U0289-405: An Open-Label, 12-Week Study to Evaluate the Efficacy and Safety of the Acne System (Benzoyl Peroxide 2.5%, Salicylic Acid 0.5%) in Subjects With Acne: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for U0289-405: An Open-Label, 12-Week Study to Evaluate the Efficacy and Safety of the Acne System (Benzoyl Peroxide 2.5%, Salicylic Acid 0.5%) in Subjects With Acne (NCT01446237), a na na study. The primary outcome is Mean Percent Changes in Inflammatory (IL), Non-inflammatory (NIL), and Total Lesion (TL) Counts From Baseline to Each Study Visit.

2. Clinical Question

In statistical terms, the study asks how facial lesion counts changed over time among participants using the Acne System. It is not designed to estimate a comparative treatment effect because no concurrent comparator group was included. The clinical question is therefore descriptive and within-group: what changes were recorded among participants with available data at each visit? Even if numerical changes were available, interpreting them as caused by the products would require caution because the design cannot separate treatment-associated change from other explanations, including natural variation over time and expectations in an open-label study.

3. Trial Design

This was a completed, open-label study with a single group and no comparator. The registry lists enrollment of 125 and classifies allocation as NA. The study start date was 2011-06-01 and primary completion was 2011-12-01. The study description characterizes the intended treatment period as 12 weeks. The record lists the phase as NA and identifies Stiefel, a GSK Company, as sponsor.

The intervention was described as the Acne System containing benzoyl peroxide 2.5% and salicylic acid 0.5%. Participants were asked to apply three commercially available, over-the-counter products daily: a Foam Deep Cleanser and Foam Advanced Acne Treatment containing benzoyl peroxide 2.5%, and a Foam Rejuvenating Toner containing salicylic acid 0.5%. There was no reference treatment. Masking was none, so the study was open label.

Investigators assessed facial inflammatory, non-inflammatory, and total lesion counts at baseline and the scheduled visits through Week 12. The efficacy area was defined as the face from the hairline to the mandible, including the forehead, cheeks, and chin while excluding the mouth, nasal region, periocular area, and superior and inferior eyelids. The registry also lists secondary outcomes of absolute changes in lesion counts and mean change in ISGA from baseline to each study visit.

The record does not report a randomized design, an allocation process, or a control arm. This matters because a single-group study can describe outcomes over time but cannot supply a concurrent comparison for separating treatment-associated changes from time trends, measurement variation, or other influences. A sample-size justification and detailed protocol rationale are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-treat (ITT) population consisted of all participants that were enrolled in the study. Only those participants with data available at the indicated time points were analyzed.

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 Mean Percent Changes in Inflammatory (IL), Non-inflammatory (NIL), and Total Lesion (TL) Counts From Baseline to Each Study Visit, measured over Baseline (Day 1) and Week 1, 2, 4, 8, 12.

The primary endpoint is mean percent change from baseline in inflammatory lesion, non-inflammatory lesion, and total lesion counts at each study visit. The registry defines inflammatory lesions as papules and pustules, and non-inflammatory lesions as open and closed comedones. Total lesion count combines the lesion categories as recorded by the investigator. The assessment area was restricted to specified parts of the face.

Lesion counts provide a direct, structured measure of visible acne signs and permit separate description of inflammatory and non-inflammatory lesions as well as the total burden counted. Expressing change as a percentage of baseline is intended to put change in relation to each participant’s starting count, rather than describing only an absolute count difference. The endpoint is summarized as a mean, with standard deviation specified as the measure of dispersion.

Baseline was Day 1. The registry defines change from baseline as the value at a given time point minus the baseline value, and states that mean percent change was presented at each visit. It does not specify in the endpoint description how individual percentage changes were handled when baseline counts were zero. Numerical endpoint estimates and their standard deviations are not reported in the registry record, so the amount of change and the spread of participant outcomes cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as a mean of a continuous outcome and specifies standard deviation as its dispersion measure. The outcome is mean percent change from baseline in lesion counts at each scheduled visit. In general, a mean summarizes the average value across analyzed participants, while a standard deviation describes how spread out individual values are around that average. Neither statistic alone gives a complete account of the distribution: a similar mean can arise from different patterns of individual change.

What does a change from baseline describe?

The registry defines change from baseline as the value at the indicated time point minus the baseline value. Baseline was Day 1, and the primary endpoint is framed as percent change from that starting assessment. In general, a baseline comparison describes how measurements within a study group differ over time. It is not the same as a comparison between groups, because it does not subtract the change observed in a concurrent control group. The study has no control group, so its design supports descriptive within-group assessment rather than a controlled estimate of comparative effect.

The endpoint separates inflammatory lesions, defined as papules and pustules, from non-inflammatory lesions, defined as open and closed comedones, and also includes total lesion counts. Such separate outcomes can help describe whether measured changes differ across lesion categories. The registry does not report numerical estimates for these categories, so their actual pattern cannot be characterized. It also does not specify in the endpoint description how a participant’s percent change is calculated when a baseline count is zero; that detail is not reported in the registry record.

Why does dispersion matter?

In general, a mean is more informative when considered alongside a measure of variability. The specified standard deviation can indicate whether participants’ changes were relatively clustered or widely spread. A mean by itself may conceal substantial differences among participants. The standard deviations are not reported in the registry record. Confidence intervals are also not reported there. In general, a confidence interval communicates uncertainty in an estimate, conditional on the analysis and its assumptions; it should not be treated as a range containing a fixed proportion of individual outcomes.

What can the study design estimate?

The study is open label and single group, with no reference treatment. In general, random allocation to concurrent groups can help make a treatment comparison less vulnerable to differences that existed before treatment, while masking can reduce some sources of expectation or assessment bias. Neither a randomized comparison nor masking is part of this record. Investigators assessed lesion counts, so open-label knowledge may be relevant to how assessments are conducted or interpreted. The record does not quantify whether such influences occurred.

Because the study has no comparator, a change from baseline cannot separate effects associated with use of the Acne System from changes that might have occurred over time for other reasons. This is a limitation of the design, not a statistical adjustment that can be resolved from the posted summary information. No adjusted comparative analysis is reported in the registry record.

How should planning illustrations be read?

The sample-size assumptions described for planning illustrations are not the trial’s own design justification. They use a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation, with the effect framed as a stated fraction of an observed effect. The record does not report a sample-size justification for this single-group study. Such illustrations are planning calculations, not observed power and not evidence that the study had a particular probability of detecting an effect. The numerical planning counts are not reported in the registry record.

In general, sample-size planning depends on the outcome, the effect size considered meaningful or worth detecting, variability, the significance criterion, and the planned analysis. Changing those assumptions changes the required number of participants. For a single-group study, a hypothetical two-arm planning illustration should not be mistaken for the actual design, which had no comparator. It also cannot replace information about observed outcome estimates, their variability, or missing data.

What analysis details are unavailable?

The registry describes the intent-to-treat population as all enrolled participants and says only participants with data available at each indicated time point were analyzed. The record does not report further details of the statistical model, any adjustment for baseline factors, or the handling of missing observations beyond that statement. It lists five outcome measures and zero analysis entries. The numerical primary estimates, standard deviations, and visit-specific analyzed counts are not reported in the registry record. As a result, the analysis methods and the precision of the reported efficacy outcomes cannot be independently characterized from the record.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome includes three related lesion-count measures: inflammatory, non-inflammatory, and total lesions. Each is assessed across baseline and the scheduled follow-up visits. The registry also lists secondary outcomes covering absolute changes in lesion counts and mean change in ISGA at each study visit. Examining several outcomes and time points creates multiple opportunities to observe changes that may appear noteworthy by chance. In general, multiplicity procedures can control or describe the consequences of making several statistical comparisons. Whether such procedures were planned or used is not reported in the registry record.

The record identifies the intent-to-treat population as all participants enrolled, but qualifies the analyses by stating that only participants with data available at the indicated time points were analyzed. This means that the analyzed participants may differ by visit if data availability differs. Visit-specific analyzed counts are not reported in the registry record, nor are reasons for missing measurements or methods for accounting for them beyond the available-data statement. It is therefore not possible to determine from the record how much information was missing or whether missingness could have affected the summaries.

The record does not report whether the analysis used imputation, a repeated-measures model, or another approach to missing observations. These methods should not be assumed. Likewise, it does not report a multiplicity adjustment, a prespecified hierarchy of outcomes, or a statistical analysis plan. Zero analysis entries are listed. The registry’s descriptions establish the intended outcomes and the stated analysis population, but not the full procedures used to analyze them.

These gaps matter because the interpretation of estimates depends on which participants contributed data, how missing values were handled, and whether multiple outcomes were considered together. Without numerical results, analyzed counts, and fuller analysis details, neither the robustness of the estimates nor the role of multiplicity can be assessed from the registry record.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists 125 participants at risk for serious adverse events and zero participants affected by serious adverse events. It lists 125 at risk for other adverse events and 12 participants affected in that category. Deaths are listed as zero. No serious adverse-event terms are listed. These are counts reported for the study group, not comparisons against another treatment group.

In general, a count of participants affected is different from a count of event episodes: one participant may experience more than one event, but the record does not provide event-level detail for the other adverse events. The record also does not provide numerical rates, severity breakdowns for the other events, or a comparator group. No percentage or comparative risk should be inferred from these counts.

Zero recorded serious adverse events means none were listed as affecting participants in this study record; it does not establish that serious events are impossible or that risk is absent. The open-label, single-group design also means these figures cannot estimate a difference in safety relative to a control treatment. The posted counts should be read as descriptive safety information for the participants included in the registry entry.

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

The registry record establishes that this was an open-label study of a topical system containing benzoyl peroxide 2.5% and salicylic acid 0.5%, with lesion counts assessed over the stated study period. It also identifies the population, facial assessment area, primary outcome definitions, visit schedule, and posted adverse-event counts. These details explain what the investigators intended to measure and how the study was structured.

However, the registry record does not report numerical primary efficacy results. It therefore does not show the mean percent changes in inflammatory, non-inflammatory, or total lesion counts, or their standard deviations. No direction or magnitude of efficacy change can be inferred from the objective or outcome description. The record’s zero analysis entries reinforce that numerical analysis results are not available in the registry entry described.

Even if numerical before-and-after changes were available, the single-group design would not establish that the changes were caused by the Acne System. Without a control or reference treatment, the study cannot distinguish changes associated with treatment from other changes over time. Open-label assessment is an additional design feature relevant to interpretation, although the registry does not report whether it affected measurements.

The posted safety figures are descriptive counts: zero participants affected by serious adverse events among 125 at risk, 12 affected by other adverse events among 125 at risk, and zero deaths. They do not provide a comparative safety estimate. The record also does not provide enough detail to characterize the events beyond the categories and counts listed.

Thus, the main contribution of the registry entry is to document the study design and planned measurements, together with limited safety counts. It does not support a numerical assessment of primary efficacy or a controlled comparison. Those distinctions separate what the record documents from conclusions that would require outcome estimates, fuller analysis details, or a comparator.

13. Why This Trial Matters Statistically

This study is statistically informative because it illustrates the difference between measuring change and estimating a comparative effect. Repeated lesion assessments can describe how counts vary over time within a group. Without a control group, however, the design cannot determine how much of any observed change is attributable to the intervention rather than to other influences. This distinction is essential when interpreting studies that report before-and-after outcomes.

The endpoint also makes the role of measurement choices visible. The registry defines inflammatory and non-inflammatory lesions separately, includes total lesion counts, specifies the facial area assessed, and sets multiple follow-up visits. These choices shape what the results would represent. They also create a set of related outcome and time-point comparisons, making it important to know whether multiplicity was addressed. That information is not reported in the registry record.

The record highlights another important statistical issue: an intent-to-treat label does not, by itself, explain exactly how every enrolled participant contributes to each analysis. Here, the stated population includes all enrolled participants, while the record says that only participants with data at a given time point were analyzed. Visit-specific counts and fuller missing-data methods are not reported. Readers therefore need to distinguish the population definition from the actual availability of outcome data at each visit.

Finally, the absence of numerical primary results limits what can be learned from this registry entry about outcome magnitude and precision. A clear protocol description does not substitute for estimates, dispersion measures, or analysis details. The entry can still support careful discussion of design, endpoint construction, and the limits of within-group evidence, while making clear which statistical questions remain unanswered.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The central limitation is the lack of a comparator. Because the study had a single group and no reference treatment, any within-group change cannot be directly contrasted with what would have occurred under another condition. The open-label design also means participants and investigators were not masked. The registry record does not report whether this affected behavior, assessment, or outcome recording, but the design does not rule out such influences.

Primary efficacy estimates are not reported in the registry record. Numerical mean percent changes, standard deviations, and visit-specific analyzed counts are unavailable, so the size, variability, and precision of the lesion-count outcomes cannot be assessed. The record lists zero analysis entries. It also does not provide the statistical analysis plan, details of any adjustment, or a sample-size justification.

The stated analysis population includes all enrolled participants, but only those with data at the indicated visit were analyzed. Further missing-data methods and reasons for missingness are not reported. The endpoint description also does not specify how percent changes were handled for participants with a baseline count of zero. These details can matter for interpreting summaries but cannot be resolved from the registry record.

Several outcomes and time points were specified, including lesion categories, total counts, absolute changes, and ISGA change. Whether multiplicity was addressed is not reported. The safety record provides counts but no serious adverse-event terms, and limited detail on other adverse events. These constraints leave the entry useful for understanding the study’s structure, but insufficient for a full evaluation of efficacy estimates, their precision, or comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: U0289-405: An Open-Label, 12-Week Study to Evaluate the Efficacy and Safety of the Acne System (Benzoyl Peroxide 2.5%, Salicylic Acid 0.5%) in Subjects With Acne — NCT01446237.
• Registry record last updated 2017-05-25; status last verified 2017-03.
• Results first posted 2017-04-18.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT01446237 is a completed, open-label, single-group study sponsored by Stiefel, a GSK Company. It enrolled 125 participants and evaluated a topical Acne System containing benzoyl peroxide 2.5% and salicylic acid 0.5% over a 12-week period. There was no comparator and masking was none. The primary outcome concerned mean percent changes from baseline in inflammatory, non-inflammatory, and total facial lesion counts at scheduled visits.

The registry record does not report numerical primary efficacy results or analysis entries. It lists zero participants affected by serious adverse events among 125 at risk, 12 affected by other adverse events among 125 at risk, and zero deaths. The record does not report a sample-size justification, full statistical analysis plan, multiplicity procedures, or further missing-data methods.