Dasatinib in Treating Patients With Relapsed Small Cell Lung Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dasatinib in Treating Patients With Relapsed Small Cell Lung Cancer (NCT00470054), a na phase 2 study. The primary outcome is 6 Week Progression Free Survival.

2. Clinical Question

The registry title identifies the study as a phase II evaluation of dasatinib in chemo-sensitive relapsed small cell lung cancer. In statistical terms, the primary question is a time-specific description of progression-free status: whether participants were alive and had not met the registry’s definition of progressive disease by the 6-week assessment point. The registry defines progressive disease using RECIST as a 20% increase in the sum of the longest diameters of target lesions.

Because the study is single-group, its primary endpoint describes outcomes among participants receiving dasatinib; it does not directly estimate a difference between dasatinib and another treatment. The record lists secondary outcomes of progression-free survival, response to therapy, overall survival, and participants with grade 3 or higher adverse events. It does not report numerical results for those outcomes in the information recorded. Nor does it provide the primary endpoint’s numerical estimate or confidence interval. The clinical question can therefore be identified, but its observed answer cannot be read from the registry record.

3. Trial Design

This is a phase II, single-group study sponsored by the National Cancer Institute. The registry reports an enrollment of 44 and a completed status. The start is listed as 2007-04 and primary completion as 2009-02. Its official title describes a study of dasatinib in patients with chemo-sensitive relapsed small cell lung cancer.

The intervention is oral dasatinib, given twice daily on days 1-21. Treatment repeats every 21 days in the absence of disease progression or unacceptable toxicity. The registry lists one treatment group, Dasatinib. Allocation is recorded as NA and masking as none. There is no listed concurrent control group, so the study does not provide a randomized, like-for-like comparison with another treatment.

The primary outcome is 6-week progression-free survival, expressed as a percentage of participants. The registry says that the estimate was to be obtained with the Kaplan-Meier method and that all eligible participants were analyzed. It defines progressive disease using RECIST as a 20% increase in the sum of the longest diameters of target lesions. The listed secondary outcomes are progression-free survival, response to therapy, overall survival, and the number of participants with grade 3 or higher adverse events.

The registry record does not report a sample-size justification, a detailed protocol, or a statistical analysis plan. It lists five outcome measures and zero analyses. The absence of a numerical primary endpoint estimate in the posted results means that the endpoint’s observed value and precision cannot be assessed from this record. The design details identify the setting and planned measure, but do not establish the result of treatment or a comparative effect.

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: One(1) participant cancelled before receiving any protocol related therapy and 1 participant was deemed ineligible. All participants receiving treatment were analyzed for adverse events and only eligible (43) participants were analyzed for al other endpoints.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All eligible participants were analyzed.

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: Only eligible participants (those who met the criteria for inclusion) were evaluated for baseline characteristics.

6. Primary Endpoint

The registry lists the primary outcome as 6 Week Progression Free Survival, measured over 6 weeks.

The primary endpoint is the percentage of participants who were alive and progression free at 6 weeks. The registry identifies Kaplan-Meier estimation as the method. In general, a Kaplan-Meier estimate uses the timing of observed events and accounts for participants whose follow-up ends before the event is observed; the registry record does not describe censoring rules or the handling of incomplete follow-up for this study.

The endpoint combines two aspects of status: being alive and having no progression by the specified time. The registry defines progressive disease according to RECIST as a 20% increase in the sum of the longest diameters of target lesions. A 6-week measure gives a time-specific summary rather than a complete account of how long each participant remained progression free. It may serve as an early disease-control measure, but it should not be treated as a substitute for the separately listed progression-free survival or overall survival outcomes.

The record says that all eligible participants were analyzed and lists a 95% confidence interval as the measure of dispersion. It does not give the endpoint estimate, its confidence interval, the number evaluated, or details of missing observations. Thus, the endpoint definition is available, while the observed percentage and its precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry names the Kaplan-Meier method for estimating 6-week progression-free survival and gives a 95% confidence interval as the measure of dispersion. No numerical estimate or interval is reported in the posted results. The statistical methods can therefore be explained, but the result’s magnitude and uncertainty cannot be evaluated from the registry record.

What does a Kaplan-Meier estimate represent?

In general, the Kaplan-Meier method estimates the probability of remaining free of a defined event over time. It uses the observed timing of events and can retain information from participants whose observation ends before an event is documented, under the method’s assumptions. The registry defines the endpoint as being alive and progression free at 6 weeks. It does not report the event dates, censoring details, follow-up pattern, or rules for incomplete observations, so the calculation cannot be independently checked from the record.

A time-specific percentage is not the same as a mean duration of progression-free survival. It describes estimated status at the selected time point, rather than how long each person remained free of progression over the entire follow-up period. The registry separately lists progression-free survival and overall survival as secondary outcomes, but numerical results for these outcomes are not reported in the registry record recorded.

What does a confidence interval add?

In general, a confidence interval communicates the statistical uncertainty around an estimate. A narrower interval indicates greater precision under the method used; a wider interval indicates less precision. The registry specifies a 95% confidence interval for the primary endpoint, but does not state its limits. Without the interval, readers cannot assess how precisely the six-week percentage was estimated. A confidence interval would describe uncertainty in the estimate, not eliminate limitations of the design or establish a causal effect.

How does the endpoint definition affect the analysis?

The registry defines progression using RECIST as a 20% increase in the sum of the longest diameters of target lesions. The endpoint also requires participants to be alive and progression free at 6 weeks. These details establish the stated clinical event and time point. The record does not provide further rules for assessment timing, confirmation of progression, or handling of observations that cannot be classified. Those details are not reported in the registry record and should not be inferred.

What does the single-group design permit?

In general, a single-group study can describe outcomes among participants receiving an intervention. It does not provide a randomized control group from which to estimate a between-group contrast. Differences between observed outcomes and an external expectation would not by themselves establish that the intervention caused those outcomes. Here, allocation is NA, masking is none, and the model is single-group. Consequently, any interpretation must remain descriptive rather than comparative.

The planning assumptions recorded for a sample-size illustration specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a fraction of the observed effect. Those assumptions are for a planning illustration, not the trial’s single-group design. A planning sample size is not an observed outcome and is not observed power. The registry record does not report a trial-specific sample-size justification or enough primary outcome information to assess such a planning calculation.

What information is needed to evaluate the result?

For a complete statistical assessment, readers would need the primary endpoint estimate and confidence interval, along with the relevant participant counts and information about follow-up and missing observations. The registry says all eligible participants were analyzed, but does not specify how eligibility was determined for the analysis or how incomplete outcome information was treated. It lists five outcome measures and zero analyses. Detailed analysis choices, including any interim analyses, are not reported in the registry record.

These limitations distinguish method description from result interpretation. The named method and endpoint definition tell readers what the study intended to estimate. They do not reveal the estimate itself, its precision, or whether assumptions needed for the analysis were met. Statistical conclusions should therefore be confined to the design and outcomes actually recorded.

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("Dasatinib")
n      <- c(43)
events <- c(18)
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  Dasatinib  43  18  41.9  27.0  57.9  28.4  56.7  28.3  56.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary 6-week progression-free survival endpoint and secondary outcomes of progression-free survival, response to therapy, overall survival, and participants with grade 3 or higher adverse events. It records five outcome measures and zero analyses. The record does not describe a multiplicity adjustment, a hierarchy for testing outcomes, or a prespecified strategy for controlling the chance of false-positive findings across multiple tests. These details are not reported in the registry record.

In general, multiplicity matters when several outcomes or comparisons are tested: interpreting each result as if it were the only test can make a chance finding more likely across the set. The registry’s list of outcomes alone does not establish that formal hypothesis tests were conducted, and no analysis results are reported in the registry record. It would be inappropriate to infer either an adjustment or a lack of adjustment beyond what the record states.

The primary population is described as all eligible participants. The record does not report the number deemed eligible, the number with endpoint observations, or the handling of participants with incomplete follow-up. It also does not describe imputation, censoring rules, exclusions after enrollment, or sensitivity analyses. These missing details limit assessment of how the stated analysis population relates to the enrollment figure and how robust the endpoint estimate would be to missing data.

In general, missing outcome information can affect an estimate when the participants without observed data differ in outcome risk from those with observed data. Without details on the extent and pattern of missingness, readers cannot judge that possibility for this study. The registry’s statement that all eligible participants were analyzed does not itself resolve these questions. The numerical primary result and its confidence interval are also absent, further limiting independent assessment.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hemoglobin (27.3%), fatigue (27.3%), dyspnea (shortness of breath) (18.2%), diarrhea (13.6%), pleural effusion (13.6%).

The registry lists 14 participants affected among 44 at risk in the serious adverse-event group. In the other adverse-event category, it lists 39 affected among 44 at risk. These are counts recorded for the dasatinib group; they are not a comparison against a control group. The registry record does not give a deaths count.

The serious adverse-event terms listed with percentages are hemoglobin and fatigue, each 27.3%; dyspnea (shortness of breath), 18.2%; diarrhea and pleural effusion, each 13.6%; and platelet count decreased, 11.4%. These percentages describe the listed terms in the registry safety record. They should not be read as measures of treatment benefit, nor do they indicate how the same events would compare under another treatment.

In general, adverse-event counts and percentages describe events recorded during a study; their interpretation depends on definitions, follow-up, attribution rules and reporting procedures. The registry record does not provide further detail on those matters. A listed event does not by itself establish that dasatinib caused it, and a missing deaths count should not be interpreted as zero. Serious-event figures and other adverse-event figures are separate registry categories; the record does not explain their relationship in further detail.

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

The registry record establishes that a phase II, single-group study evaluated dasatinib in patients with chemo-sensitive relapsed small cell lung cancer. It describes oral dosing twice daily on days 1-21, repeated every 21 days if disease progression or unacceptable toxicity had not occurred. It also defines a primary endpoint: the percentage alive and progression free at 6 weeks, estimated using Kaplan-Meier methods.

Those design details do not reveal the endpoint result. The numerical percentage and 95% confidence interval are not reported in the registry record. Although enrollment is listed as 44 and the primary population as all eligible participants, the record does not give the eligible count or endpoint denominator. It is therefore not possible to judge the estimate’s precision or independently assess how much follow-up supports it.

The single-group design can describe outcomes within the dasatinib group, but it cannot provide a randomized contrast with another treatment. Even if a numerical outcome were available, the design would not by itself establish that the intervention caused the observed result. The registry’s allocation entry is NA, and masking is listed as none. No comparator group is recorded.

The safety record lists affected counts and selected serious-event percentages. These are descriptive figures and do not establish comparative safety or causation. The deaths count is not reported in the registry record. The secondary outcomes are named, but their numerical findings are not included in the information recorded.

In short, the record supports statements about the study’s design, treatment schedule, endpoint definition, analysis method and selected safety entries. It does not support a conclusion about the size or precision of the primary endpoint result, a comparative treatment effect, or the cause of recorded adverse events. Those distinctions are essential when interpreting registry information without numerical efficacy results.

14. Why This Trial Matters Statistically

This study illustrates why a clearly named endpoint and a numerical result are both needed for statistical interpretation. The registry specifies a 6-week progression-free survival measure, its time point, the Kaplan-Meier method, and a 95% confidence interval. Yet it does not report the estimate or interval. Knowing the method tells readers what was intended to be summarized, but it cannot substitute for the observed value or its uncertainty.

The single-group design also highlights the difference between describing an outcome and estimating a comparative effect. Outcomes in the dasatinib group may be summarized descriptively, but the registry does not list a randomized control group. Without a concurrent comparison, a treatment effect relative to another strategy is not directly estimated by the design. This is a central distinction in interpreting phase II evidence.

The record also demonstrates the importance of analysis-population and follow-up details. It says all eligible participants were analyzed, but does not report the eligible count, endpoint denominator, missing-data handling, or censoring rules. Those details affect how a time-to-event estimate and its precision can be assessed. Enrollment alone does not answer how much endpoint information was available.

Finally, safety counts must be kept distinct from efficacy outcomes and comparative claims. The registry reports affected counts and selected serious-event terms, but does not provide a control group or a deaths count. Reading these figures descriptively, without inferring causality, preserves the limits of what the record establishes. The main statistical lesson is that design, endpoint definitions, analysis details, and reported estimates each answer different questions; missing numerical results constrain conclusions even when the planned method is named.

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 primary limitation for interpreting efficacy is that the registry record does not report a numerical 6-week progression-free survival estimate or its 95% confidence interval. Although the endpoint and Kaplan-Meier method are specified, readers cannot assess the observed percentage, its precision, or the data contributing to it.

The study is single-group, with allocation recorded as NA and masking as none. There is no listed control group for a randomized comparison. This limits what can be inferred about differences from another treatment or about causation. The record also does not report a detailed statistical analysis plan, sample-size justification, interim-analysis procedures, or multiplicity strategy.

The analysis population is described as all eligible participants, but the record does not give the number eligible or the number with endpoint information. It does not describe missing-data handling, censoring rules, the timing or completeness of assessments, or sensitivity analyses. These omissions make it difficult to evaluate the support and robustness of a time-specific Kaplan-Meier estimate.

The registry lists five outcome measures and zero analyses. It names several secondary outcomes but does not report their numerical findings in the registry record recorded. The adverse-event entries include affected counts and selected serious-event percentages, but the record does not provide further detail about event attribution or the relationship between the serious and other adverse-event categories. The deaths count is not reported. These limitations are specific to the information available in the registry record and should not be filled by assumptions.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Dasatinib in Treating Patients With Relapsed Small Cell Lung Cancer — NCT00470054.
• Registry record last updated 2015-05-05; status last verified 2014-06.
• Results first posted 2013-04-26.
• 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 record describes NCT00470054, a completed phase II, single-group study sponsored by the National Cancer Institute. It lists enrollment of 44, a start of 2007-04, and primary completion in 2009-02. The study concerns dasatinib in patients with chemo-sensitive relapsed small cell lung cancer.

Participants received oral dasatinib twice daily on days 1-21, with treatment repeating every 21 days in the absence of progression or unacceptable toxicity. The primary endpoint was the percentage alive and progression free at 6 weeks, estimated by Kaplan-Meier methods. The endpoint’s numerical estimate and 95% confidence interval are not reported in the registry record.

The record lists secondary outcomes for progression-free survival, response to therapy, overall survival, and grade 3 or higher adverse events. It also includes safety counts and selected serious-event percentages. Allocation is NA, masking is none, and the study has no listed comparator group. Detailed missing-data and analysis-plan information is not reported in the registry record.