PARP Inhibition for Gliomas (PI-4G or π4g): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PARP Inhibition for Gliomas (PI-4G or π4g) (NCT05297864), a na phase 2 study. The primary outcome is Number of Patients Who Experience Adverse Events.

2. Clinical Question

3. Trial Design

NCT05297864, titled “PARP Inhibition for Gliomas (PI-4G or π4g),” is registered as a phase II trial. Its official title is “Phase II Trial of Niraparib in Patients With Recurrent Glioma.” The University of Oklahoma is listed as sponsor. The registry records a planned enrollment of 15 and identifies the study model as single-group. Allocation is not applicable, and masking is listed as none.

The intervention is niraparib. The treatment description says participants would receive an individualized starting dose. The registry does not report a concurrent control arm, random allocation, or masking. Accordingly, the study design supports a descriptive account of outcomes in the treated group, but it does not provide a like-for-like treatment comparison.

The recorded start date is 2022-06-09, and the primary completion date is 2023-11-14. The status is terminated. The registry record does not report a reason for termination, so the status alone cannot explain why the study ended or whether the planned enrollment was reached. The record lists enrollment of 15, whereas the posted adverse-event group reports 9 participants at risk. The registry does not explain the relationship between these figures.

The primary outcome is the number of participants experiencing adverse events, with a timeframe of up to 17 months. Secondary outcomes listed are progression-free survival and overall survival in the dose expansion phase, and duration of disease control of all patients. The record lists 6 outcome measures, but no statistical analyses are listed. The listed secondary outcomes should not be treated as results: their outcome names alone do not establish that estimates or analyses were posted.

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 15 enrolled participants, 9 met inclusion criteria and were evaluable.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All patients enrolled in 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 Who Experience Adverse Events, measured over Up to 17 months.

The primary endpoint counts participants who experience adverse events while receiving an individualized starting dose of niraparib. Its unit is participants, and its population is described as all patients enrolled. The adverse events are assessed using CTCAE v5.0, a standardized framework used to classify adverse events. The registry gives the assessment timeframe as up to 17 months.

A participant count is a direct way to describe how many people in the observed group had an event. It is different from a count of all event episodes: a participant with more than one event may still contribute once to a count of participants with an event, depending on the outcome definition. The posted endpoint description specifies participants, not a total tally of event episodes.

Adverse-event endpoints are used to characterize the safety experience observed during a study. They can describe the frequency of events in the treated group and help readers understand what was recorded during the stated follow-up. In this record, the posted results separate serious adverse events from other adverse events and also list deaths. These categories should be read as descriptive counts, not as estimates of treatment-attributable harm. The registry does not report an analysis that determines whether an event was caused by niraparib, nor does the single-group design provide a control group for estimating what would have occurred otherwise.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a participant-level count. In general, a binary outcome records whether each participant experienced a defined event or did not. Summing the participants with the event produces a count; it does not measure how many total episodes occurred. The registry describes the primary endpoint as the number of patients who experience adverse events, and specifies participants as the unit. The posted safety results separately report participants affected by serious and other adverse events.

What does a participant count tell the reader?

A count tells the reader how many participants in the recorded group met the event definition. It is most informative when read alongside the number of participants whose outcome was assessed and the follow-up period. Here, the serious-event and other-event group lists 9 participants at risk, and the endpoint timeframe is up to 17 months. The record does not explain whether all participants had the same duration of observation or how follow-up varied. A count alone cannot describe the timing of events or distinguish a brief observation period from a longer one.

For a binary outcome, a proportion is sometimes reported alongside the count to put the number of participants with an event in context. No overall primary-endpoint proportion is stated in the record. The serious adverse-event terms are individually accompanied by percentages, but the registry does not provide enough detail in the listed terms to establish their denominators or overlap. Those percentages should therefore be quoted as recorded rather than used to infer additional counts or participant-level patterns.

Why does the design matter?

A single-group design observes outcomes in participants receiving the intervention, without a concurrent control group. In general, a control group helps distinguish the observed course under a treatment from outcomes that might occur under another condition. Without that comparison, the results cannot estimate a treatment contrast. This is particularly important for adverse events: an event observed during treatment is not, by observation alone, proven to have been caused by treatment. Underlying illness and other circumstances may also be relevant, but their contribution cannot be estimated from this single-group record.

Allocation is listed as not applicable and masking as none. The registry therefore does not describe random allocation or masking as features of this study. The record does not report other design details that might further explain how participants were selected, followed, or assessed. Those details should not be inferred from the phase or study title.

What do statistical precision measures usually add?

In general, a confidence interval presents a range of values compatible with an estimate under the chosen statistical model. A narrower interval indicates greater statistical precision than a wider interval, while neither interval width nor inclusion of a particular value resolves limitations in study design or data collection. No confidence interval is listed for the adverse-event results, and the registry lists no statistical analyses. As a result, the precision of the counts as estimates for a broader population is not quantified in the posted results.

Over-dispersion is a general concern for count data when variability exceeds what a simple count model would expect. It can affect standard errors and confidence intervals if the model does not accommodate that extra variability. The primary endpoint is a participant count for a binary event, not a reported episode-rate model. The registry does not report a model or dispersion estimate for this endpoint, so over-dispersion cannot be evaluated as a feature of the posted analysis.

How should the planning illustration be read?

The sample-size assumptions describe a planning illustration based on the observed effect, not the trial’s own design. The assumptions state a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. These assumptions are not evidence that the trial had two arms: the registry describes the actual study as single-group. Nor are planning calculations observed power or a retrospective statement about the probability that the trial detected an effect. They are hypothetical illustrations of sample sizes under specified assumptions. No sample-size justification for the trial is reported in the registry record.

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("Niraparib Treatment")
n      <- c(9)
events <- c(9)
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  Niraparib Treatment  9  9  100.0  66.4  100.0  70.1  100.0  69.2  99.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures, including the primary adverse-event endpoint and secondary outcomes for progression-free survival and overall survival in the dose expansion phase, and duration of disease control of all patients. It lists no statistical analyses. A list of outcomes does not say which were analyzed, how outcomes were prioritized in practice, or whether any adjustments were made when considering multiple outcomes.

Multiplicity is a general statistical issue that arises when several hypotheses or outcomes are examined. With more tests, the chance of at least one apparently unusual result can increase if no adjustment or interpretive strategy is used. The record does not report a multiplicity procedure or analysis plan, so it is not possible to say how this issue was handled. No unreported adjustment should be assumed.

Missing-data methods and analysis populations are also not reported in the registry record. The primary endpoint description refers to all enrolled patients, while the posted adverse-event group lists 9 participants at risk and the enrollment field lists 15. The registry does not explain this distinction, identify participants with unavailable outcome information, or describe how any missing values were handled. It also does not state whether analyses used an intention-to-treat, safety, or other defined population.

In general, missing outcome data can affect both the number of participants contributing to an estimate and the interpretation of that estimate. Without information on completeness, reasons for missingness, or analysis rules, the extent and potential influence of missing data cannot be assessed. The posted counts should be read with this reporting gap in mind.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death nos (11.1%), muscle weakness trunk (11.1%).

The registry reports 1 participant affected by a serious adverse event and 9 affected by other adverse events in the Niraparib Treatment group; 9 participants are listed as at risk. It separately lists 6 deaths. These are recorded counts, and the registry does not establish from these figures whether events were caused by niraparib. The group also lists “Death NOS” and “Muscle weakness trunk” as the top serious terms, each with a reported value of 11.1%.

The serious-event terms and the total death count are different kinds of entries. The record does not explain whether the terms overlap with one another or how they correspond to the total number of deaths. Nor does it provide additional details about timing, duration, severity grading, or attribution for each event in the results summarized. The term “Death NOS” is reported as written; the record does not state a cause of death.

Because the study has no control group, these safety counts describe events observed in the treated group rather than an excess risk relative to a comparator. They should not be read as a causal estimate or as a complete account of all safety outcomes beyond those recorded.

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

The results establish that the registry records adverse events and deaths in the Niraparib Treatment group. They give counts for participants affected by serious adverse events and other adverse events, list deaths, and identify two top serious adverse-event terms with reported percentages. This is descriptive information about the posted group, not a comparative estimate of treatment effects.

The findings do not show what the event counts would have been under a different treatment or without niraparib. The single-group design has no concurrent comparator, and the registry record lists no statistical analyses. There are no posted confidence intervals or hypothesis tests that quantify uncertainty around a comparative effect. The observed counts therefore cannot be used to conclude that niraparib caused or prevented any listed event.

The result also does not establish that all 15 enrolled participants contributed to the posted adverse-event group. Enrollment is listed as 15, while the results list 9 participants at risk; no explanation is reported. The record does not describe the completeness of follow-up, the handling of missing information, or the analysis population. Those gaps limit interpretation of how fully the counts represent the enrolled group.

The secondary outcomes identify subjects of interest, but their listing is not a report of their results. The registry status is terminated, but no reason is reported. Neither the listed outcomes nor the termination status supports conclusions about why the study ended or about the effects of the intervention. The appropriate reading is limited to the recorded safety counts and the design and reporting context around them.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a safety description and a comparative treatment estimate. A single-group study can record how many participants experienced adverse events during treatment and can identify event categories that merit attention in the study record. It cannot, by design, provide a concurrent estimate of how those counts compare with another treatment group.

The record also illustrates why denominators and analysis populations matter. Enrollment is listed as 15, but the posted adverse-event group has 9 participants at risk. The registry does not explain the relationship. Without an account of who contributed to each outcome and whether follow-up was complete, readers cannot tell how representative the posted counts are of all enrolled participants.

Another statistical lesson concerns the distinction between event labels and causal interpretation. Serious-event terms and death counts are important descriptive entries, but they do not by themselves establish attribution. A comparator, a clearly reported analysis, and adequate information about outcome collection would be needed to support more detailed comparative claims.

Finally, the registry lists several secondary outcomes but no statistical analyses. This makes it important to distinguish planned or registered outcomes from outcomes with posted estimates. The record can be read as a limited safety report, but it does not supply the analyses needed to assess precision, comparative effects, or multiplicity handling. These reporting features are relevant to interpreting the evidence without extending beyond what the registry states.

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 trial-specific limitation is the single-group design. Because the registry identifies no comparator, the adverse-event counts cannot be contrasted with outcomes in a control group. The absence of masking is also recorded, but the registry does not explain how this affected event assessment or reporting.

The enrollment field lists 15 participants, while the posted adverse-event group lists 9 at risk. The registry record does not reconcile these figures. It also does not report whether every enrolled participant was followed for the full timeframe, how many had complete outcome information, or how missing data were handled. These omissions limit assessment of the population represented by the posted counts.

No statistical analyses are listed, and the record does not report confidence intervals, hypothesis tests, an analysis population, or a multiplicity approach. The secondary outcomes are listed without corresponding analyses in the registry record. A reason for the terminated status is not reported. The record also does not provide further event-level detail sufficient to establish how the serious-event terms relate to the total death count or whether terms overlap.

These limitations restrict interpretation to the observed entries. They do not establish that unreported methods were absent in the conduct of the study; they mean those methods and details are not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: PARP Inhibition for Gliomas (PI-4G or π4g) — NCT05297864.
• Registry record last updated 2025-05-23; status last verified 2025-05.
• Results first posted 2024-11-06.
• 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

NCT05297864 is a phase II, single-group trial of individualized starting-dose niraparib for recurrent glioma, sponsored by the University of Oklahoma. The registry lists enrollment of 15, no masking, and terminated status. The start date is 2022-06-09, and the primary completion date is 2023-11-14.

The primary outcome counts participants experiencing adverse events using CTCAE v5.0, over a timeframe of up to 17 months. The posted treatment group lists 9 participants at risk, 1 participant affected by a serious adverse event, 9 affected by other adverse events, and 6 deaths. “Death NOS” and “Muscle weakness trunk” are each listed among the top serious terms at 11.1%.

No statistical analyses are listed. The registry does not explain the difference between the enrollment and at-risk counts, report a comparator, or describe missing-data handling, analysis populations, or a reason for termination. The posted results therefore support a descriptive reading of the recorded safety counts, not a comparative or causal conclusion.