This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Safety and Efficacy of Botulinum Toxin Type A to Treat Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia (NCT01107392), a randomized phase 2 study. The primary outcome is Change From Baseline in the Total International Prostate Symptom Score (IPSS) at Week 12.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01107392 |
| Phase | Phase 2 |
| Condition | Benign Prostatic Hyperplasia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 315 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Allergan |
| Results posted | Yes |
2. Clinical Question
Population
Participants with benign prostatic hyperplasia and urinary tract symptoms. The primary-outcome population was the modified intent-to-treat population: randomized and treated participants with at least one post-baseline IPSS measurement.
Intervention
Intraprostatic botulinum toxin Type A, with a total dose of 200U equally divided between the lateral prostatic lobes.
Comparator
Placebo consisting of normal saline, equally divided and administered to each lateral prostatic lobe.
Primary question
How did the total IPSS change from baseline to Week 12 in the modified intent-to-treat population? The registry record does not report a single treatment comparison or its estimate, so the relative change between groups cannot be determined from the posted results.
The trial was registered as a randomized, double-masked, parallel-group Phase 2 study. Its stated purpose was to evaluate safety and efficacy of intraprostatic botulinum toxin Type A compared with placebo for urinary tract symptoms due to benign prostatic hyperplasia. The enrollment recorded was 315. The registry lists change from baseline in total IPSS at Week 12 as the primary outcome, with peak urine flow rate, change in IPSS, and duration of effect among the secondary outcomes.
The central clinical-statistical question is not simply whether each group’s symptom score changed over time. A randomized comparison asks whether the change differed between assigned groups, while accounting for uncertainty in the estimated difference. The record describes the endpoint and the population but does not report group-level changes, a between-group estimate, or an interval or test for that comparison. Accordingly, the clinical question is identifiable, but its answer is not available from the registry record.
3. Trial Design
The registry describes a randomized, double-masked, parallel-group Phase 2 trial. Participants were assigned to botulinum toxin Type A or placebo (normal saline). The active treatment was described as a total dose of 200U, divided equally and administered to each lateral prostatic lobe. Saline was likewise divided between the lateral lobes. The registry reports enrollment of 315 and status as completed.
The study start date is 2010-08-01, and the primary completion date is 2012-03-16. The sponsor is Allergan. These dates and the completed status describe the conduct recorded in the registry; they do not provide the timing or content of any analyses.
Randomization is intended to make treatment groups comparable, on average, with respect to measured and unmeasured baseline characteristics. Masking can reduce the potential for knowledge of assignment to affect participant reporting, clinical management, or assessment. These are general design principles; the registry record does not describe how randomization was generated or concealed, who specifically was masked, or whether masking was assessed.
A parallel-group design compares participants assigned to different treatments over the study period rather than assigning each participant to both treatments. The primary outcome was change from baseline in total IPSS at Week 12. The registry also lists change from baseline in peak urine flow rate and duration of effect as secondary outcomes, along with change in total IPSS. The registry record does not report the study visit schedule beyond the primary endpoint’s stated baseline and Week 12 timeframe, or the duration used to define the secondary duration-of-effect outcome.
Although the registry marks the trial completed, the posted primary-outcome information does not supply a single comparison of the groups. The record also lists no analyses. Consequently, design features can be described, but the treatment contrast, its precision, and the analysis choices used to produce it cannot be reconstructed from this 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
| Stage | Botulinum Toxin Type A | Placebo (Normal Saline) |
|---|---|---|
| STARTED | 158 | 157 |
| COMPLETED | 153 | 154 |
| NOT COMPLETED | 5 | 3 |
Reasons for not completing this period:
| Reason | Botulinum Toxin Type A | Placebo (Normal Saline) |
|---|---|---|
| Adverse Event | 2 | 0 |
| Personal Reasons | 2 | 3 |
| Administrative decision | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Modified Intent-to-treat population included all randomized and treated participants with at least one post-baseline IPSS measurement.
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.
| Characteristic | Unit | Botulinum Toxin Type A | Placebo (Normal Saline) | Total |
|---|---|---|---|---|
| Participants analysed | 158 | 157 | 315 | |
| Age, Customized: ≤ 65 Years | Participants | 89 | 79 | 168 |
| Age, Customized: > 65 Years | Participants | 69 | 78 | 147 |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 158 | 157 | 315 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in the Total International Prostate Symptom Score (IPSS) at Week 12, measured over Baseline, Week 12.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change from baseline in the total International Prostate Symptom Score (IPSS) at Week 12. IPSS is a disease-specific questionnaire based on the American Urological Association Symptom Index. It covers incomplete emptying, frequency, hesitancy, urgency, weak stream, straining, and nocturia, asking participants to evaluate their urinary symptoms during the previous 4 weeks.
The total score ranges from 0, indicating no symptoms, to 35, indicating the most severe symptoms. A negative change from baseline indicates improvement. The endpoint therefore expresses how the symptom score changed over the interval from baseline to Week 12; it is not a direct measure of an individual symptom or of peak urine flow.
Patient-reported symptom scores are used because they capture how symptoms are experienced, which may not be fully represented by a physiological measure alone. In general, comparing change between randomized groups can help distinguish a treatment-associated difference from changes that may occur over time in both groups. That general rationale does not establish that a difference occurred in this trial.
The stated analysis population was modified intent-to-treat: participants who were randomized and treated and had at least one post-baseline IPSS measurement. The registry record does not report the group means, standard deviations, or a single between-group estimate for this endpoint. The size and precision of any Week 12 treatment contrast are therefore not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a focused primary question: whether the change in total IPSS by Week 12 differed between participants assigned intraprostatic botulinum toxin Type A and those assigned normal saline. It also defines how to interpret the direction of change: a negative change from baseline indicates improvement. However, the posted information does not include a single primary-outcome comparison or the underlying group results needed to assess that contrast.
No group-specific mean change, standard deviation, between-group estimate, confidence interval, or p-value is reported in the registry record. Without an estimate and a measure of its uncertainty, it is not possible to describe the magnitude or precision of a treatment-group difference. Nor can the posted information establish whether any observed within-group changes were similar or different across the randomized groups.
The record identifies the modified intent-to-treat population as randomized and treated participants with at least one post-baseline IPSS measurement. It does not report how many participants in each group met this definition or how many had endpoint measurements at Week 12. The enrollment of 315 is a trial-level figure and does not, by itself, provide the analyzed sample size for the primary outcome.
Four outcome measures are listed, including the primary IPSS endpoint and secondary outcomes. The primary-outcome information includes several categories or time points and is not reduced to a single comparison. This means the clinical question can be described, but the principal randomized contrast cannot be read from the posted result record. The registry also lists no analyses. Statistical significance, if any, cannot be inferred from the study’s completed status, its phase, or its enrollment.
In general, an estimate and confidence interval would help distinguish a small, imprecise difference from a larger, more precisely estimated difference. A p-value, when reported, would address compatibility of the data with a specified null model under the analysis assumptions; it would not by itself describe the size or clinical importance of an effect. These are general interpretive principles, not findings from this trial. Since no primary comparison or uncertainty measure is reported, neither statistical nor clinical importance can be assessed from the registry record.
The safety counts are reported separately and should not be treated as evidence about the primary symptom endpoint. Serious adverse events affected 5 of 158 participants in the botulinum toxin group and 8 of 157 in the placebo group, as recorded. The record does not supply a statistical comparison for these counts. The listed serious-event terms and their reported percentages describe safety entries, not a treatment-effect estimate for IPSS.
The appropriate conclusion is limited: the registry specifies the design, treatment arms, symptom measure, and analysis population, but it does not report the primary outcome result in a form that permits a treatment comparison. This absence is not evidence that the groups were the same, and it is not evidence that they differed.
9. Statistical Methods Explained
The primary outcome is a continuous score, and the registry identifies the summary parameter as a mean with standard deviation as the dispersion measure. A mean describes the group’s average score or average change. A standard deviation describes the spread of individual values around that average. These quantities answer different questions: the mean locates the group average, while the standard deviation describes participant-to-participant variability.
What does a change score represent?
For each participant with the required measurements, a change score expresses the Week 12 score relative to baseline. The registry states that negative change indicates improvement. A comparison of mean changes between randomized groups would estimate how much the average change differed between assignments. That between-group contrast is the key treatment comparison; an average change in one group alone would not show whether it changed differently from the other group.
Change scores can be useful when the outcome is measured before and after treatment, because they express movement from each participant’s starting value. In general, the precision of a group comparison depends on the number of analyzed participants and on the variability of their scores. The registry record does not report group-specific mean changes or standard deviations, so neither the contrast nor its precision can be described.
What would uncertainty measures add?
A confidence interval is a range of values that, under the statistical model and procedure used, is compatible with the observed data at a stated confidence level. It conveys both the estimated direction and the precision of an effect estimate. A narrow interval indicates greater precision than a wide interval, while the values included in the interval help readers judge which effect sizes remain plausible. This is a general explanation; no confidence interval for the primary comparison is reported in the registry record.
A p-value is a measure calculated under a specified statistical model and null hypothesis. It is not the probability that a treatment works, nor does it state the probability that the null hypothesis is true. Interpretation depends on the analysis plan, assumptions, and the size and uncertainty of the estimated effect. No primary-outcome p-value is reported, and the registry record lists no analyses. It is therefore not possible to identify a test statistic, a significance threshold used for the primary comparison, or a model used to calculate a result.
Why does the analysis population matter?
The endpoint population is described as modified intent-to-treat. It includes all randomized and treated participants with at least one post-baseline IPSS measurement. This definition makes clear that the endpoint analysis is not necessarily the same as every participant enrolled or randomized: having the required post-baseline measurement is part of inclusion in the stated population. The registry does not report the number meeting that definition in each group, the number with Week 12 data, or how participants with incomplete measurements were handled.
In general, excluding participants without post-baseline measurements can affect how well a comparison preserves the balance created by randomization, especially if measurement availability is related to prognosis or treatment assignment. Statistical approaches to missing data rely on assumptions about why values are missing. Different assumptions can produce different estimates. The record does not specify a missing-data method or describe the amount or pattern of missing IPSS data; these details are not reported in the registry record.
What is the role of randomization and masking?
Randomization is a design-based method for creating comparison groups. If implemented as intended, it reduces systematic differences in baseline characteristics on average, making a between-group difference more interpretable as an effect associated with assignment. Double masking is intended to limit influences from knowledge of assignment. These are general properties of the design labels; the record does not describe the allocation sequence, concealment procedures, or specific masking arrangements.
Because this was a parallel-group trial, the assigned groups are compared with one another. The primary outcome’s timeframe is baseline and Week 12. The registry record does not specify whether the primary comparison used a model adjusting for baseline score, an unadjusted comparison of changes, or another method. It does not report diagnostics or assumptions used for a particular analysis.
Why can variability matter?
For continuous outcomes, greater variation among participants can make a group mean less precise, all else being equal. If variation differs across groups or is not well represented by the assumed model, standard errors and confidence intervals may be affected. In general, over-dispersion refers to variability greater than a model expects; accounting for it can be important when a model assumes a narrower distribution. The registry identifies a mean and standard deviation summary, but it does not report evidence of over-dispersion or a model requiring an adjustment. No such issue should be assumed for this trial.
Planning calculations can illustrate how sample size relates to a chosen effect and assumed variability, but they are not results from participants and are not observed power. The registry record does not report a sample-size justification or its assumptions. No planning illustration can replace the missing treatment estimate, uncertainty interval, or analysis details.
Finally, an endpoint may be reported at more than one time point or in multiple categories. Selecting or emphasizing one result among several can affect interpretation, particularly if many outcomes or comparisons are examined. The registry’s primary-outcome information is not reduced to one comparison, and no multiplicity strategy is reported. Without a prespecified analysis description, it is not possible to determine how multiple outcomes or time points were handled.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome of change from baseline in total IPSS at Week 12 and several secondary outcomes, including peak urine flow rate and duration of effect. The primary-outcome information includes multiple categories or time points rather than a single reported comparison. The registry record does not describe a multiplicity adjustment or identify which comparisons, if any, were designated for confirmatory interpretation. When many outcomes or time points are examined, the chance of a nominally unusual result can increase; methods to address that issue depend on the planned analysis. This is a general statistical concern, not evidence that a particular adjustment was required or used in this trial.
The stated primary-outcome population is modified intent-to-treat: randomized and treated participants with at least one post-baseline IPSS measurement. The registry does not give the number of participants in that population by group, the number with Week 12 scores, or the amount of missing outcome data. It also does not describe imputation, a repeated-measures model, sensitivity analyses, or another method for handling missing values. These details are not reported in the registry record.
The analysis population definition matters because inclusion depends on having a post-baseline measurement. In general, if the availability of measurements is related to treatment assignment or symptom status, an analysis limited to observed data may not preserve all the advantages of randomization. The consequences depend on the missingness pattern and assumptions, which cannot be evaluated from the posted information.
The registry lists no analyses. Therefore, no multiplicity procedure, missing-data strategy, or comparison-specific analysis plan can be attributed to the trial from this record. These omissions limit assessment of how the reported endpoint was analyzed; they do not establish that a particular method was or was not used outside the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Botulinum Toxin Type A | 5 | 158 | 3.2% |
| Placebo (Normal Saline) | 8 | 157 | 5.1% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Botulinum Toxin Type A | 42 of 158 |
| Placebo (Normal Saline) | 44 of 157 |
Most frequent serious adverse event terms
| Event term | Organ system | Botulinum Toxin Type A | Placebo (Normal Saline) |
|---|---|---|---|
| Retinal detachment | Eye disorders | 1 of 158 | 0 of 157 |
| Inguinal hernia | Gastrointestinal disorders | 1 of 158 | 0 of 157 |
| Cholelithiasis | Hepatobiliary disorders | 0 of 158 | 1 of 157 |
| Cellulitis | Infections and infestations | 1 of 158 | 0 of 157 |
| Localised infection | Infections and infestations | 1 of 158 | 0 of 157 |
| Urosepsis | Infections and infestations | 0 of 158 | 1 of 157 |
| Hypoglycaemia | Metabolism and nutrition disorders | 1 of 158 | 0 of 157 |
| Osteoarthritis | Musculoskeletal and connective tissue disorders | 0 of 158 | 1 of 157 |
| Malignant melanoma | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 158 | 0 of 157 |
| Prostate cancer | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 158 | 1 of 157 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Botulinum Toxin Type A | Placebo (Normal Saline) |
|---|---|---|---|
| Haematuria | Renal and urinary disorders | 23 of 158 | 18 of 157 |
| Haematospermia | Reproductive system and breast disorders | 13 of 158 | 16 of 157 |
| Prostatic specific antigen increased | Investigations | 6 of 158 | 10 of 157 |
Serious events with the highest arm-level rate: cholelithiasis (0.6%), urosepsis (0.6%), osteoarthritis (0.6%), prostate cancer (0.6%), thyroid cancer (0.6%).
The registry reports serious adverse events affecting 5 of 158 participants in the botulinum toxin Type A group and 8 of 157 participants in the placebo (normal saline) group. Other adverse events are recorded as affecting 42 of 158 participants and 44 of 157 participants, respectively. These are counts of affected participants as presented in the safety record; they are not a statistical comparison or an estimate adjusted for differences in follow-up.
The serious-event terms listed include cholelithiasis, urosepsis, osteoarthritis, prostate cancer, thyroid cancer, and transitional cell carcinoma. Each term is accompanied by a reported percentage of 0.6%. The registry record does not provide further context for these entries, such as timing, duration, seriousness criteria, or a treatment-relatedness assessment.
Deaths are not reported in the registry record. That should not be interpreted as a confirmed count of zero. The event counts also do not establish whether a treatment caused an event. A comparison of safety would require careful attention to definitions, observation time, event attribution, and uncertainty; those details are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, double-masked, parallel Phase 2 trial compared intraprostatic botulinum toxin Type A with normal saline for urinary tract symptoms due to benign prostatic hyperplasia. It specifies the primary symptom measure, its Week 12 timeframe, the direction of change associated with improvement, and the modified intent-to-treat population. These registry entries define what the study set out to compare.
The record does not report a single primary-outcome treatment contrast, the group-level IPSS changes, or an uncertainty measure. It therefore cannot show how large a difference was observed, how precisely it was estimated, or whether the groups differed on the primary endpoint. The absence of a reported comparison does not mean that no effect occurred, and it does not mean that an effect did occur.
Even when an effect estimate is available, statistical evidence and clinical importance are distinct. Statistical uncertainty concerns the range of effects compatible with the data and analysis assumptions. Clinical importance concerns whether the magnitude of a difference matters in the context of the measure and population. The registry record does not provide the estimate or contextual information needed to make either judgment for the primary outcome.
The safety entries provide counts of participants affected and reported serious-event terms. They do not, on their own, establish whether an event was caused by treatment or whether one group had a meaningfully different safety profile. The registry does not report deaths, a comparative safety analysis, or event-relatedness assessments.
Accordingly, the strongest defensible interpretation is about the study’s design and intended measurement, not its efficacy result. The registered question is clear, but the posted results do not answer it in a form that supports a treatment comparison. A reader should not infer benefit, lack of benefit, equivalence, or safety superiority from the completed status or from the enrollment figure.
13. Why This Trial Matters Statistically
This trial is statistically notable as a randomized comparison using a patient-reported continuous symptom score. That design raises familiar questions about how to summarize change, how to compare assigned groups, and how to express uncertainty. The registry specifies the IPSS score range and states that a negative change indicates improvement, which gives the direction of the endpoint an interpretable meaning.
The record also illustrates why the endpoint definition and analysis population belong alongside the result. The primary measure is change from baseline at Week 12, while the modified intent-to-treat population requires randomization, treatment, and at least one post-baseline IPSS measurement. Those definitions determine which observations would contribute to the endpoint analysis. Without group-level outcome results or analyzed sample counts, readers cannot assess how much information supported a treatment comparison.
A randomized design can strengthen interpretation by reducing systematic baseline differences on average, but it does not remove the need to report the actual contrast and its uncertainty. The registry lists enrollment of 315 and a completed status; neither is a substitute for a result. Similarly, a study’s Phase 2 designation does not establish that a treatment effect was found or that any estimate is precise.
The record is also a reminder that outcome multiplicity and missing data are part of interpretation. Several outcomes are registered, while the primary-outcome information is not reduced to a single comparison. The missing-data approach and multiplicity strategy are not reported. Those omissions prevent readers from judging how analysis choices may have influenced an estimate.
Most importantly, statistical interpretation depends on accessible results. The registry gives enough detail to identify the clinical question and endpoint, but not enough to estimate the primary treatment contrast. Separating a clearly specified question from an unavailable answer is essential to avoid treating design information as evidence of a result.
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 principal trial-specific limitation for statistical interpretation is that the registry record does not report a single primary-outcome comparison. No group means, standard deviations, between-group estimate, confidence interval, or p-value for Week 12 IPSS change is reported. The primary question is therefore not answerable from the posted result information.
The primary-outcome information covers multiple categories or time points and is not reduced to one comparison. The record does not explain how those entries relate to the prespecified primary analysis. It also does not report an analysis plan, the statistical model, a multiplicity approach, or a sample-size justification. These details are not reported in the registry record, so the analysis cannot be independently assessed.
The modified intent-to-treat definition is stated, but the number of participants in that population by group is not reported. Neither the amount nor pattern of missing IPSS measurements is given, and the method for handling missing data is not reported. This limits assessment of the analyzed population and of possible sensitivity to incomplete follow-up.
The registry records enrollment of 315 but does not provide the primary endpoint’s analyzed sample size. Enrollment alone cannot establish how many participants contributed to the Week 12 comparison. The study’s completed status also does not supply the missing outcome estimate or its precision.
Safety reporting is limited to participant counts and listed serious-event terms with percentages. Deaths are not reported in the registry record, and event attribution and comparative statistical analyses are not described. These limitations concern what can be established from the registry record; they do not determine what information may exist outside it.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy of Botulinum Toxin Type A to Treat Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia — NCT01107392.
- Registry record last updated 2019-05-03; status last verified 2019-04.
- Results first posted 2014-04-04.
- 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.
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18. Record Summary
This completed, randomized, double-masked, parallel Phase 2 trial compared intraprostatic botulinum toxin Type A with placebo consisting of normal saline for urinary tract symptoms due to benign prostatic hyperplasia. The registry lists enrollment of 315 and names Allergan as sponsor.
The primary outcome was change from baseline in total IPSS at Week 12. The score ranges from 0 to 35, and a negative change indicates improvement. The stated population was randomized and treated participants with at least one post-baseline IPSS measurement.
The registry record does not report a single primary-outcome comparison or its uncertainty, and it lists no analyses. Safety counts are reported, but deaths and event-relatedness are not reported in the registry record. The posted information identifies the study question and design but does not establish the primary treatment contrast.