A Study Assessing the Efficacy of Combined Use of Clascoterone 1% Cream and Adapalene 0.3% for the Treatment of Acne: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study Assessing the Efficacy of Combined Use of Clascoterone 1% Cream and Adapalene 0.3% for the Treatment of Acne (NCT06336603), a na phase 4 study. The primary outcome is The Primary Endpoint of This Study is the Percent of Patients Who Achieve Clear or Almost Clear on IGA at Week 16..

2. Clinical Question

3. Trial Design

The registry describes NCT06336603 as a completed Phase 4 study of combined Winlevi (clascoterone) 1% cream and adapalene 0.3% gel for acne vulgaris. The listed enrollment is 20. The study has a single-group model, and allocation is recorded as NA. There is no separate control arm in the design described in the registry record.

The treatment description specifies combined use, with Winlevi used twice daily and adapalene once daily. Masking is listed as none, so the study is unmasked. The registry identifies Sun Pharmaceutical Industries Limited as sponsor. The study start date is 2023-11-15, the primary completion date is 2024-10-29, and the status is completed.

The primary outcome is the percentage of participants who achieve clear or almost clear on the IGA at Week 16. The record also lists secondary outcomes covering total, inflammatory, and non-inflammatory lesion reduction at Week 16, along with tolerability measures for erythema, dryness, peeling, and burning or stinging, and an assessment of skin oiliness. The registry lists 10 outcome measures and 3 analyses, but does not give a full account of how each outcome was analyzed.

The record does not report a sample-size justification, detailed eligibility criteria, baseline participant characteristics, or the protocol procedures governing treatment adherence and follow-up. Those omissions limit assessment of how the study was planned and how well the enrolled participants and treatment use represent routine practice. Its single-group, unmasked structure is central to interpretation: findings within the group would not constitute a direct comparison against another treatment or against no treatment.

4. Participant Flow and Accounting

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

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as The Primary Endpoint of This Study is the Percent of Patients Who Achieve Clear or Almost Clear on IGA at Week 16., measured over Week 16.

The primary endpoint is the percentage of participants who achieve clear or almost clear on the Investigator Global Assessment at Week 16. The IGA is an investigator assessment of overall acne severity. The registry describes its scale as ranging from 0 to 5, with 0 representing clear skin and 5 representing very severe acne. The endpoint turns that overall assessment into a binary response: participants either meet the stated clear-or-almost-clear criterion or do not.

A categorical endpoint can be clinically interpretable because it expresses the proportion reaching a specified overall status, rather than only describing an average change in a score. It also provides a defined time point for assessing response. However, the registry record does not report the precise score threshold used to classify “almost clear,” the baseline distribution of IGA scores, or the number of participants included in the endpoint analysis. Those details matter for understanding exactly how the response category was applied.

No numerical primary endpoint result, uncertainty interval, or statistical test result is reported in the registry record. Therefore, the listed endpoint defines the question the study set out to assess, but the record does not establish what percentage achieved the specified status or how precisely that percentage was estimated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Clinical trial results are easiest to interpret when the endpoint, analysis population, estimate, and uncertainty are all clear. The registry identifies the primary endpoint as a percentage achieving clear or almost clear on the IGA at Week 16. A percentage is a proportion expressed on a percentage scale: the numerator would be participants meeting the response definition, and the denominator would be the participants included in the endpoint analysis. The record does not report either count or define the analysis denominator, so no response percentage can be reconstructed from the registry information.

What does a confidence interval tell the reader?

In general, a confidence interval describes uncertainty around an estimated effect or proportion. It indicates a range of values compatible with the data under the statistical method used. It is not a guarantee that the true value lies within that particular interval, and it does not correct for limitations in study design, measurement, or missing data. No confidence interval for the primary endpoint is reported in the registry record. As a result, the precision of the primary outcome estimate cannot be assessed from the record.

Why does the single-group design matter?

In general, a controlled comparison helps separate differences associated with treatment assignment from changes that may occur over time or through other influences. Here, the registry describes a single-group study and no comparator arm. A within-group response or change would be descriptive of participants receiving the combination, not a randomized estimate of how the combination compares with another option. The record also lists masking as none. When assessments are unmasked, knowledge of treatment can potentially influence subjective judgments; the extent of any such influence cannot be determined from the registry entry.

What can a binary endpoint capture?

The primary outcome classifies participants according to whether they reach the stated IGA category at Week 16. This makes the result straightforward to express as a percentage, but it does not preserve all the detail in the underlying severity scale. Participants on either side of a response threshold may have similar scores, while those within the response category can still differ in their assessed condition. The record describes the IGA scale from 0 to 5, but it does not specify the exact score rule for “almost clear.” The classification procedure is therefore not fully defined in the registry record.

How should the planning illustration be understood?

In general, sample-size planning asks how many participants a future study might need to detect a chosen effect with a specified statistical approach. The planning illustration associated with this study is described as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers the effect to detect as a stated fraction of the observed effect. These are planning assumptions, not a description of the actual single-group design. They do not establish the study's original sample-size rationale, which is not reported in the registry record, and they are not observed power. A planning calculation is not evidence that an effect was found, nor does it resolve the lack of a comparator in the trial itself.

What do unreported statistical details mean?

In general, an analysis plan specifies how outcomes are summarized, how uncertainty is estimated, and what comparisons or tests are conducted. For a binary endpoint, methods may differ in how they estimate a response proportion and its uncertainty. For continuous or count outcomes, the distribution and variability of the measurements can affect which methods are appropriate. Over-dispersion is a general issue in count data: it occurs when variation exceeds what a simple model assumes, and ignoring it can make uncertainty estimates too small. The registry record does not identify the statistical methods used for the listed outcomes, so no particular model or adjustment should be inferred.

The record lists 10 outcome measures and 3 analyses, but does not describe the analysis procedures in enough detail to assess model choice, confidence-interval construction, or statistical testing. It also does not report numerical outcome estimates. Statistical interpretation therefore remains limited to the stated design and endpoint definitions, rather than a quantitative assessment of efficacy or precision.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Winlevi (Clascoterone) 1% & Adapalene 0.3% Gel")
n      <- c(17)
events <- c(11)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Winlevi (Clascoterone) 1% & Adapalene 0.3% Gel  17  11  64.7  38.3  85.8  41.3  82.7  41.0  82.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures and 3 analyses. When a study examines several outcomes or performs several statistical tests, the chance of at least one apparently unusual result can increase. In general, a multiplicity plan may designate a primary outcome, order tests, or adjust interpretation to account for multiple comparisons. The record identifies the IGA response at Week 16 as the primary endpoint, but it does not report a multiplicity strategy for the other outcomes or analyses. It also does not explain whether the secondary outcomes were treated as exploratory or confirmatory.

The registry record does not describe missing-data methods, participant flow, or the populations included in the analyses. It does not state how participants with missing Week 16 IGA assessments were handled, whether any outcomes were analyzed among all enrolled participants, or whether analysis required a particular amount of follow-up. These definitions are important because the percentage for a binary endpoint depends on who is included in its denominator. Missing observations may also affect interpretation if participants with and without recorded outcomes differ in relevant ways.

In general, missing-data methods make assumptions about outcomes that were not observed. Different assumptions can lead to different estimates, so transparent reporting should identify both the method and the population to which the result applies. No such approach is reported in the registry record. It is not possible to determine from the registry entry whether data were complete or how incomplete data, if any, were handled.

These omissions do not establish that multiplicity or missing data changed the results. They mean that the registry record does not provide enough information to evaluate those issues. A reader cannot judge whether the reported analyses, if any, account for multiple outcomes or how sensitive results might be to missing observations.

12. 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.

The registry safety record lists one treatment group. In that group, 17 participants are listed as at risk for serious adverse events, with 0 affected. The record also lists 17 at risk for other adverse events, with 0 affected, and deaths are recorded as 0. No serious adverse event terms are listed.

These entries describe the safety counts recorded for the listed at-risk groups. They do not establish that no adverse events could occur, and they do not provide a comparison with another treatment. The listed at-risk count is not the same as the enrollment listing of 20; the registry record does not explain the difference or provide participant flow for the safety assessment. It also does not give event follow-up details or additional information about how adverse events were collected and classified.

Zero recorded events in these categories should therefore be read as a report of the registry counts, not as proof of absence of risk. The single-group design and lack of a concurrent comparator also limit interpretation of relative safety. These safety counts do not answer the efficacy question, which concerns the IGA response at Week 16 and has no numerical result reported in the registry record.

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

The record establishes that a completed Phase 4, single-group study assessed combined clascoterone 1% cream and adapalene 0.3% gel for acne vulgaris. It specifies the dosing schedule and identifies the primary question: the percentage achieving clear or almost clear on the IGA at Week 16. It also identifies secondary outcomes concerned with lesion reduction and skin tolerability. These details help define what was intended to be assessed.

They do not establish the size of any response. The registry record does not report the primary endpoint percentage or the numerical results for the secondary outcomes. It also does not report confidence intervals or test results that would indicate statistical precision. The listed enrollment of 20 is not a substitute for the number analyzed at Week 16, which is not reported. Consequently, the registry entry does not support a quantitative statement about how participants' acne or tolerability assessments changed.

The study design further limits the interpretation of any within-group observation. With no separate comparator arm and no masking, the design cannot provide a randomized comparison of the combination against another regimen. An observed outcome in a treated group, if reported, would not by itself demonstrate that the treatment caused that outcome. It would also not show whether the combination performs differently from either component used alone.

The absence of numerical results in the registry record should not be interpreted as evidence that the treatment worked or did not work. It is a limit on what can be concluded from this record. The available information describes the study's question and structure, but not the outcome data needed to estimate response or its uncertainty.

14. Why This Trial Matters Statistically

This study raises a statistically important question about how combination treatment is evaluated in a real-life treatment context. The regimen pairs clascoterone 1% cream with adapalene 0.3% gel, and the primary endpoint uses an overall investigator assessment at Week 16. The registry also lists lesion-reduction outcomes and assessments of skin tolerability. Considering these measures together could describe different dimensions of treatment experience, provided their results and analysis methods are reported.

The single-group design is especially relevant to the statistical interpretation. It can describe outcomes among participants receiving the regimen, but it does not provide a randomized contrast with another approach. That distinction matters when moving from “an outcome was observed during treatment” to “the treatment caused a difference.” Without a concurrent comparator, changes over time and other influences cannot be separated through random allocation between groups.

Clear reporting also matters for a binary endpoint. The percentage achieving a response is meaningful only when the response rule and denominator are explicit. The registry gives the broad IGA scale and the clear-or-almost-clear wording, but does not specify the score threshold for the latter category or the number analyzed. It also does not report a confidence interval, so the precision of the estimate cannot be evaluated.

Finally, multiple outcomes, missing-data handling, and analysis populations shape how findings should be read. The registry lists several outcome measures but does not explain the multiplicity approach or the handling of missing observations. Those are not merely technical details: they affect how robustly results can be interpreted. In this case, the numerical results needed to assess those questions are not reported in the registry record.

15. Limitations

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

Several limitations specific to this study shape what can be inferred from its registry record. First, the study is single-group, with allocation listed as NA and no separate comparator. This prevents a direct estimate of the difference between the combination and another treatment. The record also lists no masking, which matters because the primary endpoint depends on an investigator assessment. The registry does not describe procedures to reduce or evaluate possible assessment bias.

Second, the primary endpoint result is not reported. The record supplies no response count, analysis denominator, percentage, confidence interval, or p-value. The precise score threshold for “almost clear” is also not reported. Without these details, the outcome cannot be independently interpreted or its precision assessed.

Third, the enrollment listing is not accompanied by participant flow, baseline characteristics, or endpoint-specific analysis populations. The safety entries list 17 at risk, while the enrollment listing is 20; the registry does not explain that difference. It is also not reported whether Week 16 data were missing or how missing observations were handled. These gaps limit assessment of who contributed to each result and whether the analyzed group differed from those enrolled.

Fourth, the registry does not report a sample-size justification, the statistical analysis methods, or a multiplicity strategy. It lists 10 outcome measures and 3 analyses, but does not explain how analyses were selected or interpreted. The planning illustration uses assumptions that are not the actual single-group design and should not be mistaken for the study's original design justification.

Finally, eligibility criteria and participant characteristics are not reported in the record. That limits judgments about how broadly the findings might apply, even if outcome data were available. Taken together, these limitations mean the record supports description of the study structure, but not a detailed evaluation of efficacy, precision, or generalizability.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study Assessing the Efficacy of Combined Use of Clascoterone 1% Cream and Adapalene 0.3% for the Treatment of Acne — NCT06336603.
• Registry record last updated 2025-10-09; status last verified 2025-09.
• Results first posted 2025-10-09.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT06336603 is a completed Phase 4, single-group study of combined Winlevi (clascoterone) 1% cream and adapalene 0.3% gel for acne vulgaris. The regimen is described as Winlevi twice daily and adapalene once daily. Enrollment is listed as 20; masking is listed as none, and there is no separate comparator arm.

The primary endpoint is the percentage achieving clear or almost clear on the IGA at Week 16. Secondary outcomes cover lesion reduction and skin tolerability. Although the registry identifies these outcomes, it does not report numerical efficacy results, analysis denominators, confidence intervals, or p-values. The safety entries list 0 serious adverse events and 0 other adverse events among 17 at risk in each category, with deaths recorded as 0.

The record does not report the statistical analysis plan, missing-data methods, analysis populations, or multiplicity approach. Its design and reporting limitations prevent a quantitative assessment of the primary outcome or a controlled comparison.