Clinical Trial to Assess Efficacy, Safety and Tolerability of Botulinum Toxin A (Xeomin®) in Treatment of Expression Wrinkles in the Upper Third of the Face: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Trial to Assess Efficacy, Safety and Tolerability of Botulinum Toxin A (Xeomin®) in Treatment of Expression Wrinkles in the Upper Third of the Face (NCT00986570), a na phase 3 study. The primary outcome is Treatment Success.

2. Clinical Question

This is a within-group question about change after treatment, not a randomized comparison of treatments. A before-and-after assessment can describe the participants’ observed change, but by itself it cannot separate a treatment effect from other explanations for change over time. The open-label design also means the registry records no masking. How wrinkle grades were assessed, and whether assessors were independent, are not reported in the registry record.

3. Trial Design

The registry identifies NCT00986570 as a Phase III open-label clinical trial assessing efficacy, safety and tolerability of Botulinum Toxin A (Xeomin®) for expression wrinkles in the upper third of the face. It records a single-group model and allocation as NA. Masking is listed as none. There is no like-for-like control group, so the design does not support a randomized between-group treatment comparison.

The study description states that the intended population was women aged 30 to 50 years with mild, moderate or severe expression lines. The condition is listed as Skin Aging, and enrollment is recorded as 121. The record names Biolab Sanus Farmaceutica as sponsor. The recorded start was 2009-09, primary completion was 2010-06, and status is completed. These dates describe the trial record; they do not establish the timing of every participant’s treatment or follow-up.

The primary outcome was treatment success, expressed as a percentage of participants. Success was defined as a reduction from any baseline grade to a lower wrinkle grade at Visit 3 (Day 15). The grade categories were absence, mild, moderate and severe. The outcome description identifies baseline and Visit 3 as the assessment points, but does not report the number or percentage meeting the definition.

Only one outcome measure is listed, and the record lists no analyses. It does not report a detailed protocol, dose, administration procedure, inclusion or exclusion criteria, recruitment setting, or complete schedule of visits. The registry also does not report whether the enrollment figure represents everyone treated, everyone assessed for the primary outcome, or an analysis population. Those details matter when interpreting both the endpoint and the safety counts.

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

Reasons for not completing this period:

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 Treatment Success, measured over Baseline (pre-treatment) and Visit 3 (Day 15).

The primary endpoint is treatment success, measured as a percentage of participants. A participant meets the stated definition if their expression-wrinkle grade at Visit 3 (Day 15) is lower than at baseline. The grades are absence, mild, moderate and severe. The endpoint therefore records whether a participant crossed at least one category in the direction of less severe wrinkles; it is not a measure of the size of change within a category or a continuous score.

A categorical endpoint can make a study question understandable: it classifies participants as meeting or not meeting a prespecified threshold. Reporting the percentage alongside a confidence interval would convey both the observed proportion and its statistical precision. The registry describes the intended dispersion measure as a 95% confidence interval, but the estimate and interval are not reported in the registry record.

This endpoint is a before-and-after measure. It can describe the proportion whose grade changed between the assessments, but it does not itself establish that treatment caused the change. There is no control group to show how often a similar change might occur without the intervention or with another treatment. The registry record also does not report who rated the wrinkles, how grading consistency was assessed, or how missing assessments were handled. These details affect how confidently the endpoint can be interpreted.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

In general, a binary endpoint classifies each participant into one of two categories, such as meeting or not meeting a success definition. A percentage expresses the share in the success category, while the denominator indicates how many participants contributed to that calculation. For this trial, the registry defines success as a lower wrinkle grade at Visit 3 (Day 15) than at baseline. It does not report the observed percentage, its denominator for the primary analysis, or a confidence interval.

What does a confidence interval convey?

In general, a confidence interval describes the uncertainty around an estimated quantity under the assumptions of the statistical method. A narrower interval indicates greater precision than a wider interval, but neither width nor position can be assessed without the endpoints of the interval. The registry identifies a 95% confidence interval as the dispersion measure for the primary endpoint, but its bounds are not reported in the registry record. It is therefore not possible to discuss the estimate’s precision, or whether a range of plausible values is compatible with different interpretations.

What does the before-and-after comparison estimate?

In general, a within-person comparison uses each participant’s baseline status and later status to describe change. This can account for stable differences between participants when describing their own change, but it does not create a control condition. Changes could also reflect time, assessment variability, expectations, or other factors. A concurrent comparison group helps estimate what might have happened over the same period in the absence of the intervention or under an alternative intervention. This trial is recorded as single-group, so that comparative contrast is not available.

The endpoint is based on ordered grades rather than a continuous measurement. In general, ordinal categories convey rank order but not necessarily equal spacing: a change between adjacent categories need not represent the same amount of change at every point on the scale. The success definition reduces the result to whether a participant moved to any lower grade. It does not, as written in the registry, retain the full size or pattern of grade changes. The record does not report how the grading scale was applied in practice.

Why do masking and assessment procedures matter?

In general, masking can reduce the influence of expectations on treatment delivery, participant reports, or outcome assessment. Here, the registry lists masking as none and describes the study as open-label. This means the design does not report masked assessment. It does not establish that a bias occurred, but it is relevant when an endpoint depends on grading appearance. The identity and training of assessors, use of standardized photographs, and any independent review are not reported in the registry record.

How should the safety counts be read?

In general, a count of participants affected is different from a count of events: one participant can potentially experience more than one event. The registry provides affected-participant counts for serious and other adverse events. It lists 1 serious adverse event participant among 121 at risk, and 94 participants with other adverse events among 121 at risk. The record does not provide event counts, timing, duration, severity beyond the serious category, or causal assessments. It lists acute gastroenteritis at 0.8% as the top serious term, but gives no further detail on the case.

Safety counts are descriptive. A single-group study cannot make a controlled comparison of event rates against an untreated or alternative-treatment group. In general, causal attribution requires considering timing, clinical context and comparison evidence; the registry entries do not provide enough detail to assess those issues. Deaths are not reported in the registry record.

What can planning calculations say?

In general, sample-size planning asks how many participants might be needed to detect a prespecified effect under stated statistical assumptions. A planning illustration based on an observed effect is not evidence that a trial had that power, and it is not a result of the trial. The record describes a planning approach using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of the observed effect. However, the actual planning outputs are not reported in the registry record. The trial itself is single-group, so a two-arm planning illustration should not be mistaken for its design or for observed comparative evidence.

The record lists no analyses and does not report the statistical analysis plan. It also does not describe the method used to calculate the planned confidence interval, any covariate adjustment, how repeated or missing assessments were handled, or whether sensitivity analyses were performed. Those methods cannot be reconstructed from the endpoint description alone.

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("Xeomin®")
n      <- c(121)
events <- c(108)
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  Xeomin®  121  108  89.3  82.3  94.2  82.5  93.6  82.5  93.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, Treatment Success, and no analyses. It does not report a statistical analysis plan or explain whether additional outcomes were assessed but not entered in the registry. Because the record does not describe multiple inferential tests, there is no basis for determining whether any multiplicity adjustment was planned or used. In general, when several outcomes or repeated tests are evaluated, the chance of a false-positive finding can increase; methods to address this depend on the analysis plan and the role of each endpoint. No such plan is reported in the registry record.

The registry describes the primary endpoint and identifies a 95% confidence interval as the dispersion measure, but does not report the estimate, the interval, or the method for computing it. It also does not report whether the primary assessment was analyzed according to a prespecified population, or how participants without a Visit 3 assessment were treated. Missing outcome data can affect an estimated percentage if participants with missing assessments differ from those assessed. The available record does not allow that possibility to be evaluated.

The enrollment figure is 121, and the safety fields also give 121 at risk for the serious and other adverse-event summaries. The record does not state whether the primary outcome denominator was the same, whether all enrolled participants received treatment, or whether exclusions occurred. It does not report an intention-to-treat, per-protocol or other analysis population. These are important distinctions: the population enrolled, treated, followed and included in an endpoint analysis need not be identical, but their relationship is not described.

The registry’s absence of posted analyses and missing-data details limits reproducibility and assessment of potential bias. No imputation method, sensitivity analysis, interim analysis, or multiplicity strategy is reported in the registry record. Their use or absence cannot be inferred from silence.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0.5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: acute gastroenteritis (0.8%).

The registry records 1 participant affected by a serious adverse event among 121 at risk. It also records 94 participants affected by other adverse events among 121 at risk. These are counts of affected participants, not a complete description of the number, timing or clinical course of events. The record does not define the “other” category in further detail.

Acute gastroenteritis is listed as the top serious adverse-event term, at 0.8%. The registry does not provide a case narrative, timing, severity details beyond the serious classification, or an assessment of whether the event was related to treatment. The listed term should therefore be read as a reported safety entry, not as proof of causation.

In general, safety counts in a single-group study describe what was observed in that study group. Without a concurrent comparator, they do not show whether events occurred more or less often than under another treatment or without treatment. Deaths are not reported in the registry record. The safety information is limited to these entries and does not establish the full range of adverse events monitored or the completeness of follow-up.

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

The registry record describes a Phase III, open-label, single-group study of Xeomin® for expression wrinkles in the upper third of the face. Its primary question concerns the percentage of participants whose wrinkle grade was lower at Visit 3 (Day 15) than at baseline. The definition of success and the assessment timing are stated, but the observed percentage and its 95% confidence interval are not reported in the registry record.

As a result, the primary outcome’s magnitude and precision cannot be assessed from this record. No conclusion about the direction or size of the observed primary result can be drawn without the estimate. The endpoint definition alone does not show how many participants met it.

Even if a before-and-after estimate were available, the single-group design would describe change in the enrolled group rather than isolate the effect of treatment against a concurrent comparison. In general, observed change can reflect the intervention as well as other influences, including time and measurement processes. The open-label design and the absence of reported masking are relevant because the endpoint relies on grading appearance, although the record does not establish that assessment bias occurred.

The safety entries report 1 participant affected by a serious adverse event among 121 at risk and 94 affected by other adverse events among 121 at risk. Acute gastroenteritis is listed as the top serious term at 0.8%. Those entries do not establish a treatment relationship, and the record does not provide details needed to assess causality or compare safety with another group. Deaths are not reported in the registry record.

Accordingly, the registry supports a description of the study’s intended population, design, endpoint definition and limited safety counts. It does not support a quantified appraisal of the primary endpoint, a controlled treatment comparison, or a complete evaluation of statistical methods. The record should not be read as proving benefit or lack of benefit.

14. Why This Trial Matters Statistically

This trial illustrates why a clearly defined endpoint and a reported result are both necessary for statistical interpretation. The registry specifies treatment success as a transition to a lower wrinkle grade at Visit 3 (Day 15), compared with baseline, and identifies a 95% confidence interval as the intended measure of dispersion. Yet it does not report the success percentage or interval. Without those estimates, readers cannot judge the observed outcome or its precision.

The design also illustrates the distinction between within-group change and a comparative treatment effect. A single-group study can describe how participants’ grades changed between two assessments. It cannot, on its own, establish what would have happened over the same period without treatment or under a different treatment. Open-label assessment adds another reason to understand how outcomes were measured, especially for an appearance-based grade. Those assessment details are not reported in the registry record.

The safety fields demonstrate the importance of distinguishing counts of participants affected from counts of events and of avoiding causal interpretation from descriptive entries. The registry gives affected-participant counts and one leading serious-event term, but does not provide event narratives or attribution. These limitations are common reasons that registry summaries should be read alongside complete methods and results when available.

Finally, a listed sample-size planning approach is not a substitute for reporting the trial’s own analysis. Planning assumptions and illustrative calculations answer design questions; they do not fill in an unreported outcome estimate, show observed power, or turn a single-group study into a controlled comparison. The absence of posted analyses and analysis-population details leaves important questions about precision, missing outcomes and reproducibility unresolved.

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.

Several limitations are specific to the information recorded for this trial. The primary endpoint is described, but its observed percentage and 95% confidence interval are not reported in the registry record. As a result, neither the size of the observed change nor its precision can be assessed.

The study is open-label and single-group, with masking listed as none and allocation listed as NA. There is no control group for a concurrent comparison. The primary endpoint uses a subjective grading of wrinkle appearance, but the identity of assessors, grading procedures, consistency checks and any independent assessment are not reported in the registry record. This prevents evaluation of how measurement decisions may have influenced the result.

The registry lists enrollment of 121 but does not specify the primary endpoint analysis population or denominator. It does not report the number with a Visit 3 assessment, the handling of missing or incomplete assessments, or whether any participants were excluded from analysis. The link between enrollment and the safety populations is also not described beyond the at-risk counts.

The record lists one outcome measure and no analyses. It does not report a detailed statistical analysis plan, the confidence-interval method, multiplicity procedures, sensitivity analyses, or interim analyses. Their use cannot be assumed either way. The record also does not describe eligibility criteria in detail, dose, administration, follow-up beyond the primary assessment, or event-level safety information. These gaps limit assessment of study conduct, generalizability, and reproducibility.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Trial to Assess Efficacy, Safety and Tolerability of Botulinum Toxin A (Xeomin®) in Treatment of Expression Wrinkles in the Upper Third of the Face — NCT00986570.
• Registry record last updated 2015-12-11; status last verified 2015-11.
• Results first posted 2010-12-06.
• 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

NCT00986570 is a completed Phase III, open-label, single-group trial sponsored by Biolab Sanus Farmaceutica. The registry records a start of 2009-09, primary completion in 2010-06, and enrollment of 121. It concerns Botulinum Toxin A (Xeomin®) for expression wrinkles in the upper third of the face.

The primary outcome is the percentage of participants with a lower wrinkle grade at Visit 3 (Day 15) than at baseline. The registry defines the categories as absence, mild, moderate and severe, and identifies a 95% confidence interval as the dispersion measure. The observed endpoint estimate and interval are not reported in the registry record.

Safety entries include 1 participant affected by a serious adverse event among 121 at risk and 94 affected by other adverse events among 121 at risk. Acute gastroenteritis is listed as the top serious term at 0.8%. Deaths and analysis details are not reported in the registry record.