Pazopanib in Treating Patients With Metastatic Urothelial Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pazopanib in Treating Patients With Metastatic Urothelial Cancer (NCT00471536), a na phase 2 study. The primary outcome is Best Tumor Response (Complete [CR] or Partial Response [PR] by Response Evaluation Criteria in Solid Tumors [RECIST]).

2. Clinical Question

The clinical question is descriptive: among the eligible participants who consented and began treatment, how many had a complete or partial tumor response during the defined assessment period? The record says evaluations were scheduled every 8 weeks during treatment and up to 1 year after treatment completion. A complete response required disappearance of all target lesions. A partial response required at least a 30% decrease in the sum of the longest diameters of target lesions from baseline. These rules define what counted as a response; they do not establish how many participants responded.

The question also includes tolerability, reflected in the listed adverse-event outcomes. The record lists serious and other adverse-event counts for the treatment group, but does not give detailed event-level timing or individual clinical courses. In the absence of a comparator, neither response nor adverse-event figures can be interpreted as a comparative treatment effect. They describe outcomes recorded for this single study group.

3. Trial Design

This was a phase II study sponsored by the National Cancer Institute (NCI), with a single-group model and no masking. The registry lists the study as completed, with enrollment of 19. The recorded start was 2008-08 and primary completion was 2010-07. The study title concerns pazopanib in patients with metastatic urothelial cancer; the formal title describes a safety and efficacy study of the VEGF receptor tyrosine kinase inhibitor GW786034 in that population.

Participants in the treatment group were assigned oral pazopanib hydrochloride at 800 mg once daily on days 1-28, with treatment repeating every 28 days in the absence of disease progression or unacceptable toxicity. The record does not describe random allocation to multiple groups. With one group and no concurrent control, the study design is suited to recording outcomes within the treated group, but it does not furnish a direct randomized comparison against another treatment or against no treatment.

The primary endpoint was the number of eligible patients with a best response of complete response or partial response according to RECIST. Response evaluation was scheduled every 8 weeks during treatment and up to 1 year after treatment completion. The response population is described as eligible patients who signed consent and began treatment. Whether every enrolled participant met that definition, and the exact denominator used for the primary outcome, are not reported in the registry record.

Other listed outcomes include adverse events using NCI CTCAE Version 3.0, confirmed tumor response, duration of response, time to disease progression, and survival time. The registry record does not provide numerical results for these outcomes in the registry record for this analysis. It also does not report the detailed protocol, the statistical analysis plan, or whether any interim analyses were conducted. Those aspects should not be inferred from the phase label or the listed outcome names.

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: Of the 19 participants accrued, one participant canceled prior to treatment evaluation, and therefore was excluded from toxicity analysis. This participant was included in the primary endpoint analysis.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants meeting the eligibility criteria who have signed a consent form and have begun treatment will be evaluated for response.

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 Best Tumor Response (Complete [CR] or Partial Response [PR] by Response Evaluation Criteria in Solid Tumors [RECIST]), measured over Participants will be evaluated every 8 weeks during treatment and up to 1 year after completion of treatment..

The primary endpoint is a count of eligible participants whose best tumor response was complete or partial. Under the stated RECIST v1.0 definitions, complete response means that all target lesions disappear. Partial response means at least a 30% decrease from baseline in the sum of the longest diameters of target lesions. The endpoint combines these two response categories into one count; it is not a measure of how long a response lasts or how long participants live.

A response count is used to summarize whether tumor shrinkage meeting the prespecified criteria occurred in the response-evaluable group. In a single-group study, that count can describe observed responses, but by itself it does not establish a causal effect of treatment. Without a concurrent comparator, the endpoint cannot separate treatment-associated changes from other explanations for changes over time.

The registry specifies evaluation every 8 weeks during treatment and up to 1 year after treatment completion. It defines the response-evaluable population as eligible participants who signed consent and began treatment. However, the numerical count meeting the endpoint, the response denominator, and an uncertainty interval are not reported in the registry record. Enrollment of 19 is recorded, but it should not be substituted for the endpoint denominator because the record defines the analysis population separately and does not report how many participants met that definition.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The methods can be understood from the endpoint definition and the study structure, while recognizing that the registry record does not report a complete statistical analysis plan. The primary outcome is a binary participant-level classification: each response-evaluable participant either met the complete-or-partial-response definition or did not. The endpoint is then expressed as a count. A rate or proportion would require both that count and a specified denominator, and those primary-result values are not reported in the registry record.

What does a binary response endpoint capture?

As a general statistical explanation, a binary endpoint turns a more detailed clinical course into one of two classifications for a particular question. Here, the positive classification combines complete response and partial response according to the stated RECIST criteria. This is useful for a concise summary, but it omits distinctions between the two response categories and does not describe the magnitude of change beyond the threshold required for partial response. Nor does a best-response count convey how long a response persisted; duration of response is separately listed as an outcome.

The endpoint depends on the criteria and the assessment process. The record defines complete response by disappearance of all target lesions and partial response by at least a 30% decrease in the sum of the longest diameters from baseline. Scheduled assessments were every 8 weeks during treatment and up to 1 year after treatment completion. The record does not report the detailed assessment procedures, handling of unevaluable scans, or how missing assessments affected the classification. Those details matter because the observed classification can depend on both the response rule and whether outcome measurements are available.

Why does the analysis population matter?

The registry says that eligible participants who signed consent and began treatment would be evaluable for response. This defines the intended population for the endpoint, but the record does not state how many participants met those conditions or whether any participants were excluded from the analysis. The listed enrollment of 19 should not automatically be treated as the endpoint denominator. As a general principle, an analysis population should be explicit because inclusion and exclusion rules determine which observations contribute to an estimate. Without the endpoint denominator and disposition information, the response count cannot be converted into a meaningful rate or assessed for potential selection effects.

The record lists no allocation to a control group and characterizes the model as single group. As a general statistical point, a controlled comparison can help distinguish changes associated with an intervention from changes that might also occur without it. A single-group study can describe outcomes among participants who received the intervention, but it cannot provide that randomized contrast. No comparator effect estimate is reported, and a comparative treatment effect should not be inferred.

What can uncertainty measures add?

In general, a confidence interval describes a range of values compatible with the observed data under a statistical method and its assumptions. It communicates precision as well as the point estimate. For a binary endpoint, the estimate and its uncertainty depend on the observed response count and denominator. Neither the primary response count nor its denominator is reported in the registry record, and no confidence interval is reported. Therefore, the precision of the response finding cannot be assessed from this record.

The record describes sample-size calculations as planning illustrations based on an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. The resulting sample-size values and the observed effect are not reported in the registry record. These calculations are planning illustrations, not observed power and not evidence that the single-group study used a two-arm design. The stated equal-allocation assumption does not describe the recorded trial structure, which has one group and no listed comparator. The registry record does not report the trial's own sample-size justification or statistical design assumptions.

How should adverse-event counts be read?

As a general statistical explanation, a count of participants with an event differs from a count of event episodes: one participant can potentially experience more than one event, while a participant-level count records whether the event occurred. The registry describes the adverse-event information as participants with an event and gives at-risk and affected counts. The serious-event group lists 18 at risk and 3 affected; the other-event group lists 18 at risk and 18 affected. The record does not provide enough detail to determine from these aggregate counts how recurrent events or overlapping terms were handled. Event counts should therefore be read according to the categories and labels in the registry, not as a complete account of each participant's course.

The study lists NCI CTCAE Version 3.0 for adverse-event assessment. The record does not report further details on grading, follow-up completeness, exposure-adjusted rates, or event adjudication. Those methods should not be assumed. Likewise, the absence of a reported death count is not evidence that no deaths occurred; deaths are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists adverse events using NCI CTCAE Version 3.0, confirmed tumor response, duration of response, time to disease progression, and survival time as secondary outcomes. It also records 6 outcome measures and 0 analyses. The record does not report a statistical plan specifying how these outcomes were analyzed, how many statistical tests were planned, or whether any adjustment for multiple comparisons was intended. Without those details, the possibility and handling of multiplicity cannot be assessed.

As a general statistical point, evaluating multiple outcomes or making multiple statistical comparisons can increase the chance of a nominally notable finding occurring by chance. Prespecified priorities and an analysis plan help readers understand how to interpret several results together. The registry record does not report such a plan, so no claim about multiplicity control should be made. The number of listed outcomes alone does not show which analyses were performed or whether they were confirmatory.

Missing-data methods are also not reported in the registry record. The primary endpoint defines eligibility for response evaluation, but the record does not provide participant-level disposition, the primary response denominator, or rules for missing assessments and unevaluable participants. It is therefore not possible to determine whether missing response information was excluded, classified in a particular way, or handled through another method.

The analysis population is described as eligible participants who signed consent and began treatment. The record does not report whether the primary analysis followed that definition for every participant, nor does it provide a separate intention-to-treat population. No interim analyses or adjustment strategy are reported in the registry record. These absences limit assessment of analysis choices; they do not establish that a particular method was or was not used outside what the record reports.

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 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 decreased (5.6%), oral hemorrhage (5.6%), vomiting (5.6%), fatigue (5.6%), bladder infection (5.6%).

The registry reports safety counts for the treatment group. For serious adverse events, 18 participants are listed as at risk and 3 as affected. For other adverse events, 18 are listed as at risk and 18 as affected. These are separate categories in the record, so the counts should be read separately rather than combined. The registry also lists Hemoglobin decreased, Oral hemorrhage, Vomiting, Fatigue, Bladder infection, and Creatinine increased among the serious-event terms, each at 5.6%.

These figures describe the safety information recorded for the study group; they do not establish that the intervention caused any particular event. The registry record does not provide event-level timing, duration, severity details beyond the serious-event categorization, or participant-level overlap across terms. The percentage listed for each term should be read as recorded, without inferring an unreported denominator or adding the terms together. Deaths are not reported in the registry record.

As a general statistical point, safety counts are most informative when the population at risk, event definitions, observation period, and handling of repeated events are clear. The record gives at-risk and affected counts but does not report all those details. With no comparator group, the figures also cannot establish whether event frequency differed from that under another treatment or no treatment. They are descriptive registry counts, not a comparative safety estimate.

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

The record establishes that this was a completed phase II, single-group study of pazopanib hydrochloride in metastatic urothelial cancer, with enrollment listed as 19. It gives the intended dosing schedule, defines a primary endpoint based on complete or partial tumor response under RECIST, and reports selected adverse-event counts. Those details describe the study question and some of the recorded safety information.

The record does not report the numerical primary response result, its denominator, or a confidence interval. As a result, it cannot establish from the recorded details how many response-evaluable participants met the endpoint or how precisely an endpoint estimate was measured. This absence is not evidence that no responses occurred; it means the response result is not reported in the registry record.

The single-group design also matters. Even if a response count were available, the design would describe outcomes within the treated group rather than estimate a randomized difference against a concurrent comparator. The record does not support a causal claim about treatment effect or a comparison with another treatment. It also does not report numerical results for the listed duration-of-response, progression, or survival outcomes.

The safety counts show that the registry recorded serious and other adverse events among participants at risk, with the listed terms and frequencies. They do not by themselves show causation, comparative risk, or the full clinical course of each participant. Missing event details and the absence of a comparator constrain interpretation. The appropriate meaning is therefore narrow: the registry documents a study design, endpoint definitions, and certain safety counts, while leaving the primary efficacy result and several analysis details unreported.

13. Why This Trial Matters Statistically

This study illustrates a central distinction in clinical-trial interpretation: a clearly defined endpoint is not the same as a reported endpoint result. The registry defines best tumor response as the count of eligible participants with a complete or partial response under RECIST, but the count and its denominator are not reported in the registry record. Readers can understand what the trial intended to measure without being able to quantify the observed response outcome.

It also demonstrates why study structure matters when describing evidence. A single-group study can provide descriptive information about outcomes among participants receiving an intervention. It cannot supply a randomized contrast with a concurrent control group. Recognizing that limitation prevents a within-group observation from being mistaken for a comparative treatment effect.

The safety record offers another statistical lesson: counts need their categories and denominators to be interpreted carefully. The registry distinguishes participants at risk and affected for serious and other adverse events, and it reports frequencies for selected serious-event terms. Those entries should not be merged or treated as causal evidence, particularly when event-level details and a comparator are not reported.

Finally, the record shows how reporting gaps affect precision and reproducibility. Without the primary response count, analysis denominator, uncertainty interval, missing-data rules, and full statistical analysis plan, readers cannot evaluate the size or precision of the primary finding or reconstruct its analysis. The study remains informative as a record of a phase II design and prespecified response criteria, but those design details cannot substitute for the missing numerical results.

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 registry record does not report the primary endpoint’s observed response count, the response-evaluable denominator, or a confidence interval. Enrollment is listed as 19, but the response population is defined separately as eligible participants who signed consent and began treatment. The record does not state how many met that definition or provide participant disposition sufficient to reconcile the populations.

The single-group model and absence of a listed comparator prevent a direct randomized comparison. No allocation to a control group is reported, and the record does not support estimation of a treatment contrast. The intervention schedule is described, but treatment exposure, adherence, and the number of participants who stopped treatment for progression or toxicity are not reported in the registry record.

Although the primary response criteria and assessment schedule are described, details about missing or unevaluable assessments are not reported. Nor are the statistical analysis plan, multiplicity approach, interim analyses, or sample-size justification reported. The sample-size material is described as a planning illustration, but its resulting values and the observed effect used for it are not reported in the registry record.

The safety information is limited to aggregate at-risk and affected counts and selected serious-event terms. Event timing, repeated-event handling, participant overlap across terms, and deaths are not reported in the registry record. The record also lists secondary outcomes without numerical results for them in the registry record for this analysis. These limitations restrict evaluation of efficacy, precision, safety context, and analysis choices; they do not establish that unreported outcomes did not occur.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pazopanib in Treating Patients With Metastatic Urothelial Cancer — NCT00471536.
• Registry record last updated 2014-05-30; status last verified 2013-12.
• Results first posted 2013-03-21.
• 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

The registry record describes a completed phase II, single-group study sponsored by the National Cancer Institute (NCI), evaluating pazopanib hydrochloride in metastatic urothelial cancer. Enrollment is listed as 19, and the study reports oral treatment at 800 mg once daily on days 1-28, repeating every 28 days in the absence of progression or unacceptable toxicity.

The primary endpoint counts eligible participants with a complete or partial RECIST response. The record defines the response criteria and assessment schedule but does not report the numerical primary response result, denominator, or precision estimate. It lists secondary outcomes concerning adverse events, response confirmation, response duration, progression, and survival.

Safety counts are reported for serious and other adverse events, alongside selected serious-event terms. The design has no listed comparator, and details of the statistical plan, missing-data handling, and several outcome results are not reported in the registry record. The available information therefore supports a description of the design and reported safety counts, but not a quantitative conclusion about the primary response outcome.