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 Vismodegib for Treatment of Basal Cell Carcinoma (NCT01543581), a randomized phase 2 study. The primary outcome is Mohs Micrographic Surgery (MMS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01543581 |
| Phase | Phase 2 |
| Condition | Basal Cell Carcinoma |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Abel Torres, MD |
| Results posted | Yes |
2. Clinical Question
Population
People with basal cell carcinoma were the intended population. The registry record gives an enrollment of 3, but does not report further eligibility details or describe the characteristics of participants who entered each arm.
Intervention
The intervention was oral vismodegib, 150mg per day for 12 weeks, as adjunctive treatment before surgery.
Comparator
The comparator was an inactive placebo. The study is described as placebo-controlled, randomized, double blind, and parallel-group.
Primary question
The primary objective was to assess efficacy using Mohs micrographic surgery (MMS) at the end of treatment. The registry defines the primary outcome as the diameter, in mm, of the final surgical wound after MMS. It does not report the observed outcome values or an analysis comparing vismodegib with placebo.
The clinical question is whether the pre-surgical treatment groups differed in the surgical wound-size measure when excision reached tumor-free tissue margins. The record also describes safety as a secondary objective and lists Complete Response Rate as a secondary outcome. It further states that the study sought to assess how often and in what types of lesions pre-surgical vismodegib treatment resulted in complete tumor eradication. Those aims describe what the trial intended to investigate; the registry record does not report results for them.
3. Trial Design
This was a randomized, double-blind, parallel-group phase 2 study comparing oral vismodegib with an inactive placebo before Mohs micrographic surgery for basal cell carcinoma. The registry lists an enrollment of 3 and a completed status. The start is recorded as 2012-05, and primary completion as 2013-06. The sponsor is listed as Abel Torres, MD.
The vismodegib arm is described as receiving 150mg per day for 12 weeks. The record identifies the comparator as inactive placebo but does not give a matching placebo schedule or other administration details. It also does not report the randomization sequence, allocation concealment procedures, or how masking was maintained. Double masking is recorded, but the roles of the people masked are not specified in the registry record.
The primary endpoint was assessed through MMS after treatment. The registry states that excision was performed within two weeks after the last day of treatment. It defines the endpoint as the diameter of the final wound, measured immediately after surgery reached tumor-free tissue margins. The description says the pre-treatment lesion outline plus an additional concentric 2mm margin was removed to establish a consistent measure.
The record lists two outcome measures and zero analyses. It does not report participant counts by randomized arm, baseline characteristics, treatment adherence, withdrawals, or the number included in the primary endpoint analysis. The absence of those details in the registry record limits assessment of how the randomized groups were formed and analyzed.
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: One subject signed the consent and was enrolled and completed the study. Two others signed the consent but were unable to continue their enrollment as one found out that he had Parkinsons Disease and the other could not arrange for transportation.
Overall Study
| Stage | Vismodegib | Inactive Placebo |
|---|---|---|
| STARTED | 1 | 0 |
| COMPLETED | 1 | 0 |
| NOT COMPLETED | 0 | 0 |
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 | Vismodegib |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 1 |
| Region of Enrollment: United States | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Mohs Micrographic Surgery (MMS), measured over The Mohs surgical excision of the target tumor was performed within two weeks, after the last day of treatment..
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | mm |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the diameter, in mm, of the final wound after Mohs micrographic surgery. The registry says the measurement was taken immediately after the surgeon reached tumor-free tissue margins. It describes an objective measurement approach using the outlined pre-treatment lesion and an additional concentric 2mm margin as the basis for the wound-size measure.
This endpoint represents the size of the surgical wound required to reach tumor-free margins after the pre-surgical treatment period. Comparing the measured wound sizes between randomized groups could address whether the groups differed on this particular surgical measure. It is not, by itself, a complete account of tumor response, safety, recurrence, or other clinical outcomes.
The registry record gives no observed wound-size values, group summaries, uncertainty estimates, or comparative result. It also does not report an outcome population or an analysis method for this endpoint. Consequently, the endpoint’s definition can be described, but the posted record does not establish the size or precision of any difference between treatment groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study was intended to compare vismodegib with placebo before Mohs micrographic surgery, using final wound diameter as its primary endpoint. The registry record reports an enrollment of 3, but does not provide the primary outcome values for either arm. It lists zero analyses. Therefore, there is no reported group comparison on which to base an estimate of the treatment-group difference or its uncertainty.
The record’s definition of the endpoint is detailed: it is the final wound diameter in mm, measured after MMS reached tumor-free tissue margins, with surgery performed within two weeks after the last treatment day. That description identifies what was intended to be measured and when. It does not show what was observed. The record also lists Complete Response Rate as a secondary outcome, but does not report its result.
The safety entries report 0 serious adverse events among 1 at risk in the vismodegib group, and 1 other adverse event among 1 at risk in that group. For inactive placebo, the record reports 0 at risk and 0 affected for both serious and other adverse events. These entries are limited counts, not a comparative safety analysis. The record does not explain why the adverse-event counts at risk differ from the overall enrollment, or how participants were distributed across randomized arms. It does not report deaths; that information is not reported in the registry record.
No confidence interval or p-value for the primary endpoint is reported in the registry record. Without those results, the size and precision of a group contrast cannot be assessed. A lack of a reported result should not be interpreted as evidence that the groups were equivalent, or that there was no difference. It means the registry record does not include the outcome analysis needed to evaluate that question.
The small enrollment recorded in the registry is important context for reading the entry, but it cannot substitute for outcome data. Enrollment alone does not reveal how many participants contributed to the primary endpoint, what the wound measurements were, or how much uncertainty would surround a comparison. Those details are not reported in the registry record.
9. Statistical Methods Explained
The registry describes a randomized, double-blind, parallel-group trial. Those design labels describe how the comparison was intended to be organized; they do not supply the missing outcome results or statistical analysis. The record lists zero analyses, so no inferential result for the primary endpoint is available to interpret.
What randomization contributes
In general, random assignment is used to make treatment groups comparable with respect to known and unknown participant characteristics, on average. It supports a causal comparison when the assignment process is preserved and the analysis follows an appropriate plan. Randomization does not guarantee that a small study will have balanced groups, and it does not make missing outcome data or departures from treatment irrelevant. The registry record does not describe its randomization procedure, allocation concealment, arm sizes, or participant-level flow.
What masking contributes
In general, masking can reduce the influence of knowledge about assigned treatment on participant behavior, clinical decisions, or outcome assessment. The record calls the study double blind, but does not specify who was masked or how masking was maintained. The primary outcome is a measured wound diameter after surgery. The record’s measurement description establishes the intended procedure, but the registry does not report whether outcome assessors were masked or provide any assessment of measurement reliability.
How to interpret a continuous measurement
In general, a measured endpoint such as wound diameter can be summarized using a group average or another prespecified summary, with an estimate of uncertainty. A treatment comparison should report the group values and the contrast between them in a form that reflects the analysis plan. A confidence interval expresses a range of values compatible with the data and model used; a narrower interval indicates greater precision than a wider interval. A p-value, when used, describes how unusual the data would be under a specified null model. Neither a confidence interval nor a p-value is reported for this study’s primary endpoint in the registry record.
The record’s primary endpoint uses mm as its unit and defines the timing and surgical context of measurement. However, it does not report a summary measure, a treatment contrast, an uncertainty measure, or the statistical model. It is therefore not possible to tell from the registry record whether the endpoint was analyzed as an individual-level measurement, how any distributional features were handled, or whether adjustment was planned.
Why the analysis plan matters
In general, a prespecified statistical plan helps establish which outcome, population, summary measure, and comparison will answer the trial question. It can also state how missing data, protocol deviations, and multiple outcomes will be addressed. A plan is especially important when more than one outcome or analysis could be considered, because selecting an analysis after seeing the results can affect interpretation. The statistical plan, model details, and multiplicity approach are not reported in the registry record.
The record names a primary outcome and lists Complete Response Rate as a secondary outcome. It also describes safety as a secondary objective. Those registry entries identify intended outcome domains, but they do not show which analysis populations or statistical procedures were used. The record lists zero analyses, so there is no reported basis for judging whether the results followed a prespecified plan.
Planning assumptions are not trial findings
In general, sample-size planning uses assumptions about the effect to be detected, variability, significance level, allocation, and statistical method. The registry’s planning illustration is described as using a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect expressed as a stated fraction of the observed effect. These assumptions describe a planning exercise, not results from a trial analysis. Any participant counts generated under such assumptions are planning illustrations, not observed power.
The registry does not report the trial’s own sample-size justification. It also does not provide the primary endpoint results needed to evaluate the observed effect in context. The planning assumptions should therefore not be read as evidence that the trial was designed or powered according to those values, nor as evidence about the precision of the actual result.
In general, over-dispersion means that observed variability exceeds what a chosen statistical model assumes. When it is present, a model that fails to account for it can understate uncertainty. The registry does not report a fitted model or distributional diagnostics for this endpoint, so there is no basis to assess whether over-dispersion was relevant or how variability was handled.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies MMS as the primary outcome and lists Complete Response Rate as a secondary outcome, with safety also described as a secondary objective. It does not report a multiplicity strategy, such as whether any adjustment was planned across outcomes or analyses. Because no analyses are listed, the record does not show which comparisons were conducted or how their interpretation was controlled.
Missing-data methods are not reported in the registry record. The entry does not state how missing wound measurements, incomplete treatment, or withdrawal from follow-up were handled. It also does not report the number of participants with available primary endpoint data or reasons for any unavailable measurements. The registry enrollment of 3 alone does not establish how many contributed to each outcome.
The analysis populations are not reported in the registry record. It does not say whether the primary analysis was intended to include all randomized participants, only those who received treatment, or another defined group. It also does not describe exclusions, protocol deviations, or how participants were assigned to an analysis population.
These omissions matter because estimates can depend on which participants and outcomes are included and how missing information is handled. Without a prespecified approach and participant-level accounting, readers cannot assess whether the reported safety counts and intended efficacy endpoint represent the same population. The registry record contains no primary endpoint analysis with which to evaluate these issues.
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 |
|---|---|---|---|
| Vismodegib | 0 | 1 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Vismodegib | 1 of 1 |
| Inactive Placebo | 0 of 0 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Vismodegib | Inactive Placebo |
|---|---|---|---|
| Chest Cold | Respiratory, thoracic and mediastinal disorders | 1 of 1 | 0 of 0 |
| Elevated AST | Blood and lymphatic system disorders | 1 of 1 | 0 of 0 |
| MRSA recurrence | Skin and subcutaneous tissue disorders | 1 of 1 | 0 of 0 |
| Upper Respiratory Infection | Respiratory, thoracic and mediastinal disorders | 1 of 1 | 0 of 0 |
| hair loss | Skin and subcutaneous tissue disorders | 1 of 1 | 0 of 0 |
| leg cramps | Musculoskeletal and connective tissue disorders | 1 of 1 | 0 of 0 |
| loss of taste sensation | Gastrointestinal disorders | 1 of 1 | 0 of 0 |
The registry reports 0 serious adverse events among 1 at risk in the vismodegib group. It reports 1 other adverse event among 1 at risk in that group. For inactive placebo, it reports 0 at risk and 0 affected for serious and other adverse events. No serious adverse-event terms are listed. Deaths are not reported in the registry record.
These are registry counts, not a comparative safety analysis. The placebo entries with 0 at risk do not provide an exposed denominator for assessing adverse-event frequency in that group. A count of 0 affected among 0 at risk should not be read as evidence of no risk. In general, safety counts are most interpretable when the number of participants at risk, follow-up period, event definitions, and method of collection are clear for each group.
The registry does not explain why the adverse-event denominators are limited to 1 in the vismodegib group and 0 in the placebo group, despite an overall enrollment of 3. It also does not report the duration of safety follow-up or details about how adverse events were collected. The reported entries therefore offer only a narrow description of the safety data recorded, not a basis for comparing safety between groups.
12. What the Result Does, and Does Not, Mean
This registry record describes a randomized, double-blind comparison of oral vismodegib and inactive placebo before Mohs micrographic surgery for basal cell carcinoma. It specifies a primary surgical endpoint: final wound diameter after excision reached tumor-free tissue margins. It also records a completed study with an enrollment of 3 and gives the intended vismodegib regimen as 150mg per day for 12 weeks.
The record does not report the observed primary endpoint values, a comparison between groups, confidence intervals, or p-values. It therefore does not establish whether the groups differed in final wound diameter, how large any difference was, or how precisely an effect was estimated. The listed secondary outcome, Complete Response Rate, also has no reported result in the registry record.
The safety entries include limited counts, with different at-risk totals for the two groups. They should be read as recorded counts rather than evidence of a treatment effect or a definitive comparison. The entry does not explain the denominators or report deaths.
In general, a randomized design can support a comparison when outcomes are observed and analyzed according to a clear plan. But design labels alone cannot answer the clinical question. The registry entry describes the study’s intended comparison and measurement, while leaving the findings and much of the analysis process unreported. No conclusion about efficacy or comparative safety can be drawn from this record alone.
13. Why This Trial Matters Statistically
This trial is statistically notable because its registry entry describes a randomized, double-blind design and a concrete surgical endpoint, while reporting an enrollment of 3 and no analyses. The contrast between a defined endpoint and absent results illustrates why trial design information and outcome evidence are distinct. A careful endpoint definition tells readers what investigators intended to measure; it does not tell them what the groups experienced.
The wound-size measure is tied to a specified surgical point: the final wound after MMS reached tumor-free tissue margins. The record also describes a consistent measurement basis using the pre-treatment lesion outline plus an additional concentric 2mm margin. Such operational detail can help make an endpoint interpretable, but it does not replace reporting group measurements, an analysis method, and uncertainty.
The sparse safety entries also show why denominators matter. An adverse-event count is difficult to interpret without clear information about how many participants were observed and for how long. The registry lists different at-risk counts for the two groups and does not explain them, so the entries cannot support a meaningful comparison.
More broadly, the record demonstrates the limits of relying on design labels, enrollment, or outcome definitions when results are absent. Statistical interpretation requires the observed data, the comparison used, and enough information about the analysis population and methods to understand how the estimate was produced. Those elements are not reported for the primary outcome in the registry record.
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 main trial-specific limitation of the registry entry is that it contains no reported primary endpoint values or analysis. Although the endpoint is described in detail, no wound-size summaries, group contrast, confidence interval, or p-value are reported. The registry lists zero analyses, so the intended efficacy question cannot be evaluated from the posted results.
The recorded enrollment is 3, but the number assigned to each arm and the number contributing to each outcome are not reported in the registry record. Baseline characteristics, participant flow, treatment adherence, withdrawals, and reasons for missing outcomes are also not reported. These omissions prevent a fuller assessment of the groups and the analysis population.
The safety entries have limited at-risk counts and do not explain how those counts relate to enrollment or arm assignment. The record does not report the duration of safety follow-up, collection methods, or deaths. These gaps constrain interpretation of the event counts.
Important design and analysis details are also absent. The registry record does not report the randomization procedure, allocation concealment, the identities of people masked, the statistical analysis plan, a sample-size justification, handling of missing data, or a multiplicity strategy. It does not report whether the primary endpoint analysis used any adjustment or how the endpoint distribution was assessed. These details should not be inferred from the trial’s design labels or from the planning assumptions recorded for an illustration.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Vismodegib for Treatment of Basal Cell Carcinoma — NCT01543581.
- Registry record last updated 2014-09-26; status last verified 2014-09.
- Results first posted 2014-09-26.
- 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
The registry describes a completed, randomized, double-blind, parallel-group phase 2 study of oral vismodegib versus inactive placebo before Mohs micrographic surgery for basal cell carcinoma. Enrollment is recorded as 3. The vismodegib regimen is listed as 150mg per day for 12 weeks.
The primary endpoint is final wound diameter in mm after MMS reached tumor-free tissue margins. The registry lists Complete Response Rate as a secondary outcome and describes safety as a secondary objective. It reports zero analyses and does not include primary endpoint results or a comparative efficacy analysis.
Safety entries record 0 serious adverse events and 1 other adverse event among 1 at risk in the vismodegib group. The inactive placebo entries report 0 at risk and 0 affected. Deaths are not reported in the registry record. The record does not provide enough outcome or analysis information to assess comparative efficacy or safety.