PPX, Temozolomide, and Concurrent Radiation for Newly Diagnosed Brain Tumors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PPX, Temozolomide, and Concurrent Radiation for Newly Diagnosed Brain Tumors (NCT00763750), a na phase 2 study. The primary outcome is Number of Patients Assessed for Toxicity According to CTC Version 3.0.

2. Clinical Question

3. Trial Design

This is a phase 2, completed, single-group study registered as NCT00763750. The registry lists an enrollment of 25 and the condition “Brain Tumor.” The study title concerns PPX, temozolomide, and concurrent radiation for newly diagnosed brain tumors. Its stated purpose is to determine antitumor activity for the combination; the listed primary outcome, however, is a toxicity-assessment count.

The intervention arm is named PPX +TMZ+XRT. Its description specifies XRT 60Gy at 2 GY/fractions x 30 fractions, TMZ 75mg/m2/day, and PPX 40mg/m2/week x 6 weeks, with treatment days also listed in the registry. The schedule is reproduced as recorded; the registry does not explain how treatment modifications, interruptions, or completion were handled.

Allocation is marked NA, masking is NONE, and the model is SINGLE GROUP. There is no listed control arm, so the study cannot directly compare the regimen with another treatment or with a concurrent untreated group. The registry does not report random assignment, masking procedures, or a comparator-based analysis. The start is recorded as 2008-10, primary completion as 2011-06, and status as COMPLETED.

The record lists one outcome measure and zero analyses. It does not report a protocol-level statistical plan, a sample-size justification, or the analysis population. The study design supports description of the enrolled group and recorded outcomes; it does not, on its own, separate a treatment effect from other explanations for observed outcomes.

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 Number of Patients Assessed for Toxicity According to CTC Version 3.0, measured over Throughout the entire study until patient is removed from study an average of 6 weeks.

The primary outcome is “Number of Patients Assessed for Toxicity According to CTC Version 3.0.” It is a count of participants assessed, not itself a count of participants who experienced toxicity. The registry defines the timeframe as throughout the entire study until a patient is removed from study, with an average of 6 weeks.

Assessment coverage is important when interpreting safety results: a toxicity summary is meaningful only in relation to who was monitored and over what period. The stated endpoint can describe how many patients underwent toxicity assessment, but it does not by itself quantify the frequency or severity of toxicities. Those are separate outcome concepts. The record does not give a value for the primary endpoint, details of assessment procedures, or criteria for removal from study.

CTC Version 3.0 is the toxicity grading reference named in the registry. A grading framework can standardize how severity is categorized, but the registry entry does not describe how assessors applied it or how incomplete assessments were treated. Because the primary outcome value and its analysis are not reported in the registry record, the extent of assessment coverage and the precision of any resulting safety estimate cannot be evaluated from this record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design allow?

A single-group study observes outcomes among participants receiving the study regimen without a concurrent comparison arm. Descriptive counts can characterize what was recorded in that group. They do not establish what would have happened to the same participants under another regimen or without the study treatment. This distinction matters because an outcome may reflect the underlying condition, other care, participant characteristics, or follow-up as well as the intervention.

Here, the registry records the model as SINGLE GROUP, allocation as NA, and masking as NONE. These entries do not describe randomization or a controlled contrast. As a result, any comparison of this group with an external population would require information and assumptions not reported in the registry record. No such comparison is reported.

What does a count measure?

A count records how many participants meet a stated definition. Its interpretation depends on that definition. The primary outcome counts patients assessed for toxicity according to CTC Version 3.0; it is not described as the number with toxicity. A count of assessed participants can be useful for understanding the reach of monitoring, while a count of affected participants answers a different question.

For a binary event outcome, participants are categorized according to whether the defined event occurred. In general, a proportion relates the number meeting the definition to the number eligible for that outcome. The numerator, denominator, event definition, and observation period must align for the proportion to be interpretable. The registry separately gives at-risk and affected counts for serious and other adverse events. It does not provide an analysis of the primary assessment-count outcome or confidence intervals for the safety entries.

Why does follow-up matter?

Events can only be captured during periods when participants are observed and assessed. The primary outcome timeframe is described as throughout the study until a patient is removed from study, with an average of 6 weeks. This statement does not specify each participant’s exact observation time, nor does it explain how removal or incomplete follow-up affected the reported outcomes. Such details are important because participants observed for different durations may have different opportunities for an event to be detected.

In general, a fixed-time risk and an event rate over person-time answer different questions. A fixed-time risk concerns whether an event occurred during a defined period; a rate accounts for differing observation time. The registry does not state that a person-time analysis was performed, and no event-time method is reported. These concepts should not be mistaken for analyses conducted in this study.

How should uncertainty be understood?

An estimate based on a study group is subject to uncertainty. In general, a confidence interval describes a range of values compatible with the data under a specified method and assumptions. A narrow interval indicates greater precision than a wide interval, but neither establishes that a result is unbiased or causal. The registry record does not report confidence intervals for the primary outcome or the adverse-event entries, so their statistical precision cannot be assessed from those entries.

Statistical testing also depends on a defined comparison and analysis plan. The record lists zero analyses and does not report a statistical analysis plan, hypothesis tests, or adjusted estimates. Therefore, no inferential result should be attributed to the registry entries. The sample-size planning assumptions recorded for an illustration—two-sided significance level 0.05, equal allocation between two arms, normal approximation, and an effect defined as a stated fraction of the observed effect—are planning assumptions, not evidence that the study had two arms or conducted those analyses. Planning illustrations are not observed power and do not replace a reported estimate with uncertainty.

Why can over-dispersion matter in other settings?

For count outcomes, a simple model may assume that variation follows a particular relationship to the average count. Over-dispersion occurs when the observed variability is greater than that model assumes. In general, ignoring over-dispersion can make uncertainty appear smaller than it is. This is a general statistical consideration, not a claim about this study: the registry does not report a count-model analysis, a dispersion estimate, or a method for handling over-dispersion.

Overall, the available record supports a design description and a reading of the posted safety counts. It does not document the statistical methods needed to evaluate a treatment effect, quantify the precision of the primary outcome, or establish how missing assessments were handled.

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("PPX +TMZ+XRT")
n      <- c(25)
events <- c(25)
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  PPX +TMZ+XRT  25  25  100.0  86.3  100.0  86.7  100.0  86.8  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and zero analyses. It does not report a statistical analysis plan, hypothesis tests, or a hierarchy of outcomes. Multiplicity arises in general when multiple outcomes, comparisons, or tests are considered; testing many questions can increase the chance of a nominally notable finding. With no analyses or testing strategy reported, multiplicity control cannot be evaluated from this record.

The primary outcome description does not include a result, and the registry does not state how many participants had complete toxicity assessments. The record also does not report how missing assessments, withdrawal, or removal from study were handled. The stated timeframe ends when a patient is removed from study, but this does not describe the analysis treatment of that participant’s incomplete follow-up.

The analysis population is not reported in the registry record. It is therefore unclear whether the outcome was intended to include all enrolled participants, only those who received treatment, or another defined group. The registry does not report a missing-data method, imputation procedure, sensitivity analysis, or reasons for missingness. In general, missingness can affect an estimate when the people with recorded outcomes differ from those without them; the direction and size of such an effect cannot be inferred without additional information.

The safety entries provide at-risk and affected counts but do not document a broader analysis population or the handling of repeated events. As a result, they should be interpreted as posted counts rather than as a fully specified inferential analysis.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: plt gr 4, anc 4, hgb 3 f/u: anc to gr3, hgb and plt to gr 2 (4.0%), gr 4 plt, anc 3, hgb2 & fu: death (4.0%), plt gr4, anc4, weakness/failure to thrive gr 3 & fu:gr 4 leuko, gr 3 hgb, anorexia gr 3, death (4.0%), weakness (gr 3) (4.0%), seizure - no grade (4.0%).

The registry lists 25 participants at risk for serious adverse events and 6 affected. For other adverse events, it lists 25 at risk and 25 affected. These are registry counts; they do not provide a comparison with another group, and the serious-event count should not be taken as a treatment effect.

Six serious adverse event terms are listed, each with a registry-reported value of 4.0%. The entries include blood-count abnormalities and follow-up descriptions, weakness, seizure, dehydration, and anorexia. Each percentage belongs to its listed term. The values should not be summed: the registry does not explain whether terms overlap within participants, and adding term-level percentages would not yield a supported overall rate.

Some term descriptions mention death, but the group-level deaths value is not reported in the registry record. A narrative term that includes a death description does not establish a total number of deaths. The record also does not provide event onset, duration, attribution, or a complete account of how each event was assessed. These limitations restrict interpretation of the safety entries to the counts and descriptions actually recorded.

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

The record establishes that this was a completed phase 2, single-group study of PPX with temozolomide and concurrent radiation for newly diagnosed brain tumors. It identifies the number of patients assessed for toxicity according to CTC Version 3.0 as the primary outcome and gives an assessment timeframe averaging 6 weeks. It also posts adverse-event counts and selected serious adverse event terms.

The record does not report the primary outcome value or an analysis of it. It therefore does not show how many patients were assessed for toxicity as the primary endpoint, how complete the assessment process was, or how precise that measure may be. Nor does the stated endpoint by itself measure the number of patients who experienced toxicity.

The adverse-event counts describe what is entered in the registry for the study group. Without a concurrent comparator, they cannot show whether those counts are higher or lower than they would have been under another treatment or in the absence of the regimen. The listed serious-event percentages are term-specific and are not a combined rate. The group-level deaths count is not reported, even though some term descriptions mention death.

The study’s stated purpose includes antitumor activity, but the registry entries do not include an antitumor outcome result. No claim about the regimen’s efficacy, benefit, or lack of benefit follows from these entries. The record also does not establish causal attribution for the adverse events. A completed study status indicates that the registry lists the study as completed; it does not fill in missing outcome analyses or resolve the design’s lack of a comparator.

14. Why This Trial Matters Statistically

This study illustrates why design and endpoint definitions are central to statistical interpretation. The stated purpose concerns antitumor activity, while the listed primary outcome is the number of patients assessed for toxicity. Those are different questions: one concerns disease-related activity, and the other concerns whether toxicity assessments took place. A reader should not treat one as a substitute for the other.

The single-group design makes the limits of descriptive safety reporting especially clear. Counts can describe events recorded among participants in the regimen group, but without a control group they cannot identify a comparative effect. This is not a technical detail that can be fixed by statistical testing alone; the design does not supply the comparison needed to distinguish the regimen’s effect from other explanations.

The registry also shows why denominators, follow-up, and definitions matter. It reports at-risk and affected counts for adverse events, while the primary outcome is an assessment count and its value is absent. The average follow-up description does not provide individual observation times or explain incomplete assessments. These distinctions shape which statistical summaries can be interpreted and how much uncertainty can be quantified.

Finally, the record demonstrates the difference between a planned calculation and an observed analysis. A planning illustration can describe assumptions for a hypothetical design, but it does not show that the study used that design, achieved a stated level of power, or produced a treatment-effect estimate. Transparent reporting of the analysis population, outcomes, uncertainty, and missing-data handling is necessary for readers to assess what the results support.

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 registry gives a broad condition label, “Brain Tumor,” but does not report tumor subtype, diagnostic criteria, stage, or baseline clinical characteristics. The enrolled population’s detailed eligibility criteria and representativeness are not reported in the registry record. This limits assessment of which patients the findings might describe.

The study has no listed comparator and is recorded as single group. Accordingly, the posted counts cannot support a direct comparative estimate. The registry does not report the primary outcome value, an antitumor activity result, or an analysis of either. The stated primary endpoint measures assessment, not toxicity occurrence, which further limits what can be concluded about safety from the endpoint itself.

For the safety entries, the record does not report event-level timing, duration, attribution, recurrence, or the method used to select the listed terms. It does not explain potential overlap between terms. The deaths field is not reported, and the entries that mention death cannot establish a group-level count. The registry also does not describe how missing assessments, removal from study, or differing follow-up were handled.

The analysis population, statistical analysis plan, confidence intervals, and sample-size justification are not reported in the registry record. Although planning assumptions are described for an illustration, those assumptions do not document the study’s own design calculations or analyses. These limitations mean that the registry supports a cautious account of the study structure and posted counts, but not a precise estimate of treatment effect or a complete assessment of uncertainty.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: PPX, Temozolomide, and Concurrent Radiation for Newly Diagnosed Brain Tumors — NCT00763750.
• Registry record last updated 2020-02-17; status last verified 2020-02.
• Results first posted 2013-12-16.
• 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

NCT00763750 is recorded as a completed phase 2, single-group study of PPX, temozolomide, and concurrent radiation for newly diagnosed brain tumors. Enrollment is listed as 25. The study started in 2008-10, and primary completion is recorded as 2011-06.

The primary outcome is the number of patients assessed for toxicity according to CTC Version 3.0, with assessment described through removal from study and an average timeframe of 6 weeks. The primary outcome value and analysis are not reported in the registry record. Safety entries list 6 participants affected by serious adverse events among 25 at risk and 25 affected by other adverse events among 25 at risk. The record does not report a group-level deaths count, a comparator, or an analysis establishing a treatment effect.