A Study of Idasanutlin With Cytarabine Versus Cytarabine Plus Placebo in Participants With Relapsed or Refractory Acute Myeloid Leukemia (AML): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Idasanutlin With Cytarabine Versus Cytarabine Plus Placebo in Participants With Relapsed or Refractory Acute Myeloid Leukemia (AML) (NCT02545283), a randomized phase 3 study. The primary outcome is Overall Survival in TP53 WT Population.

2. Clinical Question

This question concerns the time participants survived after randomization, not simply the proportion alive at a single follow-up visit. The hazard ratio compares the groups’ event rates over follow-up under the analysis method; it is not a direct comparison of the reported median survival times. A value near one is compatible with similar relative event rates, while the confidence interval indicates how much uncertainty surrounds the estimate.

The registry states that the study was terminated because of futility and did not reach its planned end. That context matters when interpreting the outcome: the posted estimate describes the observed data available for the analysis, while the record does not establish what the result would have been with completion of the planned study.

3. Trial Design

The registry describes a multicenter, randomized, double-blind, placebo-controlled, parallel-group phase III study. The treatment groups were idasanutlin plus cytarabine and matching placebo plus cytarabine. Randomization and masking are features intended to support a fair comparison by limiting systematic differences in treatment assignment and knowledge of assignment, although the registry record does not report further implementation details.

The registry reports enrollment of 447 participants. The primary result concerns the TP53 WT intention-to-treat population, with posted group counts of 123 for placebo plus cytarabine and 232 for idasanutlin plus cytarabine. These are the population counts attached to the primary result; they should not be treated as a replacement for the overall enrollment figure. The record does not explain the difference between the overall enrollment and the primary-analysis population counts.

Participants received induction treatment in Cycle 1. Responding participants could continue with up to two additional consolidation cycles, according to the brief summary. The primary outcome was overall survival. Other stated outcomes included remission measures, event-free survival, duration of remission, transplantation, and adverse events.

The study status is terminated. The primary outcome description says termination was due to futility and that the study did not reach the planned end. The registry record does not report the original sample-size justification, the detailed stopping rules, or whether interim analyses were planned or conducted. It also does not report a full statistical analysis plan or enough detail to reconstruct how the study’s termination decision was made.

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: TP53-WT ITT 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.

6. Primary Endpoint

The registry lists the primary outcome as Overall Survival in TP53 WT Population, measured over From randomization to death from any cause (up to approximately 4.5 years).

Overall survival measures the time from randomization until death from any cause. Participants who have not had a recorded death by the end of their available follow-up are generally treated as censored in time-to-event analyses; that is a general explanation, and the registry record does not describe the censoring procedures used in detail. The stated timeframe is from randomization to death from any cause, up to approximately 4.5 years.

Overall survival is used because it captures the time until a consequential event without requiring a judgment that a particular disease response qualifies as remission. It can also incorporate events occurring after treatment begins, although follow-up completeness and the analysis method affect the precision of the estimate. The median is the time by which half of the analyzed population has experienced the event, as estimated from the survival data. It does not describe every participant’s experience and is not, by itself, the same quantity as the hazard ratio.

For the TP53 WT population, the registry reports median overall survival of 9.13 months for placebo plus cytarabine and 8.28 months for idasanutlin plus cytarabine. The primary comparison is the sponsor-reported hazard ratio, with its confidence interval and p-value. The registry states that the study was terminated for futility before the planned end, which limits interpretation of the result as a complete account of the planned study.

7. Results Posted in the Registry

• Placebo Plus Cytarabine vs Idasanutlin Plus Cytarabine: hazard ratio 1.08 (95% CI 0.81–1.45), reported p = 0.575 (as reported in the registry).

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Percentage of Participants in Complete Response (CR) at the End of Induction According to Hematologic Malignancy Response Assessment (HMRA) in TP53 WT Population

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Idasanutlin Plus Cytarabine: 17.2% (40/232) versus 20.3% (25/123) on control; risk difference -3.1 percentage points (95% CI -11.7 to 5.5), risk ratio 0.85 (0.54–1.33); unadjusted two-proportion z-test p = 0.475.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Idasanutlin Plus Cytarabine and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Participants With Overall Remission (CR, CRp, and CRi) at the End of Induction According to HMRA in TP53 WT Population

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Idasanutlin Plus Cytarabine: 22.0% (51/232) versus 39.0% (48/123) on control; risk difference -17.0 percentage points (95% CI -27.2 to -6.9), risk ratio 0.56 (0.41–0.78); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Idasanutlin Plus Cytarabine than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Percentage of Participants Undergoing HSCT Following Complete Response (CR), in TP53 WT Population

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Idasanutlin Plus Cytarabine: 11.6% (27/232) versus 10.6% (13/123) on control; risk difference 1.1 percentage points (95% CI -5.8 to 7.9), risk ratio 1.10 (0.59–2.06); unadjusted two-proportion z-test p = 0.762.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Idasanutlin Plus Cytarabine and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary outcomes cover remission, transplantation, event-free survival, duration of remission, selected mutation-defined subpopulations, and adverse events. The reported remission percentages do not all move in the same way: the idasanutlin group has a lower posted percentage for complete response and for overall remission at the end of induction, while the transplantation percentages are similar in direction and scale across groups. These outcomes address different events and are not interchangeable with overall survival.

The overall-survival result remains the primary comparison. A secondary response measure can differ from survival because it captures an earlier or different clinical event, and because later events and follow-up contribute to survival. The registry record does not report enough about the timing, missing observations, or analysis procedures for all listed secondary outcomes to use them as a substitute for the primary endpoint.

The posted secondary comparisons are not accompanied by sponsor-reported analyses in the registry record. The unadjusted p-values therefore should be treated cautiously, especially because the registry lists many secondary outcomes. When multiple outcomes are examined, the chance of at least one apparently notable result can increase unless a prespecified multiplicity strategy controls that risk. The multiplicity strategy is not reported in the registry record.

The secondary findings can describe the pattern of observed outcomes and help identify questions for further study, but they do not independently establish a confirmatory treatment effect. In particular, an unadjusted secondary result should not be elevated above the primary survival analysis solely because its p-value appears more compelling.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percentage of Participants in Complete Response (CR) at the End of Induction According to Hematologic Malignancy Response Assessment (HMRA) in TP53 WT Population
• Event-Free Survival (EFS) According to HMRA in TP53 WT Population
• Percentage of Participants With Overall Remission (CR, CRp, and CRi) at the End of Induction According to HMRA in TP53 WT Population
• Duration of Remission Following CR (DOR) in TP53 WT Population
• Percentage of Participants Undergoing HSCT Following Complete Response (CR), in TP53 WT Population
• Percentage of Participants With Complete Response (CR) in Clinically Actionable Mutation-Defined Subpopulation (FLT3, IDH1 and IDH2) in TP53 WT Population
• Overall Survival in Clinically Actionable Mutation-Defined Subpopulation (FLT3, IDH1 and IDH2) in TP53 WT Population
• Number of Participants Who Experienced at Least One Adverse Event by Severity, According to National Cancer Institute Common Terminology Criteria for Adverse Events, Version 4.03 (NCI-CTCAE v4.03)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is a time-to-event outcome. Such outcomes use information about when an event occurs as well as whether it occurs during observation. In overall survival, the event is death from any cause. Participants may have different lengths of follow-up, so a time-to-event method can include participants whose follow-up ends before a death is observed, with their available event-free time contributing information up to that point. This is a general description; the registry record does not provide the detailed censoring rules or data-handling procedures.

What does a hazard ratio compare?

A hazard ratio compares the event hazards between groups over follow-up, according to the model or test used. The registry reports a hazard ratio of 1.08 for placebo plus cytarabine versus idasanutlin plus cytarabine, estimated using a log-rank analysis. A hazard ratio is a relative measure, not an absolute difference in survival time, and it should not be interpreted as a ratio of the two median survival estimates. The result is reported with a 95% confidence interval from 0.81 to 1.45.

The log-rank method is a general approach for comparing time-to-event experience between groups. It uses the ordering of event times and the group membership of participants at risk over follow-up. Its interpretation depends on the study design and data, and the registry record does not report additional modeling details, such as whether any adjusted analysis was performed. The listed sponsor analysis is the reported primary comparison.

What does the median add?

The median survival time is a point on the estimated survival distribution. It gives a time at which the estimated proportion surviving has reached one half. The registry reports 9.13 months for placebo plus cytarabine, with a 95% confidence interval from 7.59 to 10.64, and 8.28 months for idasanutlin plus cytarabine, with a 95% confidence interval from 6.67 to 10.87. Medians are easy to describe, but they compress the follow-up pattern into a single estimate. They do not show whether group differences vary over time, nor do they convey all information used in the time-to-event comparison.

How should the p-value be read?

The reported p-value is 0.575. Under the null model and the assumptions of the analysis, a p-value measures how unusual the observed test result would be if that model were true. It is not a measure of the clinical importance of a difference, and it does not show that the null hypothesis is true. It also does not quantify the probability that the result will be replicated. The confidence interval is useful alongside the p-value because it displays a range of effect estimates compatible with the data under the interval procedure.

For a confidence interval, the general interpretation is that the method would cover the true parameter at the stated rate over repeated studies under its assumptions. For an individual study, it is more useful to read the interval as a measure of uncertainty than as a probability statement about the fixed true value. Here, the interval spans estimates on either side of one, so the data do not pinpoint a single direction or precise relative effect.

What is not documented?

The registry record does not report the original sample-size justification, the planned statistical analysis in full, the handling of missing outcomes, the detailed censoring rules, or the multiplicity strategy. It also does not establish whether the proportional-hazards assumption was evaluated. These are important details when interpreting a time-to-event analysis. General statistical practice may include diagnostic checks or sensitivity analyses, but their use in this trial is not reported in the registry record and cannot be inferred from the reported hazard ratio alone.

The registry says the study was terminated because of futility and did not reach its planned end. A futility decision is generally intended to identify a situation where continuing may be unlikely to achieve the study objective, but the actual criteria and decision process for this trial are not reported. The posted primary result should therefore be read as the sponsor-reported analysis of the available trial data, not as a reconstruction of an undocumented analysis plan.

11. Confidence Intervals and Precision

The primary hazard-ratio estimate is 1.08, and its 95% confidence interval runs from 0.81 to 1.45. The interval includes one, the value corresponding to no relative difference in hazards under the ratio interpretation. It also includes estimates that point in either direction. The breadth of this interval means the result does not identify a narrowly defined relative effect.

The median survival estimates also have uncertainty intervals: 9.13 months, with an interval from 7.59 to 10.64, for placebo plus cytarabine; and 8.28 months, with an interval from 6.67 to 10.87, for idasanutlin plus cytarabine. These intervals describe uncertainty around the separate median estimates. They are not a confidence interval for the difference between medians. The registry does not report a formal comparison of the medians.

A confidence interval is not a guarantee that the true effect lies inside its endpoints, nor does it indicate that all values inside the interval are equally plausible. Its width reflects the information available and the method used, among other factors. For time-to-event results, the amount and timing of follow-up and event information affect precision. The registry record states that the trial did not reach its planned end, but it does not report enough detail to quantify the effect of early termination on precision.

The p-value of 0.575 is consistent with the interval’s inclusion of one, but it should not be used as a substitute for examining the range of effects that remain compatible with the data. The result is imprecise about the magnitude and direction of the relative effect, and it should not be read as proof of equivalence.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning illustrations translate an observed effect into hypothetical sample-size targets under stated assumptions. For the overall-survival endpoint, the listed quantities are total events, not participants per arm. The other planning illustrations use participants per arm. These are different quantities, so they should not be compared as though they were on the same scale.

The illustrations assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. For each illustration, the effect to detect is set to the stated fraction of the observed effect. The time-to-event calculations use the Schoenfeld approach. The registry record does not report the assumptions used in the trial’s original design or sample-size justification; these planning assumptions belong to the illustrations, not necessarily to the trial’s design.

The 80% power column indicates the planning quantity associated with an 80% chance of detecting the specified effect if the assumptions hold and that effect is the true one. The 90% power column makes the corresponding illustration for a higher chance of detection. These are prospective planning concepts, not summaries of how likely this completed trial was to find a result. Smaller target effects generally require more information: in these illustrations, detecting a smaller fraction of the observed effect requires more participants or events than detecting the full observed effect.

These figures are not observed power. They do not describe the probability that the trial’s reported result is correct, and they do not alter the interpretation of the sponsor-reported outcome. They are planning illustrations based on the observed effect and the assumptions stated for those calculations. The study’s own original design assumptions are not reported in the registry record.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

d is the total number of events needed (Schoenfeld's formula) with 1:1 allocation and proportional hazards.

Worked calculation for this trial

1. Hazard ratio HR = 1.080, so ln(HR) = 0.0770.
2. d = 4 × (1.96 + 0.842)² / [ln(1.080)]² = 5,300.6, rounded up to 5,301 events in total for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
hr <- 1.08                              # observed hazard ratio
events_needed <- function(power, frac = 1) ceiling(round(4 * (z_a + qnorm(power))^2 / log(hr^frac)^2, 6))   # Schoenfeld, 1:1 allocation
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: events = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(events_needed(0.80, f), big.mark = ","), format(events_needed(0.90, f), big.mark = ",")))

# Simulation: given d total events under proportional hazards, events in the treatment arm are Binomial(d, hr / (1 + hr)).
# The score (log-rank type) statistic is (D1 - d / 2) / sqrt(d / 4).
set.seed(2545283)
d    <- events_needed(0.80)
reps <- 20000
D1 <- rbinom(reps, d, hr / (1 + hr))
z  <- (D1 - d / 2) / sqrt(d / 4)
cat(sprintf("Simulated power with %s events: %.3f (%d replicates)\n", format(d, big.mark = ","), mean(abs(z) > z_a), reps))

Output from running the code

100% of observed effect: events = 5,301 (80% power), 7,097 (90% power)
 75% of observed effect: events = 9,424 (80% power), 12,616 (90% power)
 50% of observed effect: events = 21,203 (80% power), 28,385 (90% power)
Simulated power with 5,301 events: 0.802 (20000 replicates)

The simulation uses the fact that, with d events in total and proportional hazards, the number of events in the treatment arm is binomial. It is an approximation that conditions on the total number of events, and it should land close to the target power.

14. Analyses Reported by the Sponsor

The primary overall-survival analysis is reported by the sponsor as a log-rank comparison with a hazard ratio of 1.08, a 95% confidence interval from 0.81 to 1.45, and p = 0.575. That sponsor-reported analysis is the appropriate primary result to interpret. There is no flagged discrepancy between the posted primary result and a recalculation, and no separate recalculated primary estimate is needed to replace it.

The simple recalculations associated with secondary binary outcomes are unadjusted comparisons based on posted summary statistics. They are not sponsor-reported analyses in the registry record. Such calculations can help describe the posted proportions and their uncertainty, but they do not recover a full analysis plan or account for adjustments that may have been used outside the record.

The registry record does not report a complete statistical analysis plan, details of any covariate adjustment, or the exact process used to reach the futility decision. Therefore, the sponsor’s reported primary analysis takes precedence over any informal re-analysis, while the absence of additional methods detail limits independent assessment of the analytic choices.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists 34 secondary outcomes, in addition to the primary overall-survival outcome. Testing or summarizing many outcomes creates a multiplicity issue: even when there is no underlying effect, examining more outcomes can increase the chance of finding at least one result that appears statistically notable. This is a general statistical concern, not evidence that a particular secondary result is false.

The registry record does not report a multiplicity adjustment, a hierarchy among secondary endpoints, or a prespecified strategy for distinguishing confirmatory from exploratory analyses. Without those details, unadjusted secondary p-values should be interpreted as descriptive evidence rather than as stand-alone confirmation. The primary outcome remains the central trial comparison, while secondary outcomes offer supporting context with less certainty about their confirmatory status.

The record does not report how missing outcome data were handled, how censoring was defined, or whether sensitivity analyses were conducted. These matters can influence estimates, particularly when follow-up is incomplete or differs between groups. The primary endpoint is described as time from randomization to death from any cause, but that description alone does not specify the procedures used for participants whose outcome status or follow-up was incomplete.

The primary population is named as the TP53-WT ITT population. The registry also says the study included participants with and without TP53 WT mutations, but does not provide enough information to assess how the primary population was defined in practice or how participants were handled in each analysis. The posted arm counts for the primary result are not the same as the overall enrollment figure; the reason for that difference is not reported in the registry record.

Finally, the trial was terminated for futility and did not reach its planned end. The registry does not report the futility boundary, the timing or number of any interim looks, or the effects of termination on planned analyses. Those missing details make it difficult to assess how the stopping decision and incomplete planned follow-up relate to precision and multiplicity.

16. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: sepsis (11.6%), febrile neutropenia (9.6%), pneumonia (8.7%), septic shock (5.4%), diarrhoea (2.7%).

The registry reports participants with at least one serious adverse event in each group, alongside the corresponding numbers at risk: 173 of 292 for idasanutlin-cytarabine and 72 of 149 for placebo-cytarabine. It also reports participants with at least one other adverse event: 290 of 292 and 147 of 149, respectively. These are counts with the posted group denominators; no new rates or comparisons are calculated.

The listed serious adverse-event terms are sepsis at 11.6%, febrile neutropenia at 9.6%, pneumonia at 8.7%, septic shock at 5.4%, diarrhoea at 2.7%, and death at 2.1%. These term-specific percentages describe the listed events in the registry record; the record does not provide enough detail to interpret overlap between terms, timing, or causal attribution.

Safety counts should be read as descriptive, not as proof that one regimen caused more or fewer events. The groups have different posted numbers at risk, and the registry record does not report a formal comparative safety analysis or adjustment for duration of exposure. Serious adverse events and other adverse events are separate summaries and should not be combined.

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

The posted primary result estimates overall survival for the TP53 WT population in this randomized comparison. Its hazard ratio is close to one, but the confidence interval is broad enough to include relative effects in either direction. The result does not provide clear evidence of a difference under the reported analysis, and it does not prove that the groups are equivalent.

The median survival estimates provide a concise description of the observed survival distributions, but they do not capture every feature of those distributions. The hazard ratio, medians, confidence intervals, and p-value answer related but distinct statistical questions. No single number should be treated as a complete account of the comparison.

The registry states that the study was terminated because of futility and did not reach the planned end. This is important context for understanding the available result, but the record does not provide the criteria or analysis details needed to evaluate the decision independently. The observed data should not be extended beyond the population, outcome, and follow-up described in the registry.

The secondary outcomes and safety summaries add context about response and adverse events, but they do not overturn or replace the primary result. Several secondary comparisons are unadjusted, and the registry record does not report a multiplicity strategy. Their role is therefore descriptive unless further methods information establishes a confirmatory interpretation.

These findings are statistical descriptions of the posted trial data. They are not individual-level predictions, do not establish what would occur for a particular participant, and do not answer questions beyond the trial population and outcomes recorded.

18. Why This Trial Matters Statistically

This trial illustrates why a primary endpoint and its analysis need to be interpreted together. Overall survival is a time-to-event outcome, so the comparison depends on event timing and follow-up, not only on a pair of median estimates. The hazard ratio, confidence interval, and log-rank p-value provide complementary information about the relative comparison and its uncertainty.

It also shows why a result that is not statistically compelling is not the same as evidence of equivalence. The reported confidence interval spans estimates on both sides of one, leaving uncertainty about the direction and magnitude of the relative effect. Precision matters as much as the point estimate when drawing conclusions from a trial.

The termination for futility and failure to reach the planned end highlight the importance of documenting interim procedures, stopping criteria, and the effects of early termination on follow-up. Those details are not reported in the registry record, so readers cannot independently reconstruct the decision or its statistical implications.

Finally, the many secondary outcomes illustrate the need to distinguish primary evidence from exploratory findings. Unadjusted comparisons can be useful for describing patterns, but multiplicity and incomplete methods reporting limit how strongly they can support claims. Transparent reporting of the analysis plan, missing-data procedures, and endpoint hierarchy would help readers assess that evidence more fully.

19. 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 registry record does not report the original sample-size rationale, the planned statistical analysis in full, the specific futility criteria, or the details of any interim analysis. Because the study was terminated and did not reach its planned end, readers cannot use the record to assess the planned follow-up against the follow-up actually achieved.

The reported primary endpoint is restricted to the TP53 WT population. Although the registry states that the study included participants with and without TP53 WT mutations, this result should not be generalized to other populations without supporting analyses. The record does not report enough information to assess the definition and handling of the analysis population beyond its stated label.

The overall enrollment is 447, while the primary-result arm counts are 123 and 232. The registry record does not explain the difference, so it should not be attributed to a particular exclusion, missing-data process, or analysis choice. The endpoint description gives a follow-up horizon of up to approximately 4.5 years, but the record does not provide further detail on follow-up completeness or censoring.

The record does not report a multiplicity plan for the many secondary outcomes or a detailed missing-data strategy. The secondary comparisons therefore have limited confirmatory interpretation, and the posted safety counts do not provide a formal comparative analysis. These limitations constrain what can be concluded from the registry results without additional trial reporting.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study of Idasanutlin With Cytarabine Versus Cytarabine Plus Placebo in Participants With Relapsed or Refractory Acute Myeloid Leukemia (AML) — NCT02545283.
• Registry record last updated 2022-01-11; status last verified 2021-12.
• Results first posted 2021-09-14.
• 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.

23. Record Summary

This randomized, double-blind, placebo-controlled, phase III study compared idasanutlin plus cytarabine with placebo plus cytarabine in participants with relapsed or refractory AML. The primary outcome was overall survival in the TP53 WT intention-to-treat population, measured from randomization to death from any cause.

The registry reports median overall survival of 9.13 months for placebo plus cytarabine and 8.28 months for idasanutlin plus cytarabine. The sponsor-reported log-rank hazard ratio is 1.08, with a 95% confidence interval from 0.81 to 1.45 and p = 0.575. The study status is terminated; the registry says it was stopped for futility and did not reach the planned end.

Secondary outcomes include remission and transplantation measures, and the record lists serious adverse-event summaries. The registry does not report the original sample-size justification, full statistical analysis plan, missing-data procedures, or multiplicity strategy. These omissions limit independent assessment of the analysis and of the secondary findings.