Lenalidomide in Treating Older Patients With Acute Myeloid Leukemia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Lenalidomide in Treating Older Patients With Acute Myeloid Leukemia (NCT00352365), a na phase 2 study. The primary outcome is Complete Response.

2. Clinical Question

This question is about whether a specified response was recorded in the treated study population. It is not a question about comparative benefit against another treatment, because the registry describes one treatment group and no control group. The relevant population is also specific: the study concerns older patients with the stated AML and deletion 5q characteristics who declined remission induction chemotherapy. The record lists an enrollment of 41, but that enrollment figure should not be treated as the denominator for the primary endpoint. The endpoint population is described separately as eligible patients who began protocol therapy, and the number in that population is not reported in the registry record.

The registry states that the primary outcome is complete response, with a percentage of participants as the unit and a 95% confidence interval as the dispersion measure. However, the posted results do not include the observed response count, percentage, or interval. Consequently, the clinical question can be identified from the protocol description, but the record does not permit a numerical answer about the observed response proportion or its precision.

3. Trial Design

This is a phase II, single-group study sponsored by the National Cancer Institute. The registry lists lenalidomide as the intervention and describes the study as open-label, with no masking. Allocation is recorded as not applicable. These design features mean that the posted record concerns outcomes in a group receiving the study treatment, rather than a randomized comparison between treatment groups.

The study title and official title specify previously untreated non-M3 acute myeloid leukemia with deletion 5q in patients age 60 or older who declined remission induction chemotherapy. The registry lists enrollment of 41. That is the enrollment recorded for the study, not a confirmed denominator for every outcome. For the primary endpoint, the stated population is eligible patients who began protocol therapy; the size of that analysis population is not reported in the registry record.

The intervention description says patients receive oral lenalidomide once daily on days 1-14, 1-21, or 1-28 for course 1, followed by a bone marrow biopsy on day 28 or 35 to assess treatment efficacy. The remaining arm description is incomplete in the registry record, so subsequent treatment rules should not be inferred from it. The study is marked completed. Its recorded start is 2006-06 and its primary completion date is 2011-07-01.

A single-group phase II study can describe the observed response and safety experience under its treatment protocol. Without a concurrent control group, those observations do not by themselves estimate how outcomes would have differed under another treatment or under no study treatment. The registry record does not report a statistical analysis plan, a sample-size justification, or interim-analysis details.

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 Therapy

Reasons for not completing this period:

Maintenance Therapy

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Eligible patients who began protocol therapy

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: Eligible patients who began protocol therapy

6. Primary Endpoint

The registry lists the primary outcome as Complete Response, measured over Up to 5 years.

The primary endpoint is titled Complete Response. It measures the percentage of participants meeting the registry’s morphologic response definition. Morphologic complete remission requires ANC at least 1,000/mcl, platelet count at least 100,000/mcl, fewer than 5% bone marrow blasts, no Auer rods, and no evidence of extramedullary disease. The definition also includes morphologic complete remission with incomplete blood count recovery, or CRi: the same criteria, except that ANC may be below 1,000/mcl and/or platelet count may be below 100,000/mcl.

A response endpoint of this kind classifies whether participants meet specified disease and blood-count criteria. Reporting a proportion describes how common that classification was among the defined analysis population; a confidence interval expresses the uncertainty around that estimated proportion. The registry names a 95% confidence interval as the dispersion measure and gives a timeframe of up to 5 years.

The endpoint is useful for describing the response experience in the population that began protocol therapy. It does not, on its own, establish that lenalidomide caused a response or that response was more likely than it would have been with another approach. In this record, the endpoint definition is reported but the observed response count, percentage, and confidence interval are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The design and outcome definitions determine what statistical conclusions can be drawn. This study is recorded as phase II and single-group, with allocation not applicable and no masking. The registry names a binary percentage endpoint: participants are classified according to whether they meet the complete-response definition. The primary population is eligible patients who began protocol therapy.

What does a response percentage describe?

A response percentage is a proportion: it relates the number of participants meeting the endpoint to the number included in the endpoint analysis. It describes an observed frequency in a specified population and under specified outcome rules. It is not, by itself, a comparison between treatments. For this study, the record does not report the response count, the response percentage, or the analysis denominator. The enrollment entry of 41 does not fill that gap, because the registry identifies a distinct endpoint population and does not state its size.

What does a confidence interval add?

A confidence interval communicates uncertainty around an estimated quantity. For a response proportion, it indicates the range of values compatible with the data and the stated statistical procedure. A narrower interval generally indicates greater precision, while a wider interval indicates less precision. The registry specifies a 95% confidence interval as the primary endpoint’s dispersion measure, but no interval is posted. It is therefore not possible to judge how precisely the response proportion was estimated.

Confidence intervals do not remove limitations in study design or data collection. They quantify statistical uncertainty under a method and analysis population; they do not correct for missing outcomes, selection into treatment, or lack of a control group. Those concerns must be considered separately. The registry record does not report the method used to construct the interval or how missing endpoint data were handled.

Why does the single-group design matter?

A treatment comparison requires outcomes under the treatment and an appropriate comparator. In a randomized trial, allocation can help make treatment groups comparable on average, allowing a difference in outcomes to be interpreted as a treatment contrast under the assumptions of the design and analysis. This record has no concurrent comparator group and does not describe randomization. It therefore supports descriptive statements about the treated group, not a randomized estimate of the difference between lenalidomide and another intervention.

Comparing the observed response proportion with a value from another population would not create a randomized comparison. Populations, eligibility criteria, outcome definitions, follow-up, and clinical settings may differ. The registry record does not identify a historical benchmark or a prespecified threshold for evaluating the response proportion.

How should the response definition be read?

The endpoint combines morphologic complete remission with CRi, which allows incomplete recovery of ANC and/or platelet count while retaining the other specified response conditions. This makes the endpoint a rule-based classification rather than an unqualified judgment of improvement. A participant meeting the morphologic and other listed criteria can count as a response even if one or both blood-count thresholds are not met under the CRi definition. The record does not report separate results for complete remission and CRi, so their individual contributions cannot be assessed.

The stated timeframe is up to 5 years. A timeframe describes the window named for outcome assessment, but does not by itself tell the reader when assessments occurred, whether response had to be confirmed, or how events after response were treated. Those details are not reported in the registry record. They should not be inferred from the biopsy timing stated for course 1.

What can planning calculations tell readers?

The planning illustration described in the registry is explicitly not the trial’s own design. It uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. Such calculations illustrate how a hypothetical future design’s participant requirements can change with the assumed effect and statistical choices. They are not observed outcomes, and they are not observed power for this study.

Those assumptions describe a two-arm planning exercise, whereas this trial is recorded as single-group. The assumptions should not be mistaken for evidence that this study enrolled randomized arms or was planned around those particular calculations. The registry does not report the trial’s own sample-size justification, and the primary observed effect is not reported. Thus, the planning illustration cannot establish whether the study had a particular probability of detecting an effect or whether its enrollment target was met for a stated design goal.

The registry lists no analyses. It also does not describe an analysis model, adjustment variables, hypothesis-testing procedure, or multiplicity strategy. These absences limit what can be said about the inferential methods used. General statistical principles can explain the meaning of proportions, intervals, and planning assumptions, but cannot supply unreported methods or results for this study.

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("Induction Therapy")
n      <- c(37)
events <- c(4)
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  Induction Therapy  37  4  10.8  3.0  25.4  4.3  24.7  4.4  24.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures, including Complete Response as the primary outcome and secondary outcomes for the number of patients with grade 3 through 5 adverse events related to study drug, cytogenetic abnormalities, and total response. It reports no analyses. The record does not state how many hypotheses were tested, whether any formal tests were planned, or whether an approach to multiplicity was specified. It is therefore not possible to determine whether the chance of false-positive findings across multiple outcomes was addressed.

The absence of a reported multiplicity strategy does not mean that the study necessarily conducted multiple tests or that any particular adjustment was required. It means only that the registry record does not report the strategy. The primary endpoint is identified, but there is no posted estimate with which to assess its statistical uncertainty or compare it with secondary outcomes.

The analysis population for the primary endpoint is described as eligible patients who began protocol therapy. The record does not report the number in that population, the number with an evaluable response, or how participants without an endpoint assessment were handled. It does not state whether missing outcomes were excluded, imputed, or treated under another rule. No assumptions about missingness can be inferred.

The enrollment figure of 41 should not be substituted for an unreported analysis denominator. Enrollment is a study-level entry, while the endpoint definition identifies a specific analysis population. The registry also does not report the number of participants who discontinued, the amount or pattern of missing follow-up, or whether those issues differed by treatment period. Without these details, the completeness and potential influence of endpoint data cannot be assessed.

These gaps affect interpretation of both efficacy and safety summaries. A statistical analysis plan, multiplicity approach, and missing-data rules are not reported in the registry record. Conclusions about those methods should remain limited to what the record states.

12. 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: febrile neutropenia (25.0%), death - disease progression nos (21.6%), hemorrhage, gi - colon (12.5%), inf w/normal anc or gr 1-2 neutrophils - blood (12.5%), leukocytes (total wbc) (12.5%).

The registry reports adverse-event figures separately for induction therapy and maintenance therapy. For induction therapy, 37 are listed at risk, with 24 affected by serious adverse events and 34 affected by other adverse events. For maintenance therapy, 8 are listed at risk, with 4 affected by serious adverse events and 8 affected by other adverse events. These are descriptive entries for the respective treatment periods, not comparisons between randomized groups.

The registry also lists serious adverse-event terms and percentages. The entries include febrile neutropenia at 25.0%, death due to disease progression NOS at 21.6%, and hemorrhage, GI - Colon, infection with normal ANC or grade 1-2 neutrophils - Blood, leukocytes, and platelets, each at 12.5%. The record does not explain the denominator or detailed calculation for each listed percentage in the information available, so they should be read as registry-listed figures rather than reinterpreted or recalculated.

These terms do not establish that study drug caused each event. The secondary outcome specifically names grade 3 through 5 adverse events related to study drug, but the listed serious-event terms do not by themselves supply causal judgments. Nor should induction and maintenance figures be added or treated as independent group comparisons: the registry does not describe them as randomized arms, and the periods are not a like-for-like control comparison.

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

The record establishes that a phase II, single-group study evaluated lenalidomide in the stated population and named complete response as its primary endpoint. It provides a specific morphologic response definition, a primary endpoint timeframe of up to 5 years, and descriptive adverse-event entries for induction and maintenance therapy. These details identify the clinical question and the types of outcomes registered.

The record does not report the observed primary response count, percentage, or 95% confidence interval. Consequently, it does not establish from the posted results how often the defined response occurred or how precisely that proportion was estimated. The enrollment figure of 41 is not a substitute for the unreported number of eligible patients who began protocol therapy and contributed to the endpoint analysis.

The single-group design also means the record does not estimate a randomized treatment difference. An observed outcome in a treated group, even when reported, cannot on its own distinguish a treatment effect from other influences on outcomes. No control group is listed, and no comparative result is reported.

The safety entries describe adverse events recorded during the listed treatment periods. They do not establish that lenalidomide caused the events, and they do not support a comparative safety conclusion against another treatment. The event terms and percentages should be interpreted within the limits of the registry’s reporting detail.

In short, the registry record is informative about the study population, intervention, endpoint definition, and some safety reporting, but it does not provide the primary efficacy result or comparative evidence. Statistical interpretation should not extend beyond those reported elements.

14. Why This Trial Matters Statistically

This study matters statistically because it illustrates the distinction between a clearly described endpoint and a reported endpoint result. The registry defines complete response in clinical and morphologic terms and identifies the intended analysis population. Yet the response count, percentage, and confidence interval are not reported. Without those values, a reader cannot quantify the observed response experience or assess its precision, regardless of how specific the endpoint definition is.

It also highlights why the analysis population must be distinguished from overall enrollment. The registry records enrollment of 41, while defining the primary endpoint population as eligible patients who began protocol therapy. Those descriptions do not establish that the same participants contributed to the endpoint. The analysis denominator and its relationship to enrollment are not reported, so the primary proportion cannot be reconstructed from the enrollment entry.

The study’s single-group design is another important statistical feature. It is suited to describing outcomes in the treated population, but it does not supply a concurrent counterfactual comparison. A response proportion in this group cannot be converted into a randomized treatment effect, and adverse-event figures for induction and maintenance do not constitute comparative safety evidence.

Finally, the registry distinguishes a stated endpoint timeframe from the details needed to understand follow-up, and it lists secondary outcomes without describing multiplicity or missing-data procedures. These omissions show why readers need not only endpoint definitions but also results, denominators, analysis methods, and follow-up rules. In this record, several essential pieces for quantitative inference are not reported.

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.

Several limitations are specific to the information recorded for this study. The primary outcome is named and defined, but its observed result is absent. There is no reported response count, percentage, or 95% confidence interval, which prevents assessment of both magnitude and precision. The endpoint population is described as eligible patients who began protocol therapy, but its size is not reported.

The study is single-group, with allocation recorded as not applicable and no masking. No concurrent comparator is described. This limits the interpretation to descriptive experience in the treated group and prevents a randomized estimate of a treatment contrast. The registry does not report a statistical analysis plan or a sample-size justification, so the intended inferential procedures and design rationale cannot be evaluated.

The response timeframe is stated as up to 5 years, but the registry does not specify the assessment schedule, confirmation rules, or handling of incomplete follow-up. It also does not report missing-data counts or methods, analysis-population details beyond the primary population description, or how many participants had evaluable response assessments. The relationship between enrollment and outcome denominators is therefore unclear.

Although the registry lists four outcome measures, no analyses are reported, and no multiplicity strategy is described. The adverse-event figures are separated by induction and maintenance therapy, but the record does not establish these as comparable randomized groups. The listed serious-event terms and percentages also lack sufficient contextual detail to support causal attribution. The arm description is incomplete, so details beyond the stated course 1 schedule and biopsy timing should not be inferred.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Lenalidomide in Treating Older Patients With Acute Myeloid Leukemia — NCT00352365.
• Registry record last updated 2022-02-11; status last verified 2022-01.
• Results first posted 2013-07-04.
• 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.

19. Record Summary

NCT00352365 is a completed phase II, single-group study sponsored by the National Cancer Institute. It evaluated oral lenalidomide in previously untreated non-M3 acute myeloid leukemia with deletion 5q among patients age 60 or older who declined remission induction chemotherapy. The registry lists enrollment of 41 and identifies eligible patients who began protocol therapy as the primary endpoint population.

The primary outcome is Complete Response, defined to include morphologic complete remission and CRi, with a timeframe of up to 5 years and a 95% confidence interval specified as the dispersion measure. The observed primary result is not reported in the registry record. Secondary outcomes include grade 3 through 5 adverse events related to study drug, cytogenetic abnormalities, and total response. Descriptive adverse-event entries are listed for induction and maintenance therapy. The record does not report analyses, a statistical plan, multiplicity procedures, or missing-data methods.