, censoring, completeness of follow-up, or adjustment for other factors. Though the schedule of follow-up is described, the endpoint analysis method is not. Treatment pathways included risk-allocated transplantation and other listed therapies, and the primary endpoint summaries do not detail all subsequent treatment received.

In general, randomized comparisons are intended to estimate differences between assigned treatment strategies, but interpreting such a comparison requires the prespecified analysis and its uncertainty. Here, the safest reading is descriptive: the registry reports two group-specific median estimates with their confidence intervals. It does not establish from those figures alone that either treatment strategy caused better or worse survival.

13. Why This Trial Matters Statistically

This trial illustrates a common challenge in reading clinical time-to-event results: group-specific medians are easy to recognize, but they are not equivalent to a direct estimate of the randomized treatment contrast. The registry reports an overall-survival median and confidence interval for each daunorubicin group. Without a reported contrast and its uncertainty, readers cannot use the medians alone to judge the statistical evidence for a difference.

The record also makes the analysis population explicit: all randomized patients are included under an intention-to-treat approach. That is useful context because a trial’s estimand depends on whom it analyzes and how participants are assigned for analysis. At the same time, the record does not describe missing-outcome handling, censoring, or participant flow, which are important for evaluating a time-to-event result.

Another statistical consideration is that the named treatment groups sit within a broader treatment program involving risk-allocated transplantation and additional therapies. A single endpoint summary cannot convey all pathways through care or their possible relationship to outcome. This makes it especially important to distinguish the endpoint’s reported group labels from a complete description of treatment received.

The registry’s presentation also demonstrates why confidence intervals need to be matched to the quantity they describe. These intervals concern each group’s median, not the difference between groups. Clear reporting of a prespecified treatment-effect estimate, its uncertainty, analysis methods, and missing-data procedures would be needed for a fuller statistical assessment.

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 endpoint is reported as group-specific medians and 95% confidence intervals. The registry does not report a hazard ratio, confidence interval for a between-group effect, or p-value for the primary comparison. The posted summaries therefore permit descriptive reading but not a complete assessment of the randomized contrast.

The statistical method for estimating survival, medians, and confidence intervals is not reported in the registry record. The record gives a follow-up schedule but does not describe censoring rules, numbers of deaths, loss to follow-up, or missing-data handling. It does not provide a detailed participant flow or identify any endpoint exclusions.

The treatment descriptions include different chemotherapy and transplantation pathways, with transplantation described as risk-allocated. The primary endpoint results do not show treatment received after randomization or explain how later treatment choices were incorporated into the survival analysis. The extent of differences in subsequent care between the reported groups is not reported in the registry record.

The record lists a secondary overall-survival outcome for the consolidation phase, but detailed results for that outcome are not included in the registry record for this analysis. It also does not report a multiplicity strategy, interim-analysis plan, or detailed statistical analysis plan. These are limitations of what the registry record reports and do not establish what may have been addressed in other study documents.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Combination Chemotherapy With or Without Monoclonal Antibody Therapy in Treating Patients With AML Leukemia — NCT00049517.
• Registry record last updated 2023-06-15; status last verified 2023-06.
• Results first posted 2013-02-12.
• 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

NCT00049517 is a completed, randomized, unmasked, parallel-group phase III trial sponsored by the Eastern Cooperative Oncology Group. The registry records a start date of 2002-12-19, primary completion in 2009-03, and enrollment of 657.

The primary outcome is Overall Survival (Induction Phase), defined as time from randomization in the induction phase to death, with an intention-to-treat population. The registry reports median survival of 15.7 months (95% confidence interval, 12.7 to 19.0) for Standard Daunorubicin and 23.7 months (95% confidence interval, 19.0 to 31.7) for High-dose Daunorubicin.

A direct treatment-effect estimate and its statistical test are not reported in the registry record. The trial descriptions also include gemtuzumab ozogamicin and risk-allocated transplantation pathways, which are not fully represented by the two primary endpoint group summaries.