Pazopanib As Pre-Surgical Therapy In Treatment-Naive Subjects With Non-Small Cell Lung Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pazopanib As Pre-Surgical Therapy In Treatment-Naive Subjects With Non-Small Cell Lung Cancer (NCT00367679), a non-randomized phase 2 study. The primary outcome is Number of Participants Achieving Tumor Shrinkage Based on Change in Tumor Volume.

2. Clinical Question

The study asked whether participants with treatment-naive, resectable non-small cell lung cancer had a substantial reduction in tumor volume after receiving pazopanib before surgery. The primary response definition was a reduction of at least 50% from baseline tumor volume. Tumor volume was assessed from high-resolution computed tomography scans of the thorax, with assessments conducted by a central reviewer.

This is a question about an observed response in a treated group, not a randomized estimate of how pazopanib compares with another treatment or with no treatment. Without a concurrent comparator, the study cannot establish what tumor-volume changes would have occurred over the same period in otherwise comparable participants who did not receive pazopanib.

The registry record describes secondary assessments of clinical response using RECIST, tumor metabolic activity measured by standard uptake value, laboratory values, blood pressure, apoptosis, target-gene expression and tumor-biopsy mutations. Their presence broadens the outcomes considered, but does not change the main question: the primary outcome focused on the count meeting the specified tumor-volume threshold.

3. Trial Design

This was a phase 2, open-label, multicenter, non-randomized study with a single treatment group. The registry record lists an enrollment of 35 and describes the intervention as oral pazopanib at 800 mg daily. The trial status is completed. Its recorded start was 2006-11, and its primary completion was 2008-04.

Participants were treatment-naive and had resectable non-small cell lung cancer at stage IA, IB, IIA or IIB to T2. The study evaluated pazopanib as neoadjuvant therapy, meaning treatment given before surgery. The listed population for the primary outcome is the safety population, defined in the record as all participants who received at least one dose of pazopanib. The registry record does not report a separate primary-outcome denominator or explain whether any enrolled participants were excluded from that analysis.

Open-label means treatment assignment was not masked from participants or study personnel. The record also identifies no masking. It does state that tumor assessments were conducted by a central reviewer, but does not report further details about that review process or whether the reviewer was masked to other information.

Because the study had one group and no randomized comparator, its design supports describing outcomes observed after treatment, not making a direct treatment-effect comparison against a control. Non-random allocation also means the study does not create comparable treatment groups by random assignment. The registry record does not report a protocol rationale for the chosen design, the planned sample-size justification, or a statistical analysis plan.

The record lists 14 outcome measures and 15 analyses. That indicates a wider set of outcomes and analyses than the primary endpoint alone, but it does not specify how their interpretation was coordinated or whether any multiplicity adjustment was planned. The absence of a reported control group and of a reported primary response result is central to interpreting what this study can establish.

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

Analysis population for the primary outcome, as defined in the registry: Safety Population: all participants who received at least one dose of pazopanib

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 Number of Participants Achieving Tumor Shrinkage Based on Change in Tumor Volume, measured over Baseline to at least two weeks or at most six weeks.

The primary endpoint counts participants whose tumor volume decreased by at least 50% after pazopanib treatment. Tumor volume was evaluated using high-resolution computed tomography scans of the thorax, and the registry record says a central reviewer conducted the tumor assessments. The stated assessment window runs from baseline to at least two weeks or at most six weeks.

A threshold-based endpoint turns a continuous measurement—tumor volume—into a participant-level response category. A participant meeting the threshold is classified as a responder; a participant whose tumor volume did not decrease by at least 50% is classified as a non-responder. The endpoint is therefore a count of participants meeting a defined criterion, rather than an average change in tumor volume.

In general, a prespecified threshold can make a response definition easier to apply consistently and can focus attention on changes considered substantial under the study’s chosen rule. It also discards information about how far each participant’s change lies from the threshold. Two participants with different degrees of shrinkage may be grouped together if both meet the criterion, while small differences around the cutoff can place participants in different categories.

The endpoint’s count and the number of participants assessed are not reported in the registry record. As a result, the posted record does not establish the observed response proportion or the precision of an estimate of response frequency. The stated endpoint definition alone describes what was to be counted, not how many participants met the criterion.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods determine how observations are turned into estimates and how much uncertainty should accompany those estimates. The registry record identifies the primary endpoint as a participant count and describes the response rule, but does not report the primary result or a detailed analysis plan. The discussion below explains general statistical principles relevant to this design; it does not claim that the trial used methods that are not reported in the registry record.

What does a participant count represent?

The endpoint counts participants who cross a response threshold. Such a count is directly interpretable as the number meeting the stated rule, provided the analysis population and assessment status are clear. To interpret it as a response frequency, the count must be considered alongside the number of participants assessed under the same endpoint definition. That denominator is not reported for the primary outcome in the registry record. Enrollment alone cannot substitute for it, since the primary population is defined by receiving at least one dose and the record does not give the corresponding number assessed.

Counts and proportions answer related but different questions. A count indicates how many participants met the rule; a proportion relates that count to a specified population. Neither is available for the primary response outcome in the registry record. A confidence interval, in general, expresses the statistical uncertainty around an estimate under a stated method and set of assumptions. It is not a guarantee that the true value lies within the interval, and its width depends on the amount and pattern of information. No primary response estimate or interval is reported.

What does the response threshold do?

The primary endpoint classifies response using at least 50% tumor-volume reduction. In general, converting a measured change into a binary category can simplify communication and provide a clear decision rule. However, dichotomizing a continuous measure loses detail. It does not distinguish degrees of reduction among responders, and it treats participants just on opposite sides of the cutoff as different categories even when their measurements may be close. The registry record does not report the distribution of individual tumor-volume changes, so the extent of information lost through the threshold cannot be assessed.

The record names a central reviewer for tumor assessments. Central review can, in general, promote consistent interpretation across assessment sites, but the registry record does not describe reviewer procedures, repeat readings, handling of disagreements, or masking. It is therefore not possible to characterize how measurement variability was addressed.

What can a single-group design estimate?

In general, an uncontrolled single-group study can estimate outcomes observed among the participants assessed, subject to how the analysis population and missing observations are handled. It does not provide a concurrent counterfactual: the outcome those same participants would have experienced over the same period without the intervention or under another intervention. Random allocation in a comparison study is one way to support a causal comparison by balancing, on average, factors that may influence outcomes. This study was non-randomized and had one group, so that type of randomized contrast is absent.

Observed change over time is not automatically attributable to treatment. General influences can include the natural course of the condition, measurement variation, participant selection and other events occurring during follow-up. The registry record does not report an adjustment strategy or a control-based analysis that could address these possibilities.

How should planning illustrations be understood?

General sample-size calculations estimate how many participants might be needed under specified assumptions to detect a chosen effect with a stated error rate and power. The registry record describes planning illustrations using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a fraction of an observed effect. Those assumptions describe an illustration, not the trial’s single-group design. They do not establish that the trial was planned using those assumptions, and a planning calculation is not observed power.

The listed study has no randomized two-arm comparison, whereas the planning assumptions describe equal allocation between two arms. The illustrations therefore should not be read as a description of the trial actually conducted or as evidence about its primary result. The observed effect used for those illustrations is not reported in the registry record available for this account. No sample-size justification for the trial itself is reported.

Why do multiple outcomes matter?

When a study assesses multiple outcomes or conducts multiple analyses, the chance of finding an apparently notable result somewhere can increase if each result is interpreted independently. In general, multiplicity can be handled through prespecified prioritization, adjustment procedures, or cautious interpretation; the appropriate approach depends on the aims and analysis plan. The registry record lists 14 outcome measures and 15 analyses, but does not report a multiplicity strategy, analysis hierarchy, or which secondary findings, if any, were considered confirmatory. The primary efficacy result is itself not reported, so there is no basis for assessing its relationship to the other analyses.

Over-dispersion is a general issue for count outcomes when observed variability exceeds what a chosen statistical model expects. It can make standard errors too small if the model does not account for the extra variability. The primary endpoint is described as a count of participants meeting a binary response definition, not as a repeated event count, and the registry record does not report a model or dispersion estimate for it. No model-based inference should be attributed to the trial without such reporting.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 14 outcome measures and 15 analyses. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a distinction between confirmatory and exploratory analyses. In general, testing or examining many outcomes can make isolated findings more likely to appear notable by chance. Without a reported plan, the degree to which multiplicity was addressed cannot be evaluated. The record also does not report an interim-analysis plan or whether interim analyses occurred.

Missing-data methods are not reported in the registry record. For the primary endpoint, the record defines the safety population as participants who received at least one dose, but does not state how many participants had an evaluable tumor assessment or how missing, incomplete or unevaluable scans were handled. It does not report whether participants without an assessment were counted as non-responders, excluded, or handled by another method. Each approach can affect the resulting estimate, so the missing-data rule is important for interpretation.

The record does not report the primary endpoint denominator, a participant flow accounting, or reasons for missing outcome data. It also does not report whether analyses followed a prespecified statistical analysis plan. Accordingly, it is not possible to determine whether reported analyses, if any, included all members of the defined safety population or only those with observed assessments. The primary response result itself is not reported in the registry record.

The registry record identifies the population used for the primary outcome but does not give a separate efficacy population definition. Other analysis-population details, including any rules for inclusion in secondary analyses, are not reported in the registry record. These gaps limit assessment of both selection into the analysis and the robustness of any outcome estimate.

11. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hypertension (2.9%), chylothorax (2.9%), pneumonia (2.9%), anxiety (2.9%), pulmonary embolism (2.9%).

The registry record lists 35 participants at risk for the reported pazopanib safety group. It reports 7 participants affected by serious adverse events and 33 affected by other adverse events. These are counts in the recorded categories; the registry record does not say whether the categories are mutually exclusive, so they should not be added together or interpreted as separate sets of participants.

The listed serious-event terms are hypertension, chylothorax, pneumonia, anxiety, pulmonary embolism and dyspnea, each reported at 2.9%. These percentages are presented as recorded; the registry information does not provide further event-level detail in the registry record, such as event timing, duration, severity beyond the serious classification, or whether an event was considered related to treatment. Deaths are not reported in the registry record.

In general, safety counts from a single-group study describe events observed among the people monitored; without a comparator, they do not establish whether an event occurred more often because of treatment. The counts also do not by themselves characterize the full clinical course of an event or its attribution. The record’s figures should therefore be read as descriptive safety information, not as a comparative estimate of risk or as a complete account of every adverse event.

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

The registry record establishes what the investigators intended to measure: the number of treated participants whose tumor volume decreased by at least 50% within the stated assessment period. It also describes the treatment group, the eligible disease stages and the use of central review for tumor assessments. These details define the study question and the response rule.

They do not establish how many participants met the primary response definition. That result is not reported in the registry record, and the primary outcome denominator is also not given. Consequently, the primary endpoint cannot be interpreted as an observed response frequency, and its statistical precision cannot be assessed. A response criterion and an enrollment figure are not substitutes for the missing outcome count and analysis population.

Even if a response count were available, this study’s single-group, non-randomized design would support description of outcomes in the treated group rather than a randomized comparison. In general, a before-and-after observation cannot by itself distinguish a treatment-associated change from changes that might have occurred over time for other reasons. The study does not include a concurrent comparator in the registry record.

The safety counts provide descriptive information for the pazopanib group. They do not establish comparative safety, and the registry record does not report treatment attribution for the listed serious events. Secondary outcome titles identify other assessments but do not supply their results. No claims about those outcomes can be made from the outcome list alone.

The appropriate reading is therefore bounded: the record describes a phase 2 study design, a prespecified primary response definition and selected safety counts, while leaving the primary efficacy result and several analysis details unreported. It does not support a conclusion about the size or certainty of the primary response outcome, nor a causal comparison with another treatment.

13. Why This Trial Matters Statistically

Statistically, this trial illustrates the distinction between defining an endpoint and reporting its result. The registry record gives a specific tumor-volume response rule—at least 50% reduction—and identifies the imaging method, assessment window and central review. Those features make the intended outcome understandable. Yet without the reported response count and denominator, readers cannot estimate the frequency of response or its uncertainty.

The study also illustrates how design determines the scope of inference. A single-group study can describe what was observed among treated participants, but it does not provide a randomized comparison. That matters because a change from baseline is not automatically a treatment effect. The design cannot separate treatment-associated change from time-related changes, measurement variability or other influences without additional evidence or assumptions.

The distinction between enrollment and the analysis population is another important statistical issue. The record lists an enrollment of 35 and defines the primary population by receipt of at least one dose, but does not report the corresponding outcome denominator. Readers therefore cannot assume that everyone enrolled contributed an evaluable primary outcome.

Finally, the record lists multiple outcome measures and analyses. Without a reported hierarchy or multiplicity strategy, the interpretation of secondary findings would require caution even if their results were available. The main statistical lesson is that endpoint definitions, analysis populations, missing-data handling, comparison structure and complete result reporting all shape what a study can establish. Here, the primary result is not reported in the registry record, making those distinctions especially consequential.

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 principal limitation for interpreting efficacy is that the registry record does not report the primary response count or its denominator. It therefore cannot show how many participants met the at least 50% tumor-volume reduction criterion, or how precise an estimate would be. Although enrollment is listed as 35, the record does not establish how many participants received at least one dose, had an evaluable scan, or entered the primary analysis.

The trial was non-randomized and single-group, with no concurrent control. As a result, outcomes observed after treatment cannot be directly compared with outcomes under another treatment or no treatment. Open-label conduct can also leave treatment and assessment knowledge unmasked, although the tumor assessments were conducted by a central reviewer. The registry record does not report further information about reviewer masking or procedures.

Assessment timing is described as baseline to at least two weeks or at most six weeks, but participant-level timing and assessment completion are not reported. Missing-data rules, reasons for missing assessments, and sensitivity analyses are not reported in the registry record. The record also does not report the statistical analysis plan, the study’s sample-size justification, or methods for handling the multiple outcomes and analyses.

Safety information is limited to the reported serious and other adverse-event counts and selected serious-event terms. The record does not give the additional event-level context needed to assess timing, treatment attribution or duration. Deaths are not reported in the registry record. These limitations restrict both efficacy interpretation and the scope of safety conclusions.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pazopanib As Pre-Surgical Therapy In Treatment-Naive Subjects With Non-Small Cell Lung Cancer — NCT00367679.
• Registry record last updated 2012-06-12; status last verified 2012-05.
• Results first posted 2010-03-17.
• 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

NCT00367679 is a completed phase 2, open-label, multicenter, non-randomized, single-group study of oral pazopanib as neoadjuvant treatment for treatment-naive participants with resectable non-small cell lung cancer at stage IA, IB, IIA or IIB to T2. The intervention is listed as 800 mg daily. Enrollment is listed as 35; the recorded study start is 2006-11 and primary completion is 2008-04.

The primary endpoint was the number of participants with at least 50% tumor-volume reduction from baseline, assessed by high-resolution computed tomography of the thorax and central review. The primary assessment window was baseline to at least two weeks or at most six weeks. The primary response result and its denominator are not reported in the registry record.

The record lists 14 outcome measures and 15 analyses. Safety information includes 7 participants with serious adverse events and 33 with other adverse events in the pazopanib group. Selected serious-event terms are reported at 2.9% each. The record does not report a randomized comparator, multiplicity strategy, missing-data methods, or a detailed statistical analysis plan.