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 Efficacy and Safety of Aczone 7.5% Gel in the Treatment of Truncal Acne Vulgaris (NCT02944461), a na phase 4 study. The primary outcome is Percent of Subjects Who Achieve at Least a Two Grade Improvement and a Rating of Clear or Almost Clear on the Investigator Global Assessment (IGA) Scale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02944461 |
| Phase | Phase 4 |
| Condition | Acne |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Derm Research, PLLC |
| Results posted | Yes |
2. Clinical Question
Population
People with acne affecting the trunk were the focus of the study. The registry record lists acne as the condition and records an enrollment of 20. Eligibility criteria and further descriptions of the enrolled participants are not reported in the registry record.
Intervention
The intervention was dapsone 7.5% gel, identified in the record as Aczone. The arm description specifies application to truncal acne once daily for 16 weeks.
Comparator
No comparator group is described. The study is recorded as single-group, with allocation listed as NA. The registry record therefore does not offer a like-for-like control comparison.
Primary question
The primary question was whether participants achieved at least a two grade improvement and a rating of clear or almost clear on the Investigator Global Assessment (IGA) scale at 16 weeks. The registry record states this endpoint but does not report the number or percentage of participants who met it.
This question combines improvement from baseline with an endpoint severity category. The endpoint is not simply a change in lesion counts: those counts appear among the listed secondary outcomes. The primary measure instead uses an investigator assessment of overall acne severity. Without a reported outcome count, the record cannot show how often the stated response criterion was met. With no comparator group, any outcome measured in the treated group would also lack a concurrent untreated or alternative-treatment reference for interpreting change.
3. Trial Design
The registry identifies NCT02944461 as a completed Phase 4 study sponsored by Derm Research, PLLC. Its title concerns the efficacy and safety of Aczone 7.5% gel in truncal acne vulgaris. The recorded start was 2016-10, and primary completion was 2017-09. Enrollment is listed as 20.
The design is recorded as single-group, with allocation listed as NA and masking listed as none. The intervention description specifies dapsone 7.5% gel applied to truncal acne once daily for 16 weeks. No comparator arm is described, so the design does not support a direct randomized comparison between treatments. The registry record does not report a protocol rationale for the design, details of recruitment, or further information about how participants were selected.
The primary endpoint was assessed at 16 weeks and combines an improvement criterion with an IGA category of clear or almost clear. The listed secondary outcomes concern percent change in inflammatory, non-inflammatory, and total lesion counts at Week 16 compared with baseline. Although four outcome measures are recorded, the registry lists no analyses. It does not provide numerical results for the primary or secondary outcomes in the information recorded for this study.
The distinction between design and outcome reporting matters. A completed status indicates that the study is recorded as completed; it does not itself establish what the outcome findings were. Enrollment and treatment duration describe the planned or recorded study context, not the number of participants with a particular response. The available safety counts are reported separately, but they do not replace the missing efficacy result.
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 | Dapsone Gel 7.5% |
|---|---|
| STARTED | 20 |
| COMPLETED | 15 |
| NOT COMPLETED | 5 |
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 | Dapsone Gel 7.5% |
|---|---|---|
| Participants analysed | 20 | |
| Age, Continuous | years | 21 (SD 8) |
| Sex: Female, Male: Female | Participants | 11 |
| Sex: Female, Male: Male | Participants | 9 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 16 |
| Region of Enrollment: United States | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Percent of Subjects Who Achieve at Least a Two Grade Improvement and a Rating of Clear or Almost Clear on the Investigator Global Assessment (IGA) Scale, measured over 16 weeks.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percent of participants who achieve at least a two grade improvement and a rating of clear or almost clear on the Investigator Global Assessment (IGA) scale at 16 weeks. The IGA scale is described as 1 for clear skin, 2 for almost clear, 3 for mild severity, 4 for severe, and 5 for very severe. The endpoint therefore requires both improvement and a favorable final severity rating; improvement alone would not fulfill the stated criterion.
As a general statistical point, a binary response endpoint expresses whether each participant meets a defined criterion. It can make a result easier to interpret as a proportion meeting a clinically described threshold, while discarding detail about the size of changes among people who do not meet that threshold. Its meaning depends on how the threshold is defined and assessed. Here, the registry record names the IGA assessment and response rule, but it does not report the number of participants who achieved the endpoint or the resulting percentage.
The listed lesion-count outcomes offer different kinds of information: they concern percent change in inflammatory, non-inflammatory, and total lesions relative to baseline. They are secondary outcomes and should not be substituted for the primary IGA response. The record does not report numerical results for those outcomes either.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a single-group study of dapsone 7.5% gel, with once-daily application for 16 weeks, and records enrollment of 20. It identifies a primary IGA response criterion, but does not report how many participants met it or the corresponding percentage. Consequently, the primary result cannot be estimated from the registry information recorded for this trial. The absence of a reported estimate also means that its precision cannot be assessed from a confidence interval or other uncertainty measure.
The study's single-group design is important for interpretation. Without a concurrent comparator, an observed change in participants over time would not by itself distinguish a treatment effect from other explanations, such as changes that might have occurred without the intervention. The record does not provide a comparison with another treatment or with no treatment. This design limitation applies even if an outcome result is available elsewhere; in the registry record, the primary numerical result itself is not reported.
The three listed secondary outcomes concern lesion-count changes at Week 16 compared with baseline. The record does not report their numerical results, so the direction, size, and precision of those changes are not established by the registry entries. Nor does the record provide analyses that could clarify how these outcomes were calculated or interpreted. It lists four outcome measures and zero analyses.
The safety information is more specific than the efficacy information. In the dapsone gel group, the record lists zero participants with a serious adverse event among 20 at risk, three with other adverse events among 20 at risk, and zero deaths. These are reported counts, not a complete characterization of the nature, timing, or severity of all events. No serious adverse event terms are listed. The counts should be read as registry entries for this study group, not as a comparison against another group.
Overall, the posted information establishes what the primary question was, how the intervention was described, and which safety counts were recorded. It does not establish the observed primary response rate, results for lesion-count outcomes, or comparative efficacy. No confidence intervals, hypothesis tests, or adjusted estimates are reported in the registry record. Without those outcome estimates and their uncertainty, statistical precision cannot be judged. The completion status and enrollment figure do not fill this evidence gap.
9. Statistical Methods Explained
The registry records this as a single-group study with no masking and allocation listed as NA. That design description matters because statistical methods cannot create a concurrent comparison that the study design does not contain. An analysis of change from baseline, if conducted, would describe change within the treated group; without a control group, it would not isolate the effect of treatment from other possible causes of change. The registry record does not report an analysis plan or any analyses.
What does a binary response represent?
The primary outcome is a binary response: a participant either meets the stated IGA criterion or does not. The criterion requires at least a two grade improvement together with a rating of clear or almost clear at 16 weeks. In general, a binary endpoint turns an assessment into a count of responders and non-responders, which can be expressed as a response proportion when its denominator is specified. The registry record does not give the number meeting the criterion, so no response proportion can be reported from it.
As a general statistical concept, a confidence interval describes the uncertainty around an estimated quantity. For a binary endpoint, an interval around a response proportion would communicate how much the estimate may vary given the observed data and statistical assumptions. No primary response estimate or confidence interval is reported in the registry record. Therefore, neither the apparent magnitude of response nor its precision can be evaluated from the recorded efficacy information.
Why does the absence of a comparator matter?
A comparison group can help separate changes associated with the intervention from changes that may occur for other reasons. This trial is recorded as single-group, so the registry does not present a randomized contrast. A before-and-after comparison, even if it were reported, would remain a within-group description. It would not answer the same question as a comparison between concurrently assigned groups. Allocation is listed as NA, and masking as none; further design details are not reported in the registry record.
As a general point, masking can reduce the influence of expectations on some assessments, but the registry states that masking was none. This is relevant because the primary endpoint depends on an investigator's global assessment. The record does not explain the assessment procedures or describe steps used to address possible assessment bias. This observation concerns the design information recorded; it does not establish that any particular assessment was biased.
How should lesion-count outcomes be understood?
The secondary outcomes are percent changes in inflammatory lesion count, non-inflammatory lesion count, and total lesion count at Week 16 compared with baseline. In general, a change-from-baseline measure relates a follow-up value to an earlier value, while a percent-change measure expresses that change relative to the baseline value. The registry record does not report the actual values, estimates, or analysis details for these outcomes. It is therefore not possible to assess their direction, magnitude, or precision, or to determine how participants with missing measurements were handled.
Over-dispersion is a general issue that can arise when count data vary more than a simple statistical model assumes. When present, an unsuitable model can understate uncertainty. The registry record does not identify a model for lesion-count outcomes, describe the distribution of the data, or provide analysis results. There is consequently no basis to state whether over-dispersion was assessed or how it was handled.
What do the planning assumptions mean?
The registry information includes assumptions for a planning illustration: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of an observed effect. It also notes that time-to-event illustrations use a total event count, while other illustrations use participants per arm. These are planning conventions, not a description of this study's single-group design. They do not show that the trial was planned or conducted with two arms, and any sample-size illustration is not observed power. The registry record does not report the trial's own sample-size justification or design assumptions.
No recalculated efficacy estimate is available in the recorded information, so there is no recalculation to compare with a sponsor analysis. More generally, recalculations from posted summary statistics are unadjusted and should not replace a sponsor's own analysis when a discrepancy is present. Here, the registry records zero analyses and does not provide the primary outcome summary needed to make such a recalculation.
10. Multiplicity, Missing Data and Analysis Populations
The record lists four outcome measures: the primary IGA response and three secondary lesion-count outcomes. When several outcomes are assessed, multiplicity is a general statistical concern: the chance of observing a seemingly notable result can be affected by how many tests are performed and how they are interpreted. The registry record does not report a multiplicity strategy, a hierarchy for interpreting outcomes, or statistical analyses. It is therefore not possible to determine whether multiplicity was addressed.
Missing-data procedures are also not reported in the registry record. The available information does not say how missing IGA assessments or lesion counts were handled, whether participants who stopped treatment were included in outcome analyses, or how incomplete follow-up affected the results. No analysis population is described. These omissions matter because the interpretation of an outcome estimate can depend on who was included and how absent measurements were treated.
The registry records enrollment of 20, but does not report the number included in an efficacy analysis or the denominator used for the primary endpoint. Enrollment should not be treated as an outcome denominator without a reported analysis population. The record also lists zero analyses, so it does not provide results that would clarify these issues.
The safety counts have their own recorded at-risk denominators, but those counts do not establish the analysis population used for efficacy outcomes. Further details about outcome assessment, missingness, and analysis handling are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Dapsone Gel 7.5% | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Dapsone Gel 7.5% | 0 of 20 |
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 |
|---|---|
| Dapsone Gel 7.5% | 3 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Dapsone Gel 7.5% |
|---|---|---|
| infected abrasions of legs | Skin and subcutaneous tissue disorders | 1 of 20 |
| gum graft surgery | Surgical and medical procedures | 1 of 20 |
| stye, right eye | Eye disorders | 1 of 20 |
| sunburn arms/chest/back | Skin and subcutaneous tissue disorders | 1 of 20 |
For the dapsone gel group, the registry records zero participants with a serious adverse event among 20 at risk. It also records three participants with other adverse events among 20 at risk, and zero deaths. These are counts of participants in the recorded safety categories; they should not be read as evidence about a comparison with another treatment because no comparator group is described.
The record lists no serious adverse event terms. It therefore does not identify the nature of any serious events beyond reporting zero participants affected. The separate count for other adverse events gives no event descriptions in the information recorded. The registry record also does not provide timing, duration, severity grading, or details of how events were collected. These limits mean the counts offer only a narrow view of safety reporting.
In general, a count of zero recorded events does not establish that an event is impossible or that no risk exists; it describes the events recorded in the study group. The safety figures should be interpreted alongside the study's size and the absence of a comparator, without turning them into a comparative risk estimate. The record does not report a broader safety analysis.
12. What the Result Does, and Does Not, Mean
The registry information identifies a clinical question about whether participants receiving once-daily dapsone 7.5% gel for truncal acne achieved a specified IGA response at 16 weeks. It records the study as completed, lists enrollment of 20, and provides safety counts for the treated group. It also names three lesion-count outcomes. These details describe the study's scope and recorded measures.
The primary efficacy result is not reported in the registry record. No number or percentage meeting the IGA criterion is available, and no numerical results for the secondary outcomes are reported. Accordingly, the posted information does not show the size or precision of an efficacy estimate. It also does not show whether the primary criterion was met by any particular proportion of participants.
The design does not include a comparator group. Thus, even if within-group changes were reported, those changes would not by themselves establish what would have happened without the intervention or under another treatment. The registry record contains no randomized treatment contrast and no reported statistical analyses. It cannot support a comparative efficacy conclusion.
The safety counts indicate zero participants with serious adverse events, three with other adverse events, and zero deaths in the recorded group. They do not provide event descriptions or a comparison with another group, and should not be taken as a complete account of all possible safety outcomes.
In general, a trial record can describe a prespecified question and design even when outcome estimates are unavailable. Here, the recorded information is enough to explain what was intended to be measured, but not to determine the magnitude or uncertainty of the primary result. The result does not establish that the treatment works or does not work. The key efficacy findings and analysis details are not reported in the registry record.
13. Why This Trial Matters Statistically
This study illustrates why a clear endpoint description and a reported endpoint result are both important. The registry states a specific primary response rule based on improvement and final IGA category, with assessment at 16 weeks. That defines the question being asked. But without the number of participants meeting the rule, readers cannot assess the observed response or its precision. A well-defined endpoint does not substitute for a reported estimate.
The single-group design is another central statistical feature. It can describe outcomes among treated participants, but it does not provide a like-for-like control comparison. This distinction helps prevent an unsupported causal interpretation of changes over time. The registry records allocation as NA and masking as none, so the information available does not describe a randomized, masked comparison.
The listed lesion-count outcomes also show that different outcomes can answer different questions. A global severity response and changes in inflammatory, non-inflammatory, or total lesion counts are not interchangeable. Their results, if reported, would need to be interpreted according to their definitions and analysis methods. The registry does not report those results or how they were analyzed.
Finally, the safety entries demonstrate why counts need context. The record reports participants at risk and counts in serious and other adverse-event categories, but supplies no event terms for serious events and no comparator. These data can be described accurately, yet they cannot alone establish comparative safety. Overall, the trial highlights the statistical importance of outcome reporting, analysis transparency, and alignment between a design and the claims it can support.
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.
Important limitations arise from what the registry record does not report. The primary IGA response count and percentage are absent, as are numerical results for the listed secondary outcomes. No confidence intervals, hypothesis tests, or other efficacy analyses are recorded. This prevents evaluation of the observed effect and its statistical precision.
The single-group design and lack of a comparator limit causal interpretation. Allocation is listed as NA and masking as none. The record does not explain recruitment or eligibility in detail, the assessment procedures, or how investigators maintained consistency in the IGA assessment. Because the primary measure is investigator assessed, missing assessment procedures limit appraisal of how it was obtained.
Enrollment is recorded as 20, but the efficacy analysis population and outcome denominators are not reported. Missing-data methods and participant disposition are also not reported. The record does not state how absent or incomplete assessments were handled, and no analysis plan or multiplicity strategy is given. Although four outcome measures are recorded, no analyses are listed.
The safety information has limits as well. It records zero participants with serious adverse events, three with other adverse events, and zero deaths, but lists no serious adverse event terms and gives no event descriptions in the information recorded. Timing and severity details are not reported. These limits prevent a fuller characterization of safety and do not permit comparison with an alternative group.
Finally, the planning assumptions recorded for a sample-size illustration do not establish the study's own design justification. The record does not report such a justification. These limitations concern the available registry information and the recorded design; they do not determine what may be available from other sources.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety of Aczone 7.5% Gel in the Treatment of Truncal Acne Vulgaris — NCT02944461.
- Registry record last updated 2019-04-03; status last verified 2019-03.
- Results first posted 2019-03-01.
- 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
NCT02944461 is recorded as a completed Phase 4, single-group study sponsored by Derm Research, PLLC. The registry lists enrollment of 20 and dates of 2016-10 for study start and 2017-09 for primary completion. Dapsone 7.5% gel was described for once-daily application to truncal acne for 16 weeks.
The primary endpoint was the percent of participants achieving at least a two grade improvement and a clear or almost clear IGA rating at 16 weeks. The registry record does not report the primary outcome result. Three secondary outcomes concern percent changes in inflammatory, non-inflammatory, and total lesion counts, but their results are also not reported. The record lists zero analyses.
Safety entries list zero participants with serious adverse events among 20 at risk, three with other adverse events among 20 at risk, and zero deaths. No comparator group is described. Statistical analysis details, efficacy estimates, missing-data procedures, and a sample-size justification are not reported in the registry record.