Dasatinib or Nilotinib Followed by Imatinib in Patients With Newly Diagnosed, Chronic Phase Chronic Myeloid Leukemia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dasatinib or Nilotinib Followed by Imatinib in Patients With Newly Diagnosed, Chronic Phase Chronic Myeloid Leukemia (NCT02709083), a na phase 2 study. The primary outcome is The Proportion of Subjects Who Achieve Major Molecular Response (MMR).

2. Clinical Question

3. Trial Design

This was a phase II, single-group study registered as NCT02709083. Its title describes first-line dasatinib or nilotinib followed by a response-guided switch to imatinib in newly diagnosed chronic-phase chronic myeloid leukemia. The registry identifies dasatinib, nilotinib, and imatinib mesylate as drug interventions. It states that the treating hematologist selected dasatinib or nilotinib for the initial treatment. The available arm description begins to specify response thresholds at 3 months and 6 months, but the record does not contain a complete account of how those thresholds governed switching.

The registry lists enrollment as 7, identifies the study as terminated, and gives a start of 2016-10 and primary completion of 2018-07. Allocation is listed as not applicable, and masking as none. These features matter when interpreting any apparent treatment outcome: there is no randomized control arm in the recorded design, and the record does not describe a blinded assessment process. A single-group study can describe outcomes among people treated under its protocol, but it cannot isolate a treatment effect from other explanations as a randomized comparison can.

The primary outcome was the proportion achieving major molecular response at 12 months. The registry also lists secondary outcomes concerning accelerated or blast phase-free survival, patient-reported outcomes, adverse-event duration, frequency and severity, progression-free survival, and deep molecular response. It records no analyses. The stated primary outcome data were not collected following early closure; therefore, the record does not provide outcome estimates for the planned efficacy question or the listed secondary questions.

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: Data not collected since trial closed early; original study principal investigator Vamsi Kota, MD, left Emory University.

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 The Proportion of Subjects Who Achieve Major Molecular Response (MMR), measured over At 12 months.

The primary endpoint was the proportion of subjects who achieved major molecular response at 12 months. The registry describes response as a decrease in BCR-ABL1 fusion transcript or protein levels on a logarithmic scale. It defines a 1 log reduction as a drop to below 10% and defines major molecular response as a 3 log reduction, described as 0.1%. The translocation noted in the record is 9;22, associated with formation of the Philadelphia chromosome.

A proportion endpoint expresses how many people in a defined analysis population meet a prespecified response criterion by the specified assessment time. It is useful in a treatment study because it gives a direct summary of whether the measured molecular response threshold was reached. Interpreting that proportion also requires knowing who was assessed, how missing assessments were handled, and how the response was measured. Those details and the response count are not reported in the registry record.

The registry explicitly states that primary outcome data were not collected because the trial closed early and the original principal investigator left Emory University. Accordingly, there is no reported response proportion, uncertainty interval, or analysis of this endpoint in the record. The endpoint definition describes what the study intended to measure; it does not establish how many participants achieved the response.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a single-group phase II study, lists no allocation and no masking, and records no analyses. The primary endpoint is a proportion at a specified assessment time. The record does not provide the planned statistical analysis methods, and they are not reported in the registry record. The concepts below are general explanations of how such methods are commonly interpreted; they are not claims about methods used in this study.

What does a proportion estimate represent?

A proportion is the number of people meeting a defined outcome divided by the number of people included in the relevant analysis population. For a response endpoint, a clear interpretation requires both the response count and the denominator. It also requires knowing how the analysis treats people with no assessment, withdrawal, or other missing outcome information. The record reports enrollment of 7, but does not report a response count, an analyzed denominator, or an analysis population for the primary endpoint. Therefore, a response proportion cannot be recovered from the registry record.

A confidence interval, when reported, describes statistical uncertainty around an estimate under the method used to construct it. It is not a guarantee that the true value lies within the interval, nor does it account automatically for bias caused by missing data, selection, or design limitations. No confidence interval for the primary endpoint is reported in the registry record. Without an estimate and its uncertainty, precision cannot be assessed.

Why does the study design matter?

A single-group design records outcomes under a treatment approach without a concurrent randomized control group. It may describe what happened among assessed participants, but interpretation is limited when the question is whether treatment caused an outcome or performed differently from another approach. In randomized studies, allocation aims to make the groups comparable on average; this study has no randomized comparison recorded. Because the initial choice between dasatinib and nilotinib was at the treating hematologist’s discretion, treatment assignment was not described as a randomized contrast.

Masking can reduce the influence of knowledge about treatment assignment on some aspects of measurement or assessment. The registry lists masking as none. This does not establish that outcome assessment was biased, but it means the record does not describe masking as a safeguard. The exact outcome assessment procedures are not reported in the registry record.

How should a response threshold be understood?

The endpoint definition sets a threshold for classifying response: major molecular response is a 3 log reduction in BCR-ABL1 levels, described as 0.1%. A threshold simplifies a continuous molecular measurement into a response category. That can make a result easier to communicate, but it also means that people just on either side of the cutoff are classified differently despite potentially similar measurements. The registry does not report individual measurements or the observed distribution around the threshold.

The description also refers to a 1 log reduction as a drop to below 10%, and the arm description begins to refer to a 1 log reduction at 3 months or a 2 log reduction at 6 months. Because that arm description is incomplete, the precise role of those response levels in treatment switching is not reported in the registry record. They should not be treated as a complete account of the protocol’s decision rules.

What can be inferred from the missing analysis?

No analyses are recorded, and the primary outcome is explicitly described as not collected. These are distinct from a reported analysis with a nonsignificant result: a nonsignificant estimate would still require outcome data and an analysis, whereas this record presents neither for the primary endpoint. No p-value, effect estimate, or uncertainty measure is reported. The registry’s lack of an analysis does not support a conclusion that an effect is absent.

General sample-size calculations can illustrate how many participants per arm might be needed under specified assumptions for a future two-arm comparison. Such calculations depend on an effect size, a significance level, allocation, a statistical model, and other design choices. They are planning illustrations, not observed power and not evidence of a trial result. The registry record does not report a trial-specific statistical plan or a sample-size justification, and no efficacy estimate is available in the record to interpret as an observed effect.

For time-to-event outcomes, general methods account for when events occur and how long participants are observed. For a proportion outcome, methods focus on the response status and denominator at the assessment time. Which methods were intended for the listed survival outcomes, and how censoring or incomplete follow-up would be handled, are not reported in the registry record. These distinctions matter because an outcome title alone does not identify the analysis method.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and several secondary outcomes, including survival outcomes, patient-reported outcomes, adverse-event summaries, and deep molecular response. It records no analyses. The statistical plan is not reported in the registry record, including whether the investigators planned adjustments for testing multiple outcomes or how they intended to prioritize secondary findings. When many outcomes are examined, the chance of finding an apparently notable result by chance can increase; a prespecified multiplicity strategy can help readers interpret that situation. This is a general consideration, not a description of a method used in this study.

The primary outcome is not simply an analysis with incomplete follow-up: the registry states that the data were not collected because the trial closed early and the original principal investigator left Emory University. The registry does not report the extent or pattern of missing data for individual participants, whether any partial outcome data exist, or whether any imputation or sensitivity analysis was performed. It also does not report the analysis population for the primary or secondary outcomes.

In general, missing outcome data can affect both the estimated response and its uncertainty. The direction and size of any effect depend on why data are missing and on the outcomes among those not observed; those cannot be inferred from the recorded enrollment alone. No assumptions about the missing outcomes can be checked from the registry record. An interpretation should therefore distinguish the absence of collected or reported results from evidence of no effect.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry’s adverse-event entry lists a treatment group titled “Treatment-dasatinib, Nilotinib, Imatinib.” It reports 7 at risk for serious adverse events and 0 affected; for other adverse events, it reports 7 at risk and 0 affected. Deaths are recorded as 0. These are the registry’s reported counts, not estimates from a comparative safety analysis.

A count of zero affected in the recorded group means that no events were entered in those categories for the listed group in this record. It does not establish that the treatments have no risk. The registry does not report person-time, duration of exposure, completeness of event collection, or a confidence interval for these counts. The record also does not provide detailed event terms in the serious adverse-event listing. Consequently, the counts do not show how safety would compare with a different treatment or what the event rate would be under longer observation.

The trial was terminated, and the stated absence of primary outcome data reflects early closure. The registry does not explain whether safety follow-up was complete for every person at risk or whether the adverse-event reporting period matched the intended treatment duration. That uncertainty limits interpretation of zero reported events. The listed secondary outcomes include adverse-event frequency, severity, and duration using CTCAE v4.03 criteria, but the registry reports no analyses for those outcomes.

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

The registry record establishes that a phase II, single-group study was registered to examine dasatinib or nilotinib followed by imatinib in newly diagnosed chronic-phase chronic myeloid leukemia. It identifies major molecular response at 12 months as the primary outcome and describes the molecular threshold used to define that response. It also records enrollment of 7 and a terminated status.

The record does not establish the proportion of participants who achieved major molecular response. It explicitly says those primary outcome data were not collected after early closure and the original principal investigator’s departure from Emory University. No response estimate or uncertainty interval is reported. This should not be read as a zero response, a negative trial result, or proof that the treatment approach has no effect.

The single-group design also limits what could be concluded about comparative effects, even if response data were available. Without a randomized control group, a descriptive outcome would not by itself show how the same population would have fared under another treatment. The record states that the hematologist selected dasatinib or nilotinib, and it does not report a separate comparison group.

The safety figures report no serious adverse events, other adverse events, or deaths in the listed group, with 7 at risk in each adverse-event category. Those counts do not by themselves demonstrate absence of risk, establish the completeness of follow-up, or support comparisons with other regimens. The record gives no analyses for the listed secondary outcomes.

In short, the registry documents the study question, design features, intended outcomes, and a small recorded enrollment, but it does not supply outcome analyses that answer the efficacy question. Its strongest statistical message is that the planned primary endpoint cannot be evaluated from the posted results.

13. Why This Trial Matters Statistically

This trial is statistically informative in part because it illustrates the difference between a defined endpoint and an observed endpoint result. The registry gives a clear intended question—major molecular response at 12 months—and a molecular definition for the response threshold. But it also states that the outcome data were not collected. A precise endpoint definition cannot substitute for the response counts and analysis needed to estimate the outcome.

The design features also help frame what the study could have answered. A single-group study can describe outcomes in its treatment setting, but it is not a randomized comparison. The record notes that the hematologist chose between dasatinib and nilotinib, and it identifies no control group. These registry entries matter when distinguishing descriptive experience from evidence about comparative treatment effects.

The record further shows why enrollment, outcome availability, and analysis population must not be treated as interchangeable. Enrollment is listed as 7, but the number assessed for the primary endpoint is not reported. The trial’s early termination and missing primary data prevent calculation of the response proportion from the record. Reporting these distinctions guards against interpreting the enrollment count as the denominator for an outcome that was not collected.

Finally, the listed secondary endpoints demonstrate the breadth of outcomes a study may plan to monitor, from survival and molecular response to patient-reported outcomes and adverse events. Yet without analyses, endpoint titles do not constitute findings. Statistically, the key lesson is that readers need both a transparent design and reported outcome data, including denominators and uncertainty, before judging the magnitude or precision of a result.

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 this study is that the registry states that primary outcome data were not collected. The record attributes this to early trial closure and the original principal investigator leaving Emory University. It therefore contains no primary response estimate or analysis. The listed enrollment of 7 does not reveal how many participants were treated, followed, or assessed at 12 months.

The study is recorded as single-group, with no allocation and no masking. There is no randomized control group for a like-for-like comparison. The registry also says that the treating hematologist chose between dasatinib and nilotinib, so the record does not describe randomized selection of the initial drug. The complete regimen details are not available in the arm description, which ends during the response-guided treatment explanation.

The record lists secondary outcome measures but gives no analyses. It does not report the statistical analysis plan, sample-size justification, analysis populations, handling of missing data, confidence intervals, or hypothesis tests. Details of follow-up and outcome measurement are also not reported in the registry record. As a result, neither planned methods nor the precision of any outcome estimate can be assessed.

Safety counts are recorded, including zero affected for serious and other adverse events and zero deaths, but the registry does not report exposure duration or enough follow-up detail to assess completeness. The listed adverse-event outcomes concerning duration, frequency, and severity have no recorded analyses. These limitations mean the safety counts should be read as registry entries, not as comprehensive comparative evidence.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Dasatinib or Nilotinib Followed by Imatinib in Patients With Newly Diagnosed, Chronic Phase Chronic Myeloid Leukemia — NCT02709083.
• Registry record last updated 2018-11-02; status last verified 2018-11.
• Results first posted 2018-11-02.
• 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

NCT02709083 is a phase II, single-group study of dasatinib or nilotinib followed by imatinib in newly diagnosed chronic-phase chronic myeloid leukemia. The registry lists enrollment of 7, a start of 2016-10, primary completion of 2018-07, and terminated status. Allocation is not applicable, and masking is none.

The primary outcome was the proportion achieving major molecular response at 12 months, defined as a 3 log reduction in BCR-ABL1 levels and described as 0.1%. The registry says those data were not collected because the trial closed early and the original principal investigator left Emory University. No analyses are recorded. The listed secondary outcomes also have no analyses reported.

The adverse-event entry reports 0 affected for serious events and 0 for other events among 7 at risk in each category, with deaths recorded as 0. These counts do not provide a comparative safety estimate. Overall, the registry describes the intended study and its outcomes but does not report an efficacy analysis answering the primary question.