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 A Study to Evaluate the Safety and Efficacy of Tazarotene Foam, 0.1%, in Subjects With Common Facial Acne - W0260-301 (NCT01017146), a randomized phase 3 study. The primary outcome is Absolute Change in Lesion Counts (LCs) From Baseline to Week 12.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01017146 |
| Phase | Phase 3 |
| Condition | Acne Vulgaris |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 744 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Stiefel, a GSK Company |
| Results posted | Yes |
2. Clinical Question
Population
Participants with acne vulgaris were enrolled. The primary endpoint was described for the Intent-to-Treat (ITT) Analysis Set: randomized participants who were dispensed study product. The registry record reports enrollment of 744, but that enrollment figure should not be read as the number included in every endpoint analysis.
Intervention
The intervention was tazarotene foam, 0.1%. The study assessed its safety and efficacy in subjects with common facial acne, and lesion counts were confined to the face.
Comparator
The comparison group received vehicle foam. The registry identifies the study as vehicle-controlled and describes a parallel-group design.
Primary question
The primary endpoint was absolute change in lesion counts from baseline to Week 12. The registry defines that change as the Week 12 value minus the baseline value. The posted results needed to quantify and compare the change between the treatment groups are not reported in the registry record, so the treatment contrast and its precision cannot be assessed from this record.
The clinical question is whether facial lesion counts changed over the study period in participants assigned to tazarotene foam compared with participants assigned to vehicle foam. The endpoint includes inflammatory and non-inflammatory lesions, rather than a single lesion subtype. The study also listed secondary outcomes addressing lesion-count changes at other time points, time to a reduction in total lesion counts, global assessment scores, and quality-of-life scores. Those outcomes provide additional planned areas of evaluation, but their mention does not establish what the results were. The registry record describes the purpose as assessing both safety and efficacy; it does not report a numerical primary endpoint result or a treatment-group comparison for that endpoint.
3. Trial Design
The registry describes a Phase 3, randomized, multicenter, double-blind, vehicle-controlled, parallel-group study. Participants were assigned to tazarotene foam, 0.1%, or vehicle foam. The masking entry is “QUADRUPLE.” These labels describe features of the recorded design; the registry record does not provide further detail about who was masked or how masking was maintained.
Enrollment is reported as 744. The listed study start is 2009-10, primary completion is 2010-11, and status is completed. Those dates describe the record’s timing fields and do not supply endpoint follow-up details beyond the primary endpoint timeframe, which is baseline and Week 12. The sponsor is Stiefel, a GSK Company.
Random allocation is intended, as a general design principle, to reduce systematic differences between groups at assignment. A parallel-group design means the assigned groups are compared over the study rather than participants crossing between treatments. Blinding is intended to limit the influence of knowledge of assignment on participant experience, clinical assessment, or study conduct; the particular masking procedures are not reported in the registry record. Vehicle control helps define the comparison as tazarotene foam versus the foam vehicle, rather than versus no study product.
The primary endpoint was an average change in lesion counts, and the record identifies the parameter as a mean with standard deviation as the dispersion measure. It describes an ITT Analysis Set of randomized participants dispensed study product and says missing final values were handled using last observation carried forward (LOCF). The record does not report the number analyzed for the primary endpoint, the outcome values by group, or the treatment contrast. It also does not report the statistical test or model used for the primary comparison, a confidence interval, or a p-value. The listed design features alone cannot establish the magnitude or precision of the treatment-group difference.
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 | Tazarotene Foam | Vehicle Foam |
|---|---|---|
| STARTED | 372 | 372 |
| COMPLETED | 306 | 333 |
| NOT COMPLETED | 66 | 39 |
Reasons for not completing this period:
| Reason | Tazarotene Foam | Vehicle Foam |
|---|---|---|
| Adverse Event | 11 | 1 |
| Lost to Follow-up | 14 | 14 |
| Noncompliance with Study Product | 1 | 1 |
| Withdrawal by Subject | 32 | 16 |
| Relocation | 0 | 4 |
| Pregnancy | 2 | 1 |
| Protocol Violation | 2 | 0 |
| Took Excluded Medication | 2 | 0 |
| Did Not Meet Eligibility Criteria | 1 | 2 |
| Change in Work Situation | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT) Analysis Set: all randomized participants who were dispensed study product. Calculation was based on the last observation carried forward (LOCF) imputation method for missing data, in which missing final values of the outcome variable are replaced by the last known value before the participant was lost to follow up.
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 | Tazarotene Foam | Vehicle Foam | Total |
|---|---|---|---|---|
| Participants analysed | 371 | 372 | 743 | |
| Age, Continuous: Years | Years | 18.2 (SD 5.7) | 18.6 (SD 6.4) | 18.4 (SD 6.1) |
| Gender: Female | Participants | 182 | 192 | 374 |
| Gender: Male | Participants | 189 | 180 | 369 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | participants | 12 | 3 | 15 |
| Race/Ethnicity, Customized: Asian | participants | 11 | 4 | 15 |
| Race/Ethnicity, Customized: Black | participants | 53 | 50 | 103 |
| Race/Ethnicity, Customized: Native Hawaiian or Other Pacific Islander | participants | 0 | 1 | 1 |
| Race/Ethnicity, Customized: White | participants | 285 | 307 | 592 |
| Race/Ethnicity, Customized: Mixed Race | participants | 10 | 7 | 17 |
6. Primary Endpoint
The registry lists the primary outcome as Absolute Change in Lesion Counts (LCs) From Baseline to Week 12, measured over Baseline (Week 0/Day 1) and Week 12.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | lesion counts |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is absolute change in lesion counts from baseline to Week 12. Lesion counts included inflammatory lesions—papules, pustules, and nodules—and non-inflammatory lesions—open and closed comedones. Total lesions were calculated from the inflammatory and non-inflammatory lesion counts. Assessment was confined to the face, including the forehead, nose, cheeks, and chin.
Change was defined as the Week 12 value minus the baseline value. Under that definition, a negative change indicates fewer counted lesions at Week 12 than at baseline, while a positive change indicates more. This describes the direction of the endpoint, not the results for either study group.
A combined count can provide a summary of lesion burden across the specified lesion types. Using change from baseline relates the follow-up value to each participant’s starting value, and comparing average changes between randomized groups can address whether their observed changes differed. The registry specifies the mean as the summary parameter and standard deviation as the measure of dispersion. The standard deviation describes variability among participant-level values; it is not a measure of uncertainty in the estimated group mean.
The registry record does not report the group means, the between-group estimate, or a confidence interval for the primary endpoint. Consequently, the endpoint definition is available, but the size and precision of the observed treatment contrast are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record defines a clinically interpretable count-based endpoint: change in facial inflammatory and non-inflammatory lesion counts from baseline to Week 12. It also states the direction of subtraction, which matters when reading a change score. A negative value would represent a lower count at follow-up than at baseline, whereas a positive value would represent a higher count. These are general interpretations of the endpoint definition; they do not describe an observed result in this trial.
The registry record does not report the primary outcome values by group or a direct comparison between tazarotene foam and vehicle foam. It therefore does not establish the direction or magnitude of the group contrast, how variable the results were, or how precisely any contrast was estimated. A p-value and confidence interval for this primary comparison are also not reported in the registry record. Without those results, the design and endpoint description cannot support a conclusion about the statistical evidence for a difference.
Enrollment of 744 is a trial-level record entry, not an endpoint-specific analysis count. The record defines the primary population as randomized participants who were dispensed study product, but it does not report the number included in the primary analysis. Nor does it report how many participants contributed observed Week 12 counts or how missing values were distributed between groups.
Safety figures are reported separately from the primary lesion-count endpoint. Serious adverse events affected 1 participant in each group, with 371 at risk in the tazarotene foam group and 372 at risk in the vehicle foam group. Other adverse events affected 88 participants in the tazarotene foam group and 17 in the vehicle foam group, with the same respective at-risk counts of 371 and 372. These counts should be read as the registry’s reported safety figures, not as a substitute for the missing primary efficacy comparison. Death counts are not reported in the registry record.
The record lists secondary measures including lesion-count changes at Weeks 2, 4, 8, and 12; global assessment outcomes; time to a 50 Percent Reduction in Total Lesion Counts; and quality-of-life measures. Listing an outcome does not show that its analysis was statistically significant or that it supports the primary endpoint. Results for these secondary outcomes are not reported in the registry record in the registry record for this analysis.
Any interpretation should therefore distinguish the trial’s planned comparison and outcome definitions from evidence about what happened. The randomized, masked, vehicle-controlled design describes how the study was structured. The numerical primary endpoint results needed to quantify the comparison are not reported in the registry record.
9. Statistical Methods Explained
The registry identifies the primary measure as a mean of a continuous outcome, with standard deviation as its dispersion measure. The endpoint is participant-level change in lesion counts between baseline and Week 12. The record defines the ITT Analysis Set as randomized participants who were dispensed study product and says that LOCF was used to replace missing final outcome values with the last known value before the missing final value.
Why summarize change with a mean?
In general, a mean summarizes the central value of a set of numerical observations. For a change endpoint, each participant’s follow-up value is compared with that participant’s baseline value before group-level summaries are considered. A comparison of group means can describe the average difference in change between assigned groups. The registry names the mean as the parameter, but the group means and the between-group estimate are not reported in the registry record.
The standard deviation describes how spread out individual observations are around the mean. It is not the same as a standard error or a confidence interval: those latter quantities concern uncertainty in an estimated parameter. The registry record does not report a confidence interval for the primary comparison, so the precision of a treatment contrast cannot be assessed from the endpoint summary information alone. No distributional description of the observed change scores is reported in the registry record.
What does randomization contribute?
As a general statistical principle, random assignment can help balance measured and unmeasured participant characteristics across groups on average. It supports an interpretation of a between-group contrast as a comparison of assigned treatment strategies, subject to the analysis population, missing-data handling, adherence, and other design and conduct considerations. Randomization does not guarantee that the groups are identical in every characteristic in a particular trial. The registry record does not report baseline balance details or adherence information for this endpoint.
The study is recorded as double-blind and quadruple-masked in its design fields, with a vehicle-controlled parallel-group structure. In general, masking can reduce the risk that knowledge of assignment influences outcome assessment or study behavior. Vehicle control specifies the comparator as vehicle foam. The registry record does not describe masking procedures or provide enough detail to assess whether masking was maintained.
How should the primary estimate be read?
The subtraction order is Week 12 minus baseline. As a general reading rule, a negative mean change indicates a lower average count at follow-up than at baseline, and a positive mean change indicates a higher average count. To assess the randomized comparison, the relevant quantity would be the difference between the groups’ mean changes, accompanied by an uncertainty interval and an appropriate analysis. The registry record does not report those primary comparison results, and no test or model is specified in the available record.
Standard deviations help describe participant-to-participant variability, but a group mean alone would not show that variability. A confidence interval, in general, expresses a range of values compatible with the data and the analysis assumptions at a stated confidence level. It conveys precision, not the probability that a particular treatment effect is true. No confidence interval or confidence level for the primary treatment contrast is reported in the registry record.
What does LOCF imply?
LOCF is an imputation approach: when a final outcome value is missing, the last known value is carried forward to stand in for that missing value. In general, this creates an analysis dataset with imputed final values, but it relies on assumptions about how the unobserved outcome relates to the last observed value. If participants’ outcomes would have changed after their last measurement, carrying that earlier value forward may not represent their actual Week 12 status. The direction and size of any resulting bias depend on the missingness and outcome patterns; those patterns are not reported in the registry record. No sensitivity analysis for missing data is reported in the registry record.
How should planning illustrations be understood?
The record describes a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is expressed as a stated fraction of the observed effect. Such calculations are prospective planning illustrations, not observed power for the completed trial. The record also distinguishes participant-per-arm quantities for non-time-to-event calculations from total-event quantities for time-to-event calculations. Specific planning estimates and the fractions used are not reported in the registry record details, so no particular sample-size target can be interpreted.
General statistical interpretation also depends on a prespecified analysis plan, including the estimand, test or model, handling of missing data, and multiplicity strategy. Those details are not reported in the registry record. The design description and endpoint definition should therefore not be mistaken for a complete account of the statistical analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple secondary outcomes, including lesion-count changes at several follow-up times, global assessment outcomes, and quality-of-life measures. It reports 16 outcome measures and 7 analyses. When multiple outcomes or time points are examined, general statistical practice recognizes that the chance of at least one apparently unusual result can increase if each comparison is interpreted separately. Procedures such as prespecified outcome hierarchies or multiplicity adjustments can address that issue, but no such strategy is reported in the registry record. The record also does not identify which secondary comparisons, if any, were designated for formal confirmatory inference.
The primary population is described as randomized participants who were dispensed study product. The record says the primary outcome calculation used LOCF for missing final values. In general, LOCF substitutes the last known outcome for a missing final value; that approach can be sensitive to why data are missing and whether the outcome would have changed after the last observation. The amount and pattern of missing outcome data, and any sensitivity analyses, are not reported in the registry record.
The enrollment entry of 744 does not establish the number contributing data to each analysis. The primary analysis count and the numbers with observed baseline and Week 12 assessments are not reported in the registry record. The statistical plan, including any other analysis populations or adjustments, is also not reported in the registry record. These omissions limit assessment of how the posted endpoint summaries, if available, relate to the intended analysis population and how robust conclusions would be to missing-data or multiplicity choices.
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 |
|---|---|---|---|
| Tazarotene Foam | 1 | 371 | 0.3% |
| Vehicle Foam | 1 | 372 | 0.3% |
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 |
|---|---|
| Tazarotene Foam | 88 of 371 |
| Vehicle Foam | 17 of 372 |
Most frequent serious adverse event terms
| Event term | Organ system | Tazarotene Foam | Vehicle Foam |
|---|---|---|---|
| Brain contusion | Injury, poisoning and procedural complications | 0 of 371 | 1 of 372 |
| Intracranial pressure increased | Nervous system disorders | 0 of 371 | 1 of 372 |
| Adjustment disorder with mixed disturbance of emotion, condu | Psychiatric disorders | 1 of 371 | 0 of 372 |
| Depression | Psychiatric disorders | 1 of 371 | 0 of 372 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Tazarotene Foam | Vehicle Foam |
|---|---|---|---|
| Application Site Irritation | General disorders | 66 of 371 | 15 of 372 |
| Application Site Dryness | General disorders | 22 of 371 | 2 of 372 |
Serious events with the highest arm-level rate: adjustment disorder with mixed disturbance of emotion, condu (0.3%), depression (0.3%), brain contusion (0.3%), intracranial pressure increased (0.3%).
The registry reports serious adverse events for the tazarotene foam and vehicle foam groups separately. The at-risk counts are 371 and 372, respectively, and serious adverse events affected 1 participant in each group. These are counts, not a full account of event duration, severity beyond the serious classification, relatedness to study product, or recurrent events. Those additional details are not reported in the registry record.
Other adverse events affected 88 participants in the tazarotene foam group and 17 in the vehicle foam group. The corresponding at-risk counts are 371 and 372. The registry record does not provide additional definitions or event-level detail for these “other” figures in the registry entries. Death counts are not reported in the registry record.
The listed serious-event terms are “Adjustment disorder with mixed disturbance of emotion, condu,” “Depression,” “Brain contusion,” and “Intracranial pressure increased”; each is listed at 0.3%. These entries should be read as registry-listed terms and percentages, not as evidence of causation or comparative risk. The record does not report enough detail to infer whether an event was considered related to treatment. Safety counts should be interpreted separately from the lesion-count efficacy endpoint.
12. What the Result Does, and Does Not, Mean
The record establishes the study question, the randomized vehicle-controlled comparison, the primary endpoint definition, and selected safety counts. It documents that facial lesion counts were to be assessed at baseline and Week 12, with change defined as follow-up minus baseline. It also identifies a mean-based summary and standard deviation, and names an ITT Analysis Set with LOCF handling for missing final values.
Those details do not establish the primary result. Group-specific lesion-count changes and the between-group comparison are not reported in the registry record. No confidence interval or p-value for that comparison is reported in the registry record. It is therefore not possible from these registry entries to describe the magnitude, direction, or precision of the primary treatment contrast, or to characterize its statistical evidence.
Likewise, the presence of secondary outcomes in the record does not establish their results. The safety counts provide a limited view of reported adverse events, but they do not on their own establish causation, comparative risk, or the full safety profile. The reported at-risk counts and affected-participant counts should not be converted into additional measures or interpreted beyond the registry’s stated categories.
In general, a randomized, masked, vehicle-controlled design can support a structured comparison when its analyses are fully reported and their assumptions are considered. The design label alone is not a treatment-effect estimate. Interpretation also depends on analysis details, missing data, outcome variability, and multiplicity handling. Several of these details are not reported in the registry record.
The appropriate statistical reading is consequently limited: the trial’s endpoint and design can be described, but the primary results needed to evaluate the observed difference cannot be characterized. Absence of those results in the registry record is not evidence that the groups were the same, nor is it evidence of a particular benefit or harm.
13. Why This Trial Matters Statistically
This trial illustrates why a clear endpoint definition and a reported treatment contrast are both necessary for statistical interpretation. The primary measure is specific about what was counted, where it was counted, when it was assessed, and how change was calculated. It combines inflammatory and non-inflammatory facial lesions and defines the Week 12 change relative to baseline. Those details make the intended outcome understandable.
The randomized, masked, vehicle-controlled parallel-group design also describes a framework for comparing assigned groups. In general, randomization supports fair comparison by reducing systematic allocation differences, while masking can reduce influence from knowledge of assignment. These are design strengths in principle, but their presence does not substitute for reporting the outcome estimates or the analysis used to obtain them.
Statistical interpretation requires both an estimate and information about its uncertainty. A mean and standard deviation describe different features of outcome data; a confidence interval for the between-group contrast would communicate precision. The registry record identifies the summary approach but does not report the primary group results or contrast. This leaves the central statistical question unresolved in the available record.
The study also underscores the importance of transparent handling of missing outcomes and multiple assessments. LOCF is named, but the extent and pattern of missingness and sensitivity analyses are not reported. Multiple secondary outcomes and analyses are listed, while a multiplicity strategy is not reported in the registry record. These details matter when judging how robust and confirmatory findings would be.
Thus, the trial is statistically informative as an example of a defined randomized comparison with a specified count-based endpoint, but the registry record does not supply the numerical primary result required to quantify that comparison.
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 limitation for interpreting efficacy is that the primary outcome values and treatment-group comparison are not reported in the registry record. The record gives the endpoint definition but not the estimate, its uncertainty, or a p-value. The direction and precision of the observed contrast therefore cannot be assessed.
The primary analysis population is described, and LOCF is identified for missing final values, but the number analyzed and the extent or pattern of missing data are not reported in the registry record. The assumptions behind the imputation cannot be evaluated without information on missingness and later outcomes. Sensitivity analyses are not reported in the registry record.
The record lists multiple secondary outcomes and reports 16 outcome measures and 7 analyses, but a multiplicity strategy is not reported. Without that information, the intended interpretation of multiple time points and outcomes is unclear. The statistical test or model for the primary comparison is also not reported in the registry record.
Although the study is described as double-blind and quadruple-masked, the masking procedures and details about who was masked are not reported in the registry record. Baseline characteristics, adherence information, and endpoint-specific analysis counts are also not reported in the registry record for this analysis. These omissions limit assessment of trial conduct and analysis, beyond the limitations caused by the absence of primary outcome results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study to Evaluate the Safety and Efficacy of Tazarotene Foam, 0.1%, in Subjects With Common Facial Acne - W0260-301 — NCT01017146.
- Registry record last updated 2017-01-18; status last verified 2016-11.
- Results first posted 2012-07-06.
- 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.
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18. Record Summary
NCT01017146 is a completed Phase 3 randomized, multicenter, double-blind, vehicle-controlled, parallel-group study of tazarotene foam, 0.1%, versus vehicle foam in subjects with acne vulgaris. The registry reports enrollment of 744, a study start of 2009-10, and primary completion in 2010-11.
The primary endpoint was absolute change in facial lesion counts from baseline to Week 12, summarized as a mean with standard deviation. The defined ITT Analysis Set included randomized participants dispensed study product, and LOCF was used for missing final values. The primary outcome results and treatment-group comparison are not reported in the registry record.
Safety entries report serious adverse events affecting 1 participant in each group and other adverse events affecting 88 participants in the tazarotene foam group and 17 in the vehicle foam group. Death counts are not reported in the registry record. The statistical analysis plan, multiplicity strategy, and detailed missing-data information are also not reported in the registry record.