Study of Nilotinib as First Line Treatment in Philadelphia Chromosome Positive(Ph+) Chronic Myelogenous Leukemia in Chronic Phase (CML-CP): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Nilotinib as First Line Treatment in Philadelphia Chromosome Positive(Ph+) Chronic Myelogenous Leukemia in Chronic Phase (CML-CP) (NCT01274351), a na phase 2 study. The primary outcome is Percentage of Participants Who Achieved Major Molecular Response (MMR) During the First 12 Months.

2. Clinical Question

3. Trial Design

This was a phase II, multicenter, open-label, non-randomized study of nilotinib as first-line treatment for adults with newly diagnosed Ph+ CML-CP. The registry identifies a single-group model and records enrollment of 112 participants. Since there was no randomized comparison group, the design can describe outcomes among participants treated in the study but cannot, by itself, isolate treatment effects from other influences or compare treatments fairly.

The intervention is described as oral nilotinib at 300 mg twice daily for 24 months. The study started on 2011-01-25, reached primary completion on 2019-08-01, and is marked completed. Novartis Pharmaceuticals is listed as the sponsor. The record calls the study local and multicenter in its summary; additional details about sites or conduct are not reported in the registry record.

The primary outcome concerns MMR during the first 12 months, while the listed secondary outcomes include MMR up to 24 months, complete cytogenetic response at Month 6 and Month 12, complete hematologic response at specified visits through Month 24, time to MMR, and duration of MMR. These outcomes describe different aspects and timings of response; they should not be treated as interchangeable measures.

Allocation is recorded as not applicable, consistent with the single-group, non-randomized design. Masking is listed as none. The registry record does not report a statistical analysis plan, a sample-size justification, interim analyses, or details of how site-level variation was handled. The absence of these details limits what can be concluded about the intended analysis strategy.

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: This was an open-label study with one treatment arm. The study did not involve a reference treatment.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-treat (ITT) analysis set

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 Percentage of Participants Who Achieved Major Molecular Response (MMR) During the First 12 Months, measured over 12 months.

The primary endpoint is the percentage of participants who achieved MMR during the first 12 months. The registry defines MMR as BCR-ABL1 on the International Scale at or below 0.1%. This molecular measure describes the level of the BCR-ABL fusion gene product in the blood, using a standardized scale. The record also explains that BCR and ABL refer to the genes involved in the fusion.

A response percentage is used to express how often the defined endpoint occurred among the analysis population. It is important to distinguish the endpoint definition from an endpoint result: the registry describes what qualifies as MMR, but does not report the observed percentage, the number achieving response, or an uncertainty interval for the primary outcome.

The outcome is specified for an ITT analysis set. Participants who withdrew prematurely or were inevaluable because they did not provide study data for other reasons were designated non-responders in that analysis. This rule makes the handling of these participants explicit for the primary endpoint, although the record does not state how many participants fell into either category.

In general, a molecular-response endpoint can provide a defined measure of biological response over a specified follow-up period. Its interpretation depends on consistent measurement and complete enough follow-up, as well as on the definition and analysis population. The registry record does not report additional information about measurement procedures or the completeness of endpoint assessments.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

In general, a single-group study estimates outcomes among participants receiving the study intervention. A randomized comparison assigns participants to different groups using a random process, which supports a direct comparison by helping balance measured and unmeasured characteristics on average. This study is listed as single-group and non-randomized, so it does not offer that kind of concurrent treatment contrast. Its open-label status also means the treatment was not masked, which can matter for outcomes influenced by assessment or reporting. The registry record does not describe additional procedures intended to reduce those influences.

What does a response percentage represent?

In general, a response percentage is the number of participants meeting a stated response definition divided by the relevant analysis population, expressed as a proportion or percentage. The primary definition is MMR within the first 12 months, with BCR-ABL1 at or below 0.1% on the International Scale. A response percentage is interpretable only alongside its denominator, analysis population, outcome definition, and handling of missing observations. The registry specifies the ITT population and a non-responder rule for premature withdrawal or inevaluable status, but does not post the response count or percentage.

For a binary endpoint such as whether MMR was achieved, an analysis may report an estimate together with a confidence interval. In general, the estimate describes the observed response frequency, while the interval communicates uncertainty arising from sampling variability under the statistical model. The interval does not capture every source of uncertainty, such as bias from study conduct or limited generalizability. No primary estimate or confidence interval is reported in the registry record, so neither the response frequency nor its statistical precision can be assessed from the posted results.

Why does the analysis population matter?

The primary endpoint names an ITT analysis set and says that premature withdrawals and participants without study data for other reasons were included as non-responders. In general, this approach preserves participants in the analysis according to the study’s defined population and avoids excluding those participants from the endpoint solely because their outcome data are unavailable. It is a specific analysis rule, not proof that all missing information has been resolved. The record does not say how many participants were withdrawn or inevaluable, whether other missing-data situations occurred, or whether sensitivity analyses were conducted.

Different missing-data assumptions can change an estimate. Treating an unobserved response as a non-response is one explicit convention for this endpoint; other approaches could make different assumptions. General statistical practice is to describe the amount and pattern of missingness and assess whether conclusions depend on assumptions. Such descriptions and sensitivity analyses are not reported in the registry record.

What can the planning illustrations tell readers?

The stated sample-size assumptions describe planning illustrations computed from an observed effect, not the trial’s own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. This hypothetical two-arm setup does not match the registry’s single-group design. The illustrations are not observed power, do not demonstrate that the study was adequately powered, and are not trial results. The registry record does not report a sample-size justification for the study itself.

In general, a significance level is a threshold used in a testing procedure, and a two-sided test considers departures in either direction. A normal approximation is a mathematical method for estimating a sampling distribution; its suitability depends on the setting and data. Equal allocation is an assumed distribution of participants across hypothetical arms. These assumptions describe how a planning calculation is framed, not what happened in this non-randomized study. The registry record does not report the calculation inputs or an observed primary effect estimate beyond the stated description of the illustrations.

How should multiple outcomes be considered?

The record lists several secondary outcomes as well as the primary endpoint. In general, testing or estimating many outcomes can create interpretive challenges: chance findings may occur, outcomes may be correlated, and differing time points can complicate comparisons. A statistical plan may prioritize outcomes, adjust for multiple comparisons, or treat secondary findings as exploratory. The registry record does not report whether any multiplicity strategy was planned or used. No secondary analyses are posted, so their results and the treatment of multiple outcomes cannot be evaluated.

The registry also does not report model details, covariate adjustment, confidence-interval methods, interim monitoring, or an analysis plan. These are distinct from the endpoint definition and cannot be inferred from the phase, design, or outcome list. Accordingly, interpretation should remain limited to the design and endpoint rules that the record explicitly describes.

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("Nilotinib")
n      <- c(112)
events <- c(74)
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  Nilotinib  112  74  66.1  56.5  74.7  56.9  74.2  56.9  74.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary MMR endpoint during the first 12 months and secondary outcomes covering MMR through 24 months, cytogenetic response, hematologic response, time to MMR, and duration of MMR. The record does not report whether analyses of multiple outcomes were adjusted for multiplicity, whether any outcomes were treated as exploratory, or how the primary endpoint was prioritized in a statistical analysis plan. Without those details and without posted outcome analyses, it is not possible to assess the strength or consistency of any findings across outcomes.

For the primary endpoint, the record states that participants who withdrew prematurely or were inevaluable because they did not provide study data for other reasons were counted as non-responders in the ITT analysis. This is a specified handling rule. The numbers of participants in those categories, the completeness of follow-up, and any other missing-data patterns are not reported in the registry record. Nor does the record describe sensitivity analyses to examine alternative assumptions about missing outcomes.

The primary analysis population is identified as ITT, but further details about its implementation are not reported. The registry does not provide a statistical analysis plan, methods for handling missing observations beyond the stated non-responder rule, or information about interim analyses. The record lists zero analyses, so the posted registry information does not permit evaluation of multiplicity procedures, model choices, or the relationship between planned and reported analyses.

12. 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: thrombocytopenia (3.6%), chest pain (2.7%), arteriogram coronary (2.7%), neutropenia (1.8%), acute myocardial infarction (1.8%).

The registry records 43 participants affected by serious adverse events and 90 affected by other adverse events, with 112 participants at risk in each category. It also records 2 deaths. These are descriptive counts for the nilotinib group, not comparative estimates. A participant may contribute to more than one adverse-event category or term, so the counts should not be added together to infer a total number of affected participants.

The listed serious adverse event terms include Thrombocytopenia (3.6%), Chest Pain (2.7%), Arteriogram coronary (2.7%), Neutropenia (1.8%), Acute myocardial infarction (1.8%), and Abdominal pain (1.8%). These are the percentages shown in the registry record; the record does not provide corresponding counts for each listed term in this summary. The terms should not be interpreted as mutually exclusive.

In general, adverse-event counts describe events recorded during a study and do not by themselves establish causation. With no randomized comparator, the record cannot quantify how these events compare with another treatment group. The recorded deaths likewise do not establish cause. Further details on event timing, severity criteria, relatedness assessments, and participant-level overlap are not reported in the registry record.

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

The registry record establishes that a phase II, open-label, non-randomized, single-group study evaluated nilotinib as first-line treatment in adults with newly diagnosed Ph+ CML-CP. It defines the primary endpoint as MMR during the first 12 months and specifies how premature withdrawal or inevaluable status was handled in the ITT analysis. It also records safety counts and a list of selected serious adverse event terms.

It does not report the primary MMR result, a confidence interval, or a statistical test. As a result, the record does not show the observed response frequency or how precisely that response was estimated. The absence of a posted efficacy analysis should not be interpreted as a positive or negative finding; it means the registry entry does not supply the result needed to assess the primary endpoint.

Even with an outcome estimate, a single-group non-randomized study would not provide a randomized comparison against another treatment. Observed outcomes in the study group could be described, but a causal treatment contrast would remain unavailable from this design alone. The open-label conduct is another feature relevant to interpretation, particularly for outcomes involving assessment or reporting; the registry does not describe masking or other measures to address potential assessment effects.

The safety counts are also descriptive. They do not establish that nilotinib caused a particular event, and they cannot be compared with a concurrent control group because none is described. The record does not provide the additional event details needed to assess timing or attribution.

Overall, the registry supports a description of the study design, treatment schedule, endpoint definitions, and reported safety counts. It does not support a quantitative conclusion about the primary efficacy result, its precision, or comparative treatment effects. The listed planning illustrations, if considered, are hypothetical calculations rather than evidence of observed treatment performance.

14. Why This Trial Matters Statistically

This study illustrates a common statistical distinction between defining an endpoint and reporting its result. The record gives a clear molecular-response threshold and follow-up period for the primary outcome, but does not post the resulting response estimate or an uncertainty interval. Without those results, readers cannot assess either the observed frequency of MMR or its precision from the registry entry.

The single-group, non-randomized design also makes the limits of descriptive evidence especially important. Outcomes in the treated group can characterize what was recorded in that study, but do not furnish a concurrent randomized contrast. Statistical interpretation should not turn a within-group observation into evidence of comparative benefit or harm. The absence of masking is another design feature to consider when outcomes can depend on assessment or reporting.

The ITT definition shows why analysis populations and missing-data rules matter. The record explicitly counts premature withdrawals and inevaluable participants as non-responders for the primary endpoint, but gives no counts for those categories. Readers therefore know the rule but cannot assess its practical impact on the reported endpoint, especially because no endpoint result is posted.

The safety figures similarly show the importance of separating descriptive counts from causal or comparative claims. Serious and other adverse events, listed terms, and deaths are recorded for the study group, but there is no randomized comparator and no detailed attribution information in the registry summary. The information is relevant to describing the record, while remaining insufficient for a comparative safety estimate.

Finally, planning calculations and observed results answer different questions. The stated planning assumptions concern hypothetical two-arm sample-size illustrations, whereas the study itself is listed as a single group. Such illustrations cannot replace a reported endpoint analysis or establish observed power. Together, these features make transparent reporting of results, analysis populations, uncertainty, and design limitations essential for statistical interpretation.

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.

The most consequential limitation of the registry entry is that it does not report the primary endpoint result. There is no posted MMR percentage, response count, confidence interval, or p-value, and the record lists zero analyses. The statistical evidence for the primary question therefore cannot be evaluated from the registry record.

The study was non-randomized and single-group, with no concurrent comparator described. This restricts interpretation to outcomes recorded in the treated group and prevents a direct randomized comparison. Open-label conduct may also affect outcomes involving assessment or reporting. The registry record does not describe any additional procedures for addressing these concerns.

The record specifies an ITT non-responder rule for premature withdrawals and inevaluable participants, but does not report how many participants were affected, the completeness of follow-up, or any sensitivity analyses. It also does not report baseline characteristics in detail, the statistical analysis plan, a sample-size justification, interim analyses, or methods for evaluating multiple outcomes. The lack of these details limits assessment of analysis choices and potential sources of bias.

Safety reporting in the registry summary is descriptive and lacks a concurrent control group. Details about event timing, attribution, and overlap are not reported. The listed adverse-event percentages should not be used to infer unreported counts or causal relationships.

The registry records enrollment of 112 participants, but the number contributing data to each outcome is not stated. The planning illustrations use assumptions for a hypothetical two-arm comparison and are not a description of the trial’s single-group design. No trial-specific design justification is reported. These limitations concern what can be learned from the registry record and do not, by themselves, establish how the study was conducted beyond the details it records.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study of Nilotinib as First Line Treatment in Philadelphia Chromosome Positive(Ph+) Chronic Myelogenous Leukemia in Chronic Phase (CML-CP) — NCT01274351.
• Registry record last updated 2020-09-01; status last verified 2020-08.
• Results first posted 2020-09-01.
• 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

The registry describes a completed phase II, open-label, non-randomized, single-group study of nilotinib as first-line treatment for adults with newly diagnosed Ph+ CML-CP. Nilotinib was administered orally at 300 mg twice daily for 24 months. The recorded enrollment is 112 participants; the study started on 2011-01-25 and reached primary completion on 2019-08-01.

The primary endpoint is MMR during the first 12 months, defined as BCR-ABL1 at or below 0.1% on the International Scale. The record specifies an ITT non-responder rule for premature withdrawal or inevaluable status but does not report the primary outcome result or an analysis. Safety counts include 43 participants with serious adverse events, 90 with other adverse events, and 2 deaths. These are descriptive figures without a randomized comparator.

The registry does not report an efficacy estimate, its precision, a statistical analysis plan, or a sample-size justification. The design and missing results limit comparative interpretation.