Phase II Clinical Trial of Gemcitabine and Doxil® for Metastatic Renal Cell Carcinoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Phase II Clinical Trial of Gemcitabine and Doxil® for Metastatic Renal Cell Carcinoma (NCT00630409), a na phase 2 study. The primary outcome is Response Rate.

2. Clinical Question

3. Trial Design

This was a Phase II clinical trial of gemcitabine and Doxil® for metastatic renal cell carcinoma. The registry records a single-group model, allocation as NA, and no masking. Enrollment was 5. The study is marked completed; the recorded start was 2004-09 and primary completion was 2009-09. The sponsor was the University of Pittsburgh.

With a single group, the study describes outcomes among participants receiving the combination rather than estimating a treatment contrast against a concurrent control group. There is therefore no randomized or like-for-like control comparison in the registry record. Any response or safety count must be interpreted as an observation within this small treated group, not as a comparative effect.

The recorded treatment schedule describes outpatient 21-day cycles, with gemcitabine intravenously on days 1 and 8 and Doxil on day 1. Participants with responding or stable disease were described as continuing in additional 3-cycle blocks. The registry’s treatment description ends before all continuation details are available, so the full treatment rule is not reported in the registry record.

Time to Progression is listed as a secondary outcome. The registry also records 2 outcome measures, but reports 0 analyses. It does not provide a reported analysis population, a statistical analysis plan, or detailed eligibility and participant characteristics. The design information establishes the broad structure of the trial, but does not fill in those missing details.

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 Response Rate, measured over Up to 18 weeks for individual; Up to 40 months for cohort.

The primary endpoint, Response Rate, is defined as the number of participants who experienced a response divided by the total number of participants. Response was assessed using RECIST v1.0 for target lesions and CT scans. Complete response meant disappearance of all target lesions; partial response meant a 30% or greater decrease in the sum of the longest diameter of target lesions.

This endpoint is used to describe tumor response in a study population. In general, a defined response criterion makes it possible to classify outcomes consistently rather than relying only on an informal description of change. It is a binary participant-level outcome: each participant either meets the stated response definition or does not. That classification can be summarized as a count and a proportion.

The registry gives the timeframe as up to 18 weeks for an individual and up to 40 months for the cohort. These labels describe the stated observation windows; they do not supply the observed response count. The response result itself is not reported in the registry record. Accordingly, neither the number of participants meeting the endpoint nor the estimated response rate can be interpreted from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary participant-level measure. Under the registry’s definition, a participant is classified as having experienced a response if the stated RECIST v1.0 criteria are met; otherwise the participant is not counted as a responder. A response proportion summarizes the count meeting the definition relative to the total assessed population. This is a general description of how such an endpoint is analyzed, not a claim about the outcome in this trial.

For a binary endpoint, the observed count is central to interpretation. Counts allow readers to see how many participants contributed to the result, while a proportion expresses the frequency relative to the relevant group. In this trial the registry records enrollment of 5, but does not report the primary response count or response rate. It also does not identify the number assessed for this endpoint or explain how participants without an assessment were handled. The denominator used in any endpoint analysis is therefore not reported in the registry record.

A confidence interval is a statistical range that conveys uncertainty around an estimate under the assumptions of a chosen method. It is not a guarantee that the true value lies in the interval, and it does not replace the underlying count. For a small sample, estimates can be imprecise: a change in the outcome of a participant can have a substantial influence on the observed proportion. No response estimate or confidence interval is reported, so there is no numerical precision measure to interpret.

The design is single-group, rather than a randomized comparison. In a comparative trial, an analysis may estimate a difference or ratio between groups, depending on the outcome and analysis plan. A one-group response proportion instead describes outcomes in that group. It does not isolate the effect of the intervention from other explanations, such as the course of the condition or characteristics of the participants. This is a general distinction between descriptive single-group evidence and comparative evidence.

The registry’s sample-size assumptions describe a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Those are planning assumptions, not evidence that this study randomized participants between two arms. They do not turn this single-group trial into a controlled comparison, and a planning calculation is not observed power. The registry record does not report the trial’s own sample-size justification or design calculations.

Over-dispersion is a general issue for count data when variability exceeds what a simple model assumes. It can lead to uncertainty estimates that are too narrow if the model does not account for the extra variability. The primary outcome is a binary participant response, not a reported count-rate outcome, and the registry record does not identify an over-dispersion model or any fitted model. No claim about such a model can be made for this trial.

Statistical methods also depend on how the analysis population is defined, how missing outcome assessments are handled, and whether the analysis follows a prespecified plan. Those details are not reported in the registry record. No adjusted analysis, hypothesis test, or confidence interval for the primary endpoint is reported. As a result, interpretation is limited to the endpoint definition, broad study structure, and the posted safety counts; it cannot extend to an estimate of response or its statistical uncertainty.

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("Gemcitabine 800 mg/m^2 + Doxil 24 mg/m^2 (IV)")
n      <- c(5)
events <- c(0)
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  Gemcitabine 800 mg/m^2 + Doxil 24 mg/m^2 (IV)  5  0  0.0  0.0  52.2  0.0  43.4  0.4  45.9

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates several outcomes, comparisons, or analyses, because repeated testing can increase the chance of at least one apparently notable result. The registry lists 2 outcome measures and identifies Response Rate as primary and Time to Progression as secondary. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a statistical analysis plan. Whether any adjustment was intended is not reported in the registry record.

The record lists 0 analyses. No primary endpoint test, secondary endpoint analysis, or confidence interval is posted. This absence should not be interpreted as proof that no analyses occurred; it means their methods and results are not reported in the registry record. Without those details, there is no basis for assessing how outcomes were selected for analysis or whether analyses followed a prespecified plan.

Missing-data handling is also not described. The registry does not state whether all enrolled participants had an endpoint assessment, how an unavailable assessment would be classified, or what analysis population was used. Since the primary response count and denominator are not reported, the effect of missing outcome information cannot be evaluated. General statistical practice distinguishes the enrolled population from the participants with observed outcomes, but the registry does not give the information needed to make that distinction for this endpoint.

These omissions limit both reproducibility and interpretation. They do not establish that the study’s conduct or analysis was improper; rather, the relevant methods and results are not reported in the registry record.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry records 5 participants at risk for serious adverse events and 0 participants affected. For other adverse events, it records 5 participants at risk and 5 affected. These figures are participant counts in the treatment group. The registry lists no serious adverse event terms, and the death count is not reported in the registry record.

Serious and other adverse events are separate categories in the posted figures. The count of 0 affected for serious events does not mean that no adverse events of any kind occurred; the other adverse event figure records 5 affected participants. Conversely, the other adverse event count does not describe the nature, intensity, duration, or clinical importance of those events.

In general, safety counts are easier to interpret when accompanied by event names, severity, timing, exposure information, and attribution. Those details are not reported in the registry record. With 5 participants at risk, the counts describe this small group and do not establish how frequently similar events would occur in a broader population.

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

The record establishes that a completed Phase II, single-group study enrolled 5 participants with metastatic renal cell carcinoma and evaluated a gemcitabine and Doxil® regimen. It defines a primary response endpoint based on RECIST v1.0 and lists Time to Progression as a secondary outcome. It also reports the stated safety counts. Those are the limits of what can be concluded from the posted results.

The primary response result is not reported in the registry record. Therefore, the record does not show whether any participant met the response definition, what the response proportion was, or how precise an estimate might be. The time-to-progression result is also not reported. The absence of these results means the stated primary clinical-activity question cannot be resolved using the registry record alone.

Even if a response estimate were available, a single-group study would not provide a direct comparison with another treatment or control. Its observed outcomes could describe the participants in the study, but would not by themselves identify a comparative treatment effect. General interpretation of a treatment effect requires attention to design, outcome ascertainment, analysis methods, and uncertainty, not just whether an outcome was recorded.

The safety figures show no participants affected by serious adverse events among the 5 at risk and 5 participants affected by other adverse events among the 5 at risk. The record does not provide the event terms or a reported death count. Those limitations prevent a detailed safety profile from being inferred. These findings do not amount to medical advice or a conclusion about treatment choice.

14. Why This Trial Matters Statistically

This trial is statistically notable for the contrast between a clearly stated primary endpoint and the absence of its reported result. A response definition allows an outcome to be assessed consistently, but without the response count and denominator an estimate cannot be reconstructed. The registry record lists the endpoint’s criteria and observation timeframe, yet does not report the result needed to interpret the trial’s primary question.

The single-group structure also matters. It supports description of outcomes in the treated participants, but does not provide a concurrent control for estimating a comparative effect. This is a design limitation distinct from the missing result: even complete reporting would not create a control comparison that the study design does not contain.

The enrollment of 5 participants makes the scale of the evidence important to keep in view. In general, estimates from small groups are sensitive to individual outcomes and can be imprecise. Here, because the primary result is absent, readers cannot assess the actual estimate or its precision. The safety counts remain descriptive and similarly apply only to the small group recorded.

Finally, the record lists 0 analyses and does not report the analysis plan, missing-data approach, or multiplicity handling. Transparent reporting of these details helps readers judge how endpoints were analyzed and what conclusions are justified. Their absence does not establish what analysis was conducted, but it narrows the conclusions that can be drawn from the registry.

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 main limitation for interpreting efficacy is that the registry record does not report the primary response count or rate. It also does not report the result for Time to Progression, despite listing it as a secondary outcome. Therefore, the posted record does not permit an estimate of either outcome or an assessment of its precision.

The study is single-group and has no like-for-like control comparison. Enrollment was 5, limiting the amount of outcome information available even if results were reported. The registry does not provide participant characteristics, detailed eligibility criteria, or the number with an evaluable primary endpoint, so the represented population and endpoint denominator cannot be assessed.

Methods relevant to interpretation are also absent: no analysis plan, analysis population, missing-data handling, or multiplicity approach is reported. Although the treatment description gives the initial schedule and refers to further 3-cycle treatment for participants with responding or stable disease, the remaining continuation details are not reported in the registry record.

Safety reporting is limited to participant counts. Serious adverse event terms are not listed, details for other adverse events are not given, and a death count is not reported. These limitations mean that the record supports only a narrow description of the trial structure and posted safety figures, not a comprehensive assessment of outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Phase II Clinical Trial of Gemcitabine and Doxil® for Metastatic Renal Cell Carcinoma — NCT00630409.
• Registry record last updated 2017-03-10; status last verified 2017-01.
• Results first posted 2017-03-10.
• 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

NCT00630409 is a completed Phase II, single-group study sponsored by the University of Pittsburgh, with enrollment of 5 participants. It evaluated gemcitabine and Doxil® for metastatic renal cell carcinoma. The primary endpoint was Response Rate using RECIST v1.0; Time to Progression was listed as a secondary outcome.

The registry reports 0 analyses. It does not report the primary response result or the time-to-progression result. Safety figures record 0 serious adverse events among 5 participants at risk and 5 participants affected by other adverse events among 5 at risk. Serious event terms are not listed, and a death count is not reported in the registry record.