Paxerol™ for Treatment of Nocturia - A Phase II Placebo-Controlled Trial: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Paxerol™ for Treatment of Nocturia - A Phase II Placebo-Controlled Trial (NCT02646826), a non-randomized phase 2 study. The primary outcome is Change in Nocturia Episodes.

2. Clinical Question

In statistical terms, the question is whether the observed changes in average nightly voids differed among the treatment groups over the stated treatment period, and how precisely any such differences were estimated. The registry record gives the planned endpoint but not the direction or size of the results, confidence intervals, or hypothesis-test results. Therefore, it does not permit a conclusion about the magnitude or uncertainty of a treatment-group contrast.

The registry summary also describes assessment of Nocturia Quality of Life, Duration of First Undisturbed Sleep, total hours of nightly sleep, safety, and tolerability. Baseline urinary prostaglandin E2 production was to be assayed for a potential association with responsiveness. These are described as monitored measures or aims; the registry record does not report their results or the detailed analyses used for them.

3. Trial Design

The registry identifies this as a Phase II, parallel-group study of Paxerol for nocturia, with placebo as the comparator. It lists four groups: placebo and Paxerol at Dose Level 1, Dose Level 2, and Dose Level 3. The study is marked completed, with enrollment of 86. The registry records start as 2016-01 and primary completion as 2017-10.

The design has an important distinction: the record describes the study as placebo-controlled and quadruple-masked, but also records allocation as nonrandomized. Masking concerns whether specified people know which treatment was assigned; it does not establish that treatment assignment was random. The registry summary says that an even assignment across treatment groups according to gender and body mass index categories would be attempted because stratification was expected to be difficult. This description does not establish that the groups were balanced on those or other prognostic characteristics.

The study summary describes daily oral treatment 30 minutes before bedtime for two weeks. Nocturia frequency and other measures were to be recorded before and after treatment. The primary endpoint is described as change in the number of nocturia episodes during the 2-week treatment period, with results from the dose groups to be assessed against placebo.

Nonrandomized allocation matters when interpreting any group comparison. If treatment assignment is related to participant characteristics that also influence nocturia, an observed difference may reflect those characteristics as well as treatment. Masking may help limit some sources of bias, but it does not remove this potential confounding. The registry record does not report how assignment was implemented in practice, whether any adjustment was made for baseline differences, or the details of the statistical model. The study summary calls this a proof-of-principle, dose-finding trial; a sample-size justification is not reported in the registry record.

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.

Population: During the two week baseline period, patients completed a diary of their nightly voids. Those whose voids averaged less than 2.5 voids per night were excluded from the second two weeks of the trial. Only 86 out of the original 129 patients met this criterion.

6. Primary Endpoint

The registry lists the primary outcome as Change in Nocturia Episodes, measured over Up to 2 weeks.

The primary endpoint is change in nocturia episodes, expressed as average nightly voids, with assessment during up to 2 weeks. Nocturia frequency is a direct measure of the symptom targeted by the study. Measuring change compares the endpoint after treatment with its baseline value, allowing the analysis to describe whether the recorded frequency shifted over the treatment period.

The registry describes the endpoint as a mean of a continuous measure and identifies standard deviation as its dispersion measure. A mean summarizes the group’s average recorded change, while a standard deviation describes how spread out individual observations are around that average. The mean alone does not show whether participants had similar changes or widely varying responses.

The planned comparison is change in each Paxerol dose group versus placebo. Such a comparison can help distinguish change occurring during treatment from change observed in a placebo group, but the nonrandomized allocation means that group differences may also reflect baseline differences or other factors related to assignment. The registry record does not report the endpoint values, the exact convention for calculating change, the handling of baseline values, or the estimated treatment contrasts. The reason the endpoint is used can be described from its relevance to the symptom; the observed treatment effect and its precision cannot be judged from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What kind of outcome is being analyzed? The primary outcome is described as a mean of a continuous measure: change in average nightly voids. Continuous outcomes can take a range of values rather than being limited to categories. A group mean gives a concise summary, and the standard deviation describes variability among recorded observations. Neither statistic, by itself, gives the precision of a comparison between groups. Precision depends on the amount of information in the analysis and the variation in the observations, among other factors.

What would a treatment contrast represent? The registry describes assessing each Paxerol dose level against placebo. In general, a contrast expresses the difference between outcome summaries for two groups. For a change endpoint, interpretation also depends on how change is defined and which direction corresponds to fewer or more nightly voids. The registry record does not report the calculation convention or any contrast estimates, so no numerical treatment difference or direction can be stated.

Why does allocation matter? General statistical principle: random assignment helps make treatment groups comparable in expectation, including for characteristics that were not measured. This record states that allocation was nonrandomized. Therefore, observed differences can be associated with treatment assignment and with baseline or other characteristics related to assignment. Attempted balancing by gender and body mass index, as described in the study summary, does not establish that all relevant factors were balanced. Statistical adjustment can sometimes account for measured characteristics, but the registry record does not report whether adjustment was used, which variables would have been included, or how the assignment process was modeled.

What does masking contribute? The registry records quadruple masking, while the summary describes the study as double-blind. In general, masking is intended to limit the influence of knowledge about treatment assignment on participant experience, care, or outcome assessment. It does not make allocation random, and it cannot guarantee that all sources of bias are absent. The roles covered by the masking label and its practical implementation are not reported in the registry record.

How should uncertainty be assessed? General statistical principle: an estimate is more informative when accompanied by a measure of uncertainty, such as a confidence interval. A confidence interval represents uncertainty under the assumptions of the analysis; it is not a guarantee that the true effect lies within its limits. A p-value, if reported, addresses compatibility of the observed data with a specified null model and does not measure the size or clinical importance of an effect. Neither confidence intervals nor p-values for the primary comparison are reported in the registry record. Thus, the precision and statistical evidence for the endpoint comparison cannot be assessed from the record.

What do the planning assumptions mean? The sample-size assumptions describe a planning illustration, not observed power. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect defined as a stated fraction of the observed effect. For time-to-event planning, the record specifies a total number of events using the Schoenfeld approach; other planning values are expressed as participants per arm for 80% power or other stated power levels. These are planning conventions, not results from the enrolled participants. The registry record does not report the trial's own sample-size justification. The primary outcome in this trial is continuous, rather than a time-to-event endpoint.

Why can over-dispersion matter? General statistical principle: over-dispersion means that observed variability is greater than a model assumes. When a model underestimates variability, standard errors may be too small and confidence intervals too narrow. The registry describes a mean and standard deviation for the primary measure, but does not report a model or an over-dispersion assessment. This concept therefore explains a general modeling concern; it does not establish that over-dispersion occurred in this trial.

What is not documented? The registry lists two analyses and four outcome measures, but does not provide the statistical plan, model specifications, covariates, analysis populations, missing-data procedures, or endpoint comparison results. It also does not describe interim analyses. These details are necessary to evaluate choices such as covariate adjustment, repeated-measure handling, and the interpretation of multiple comparisons. Their status is not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and two analyses. The primary measure is change in nocturia episodes; the secondary outcomes listed are Duration of First Undisturbed Sleep and total hours of nightly sleep. The study summary also describes monitoring Nocturia Quality of Life, safety, and tolerability, and assessing a potential relationship between baseline urinary prostaglandin E2 and response. The registry record does not report a multiplicity strategy for the several dose comparisons or outcomes. It is therefore not possible to determine whether any reported statistical thresholds were adjusted, or how the analyses were prioritized.

Multiplicity is a general concern when several hypotheses are tested: considering many results can increase the chance that an apparently notable finding arises by chance. The appropriate approach depends on which outcomes and comparisons were prespecified and whether the goal is confirmatory or exploratory. The registry record does not report enough detail to assess the approach used.

Missing-data handling and analysis populations are also not reported in the registry record. It does not state how many primary outcome observations were available at baseline or follow-up, how missing measurements were treated, or whether participants were analyzed according to assigned group, treatment received, or another definition. These choices can affect both the estimate and its uncertainty, especially when missingness is related to outcome or treatment experience. The registry record does not provide reasons for missingness or a sensitivity analysis.

The outcome description says measurements were to be taken before and after treatment, but does not specify the analytic method for repeated observations or adjustment for baseline. A complete statistical interpretation would require these details alongside estimates and uncertainty intervals; they are not reported in the registry record.

11. 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 non-serious adverse event terms

The adverse-event record reports serious adverse events affecting 0 participants in each of the four groups. It also reports 0 deaths in each group. For other adverse events, the recorded counts are 4 among 21 at risk in the placebo group, 2 among 22 at risk in Dose Level 1, 3 among 21 at risk in Dose Level 2, and 3 among 22 at risk in Dose Level 3.

These are descriptive counts, not evidence that the groups had equivalent safety profiles. The registry record does not provide event types for the other adverse events, definitions, severity, timing, relatedness assessments, or statistical comparisons. It also does not state whether every event was counted once per participant or how recurrent events were handled. The at-risk counts are the denominators recorded for these adverse-event summaries; they should not be assumed to represent the analysis population for the primary endpoint.

A recorded count of zero means that no event was reported in that category for the listed group in this record. It does not establish that the possibility of such an event is absent. Interpretation of safety requires the event definitions, duration of observation, completeness of reporting, and the clinical context, none of which is detailed.

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

This trial addresses a relevant statistical question: whether change in nocturia frequency differs between placebo and three dose levels of Paxerol over a short treatment period. Its registry record identifies a continuous primary endpoint and describes a masked, parallel-group, placebo-controlled study. It also records nonrandomized allocation, which is essential context for interpreting comparisons.

The record does not report the primary outcome estimates or their uncertainty. It therefore does not establish the direction, size, or precision of any difference between Paxerol and placebo. No conclusion about treatment effect can be drawn from the design description or the adverse-event counts. The record also does not report results for the secondary outcomes or the proposed assessment of baseline urinary prostaglandin E2 in relation to response.

Even if group differences were available, nonrandomized allocation would require careful interpretation. Differences could reflect treatment, baseline imbalance, or other factors linked to assignment. Masking may reduce some biases, but it does not remove confounding created by nonrandom assignment. The registry record does not describe adjusted analyses that could help account for measured differences.

Likewise, the absence of reported serious adverse events in the listed groups is not proof that serious harms cannot occur. The record gives event counts but not detailed definitions, event descriptions, or the broader context needed for a full safety assessment. The adverse-event summaries should be read as what was recorded, not as a complete characterization of risk.

The appropriate conclusion is limited: the registry documents the trial's planned clinical question, design, endpoint, and selected safety counts. It does not report enough outcome or analysis information to quantify the primary comparison or establish its statistical precision.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of why design labels need to be read together. A placebo-controlled and masked design can reduce some sources of bias, but the record also identifies allocation as nonrandomized. That feature changes how group comparisons should be interpreted: baseline comparability cannot be assumed solely from masking or from an effort to balance selected characteristics.

The dose-finding purpose also makes the distinction between exploratory evidence and a definitive comparison important. The summary describes three Paxerol dose levels and several outcomes, while the primary outcome is a continuous measure of nocturia frequency. A useful report would connect each comparison to a prespecified question and present effect estimates with uncertainty, rather than relying on a significance label alone. Those results and analysis details are not reported in the registry record.

The record also illustrates the limits of an endpoint description without posted results. Knowing that change in average nightly voids was to be assessed clarifies what the trial sought to measure, but it does not tell readers how much change occurred or how variable participant outcomes were. Standard deviations, treatment contrasts, and confidence intervals would each answer different questions about the data.

Finally, the presence of several outcomes and dose comparisons raises questions about multiplicity, missing data, and analysis populations. These are not merely technical details: they affect how confidently findings can be interpreted and reproduced. Their absence from the registry record limits statistical assessment, regardless of the study's completed status.

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 central limitation for interpretation is that the registry record does not report primary endpoint results. It gives no group summaries, treatment contrasts, confidence intervals, or p-values. As a result, the magnitude and precision of the principal comparison cannot be evaluated.

Nonrandomized allocation is a design limitation for causal interpretation. The study summary describes efforts to assign similar distributions across gender and body mass index categories, but it does not report the achieved balance or any adjustment for baseline factors. Potential confounding therefore remains an important concern. The record also does not describe how allocation was conducted in practice.

Other important methodological details are not reported in the registry record: the statistical model, baseline adjustment, analysis population, treatment of missing outcomes, reasons for missingness, and any sensitivity analyses. The record lists multiple outcome measures and analyses without describing a multiplicity plan. It does not report an interim-analysis plan or a sample-size justification for the trial itself.

The registry gives selected adverse-event counts but does not provide event terms, definitions, severity, timing, or relationship to treatment. It also does not provide detailed results for the listed secondary outcomes or the proposed urinary prostaglandin E2 assessment. These limitations mean that the trial's results and their robustness cannot be assessed from the registry record alone.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Paxerol™ for Treatment of Nocturia - A Phase II Placebo-Controlled Trial — NCT02646826.
• Registry record last updated 2019-06-14; status last verified 2019-06.
• Results first posted 2019-06-14.
• 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 identifies NCT02646826 as a completed Phase II, parallel-group, nonrandomized, quadruple-masked study of Paxerol for nocturia. It records enrollment of 86 and a placebo group alongside three Paxerol dose levels. The study summary describes daily oral treatment 30 minutes before bedtime for two weeks.

The primary endpoint was change in nocturia episodes, measured as average nightly voids during up to 2 weeks. The record lists Duration of First Undisturbed Sleep and total hours of nightly sleep as secondary outcomes. It also describes monitoring other measures and assessing a possible relationship between baseline urinary prostaglandin E2 and response.

For safety, the record reports no serious adverse events or deaths in the listed groups and provides counts for other adverse events. It does not report the primary outcome results, statistical comparisons, or key analysis details, including missing-data methods and the analysis population. Consequently, the treatment effect and its precision are not reported in the registry record.