Neoadjuvant Pazopanib in Renal Cell Carcinoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Neoadjuvant Pazopanib in Renal Cell Carcinoma (NCT01361113), a na phase 2 study. The primary outcome is Response Rate.

2. Clinical Question

The title identifies the study as neoadjuvant pazopanib in renal cell carcinoma and describes the goals as evaluating disease response and recurrence and establishing predictive biomarkers of drug activity. The posted primary endpoint is response, while the listed secondary outcomes include recurrence-free survival, changes to the surgical approach, and adverse events related to treatment. These questions concern different aspects of the study: short-term tumor response, subsequent recurrence, surgical planning, and safety. A response assessment at a specified time does not by itself answer the longer-term recurrence question, and neither outcome can be interpreted as a comparison against an untreated or alternative-treatment group in this single-arm design.

3. Trial Design

This is a completed phase II study sponsored by UNC Lineberger Comprehensive Cancer Center. The registry record gives a start date of 2011-06 and a primary completion date of 2015-01-07. It records enrollment of 21 participants. The study is identified as single-group, with allocation recorded as not applicable and no masking. No randomized control arm is described.

The intervention was pazopanib before nephrectomy. The arm description specifies 800 mg orally once daily for 8 weeks. The brief summary describes a planned single-arm study of 39 evaluable patients, whereas the registry enrollment is 21. These figures have different labels in the record: one is the planned number of evaluable patients in the summary, and the other is the recorded enrollment. The registry record does not explain the difference, identify the final number evaluable for the primary endpoint, or state why the study enrolled fewer participants than the summary’s planned evaluable count.

The primary outcome is a participant count for objective response, assessed at 8 weeks after neoadjuvant treatment using RECIST 1.1. Listed secondary outcomes are recurrence-free survival, the number of participants needing an altered surgical approach after pazopanib, and the number with adverse events related to treatment. Four outcome measures are recorded, but detailed definitions, assessment schedules, and results for all measures are not included in the information. The registry record lists no statistical analyses. Details of the protocol’s sample-size justification, planned hypothesis test, analysis population, handling of missing outcome data, and interim monitoring are not reported in the registry record.

Because all participants received the same study intervention and there is no control group, the design can describe outcomes observed during the study but cannot isolate the effect of pazopanib from other possible explanations for those outcomes. The absence of masking also means that treatment assignment was known; the record does not describe whether response assessments or other evaluations were independently reviewed or blinded.

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: 28 patients consented to participate in this study; 6 patients were found ineligible and 1 patient refused treatment leaving 21 patients on study.

Overall Study

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 Response Rate, measured over 8 weeks after neoadjuvant treatment.

The primary endpoint is the number of participants with an objective response 8 weeks after neoadjuvant treatment. Objective response combines complete response and partial response under RECIST 1.1. A complete response is defined as disappearance of all target lesions, with any pathological lymph node target decreasing in short axis to <10 mm. A partial response requires at least a 30% decrease in the sum of the longest diameters of target lesions, using the baseline sum as the reference.

Response criteria make the endpoint more operational than an informal impression of whether disease has changed: they specify what tumor findings count as a response and when the assessment is made. A fixed assessment time also helps define the outcome consistently across participants. The endpoint is expressed as a participant count, so interpretation ordinarily depends on both the number meeting the definition and the number assessed. The registry record does not report either an observed response count or an observed response rate, and it does not report how participants without an assessment at the stated time were handled.

Response is a short-term measure. It is distinct from recurrence-free survival and from whether the surgical approach changed, which are listed as secondary outcomes. A response result would describe the RECIST assessment in this study population; in a single-group study, it would not estimate a comparative treatment effect against a control group.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

The primary endpoint is a count of participants meeting the response definition. A count is a direct description of how many people satisfy a stated outcome rule; by itself, it does not account for how many people were assessed. For a binary outcome such as response or no response, interpretation commonly considers the count alongside the number of participants with an evaluable assessment. A proportion communicates the share of assessed participants meeting the definition, while an interval estimate communicates uncertainty around that estimate. The registry record reports the endpoint definition but not the response count, assessed denominator, proportion, or interval.

Counts also depend on clear outcome rules. Here, RECIST 1.1 defines complete response and partial response using target-lesion measurements and a specified assessment time. Combining CR and PR means the primary outcome treats either category as an objective response. The registry record does not say whether response categories were centrally reviewed, how non-target lesions were handled, or how an assessment that could not be classified was treated. Those details should not be inferred from the stated endpoint definition alone.

How does the single-group design affect interpretation?

In a single-group study, outcomes are observed among participants receiving the study intervention without a concurrent control group. This design can describe the frequency of an outcome under the study conditions. It does not directly estimate the difference between outcomes under two assigned treatments. Any comparison to an external expectation would require a clearly stated reference and assumptions about comparability; no such reference is described in the registry record.

Randomization, when used, helps balance participant characteristics across comparison groups on average. This study is recorded as nonrandomized and single-group, so it does not create randomized groups for a treatment contrast. Lack of masking means the study is recorded as unmasked. The registry record does not say whether outcome assessors were masked separately or whether independent review was used. These design features matter when judging how directly an observed outcome can be attributed to treatment rather than to other differences or assessment processes.

What do uncertainty and precision mean?

In general, a confidence interval is a range of values compatible with the observed data under a specified statistical method. A narrower interval generally indicates greater precision, while a wider interval indicates more uncertainty. The interval does not resolve design limitations: an estimate can be precise for the observed group while still not provide a causal comparison without a suitable control group. No confidence interval for response is reported in the registry record, so the precision of the primary result cannot be assessed.

A p-value, in general, describes how unusual data at least as inconsistent with a specified null hypothesis would be if that hypothesis and the test assumptions held. It is not the probability that a treatment works, nor does it measure the size or clinical importance of an effect. The registry record lists no statistical analyses and reports no primary endpoint p-value or stated null hypothesis. It is therefore not possible to identify a test used for the primary endpoint or to interpret a reported test result.

What do the planning assumptions mean?

The record describes a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also describes the target effect as a stated fraction of the observed effect. These are assumptions for a hypothetical planning calculation, not a description of the enrolled trial’s design: the actual trial is single-group. A two-sided significance level refers generally to considering departures in either direction under a specified test. Equal allocation refers to assigning the same planned number of participants to each of two hypothetical arms. A normal approximation uses a normal distribution to approximate the sampling behavior of a statistic under the relevant assumptions.

The record says that non-time-to-event planning illustrations express participants per arm, while time-to-event illustrations express total events. These are different planning units and should not be confused with the study’s observed enrollment or outcomes. Planning illustrations are not observed power: they do not measure the probability that this completed study found a result, and they do not substitute for the study’s actual analysis. The registry record does not report the observed effect value, the resulting planning counts, or a trial-specific sample-size justification. The stated assumptions therefore cannot be used to reconstruct the study’s design rationale.

For binary outcomes, the observed count varies from study to study even if the underlying response probability were unchanged. In general, uncertainty depends on the number assessed and the proportion observed. Over-dispersion is a general term for variation greater than a model assumes; when present, a model that ignores it may understate uncertainty. The registry record does not report a dispersion estimate or a model for the primary endpoint. The outcome is described as a participant count, but that alone does not establish which statistical model, if any, was used.

What can be inferred from the posted analysis record?

The registry record lists zero analyses and does not report an analysis method for the primary outcome. This means there is no posted test, model, adjusted estimate, or analysis population to interpret from the information recorded. It does not establish that no analyses were performed outside the registry; those details are simply not reported in the registry record. No recalculated estimate is available in the reported details, and there is no sponsor analysis result to compare against a recalculation.

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("Single Arm Neoadjuvant Pazopanib")
n      <- c(21)
events <- c(8)
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  Single Arm Neoadjuvant Pazopanib  21  8  38.1  18.1  61.6  20.8  59.1  20.7  59.3

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists four outcome measures, including the primary response endpoint and secondary outcomes concerning recurrence-free survival, surgical approach changes, and adverse events related to treatment. When several outcomes or hypotheses are examined, the chance of at least one apparently notable finding can increase if each is tested without accounting for the number of tests. General approaches to multiplicity include prespecifying a hierarchy, adjusting significance thresholds, or clearly distinguishing confirmatory from exploratory analyses. The registry record does not report whether any such approach was planned or used.

Missing-data handling is also not reported in the registry record. The record does not state how participants without an 8-week response assessment were classified, whether assessments outside the intended time were accepted, or how incomplete lesion measurements were handled. It also does not report the final number evaluable for the primary endpoint. These omissions matter because a response count depends on who was assessed and on the rule for participants whose response status is unavailable.

The record does not identify an intention-to-treat, per-protocol, or other analysis population. It does not state which participants were included in each outcome analysis or how protocol deviations and withdrawals were handled. Interim analyses and stopping rules are not reported in the registry record. The absence of those details prevents a reader from determining whether the reported enrollment, planned evaluable population, and analysis population were the same. No specific missingness mechanism or statistical remedy should be inferred.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hypertension (9.5%), anorexia (4.8%), atrial fibrillation (4.8%), cardiac troponin i increased (4.8%), cpk increased (4.8%).

The registry safety summary lists 21 participants at risk in the single pazopanib group, 6 with serious adverse events, 21 with other adverse events, and 2 deaths. These are descriptive counts for the recorded group, not comparisons against another treatment. The registry record does not report exposure-adjusted event rates, event timing, duration of treatment, or a comparison group that could place these counts in a relative context.

The listed serious-event terms and percentages are hypertension, 9.5%; anorexia, 4.8%; atrial fibrillation, 4.8%; cardiac troponin I increased, 4.8%; CPK increased, 4.8%; and dizziness, 4.8%. These are the terms identified in the registry safety summary. The record does not clarify whether participants could contribute more than one listed term or give event-level counts for each term. The percentages should therefore be read as recorded term frequencies, not summed or treated as mutually exclusive categories.

The record lists 2 deaths, but does not report their causes, timing, or relationship to treatment. The summary also does not establish that every adverse event was caused by pazopanib. Serious adverse events and other adverse events are distinct reporting categories; the counts should not be combined into a new total. These data describe what is recorded, while causal attribution and comparative safety are not established by a single-arm summary.

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

The study record describes a focused clinical question: whether participants had a complete or partial response at 8 weeks after neoadjuvant pazopanib, assessed using RECIST 1.1. It also records a completed phase II, single-group study, an enrollment of 21, and a planned evaluable population of 39 in the brief summary. The endpoint definition and design are informative about what the investigators intended to assess.

The primary response result itself is not reported in the registry record. No response count, response proportion, denominator assessed, or uncertainty interval is available in the recorded information. Thus, the posted record cannot establish the frequency or precision of response in the study. This should not be interpreted as a zero response result; the outcome data needed to reach that conclusion are not reported.

Even if a response result were available, the single-group design would describe outcomes in participants receiving the intervention but would not establish how those outcomes compare with another treatment or with no study treatment. An observed change or response is not, by itself, a randomized estimate of treatment effect. The absence of masking and the lack of reported details about assessment review also limit what can be inferred about outcome assessment procedures.

The safety counts likewise describe events recorded in the study group. They do not establish that pazopanib caused each event, and they do not quantify a comparative increase or decrease in risk. The deaths are listed without cause or attribution. The secondary outcomes have no reported results in the registry information, so their mention cannot support conclusions about recurrence-free survival or surgical approach.

Overall, the record supports understanding the planned question, treatment schedule, endpoint definition, and some descriptive safety information. It does not provide the primary outcome estimate or a comparative analysis. Statistical interpretation should remain within those boundaries rather than treating a study title, endpoint definition, or planning illustration as evidence of an observed treatment effect.

14. Why This Trial Matters Statistically

This trial is statistically instructive because its clinical question is clear while the registry information needed to quantify the primary finding is absent. The response endpoint has a defined assessment time and RECIST-based criteria, which illustrate how an outcome can be operationalized. Yet a definition is not a result: without the response count and the number assessed, readers cannot estimate the observed response frequency or judge its precision.

The contrast between the brief summary’s intended 39 evaluable patients and the recorded enrollment of 21 also highlights why planned sample size, enrollment, and analyzed population should be distinguished. Each describes a different stage or concept. The registry record does not explain the difference or report the final evaluable count, so the outcome denominator cannot be reconstructed from those figures alone.

The design is equally important to the statistical interpretation. A single-arm study can describe outcomes in a treated group, but it does not directly estimate a treatment contrast. This distinction is useful when reading response counts and safety summaries: descriptive data may be meaningful, but they do not by themselves establish comparative effectiveness or comparative safety.

Finally, the planning assumptions are not the trial’s statistical analysis. The illustration’s two-arm, equal-allocation framework differs from the single-group design, and planning values do not substitute for an observed outcome. Separating design, endpoint definition, analysis, and results helps avoid treating an intended question as though it had been answered by a reported estimate.

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 important trial-specific limitation in the registry record is that the primary response result is not reported. There is no observed response count, rate, assessed denominator, confidence interval, or test result. As a result, the primary endpoint cannot be quantitatively interpreted from the posted record. The record also does not explain the difference between enrollment of 21 and the summary’s plan for 39 evaluable patients.

The study is single-group and nonrandomized, with no comparator and no masking. Accordingly, even a reported response frequency would not provide a direct randomized estimate of a treatment difference. The registry record does not describe whether response assessment was independently reviewed or whether assessors were masked. It also does not report eligibility details beyond the summary descriptions, which refer respectively to localized and locally advanced renal cell carcinoma.

Important analysis details are absent: the final analysis population, missing-response rules, statistical methods, multiplicity approach, interim analyses, and sample-size justification are not reported in the registry record. The listed secondary outcomes have no results in the available record. For safety, counts and serious-event terms are available, but event timing, causes of death, treatment attribution, and comparative rates are not reported. These limitations restrict both the precision of interpretation and the conclusions that can be drawn about treatment effects or causation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Neoadjuvant Pazopanib in Renal Cell Carcinoma — NCT01361113.
• Registry record last updated 2018-04-25; status last verified 2018-03.
• Results first posted 2017-05-10.
• 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

NCT01361113 is a completed phase II, single-group study titled Neoadjuvant Pazopanib in Renal Cell Carcinoma, sponsored by UNC Lineberger Comprehensive Cancer Center. The registry record gives a start date of 2011-06, a primary completion date of 2015-01-07, and enrollment of 21. The brief summary describes a plan for 39 evaluable patients.

The intervention was pazopanib 800 mg orally once daily for 8 weeks before nephrectomy. The primary endpoint was the participant count with complete or partial response at 8 weeks after treatment under RECIST 1.1. Secondary outcomes include recurrence-free survival, altered surgical approach, and treatment-related adverse events.

The registry record does not report the primary response result or statistical analyses. It lists 6 participants with serious adverse events, 21 with other adverse events, and 2 deaths in the single-arm safety group. The listed safety information is descriptive and does not provide a comparison or establish event attribution.