A Study to Assess the Safety and Efficacy of Ruxolitinib Cream in Participants With Genital Vitiligo: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Assess the Safety and Efficacy of Ruxolitinib Cream in Participants With Genital Vitiligo (NCT05750823), a na phase 2 study. The primary outcome is Percentage of Participants Achieving a Genital Vitiligo Noticeability Scale (VNS) of "4 - A Lot Less Noticeable" or "5 - No Longer Noticeable" at Week 48.

2. Clinical Question

The primary question concerns participants’ own assessment of how noticeable genital vitiligo was compared with before treatment. The scale includes five response categories, from more noticeable to no longer noticeable, and the baseline genital photograph was shown to participants for reference. Scores of 4 or 5 were defined as representing treatment success for this measure.

This is a question about reported noticeability at a specified follow-up, not a direct comparison between treatment options. Because there is no control group and treatment is open-label, the study can describe outcomes among participants treated in this study, but it cannot isolate treatment effects from other explanations for observed changes. The registry record does not report the Week 48 percentage, the number with available Week 48 responses, or an estimate of uncertainty for that percentage.

3. Trial Design

The registry record describes a Phase 2, open-label, single-group study of ruxolitinib cream in participants with nonsegmental vitiligo involving the genital region. Allocation is listed as not applicable, and masking is listed as none. There is no randomized allocation or separate control arm described. The study is marked completed, with 49 participants enrolled. It began on 2023-04-11, and primary completion is listed as 2025-03-06.

Participants were to apply ruxolitinib 1.5% cream twice daily for up to 48 weeks. Treatment was directed to depigmented areas, up to 10% body surface area. The treatment description says baseline areas were to remain under treatment even if they began to improve or fully repigment. The registry record does not report whether every participant completed the planned treatment period or how much treatment participants received.

The primary outcome is a participant-reported measure at Week 48: the percentage with a genital Vitiligo Noticeability Scale score of 4 or 5. The scale asks how noticeable vitiligo is compared with before treatment, with a baseline genital photograph available as a reference. The record also lists secondary outcomes concerning adverse events, a clinician global assessment, genital affected body surface area, total-body VASI response thresholds, noticeability at Week 24, and color matching at Weeks 24 and 48. Results for these outcomes are not reported in the registry record.

A single-group, open-label design can describe the experience and measured outcomes of enrolled participants. It does not provide a concurrent estimate of what would have happened without the study treatment or under a different treatment. The registry record does not report further details of the protocol, the statistical plan, or the reasons for the design choices.

4. Participant Flow and Accounting

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

Before assignment: This study was conducted at 12 study centers in Canada, France, and the United States.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set: all participants enrolled in the study who applied ruxolitinib cream at least once. Only participants with available data 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 Percentage of Participants Achieving a Genital Vitiligo Noticeability Scale (VNS) of "4 - A Lot Less Noticeable" or "5 - No Longer Noticeable" at Week 48, measured over Baseline; Week 48.

The primary endpoint is the percentage of participants who report a genital Vitiligo Noticeability Scale score of 4, “A Lot Less Noticeable,” or 5, “No Longer Noticeable,” at Week 48. The scale asks participants to compare the current noticeability of vitiligo with its noticeability before treatment. Participants could refer to a baseline genital photograph while answering. The registry record defines a score of 4 or 5 as representing treatment success for this measure.

This endpoint captures the participant’s perception of visible change, rather than a clinician’s rating or a body-surface-area measurement. A patient-reported measure can address an aspect of the treatment experience that may not be fully represented by clinical assessments. It is also important to distinguish the endpoint’s definition from its result: the registry record states which responses count toward the endpoint, but does not report the percentage who met it, the number of participants with an available Week 48 response, or an interval describing precision.

Because the study is open-label, participants knew they were receiving the study treatment. In general, expectations and awareness of treatment can influence responses to subjective measures. This does not establish that responses were biased in this study, but it is relevant when interpreting a patient-reported endpoint without a masked control group. The result for the primary endpoint is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary percentage represent?

The primary endpoint is a proportion: the number of participants meeting the defined response category divided by the relevant analysis population with outcome data. The registry record defines response as a Week 48 genital Vitiligo Noticeability Scale score of 4 or 5. The record does not report the numerator, the number with available Week 48 data, or the resulting percentage. No value for this proportion can therefore be interpreted from the registry entry.

In general, a percentage communicates how common an outcome was within a specified group. Its denominator is essential. A percentage among all enrolled participants may differ from a percentage among only those with an available assessment. The registry record says that only participants with available data were analyzed for the primary outcome, but it does not report how many had such data.

How should uncertainty be understood?

In general, a confidence interval gives a range of values compatible with the observed data under a statistical procedure and its assumptions. It helps readers judge precision: a wider interval indicates more uncertainty about the underlying proportion than a narrower interval. A confidence interval does not guarantee that the true value lies within its endpoints, and it does not remedy limitations in study design.

No confidence interval or other uncertainty estimate for the primary endpoint is reported in the registry record. Without an estimate and its uncertainty, readers cannot judge how stable or precise the primary response percentage would be. The enrollment count alone does not establish precision for this endpoint because the number with available Week 48 data is not reported.

What does the single-group design imply?

The study has one treatment group and no separate comparator. In general, a within-group outcome can describe what was measured among people receiving the study treatment, but it does not establish what would have occurred in a comparison group. A before-and-after difference, if reported, would still be subject to time-related and other influences that are not separated by a concurrent control. No primary before-and-after estimate is reported in the registry record.

Open-label means participants and study personnel were not masked to treatment, according to the registry record. In general, awareness of treatment can matter especially for subjective outcomes, because expectations or awareness may influence reporting or assessment. This is a design consideration, not evidence that the reported responses in this study were affected in a particular way. The registry record does not describe additional steps to address this possibility.

What can be concluded from the listed planning assumptions?

The registry record describes a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect, and that non-time-to-event planning results are expressed as participants per arm. These are assumptions for a planning illustration, not evidence that the study was designed or analyzed as a two-arm trial.

The actual study is listed as single-group, with allocation not applicable. A two-arm planning framework does not create a control group or turn the study into a randomized comparison. The record does not report numerical planning outputs in the registry record described for this analysis, and it does not report the trial’s own sample-size justification. Such an illustration should not be read as observed power, as a test of the primary outcome, or as an estimate of treatment effect.

In general, power calculations depend on assumptions about the effect to detect, variability or event rates, allocation, significance level, and analysis method. Changing those assumptions changes the planning result. When planning uses an effect observed in the same study or another source, that observed effect is an assumption for planning rather than a guarantee of future results. The registry record does not report further details of the trial’s own design rationale.

How do multiple outcomes affect interpretation?

The registry record lists a primary outcome and several secondary outcomes, at different follow-up times and using different measures. In general, testing multiple outcomes can increase the chance of obtaining at least one apparently notable result by chance if no adjustment or prespecified testing strategy is used. Methods such as adjusting significance thresholds or ordering tests can address some multiplicity concerns, but the appropriate approach depends on the study’s statistical plan.

The record does not report a multiplicity strategy, the full statistical analysis plan, or inferential results for the listed outcomes. It is therefore not possible to determine whether any planned multiplicity control was used. The presence of several outcomes alone does not establish that results were adjusted or unadjusted.

These concepts explain how design and analysis information would ordinarily inform interpretation. They do not fill in missing results. The registry record does not report the primary endpoint estimate, its uncertainty, the analysis population count, or the methods used to analyze the endpoint.

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("Ruxolitinib 1.5% Cream BID")
n      <- c(37)
events <- c(10)
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  Ruxolitinib 1.5% Cream BID  37  10  27.0  13.8  44.1  15.4  43.0  15.4  43.1

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary outcome and multiple secondary outcomes, including assessments at Week 24 and Week 48. It does not report a strategy for controlling multiplicity, such as an adjustment procedure or a prespecified order for testing outcomes. The statistical analysis plan is not reported in the registry record. Without those details, readers cannot determine how the study handled the possibility of chance findings across several outcomes and follow-up times.

The primary population is described as enrolled participants who applied ruxolitinib cream at least once, with only participants who had available data included in the analysis. The number meeting this definition is not reported in the registry record. The count with a Week 48 primary assessment and the amount or pattern of missing outcome data are also not reported.

In general, missing outcome data can affect both the denominator and the interpretation of an estimated response. If availability is related to outcome or participant characteristics, an analysis limited to those with data may not represent all enrolled participants. This is a general concern, not evidence that missingness had a particular pattern in this study. The registry record does not report an imputation method, sensitivity analysis, or other missing-data procedure.

The full analysis set definition does not establish that all enrolled participants contributed to the primary outcome. It specifies eligibility for analysis, including having available data, but the actual analyzed number is not reported. As a result, the primary percentage and its precision cannot be assessed from the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: substance-induced psychotic disorder (2.0%).

The safety figures listed for the ruxolitinib 1.5% cream twice-daily group are 49 participants at risk for serious adverse events and 1 participant with a serious adverse event. The registry record lists 49 participants at risk and 0 participants with other, non-serious adverse events in the corresponding category. Deaths are listed as 0. The serious adverse event term identified in the record is “Substance-induced psychotic disorder,” with 2.0% shown for that term.

These entries should be read as counts and a reported percentage, not as proof of cause. The record does not establish that the serious event was caused by the study treatment. The registry entry does not provide further clinical details about the event, its timing, outcome, or relationship assessment. The term’s listed percentage should not be used to infer additional event details beyond what the record states.

In general, adverse-event counts describe events recorded during a study, while causal attribution is a separate assessment. A single-group study without a comparator cannot determine how event occurrence compares with another treatment or with no study treatment. These figures are safety observations from this study, not a comparative estimate. They do not provide a complete account of risks beyond the categories and information recorded.

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

The registry record establishes that an open-label, single-group study enrolled 49 participants with nonsegmental vitiligo involving the genital region and used ruxolitinib 1.5% cream twice daily for up to 48 weeks. It also defines the primary outcome as the percentage reporting a genital noticeability score of 4 or 5 at Week 48. The primary result itself is not reported in the registry record.

Accordingly, the record does not show the observed primary response percentage, the number of participants with available Week 48 responses, or the precision of an estimate. It also does not report results for the listed secondary outcomes. A completed study status does not indicate whether outcomes were favorable or unfavorable, and it cannot replace endpoint estimates.

The study’s design also limits what an outcome could establish. In general, a single-group study can describe observed outcomes among participants receiving treatment, but without a concurrent comparator it cannot separate treatment effects from other explanations for change. Open-label assessment is particularly relevant to a participant-reported endpoint because participants knew they were receiving the study treatment. These are limits on interpretation, not claims about what caused any individual response.

The record does not report the trial’s own sample-size justification, statistical analysis plan, multiplicity strategy, or missing-data methods. It also does not give the analysis population count. These omissions make it difficult to assess how analyses were planned and how complete the primary assessment was.

The posted information therefore supports a description of the question, treatment schedule, design, and selected safety counts. It does not support a conclusion about the primary outcome’s observed magnitude, its precision, or a causal treatment effect. Those distinctions are important when reading a registry entry that includes outcome definitions without outcome results.

14. Why This Trial Matters Statistically

This study addresses an outcome focused on genital vitiligo noticeability, a participant-reported dimension distinct from clinician global assessment or body-surface-area measurement. The registry record defines how the primary response category was constructed: scores of 4 or 5 on a five-point scale at Week 48. Defining the outcome makes the research question interpretable, even though the outcome estimate is not reported.

Statistically, the study is also an example of why design and outcome results must be read together. The open-label, single-group structure can describe participants’ measured experiences, but it does not provide a concurrent control for estimating what would have happened under another condition. A primary percentage, if available, would need to be interpreted with that limitation and with attention to who had data at follow-up.

The registry record lists 49 enrolled participants and describes a full analysis set that includes participants who applied treatment at least once and had available data. The number actually analyzed is not reported. This highlights a basic reporting need: an outcome proportion is most interpretable when readers can see both the response count and its denominator, together with uncertainty and the handling of missing assessments.

The entry also lists multiple secondary outcomes and follow-up times, while the multiplicity strategy and statistical analysis plan are not reported. In general, such information helps readers distinguish confirmatory questions from exploratory analyses and understand how statistical uncertainty was handled. Its absence does not establish that a particular procedure was omitted; it means the registry record does not document one.

The main statistical value of the record is therefore in clarifying the study framework and endpoint definition. It also illustrates why enrollment, completion status, and a clearly specified endpoint are not substitutes for outcome estimates. Since the primary result is not reported, the treatment response and its precision cannot be evaluated from 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.

The most important limitation for interpreting this study is the absence of reported results for the primary endpoint. The registry record specifies the Week 48 response definition but does not provide the observed percentage, the number meeting the definition, the number with available data, or an uncertainty estimate. Results for the listed secondary outcomes are also not reported.

The design is open-label and single-group, with no separate comparator. Thus, even if outcome estimates were available, the design would not support a direct comparison with an untreated or differently treated group. For a participant-reported noticeability measure, awareness of treatment is an additional consideration. These features limit causal interpretation but do not establish that a measured response, if reported, would be biased.

The primary analysis population is defined by treatment exposure and available data, but its size is not reported. The registry record also does not describe missing-data handling, sensitivity analyses, or the distribution of follow-up availability. This prevents assessment of how missing Week 48 responses might affect the analysis.

The statistical analysis plan, trial-specific sample-size justification, and multiplicity strategy are not reported in the registry record. The record includes a planning illustration based on a two-arm framework, but the study itself is single-group; such planning assumptions do not supply a control comparison or establish how the trial was analyzed.

Finally, the serious adverse event information is limited to counts and a listed event term. Further details about timing, outcomes, and causal assessment are not reported in the registry record. These limitations concern the information available for interpretation and should not be mistaken for evidence about unreported outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Assess the Safety and Efficacy of Ruxolitinib Cream in Participants With Genital Vitiligo — NCT05750823.
• Registry record last updated 2026-03-20; status last verified 2026-01.
• Results first posted 2026-03-20.
• 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

The registry record describes a completed Phase 2, open-label, single-group study of ruxolitinib cream in participants with nonsegmental vitiligo involving the genital region. It lists 49 enrolled participants. Treatment was ruxolitinib 1.5% cream applied twice daily for up to 48 weeks to depigmented areas, up to 10% body surface area.

The primary outcome was the percentage reporting a genital Vitiligo Noticeability Scale score of 4 or 5 at Week 48. The primary result and results for the listed secondary outcomes are not reported in the registry record. The record lists 1 participant with a serious adverse event, 0 in the other adverse-event category, and 0 deaths; the serious event term listed is “Substance-induced psychotic disorder.”

The design has no separate comparator, and the record does not report the analysis population count, statistical analysis plan, missing-data methods, or multiplicity strategy. The study description and endpoint definition can be identified, but the primary response and its precision cannot be evaluated from the registry record.