Pazopanib as Front-Line Therapy in Patients With Non-Resectable or Metastatic Soft Tissue Sarcomas Who Are Not Candidates for Chemotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pazopanib as Front-Line Therapy in Patients With Non-Resectable or Metastatic Soft Tissue Sarcomas Who Are Not Candidates for Chemotherapy (NCT02300545), a na phase 2 study. The primary outcome is Clinical Benefit Rate.

2. Clinical Question

The question is about disease status at a specified time point, rather than a direct comparison of treatment strategies. A single-group phase II study can describe outcomes among enrolled participants, but without a concurrent comparator it cannot separate the treatment’s contribution from other explanations for those outcomes. The registry identifies pazopanib as the intervention and describes the intended use as front-line therapy for patients who could not receive chemotherapy. It does not report a control group or a randomized allocation process.

Other outcomes listed include progression-free survival, overall survival, quality of life, and associations between clinical outcomes and serum biomarker levels. The registry record does not report results for these outcomes. It also does not provide a fuller description of the patient characteristics, eligibility criteria, or analysis populations needed to assess how closely the enrolled participants represent the intended population.

3. Trial Design

This is a phase II, single-group study sponsored by Washington University School of Medicine. The registry lists an enrollment of 56 and a completed status. The recorded start date is 2015-04-08, and the primary completion date is 2019-05-31. Enrollment is a study-level registry figure; the number included in each endpoint analysis is not reported in the registry record.

There is one listed intervention, pazopanib, and no separate control arm. Allocation is recorded as NA and masking as none. These features mean the study is not a blinded randomized comparison. The record describes a dose escalation: 200 mg BID for four days, then 400 mg BID for four days, followed by 800 mg QD for the duration of participation or until dose reduction if necessary. The dosing instruction in the arm description ends mid-sentence after an additional direction about taking the drug without food; the remainder of that instruction is not reported in the registry record.

The primary outcome is clinical benefit rate, expressed as a count of participants and assessed at 16 weeks. The record defines clinical benefit as complete response, partial response, or stable disease. Additional listed outcomes include progression-free survival, overall survival, median overall change in quality of life, and biomarker-related outcomes involving serum sVEGFR2 and PIGF. Their measurement results and analysis details are not reported in the registry record.

The record does not report a statistical analysis plan, a sample-size justification, interim analyses, or analysis populations. It lists no analyses. These omissions limit what can be concluded about how the endpoint was handled, how missing observations were treated, or whether any reported outcome estimates would be adjusted for other factors. The single-group design also means that any outcome description would be an observation within the treated group, not a randomized estimate of the difference between treatment options.

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

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 Clinical Benefit Rate, measured over 16 weeks.

The primary endpoint is clinical benefit rate at 16 weeks, recorded as a count of participants. The registry defines clinical benefit as having a complete response, partial response, or stable disease. Complete response means disappearance of all target lesions, with any pathological lymph nodes reduced to a short axis under 10 mm. Partial response means at least a 30% decrease in the sum of target-lesion diameters relative to baseline. Stable disease means neither enough shrinkage to meet the partial-response definition nor enough increase to meet progressive disease, using the smallest on-study sum of diameters as the reference.

Combining these three categories makes the endpoint broader than tumor shrinkage alone: participants can meet the definition through complete or partial response, or through stable disease. That can be useful in a study where maintaining disease status is part of the clinical-benefit concept. It also means the count does not, by itself, show how many participants had tumor shrinkage versus stable disease. Those component counts are not reported in the registry record.

The specified assessment time is 16 weeks. A fixed time point can make the outcome easier to interpret as a status measure, but its meaning depends on how participants who lack an assessment at that time are handled and on the response-assessment procedures. Those details are not reported in the registry record. Most importantly, the registry record does not provide the observed count or rate for the primary endpoint. The endpoint definition is available, but its observed result and precision cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The trial is listed as phase II and single group. In a single-group design, participants receive the intervention under study and outcomes are described within that group. General statistical interpretation: such a design can estimate the frequency of an outcome in the enrolled group when the result and its denominator are reported, but it does not create a randomized contrast against another group. Here, the registry lists no comparator and no randomized allocation. A difference from an external benchmark, if one were considered, would not have the protection against confounding that random assignment can provide.

What does the primary endpoint count?

The primary endpoint is a participant count for clinical benefit at 16 weeks. The registry definition combines complete response, partial response, and stable disease. General statistical explanation: a binary endpoint classifies each participant as either meeting or not meeting a defined condition, while a count records how many meet it. To interpret such a count, readers need both the number meeting the definition and the number assessed under the endpoint rules. The record provides neither an observed clinical-benefit count nor an endpoint analysis denominator. The enrollment figure of 56 is not a substitute for an analysis denominator.

The endpoint’s component definitions matter. Complete response, partial response, and stable disease are not interchangeable descriptions of tumor status; they are grouped together to form one clinical-benefit category. General statistical explanation: a composite endpoint can increase the range of events captured, but its overall result may be driven by one component more than another. Component-specific counts are therefore useful for understanding what a composite result represents. They are not reported in the registry record.

How should a confidence interval be understood?

General statistical explanation: a confidence interval expresses uncertainty around an estimated quantity, such as a proportion. A narrower interval indicates greater precision under the assumptions of the method; a wider interval indicates less precision. An interval does not establish that a treatment caused an outcome, and it cannot repair the absence of a comparator. The registry record does not report a clinical-benefit estimate or a confidence interval, so neither the observed frequency nor its precision can be evaluated.

For a participant count to be interpreted as a rate, the relevant denominator and rules for handling unavailable assessments must be clear. General statistical explanation: excluding participants without an endpoint assessment can produce a different result from counting them as not having clinical benefit, and assumptions about missing observations can affect an estimate. The registry record does not say how missing 16-week assessments were handled, how many participants were assessed, or which analysis population was used. No particular approach should be presumed.

What does the design imply for statistical comparisons?

The record has one group and no allocation to a comparator. General statistical explanation: randomization helps make groups comparable, on average, with respect to measured and unmeasured characteristics. Without a randomized control group, an outcome frequency cannot be read as a treatment-versus-control effect. Within-group estimates may still describe what was observed among participants, but they do not establish what would have happened to those same participants under another approach.

The registry lists no analyses. No model, adjustment strategy, hypothesis test, or method for estimating uncertainty is reported. This means there is no basis in the record to describe a particular inferential method as having been used. It also prevents assessment of whether the primary outcome was analyzed according to a prespecified plan or whether analyses accounted for participant characteristics.

What can planning illustrations tell readers?

General statistical explanation: a sample-size calculation depends on choices such as the target effect, the significance level, the desired power, the allocation plan, and assumptions about the outcome. A planning illustration based on an observed effect is a hypothetical calculation using that effect as an input; it does not show that the trial had that level of power, and it is not an observed trial outcome. The stated assumptions for the planning illustration are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect.

Those assumptions describe an illustration rather than the design of this single-group trial: there are not two randomized arms to which participants were equally allocated. The registry does not report the trial’s own sample-size justification. The observed primary effect needed to interpret effect-based planning values is also not reported in the registry record. No planning value should therefore be treated as a trial finding or as evidence that the study was adequately powered.

Why does over-dispersion matter in some analyses?

General statistical explanation: over-dispersion occurs when count outcomes vary more than a statistical model assumes. If ignored, uncertainty estimates can be too small and statistical tests can appear more decisive than warranted. This concept is relevant to some count-data models, but the primary endpoint is described as a participant count for a binary clinical-benefit definition, and the registry does not report a model or an analysis of that endpoint. There is no evidence in the record that an over-dispersion adjustment was used or needed.

Other outcomes, including time-to-event outcomes and biomarker associations, require outcome-specific methods and assumptions. The registry lists progression-free survival, overall survival, and biomarker-related outcomes, but does not report their results or analysis methods. It would be speculative to assign particular estimators, correlation methods, censoring rules, or model assumptions to those outcomes. The registry’s absence of analysis details limits statistical interpretation across the trial, rather than merely leaving one technical choice unclear.

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("Pazopanib")
n      <- c(56)
events <- c(22)
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  Pazopanib  56  22  39.3  26.5  53.2  27.6  52.4  27.6  52.4

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and several secondary outcomes, including progression-free survival, overall survival, quality of life, and biomarker-related outcomes. It does not report a multiplicity strategy. General statistical explanation: when many outcomes or hypotheses are assessed, the chance of at least one apparently notable result can increase unless the analysis plan addresses multiple testing. Without a stated approach, the interpretation of any collection of outcome tests would need caution. No test results are reported in the registry record, so the effect of multiplicity on findings cannot be evaluated.

Missing-data procedures are not reported. In particular, the record does not state how participants without a 16-week assessment were handled, whether any measurements were imputed, or how incomplete follow-up affected the secondary outcomes. General statistical explanation: missingness can matter when the likelihood of an unavailable measurement is related to participant status or outcome. Different reasonable handling choices can yield different estimates. No approach should be attributed to this trial without a record of it.

Analysis populations are also not described. The registry enrollment is 56, but it does not state how many participants were included in the primary endpoint analysis, whether all enrolled participants were analyzed, or how treatment interruptions or dose reductions were handled analytically. The dose description allows for dose reduction if necessary, but does not specify how such changes entered the outcome analysis.

The registry lists no analyses, and does not report a statistical analysis plan, interim analyses, or sample-size justification. These gaps mean the conduct and interpretation of the planned statistical analyses cannot be checked against a documented plan. They do not establish that analyses or procedures were absent in practice; the relevant information is not reported in the registry record.

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: alanine aminotransferase increased (7.1%), pneumothorax (5.4%), thromboembolic event (5.4%), heart failure (3.6%), colitis (3.6%).

For the pazopanib group, the registry lists 56 participants at risk for serious adverse events and 27 affected. It separately lists 56 at risk for other adverse events and 56 affected, and records 24 deaths. These are safety entries in the registry; the record does not provide event timing, exposure duration, the number of events per participant, or the relationship of each event to treatment.

The serious adverse-event terms listed with percentages are alanine aminotransferase increased at 7.1%, pneumothorax at 5.4%, thromboembolic event at 5.4%, heart failure at 3.6%, colitis at 3.6%, and lung infection at 3.6%. The registry listing does not explain whether participants could contribute to more than one term or state the denominator used for each percentage. These percentages should be read as recorded figures, not added together or treated as mutually exclusive categories.

General statistical explanation: a safety count identifies participants with a recorded event in the defined reporting period, while an adverse-event term describes the type of event. Neither alone demonstrates causation. A comparison of safety risks would require a suitable comparator and consistent information about exposure, follow-up, event definitions, and ascertainment. This study has no comparator group in the registry record. The listed counts and terms therefore describe reported safety observations, not comparative risks or proof that the intervention caused an event.

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

The record establishes that a phase II study of pazopanib was completed, with an enrollment of 56, in a single-group design. It states that the primary endpoint was clinical benefit at 16 weeks and defines that endpoint using complete response, partial response, and stable disease. These details identify what the study set out to assess.

The record does not report the observed primary endpoint result. It therefore cannot establish how many participants met the clinical-benefit definition, what proportion they represented, or how precise an estimate would be. It also does not report the secondary outcome results, including progression-free survival, overall survival, quality of life, or biomarker associations. The trial’s completed status is not a substitute for outcome data.

Even if a within-group clinical-benefit result were available, a single-group study would describe observed outcomes rather than provide a randomized estimate of a treatment effect relative to another option. The absence of a comparator means that no difference between treatment strategies can be estimated from this design alone. The registry record does not report a hypothesis test or confidence interval that would permit a claim about statistical significance or precision.

The safety entries provide counts and listed adverse-event terms, but do not establish that the intervention caused them. There is no comparative safety group in the record, and important details about event timing, exposure, and overlap are not reported. These limitations apply independently of whether an event is clinically important.

Thus, the registry record supports a description of the study question, design, endpoint definition, and selected safety entries. It does not support a numerical conclusion about clinical benefit, survival, quality of life, biomarker relationships, or comparative effectiveness. Those conclusions would require reported outcome estimates and, for comparative claims, an appropriate comparison design and analysis.

14. Why This Trial Matters Statistically

This study raises a statistical question that is important in single-group phase II research: what can an observed outcome within one group tell readers, and what remains unanswered without a comparator? The design can be used to describe outcomes in the enrolled participants, but it does not randomize participants between treatment options. Statistical interpretation must therefore distinguish a within-group outcome from a comparative treatment effect.

The primary endpoint also illustrates how a composite outcome shapes interpretation. Clinical benefit includes complete response, partial response, and stable disease, which are different response states grouped under one definition. Reporting the total count alone would not show the contribution of each component. Component results and a clear denominator would help readers understand what the endpoint represents, but these are not reported in the registry record.

Another important issue is the difference between a completed study and a fully interpretable result. The registry records completion and enrollment, but does not report the primary endpoint estimate, its precision, or the analysis population. Without those elements, the trial’s central statistical result cannot be evaluated. The absence of a reported sample-size justification and analysis plan further limits assessment of how the study’s design was intended to support inference.

Finally, the listed safety counts show why descriptive reporting should be kept separate from causal conclusions. A count of participants with recorded events is useful information, but without a comparator it does not quantify excess risk attributable to treatment. These distinctions—between description and comparison, composite and component outcomes, and event reporting and causation—are central to reading clinical trial statistics carefully.

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 principal limitation for interpretation is that the registry record does not report the primary clinical-benefit result. There is no count of participants meeting the definition, no reported endpoint denominator, and no confidence interval. As a result, the outcome magnitude and its precision cannot be assessed. The record also does not give the component counts for complete response, partial response, and stable disease.

The design is single group, with no separate comparator and no randomized allocation. This precludes a direct randomized comparison and limits conclusions to outcomes observed within the study group, if those outcomes are reported. The record does not describe participant characteristics in enough detail to assess how the enrolled group compares with the broader population specified by the study question.

Although enrollment is 56, the number included in each analysis is not reported. The record does not specify the handling of participants who lacked a 16-week assessment, the analysis population, or the treatment of dose reductions and discontinuations in analyses. It also does not report detailed response-assessment procedures beyond the endpoint definitions.

Statistical methods are not described: no analysis plan, sample-size justification, interim analysis information, or analysis results are listed. Multiple secondary outcomes are named, but no multiplicity approach or outcome results are reported. The safety record gives selected counts and percentages, but does not report timing, exposure, event overlap, or a comparator. These are limitations of the information available in the registry record; they do not establish what may or may not have been done outside that record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Pazopanib as Front-Line Therapy in Patients With Non-Resectable or Metastatic Soft Tissue Sarcomas Who Are Not Candidates for Chemotherapy — NCT02300545.
• Registry record last updated 2020-08-05; status last verified 2020-07.
• Results first posted 2020-06-09.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry identifies NCT02300545 as a completed phase II, single-group study sponsored by Washington University School of Medicine. It lists enrollment of 56, a start date of 2015-04-08, and a primary completion date of 2019-05-31. Pazopanib is the listed intervention, with a dose-escalation schedule described in the arm record.

The primary outcome is a count of participants with clinical benefit at 16 weeks, defined as complete response, partial response, or stable disease. The observed primary outcome result is not reported in the registry record. Secondary outcomes include progression-free survival, overall survival, quality of life, and biomarker-related measures; their results are also not reported.

The record lists serious and other adverse-event counts and selected serious adverse-event terms. It does not report a comparator group, statistical analysis results, analysis populations, missing-data procedures, multiplicity methods, or a statistical analysis plan. The available record therefore describes the study structure and selected safety entries but does not allow quantitative evaluation of the primary endpoint or comparative treatment effects.