A Study of Midostaurin Efficacy and Safety in Newly Diagnosed Patients With FLT3-mutated AML: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Midostaurin Efficacy and Safety in Newly Diagnosed Patients With FLT3-mutated AML (NCT03280030), a randomized phase 2 study. The primary outcome is Percentage of Safety Events (Part 1, Japan Only).

2. Clinical Question

The study also describes overall survival, complete remission, cumulative incidence of relapse and pharmacokinetic outcomes among its secondary outcomes. The registry record does not report results for those outcomes in the registry record for this analysis. Nor does it provide a numerical primary-endpoint result, a comparison estimate, or a confidence interval. The clinical question can therefore be described from the protocol record, but the posted information does not establish the observed primary-endpoint result or quantify uncertainty around it.

3. Trial Design

This was a phase II, randomized, double-blind, multicenter, placebo-controlled, parallel-group study sponsored by Novartis Pharmaceuticals. It enrolled 67 participants and is marked completed. The study began on 2018-04-06, and primary completion is recorded as 2022-11-14. Its stated objective was to evaluate the efficacy and safety of midostaurin in newly diagnosed patients with FLT3-mutated AML when used with induction and consolidation chemotherapy and then as continuation therapy.

The intervention descriptions distinguish Part 1, identified as Japan only, from Part 2. The primary outcome is specific to Part 1 and counts safety events among the evaluable participants in that part. The adverse-event record separately lists on-treatment groups for Midostaurin Part 1, Midostaurin Part 2, and Placebo Part 2, as well as post-treatment survival follow-up groups. The registry record does not describe the allocation ratio, randomization procedure, stratification factors, or the numbers assigned to each treatment arm in the full trial.

During induction and consolidation, the described dosing schedule was day 8-21; continuation dosing was days 1-28 for 12 cycles. The continuation phase followed consolidation. The primary endpoint timeframe was up to Day 21 of the first consolidation cycle, with a cycle defined as 28 days. The registry record does not report further protocol details such as eligibility criteria beyond the stated population, treatment adherence, or rules for modifying or stopping study treatment.

Randomized allocation and double masking are design features intended, in general, to support a fair comparison and limit the influence of expectations on outcome assessment. Their presence does not by itself establish that groups were comparable in every respect or that masking was maintained. The available registry information does not report how these features were implemented or assessed.

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.

Before assignment: Subjects were enrolled in 6 countries and at 34 study centers. In Part 1, subjects started chemotherapy at day 1 and midostaurin at day 8. In Part 2, subjects started chemotherapy at day 1 and were randomized to midostaurin or placebo at day 8.

Part 1 - Safety Evaluation

Reasons for not completing this period:

Part 2 - Efficacy

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Patients enrolled in Part 1: 3 patients out of 5 patients in Part 1 were evaluable for safety evaluation as determined by Independent Safety Committee (ISC).

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: Full Analysis Set (FAS): The FAS comprised of all subjects to whom study drug (midostaurin/placebo) had been assigned by randomization. Therefore, all Japanese subjects treated during Part 1 were not eligible for the FAS.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Safety Events (Part 1, Japan Only), measured over up to Day 21 of the first Consolidation cycle; cycle = 28 days.

The primary endpoint is titled “Percentage of Safety Events (Part 1, Japan Only)” and is recorded with participants as its unit and number as its parameter. It concerns events through Day 21 of the first consolidation cycle, defined as a 28-day cycle. A qualifying event was death or a serious adverse event leading to treatment discontinuation, occurring by that time and judged by the ISC to be definitely or probably related to midostaurin. The percentage was defined using the 3 evaluable participants out of 5 enrolled in Part 1.

In general, a safety endpoint focused on serious events and treatment discontinuation can describe a particular clinically important aspect of treatment tolerability during a specified period. Here, the endpoint is not a general count of all adverse events: it requires the stated seriousness or death criterion, treatment discontinuation for the serious adverse event, the time window, and an ISC assessment of relationship to midostaurin. Those conditions determine what is counted and limit what the endpoint represents.

The registry record does not report the number or percentage of qualifying primary-endpoint events. It also does not report a confidence interval, a comparison with placebo for this endpoint, or a statistical test. The endpoint definition and the count of evaluable participants are available, but the result needed to describe the observed frequency is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, double-blind, parallel-group phase II trial with a placebo comparator. The primary outcome is a binary event-count endpoint: participants either met the specified safety-event definition during the stated window or did not. The registry’s outcome parameter is number, while its title and definition describe a percentage based on evaluable participants. The observed primary result is not reported in the registry record, so no estimated event frequency or treatment contrast can be interpreted.

What does randomization contribute?

In general, randomization assigns participants to treatment groups using a chance-based process. When implemented as planned, it can reduce systematic differences between groups at study entry and make a treatment comparison more interpretable. It does not guarantee identical groups, especially in a phase II study, and does not remove uncertainty from a comparison. The registry record identifies randomized allocation but does not report the sequence-generation method, allocation concealment, allocation ratio, or stratification factors.

What does double masking mean?

In general, masking aims to limit the influence of knowledge about assigned treatment on participants, clinicians, and outcome assessment. The record identifies the study as double-blind and placebo-controlled, but does not specify which roles were masked or report whether masking was maintained. These details cannot be inferred from the design label alone.

How should the endpoint be understood?

The primary safety endpoint combines a defined event type, a treatment-discontinuation condition for serious adverse events, a specified time window, and an ISC judgment about relationship to midostaurin. In general, defining these elements in advance helps make event classification more consistent. It also means the endpoint does not capture every event that might be relevant to safety. The registry record does not describe the ISC's decision process, blinding, or how disagreements were handled.

What would uncertainty measures add?

In general, a confidence interval gives a range of values compatible with the observed data under the statistical model and shows how imprecisely an estimate is measured. A p-value, when reported, addresses compatibility of the data with a specified null hypothesis under stated assumptions; it is not the probability that the null hypothesis is true. Neither a confidence interval nor a p-value for the primary endpoint is reported in the registry record. There is therefore no inferential result to interpret, and a point estimate cannot be reconstructed from the endpoint definition alone.

What does the planning illustration describe?

The registry's planning assumptions describe an illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that a given effect was detected. The primary outcome is flagged as having several categories or time points and is not reduced to one comparison. No numerical sample-size illustration or trial-specific sample-size justification is reported in the registry record.

What is not described about the analysis?

The registry records 14 outcome measures and one analysis, but the registry entries do not give a statistical analysis plan, a model for the primary endpoint, an adjustment strategy, or details of interim analyses. The number of listed analyses does not, by itself, specify how outcomes were analyzed or how multiplicity was handled. The record also does not report how missing observations were treated, whether analysis populations were defined by intention to treat or another rule, or how participants not evaluable for the primary endpoint were handled beyond stating that 3 of 5 Part 1 participants were evaluable. These omissions limit assessment of the analysis and its assumptions.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 14 outcome measures, including overall survival, complete remission, cumulative incidence of relapse, and several pharmacokinetic outcomes. Considering multiple outcomes can create a multiplicity issue: in general, testing many hypotheses increases the chance that some results appear notable by chance if no adjustment or prioritization is specified. The registry entries identify the primary endpoint but do not report a multiplicity strategy, hierarchy of secondary outcomes, or correction for multiple testing. The record also notes one analysis, but that alone does not explain the handling of multiple endpoints or time points.

The primary endpoint was based on 3 evaluable participants out of 5 enrolled in Part 1, with evaluability determined by the ISC. The record does not explain why the other participants were not evaluable, whether data were missing, or how any unavailable outcome information was handled. It does not report an imputation method, sensitivity analysis, or missing-data assumptions. These details are not reported in the registry record.

Analysis populations are also not described beyond the stated Part 1 evaluable population. The registry record does not say whether the main analyses used all randomized participants, treated participants, or another defined set, nor does it explain exclusions from analyses. As a general matter, analysis population definitions affect which participants contribute to an estimate and how the estimate should be interpreted. Without the definitions and missing-data procedures, the analysis cannot be fully assessed from the registry information.

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 4.99% 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 (20.0%), cardiac failure acute (20.0%), multiple organ dysfunction syndrome (20.0%), pneumonia (20.0%), sepsis (20.0%).

The on-treatment safety summaries distinguish Midostaurin Part 1 (Japan Only), Midostaurin Part 2, and Placebo Part 2. The serious-event counts are listed as 2 among 5 at risk in Midostaurin Part 1, 12 among 30 at risk in Midostaurin Part 2, and 10 among 31 at risk in Placebo Part 2. These are group-level on-treatment summaries. They should not be treated as the primary endpoint result, which has a specific ISC attribution rule, discontinuation condition, and time window.

The registry also lists deaths in the on-treatment groups and in post-treatment survival follow-up groups. These counts are recorded separately, and the safety summaries do not establish that deaths were caused by study treatment. The serious-event terms listed include febrile neutropenia, cardiac failure acute, multiple organ dysfunction syndrome, pneumonia, sepsis, and septic shock. Their reported percentages are registry summaries; the record does not provide enough detail to determine overlap among terms or to interpret each as a separate participant-level rate.

In general, adverse-event counts describe events or affected participants within the record's reporting definitions, not a causal comparison by themselves. Interpretation depends on definitions, observation periods, group membership, and analysis methods. The registry record does not report a formal comparative safety analysis or uncertainty estimates for these figures.

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

The record establishes that this was a randomized, double-blind, placebo-controlled phase II study of midostaurin with chemotherapy and continuation therapy in newly diagnosed patients with FLT3-mutated AML. It identifies a primary safety endpoint for Part 1 in Japan and states how a qualifying event was defined. It also shows that 3 participants out of 5 enrolled in Part 1 were evaluable for that endpoint's safety evaluation.

These registry entries do not provide the primary endpoint result. Without its event count or percentage, it is not possible to describe the observed frequency, determine whether the endpoint was met, or quantify precision. The record also lacks a reported comparison estimate and confidence interval for that endpoint. The design label and endpoint definition cannot substitute for these results.

The adverse-event listings provide serious-event counts and event-term percentages for specified groups, along with death counts in on-treatment and follow-up categories. They are descriptive safety information, not proof that an event was caused by midostaurin or that one treatment had more or fewer events than another. In general, a comparative claim requires appropriate outcome definitions, group-specific analyses, and an assessment of statistical uncertainty.

Although efficacy outcomes such as overall survival, complete remission, and cumulative incidence of relapse are named as secondary outcomes, their results are not reported in the registry record details available for this analysis. The available information therefore does not establish an efficacy effect, a safety advantage, or a treatment recommendation. It describes the trial and what its registry record does and does not make assessable.

13. Why This Trial Matters Statistically

This trial illustrates why endpoint definitions and analysis populations matter in clinical research. The primary outcome's title refers to a percentage, while its parameter is recorded as a number and its description defines a percentage using the Part 1 evaluable participants. The population is narrowly specified: 3 participants out of 5 enrolled in Part 1 were evaluable, according to the ISC. That denominator and the ISC's event classification are central to understanding the endpoint.

The study also demonstrates the difference between a prespecified clinical question and a reported result. The record gives a detailed safety-event definition and timeframe, but does not provide the event count, percentage, or inferential statistics for that primary endpoint. A well-defined endpoint is necessary for interpretation, but it is not sufficient to assess the observed outcome or its precision.

Finally, the coexistence of a randomized design and descriptive adverse-event listings does not itself yield a treatment comparison. In general, a randomized trial's conclusions depend on how outcomes are analyzed, how missing observations and multiple endpoints are handled, and how uncertainty is reported. Those analysis details and results are not fully described in the registry record. This makes the boundary between design information and evidence from observed outcomes especially important.

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 limitation for interpreting the main question is that its numerical result is not reported in the registry record. The record defines the qualifying safety event and identifies 3 evaluable participants out of 5 in Part 1, but does not state how many had an event or provide a percentage, interval, or test result. The small evaluable group is a feature of the reported endpoint population; no broader precision claim can be made from the record.

The primary endpoint applies only to Part 1 in Japan and is limited to events through Day 21 of the first consolidation cycle. It requires a serious adverse event leading to treatment discontinuation or death, along with an ISC judgment that it was definitely or probably related to midostaurin. This is not interchangeable with the broader on-treatment adverse-event summaries, which include different groups and are not described as applying all of these endpoint conditions.

The registry entries do not report a statistical analysis plan, the primary endpoint analysis method, allocation ratio, detailed analysis populations, missing-data procedures, multiplicity handling, or interim analyses. They also do not include results for the listed efficacy and pharmacokinetic secondary outcomes. These gaps prevent a full assessment of statistical methods, endpoint precision, and comparative treatment effects. The record's completion status does not fill in these missing outcome and analysis details.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Midostaurin Efficacy and Safety in Newly Diagnosed Patients With FLT3-mutated AML — NCT03280030.
• Registry record last updated 2025-03-20; status last verified 2025-03.
• Results first posted 2025-02-11.
• 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

NCT03280030 is a completed, randomized, double-blind, parallel-group phase II study sponsored by Novartis Pharmaceuticals. It enrolled 67 participants with newly diagnosed FLT3-mutated AML and compared midostaurin with placebo alongside induction and consolidation chemotherapy, followed by continuation therapy.

The primary endpoint concerns safety events in Part 1 in Japan through Day 21 of the first consolidation cycle. The endpoint definition and evaluable population are reported, but the observed primary result is not reported in the registry record. On-treatment serious-event and death counts are listed for several groups, but they are not a substitute for the primary endpoint analysis or evidence of causation. Analysis details, missing-data handling, and results for the listed secondary outcomes are not reported in the registry record.