Efficacy and Safety of LEO 19123 Cream in the Treatment of Psoriasis Vulgaris: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy and Safety of LEO 19123 Cream in the Treatment of Psoriasis Vulgaris (NCT00764751), a randomized phase 2 study. The primary outcome is The Percentage Change in PASI (Psoriasis Area Severity Index).

2. Clinical Question

The trial examined treatment of psoriasis vulgaris with LEO 19123 cream, a combination of calcipotriol and LEO 80122. Its primary question concerned percentage change in the Psoriasis Area Severity Index (PASI) from baseline (Day 0) to the end of treatment (Day 28). The registry describes a four-week study comparing once-daily LEO 19123 cream with Dovonex® cream applied twice daily and with cream vehicle applied twice daily.

The treatment arrangement was side-based: participants applied LEO 19123 cream to psoriasis lesions on one side of the body and either Dovonex® cream or vehicle to lesions on the other side. The results distinguish Group A, which contributes LEO 19123 and Dovonex® observations, from Group B, which contributes LEO 19123 and vehicle observations. These paired treatment comparisons are important when interpreting the sponsor’s analysis.

The registry does not report the exact body-side assignment procedure or the precise masking arrangements. It also does not report a formal hypothesis statement defining a preferred treatment comparison or a clinically important difference in PASI. Accordingly, the posted results describe changes and comparisons in PASI but do not, on their own, define what size of change would matter clinically.

The clinical question is therefore about the observed short-term PASI changes under these treatment conditions, and about how the within-participant comparisons were analyzed. The posted results also include secondary measures of disease severity, treatment response and preference, alongside adverse-event counts. Their interpretation depends on the distinction between the paired comparisons described by the trial and recalculations that use separate arm-level summary statistics.

3. Trial Design

This was a completed Phase 2 randomized, single-masked, parallel-group trial sponsored by LEO Pharma. The registry reports enrollment of 51. The study began in 2008-09 and reached primary completion in 2008-12. The registry describes treatment for four weeks, with the primary outcome assessed from baseline (Day 0) to Day 28.

The treatment procedure was side-based. Each participant applied LEO 19123 cream to lesions on one side of the body and either Dovonex® cream or cream vehicle to lesions on the other side. Group A results are reported for LEO 19123 and Dovonex®; Group B results are reported for LEO 19123 and vehicle. Arm-level outcome records list 39 observations for each Group A treatment and 12 for each Group B treatment. These are outcome-specific reported counts; the registry record does not explain the difference between the enrolled number and the counts shown for these results.

The registry classifies allocation as randomized and masking as single, but the method used to generate the random sequence, allocation concealment, and which people were masked are not reported in the registry record. Nor is the method for assigning treatments to body sides reported. The registry labels the study model parallel, while the treatment description specifies comparisons between different sides of a participant’s body. That side-based feature matters because the sponsor’s reported analyses use paired t-tests.

The original sample-size justification, target enrollment, and design assumptions are not reported in the registry record. The planning illustrations associated with the posted results use assumptions based on observed effects; they should not be mistaken for the trial’s original design rationale. The registry does not report whether there were interim analyses, protocol amendments, or deviations from the planned design.

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 Percentage Change in PASI (Psoriasis Area Severity Index), measured over From baseline (Day 0) to end of treatment (Day 28).

The primary endpoint was the percentage change in PASI from baseline (Day 0) to the end of treatment (Day 28), reported as a mean with a standard deviation. PASI is a measure of psoriasis severity that combines scores for redness, thickness, scaliness, and extent across body regions. The registry describes a modified PASI that excludes the head because study treatment was not used there. The total modified score can range from 0 to 64.8.

A percentage change expresses the change relative to a participant’s baseline PASI, rather than simply reporting the final score. In the posted arm summaries, negative mean percentage changes indicate that PASI decreased on average over the treatment period. The mean describes the average change in the recorded group; the standard deviation describes how much individual changes varied around that average. The average alone does not show whether changes were similar across participants.

PASI is used in psoriasis trials because it combines several features of disease severity into a single measure that can be compared over time. The registry also lists secondary outcomes that assess investigator and participant judgments, threshold reductions in PASI, and absolute PASI change. These measures address related but not identical aspects of response. The registry record does not report a clinically important threshold for the primary percentage-change measure, so the size of an observed change should be considered alongside its uncertainty and the paired comparison structure.

7. Results Posted in the Registry

• Group A: LEO 19123: mean -24.80 versus -29.80 on control; difference 5.00 (95% CI -10.76 to 20.76), standardized effect d = 0.16; z-test p = 0.534.
• Group A: Dovonex®: mean -40.20 versus -29.80 on control; difference -10.40 (95% CI -25.10 to 4.30), standardized effect d = -0.39; z-test p = 0.165.
• Group B: LEO 19123: mean -46.80 versus -29.80 on control; difference -17.00 (95% CI -36.32 to 2.32), standardized effect d = -0.70; z-test p = 0.085.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

The Absolute Change in PASI (Psoriasis Area Severity Index)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Group A: LEO 19123: mean -2.60 versus -2.50 on control; difference -0.10 (95% CI -1.83 to 1.63), standardized effect d = -0.03; z-test p = 0.910.
  • Group A: Dovonex®: mean -3.80 versus -2.50 on control; difference -1.30 (95% CI -2.94 to 0.34), standardized effect d = -0.39; z-test p = 0.120.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Group A: LEO 19123 and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Group A: Dovonex® and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover several perspectives: investigator-rated disease severity and control, participants’ overall assessment and treatment preference, threshold reductions in PASI, and absolute PASI change. These outcomes are related to the primary PASI measure but are not identical to it. Some describe categorical thresholds or judgments, while absolute change retains the PASI scale rather than expressing change as a percentage.

The posted absolute-change summaries show decreases on average across the treatment records, broadly aligning in direction with the negative mean percentage changes in the primary outcome summaries. That directional consistency is contextual, not an independent confirmation of a treatment effect. The comparisons remain subject to the same distinction between within-participant treatment contrasts and arm-level summaries.

The registry lists the investigator and participant assessments and PASI threshold outcomes, but results for those named outcomes are not reported in the registry record. The posted secondary results therefore do not offer a complete picture across all listed measures. Nor does the record report paired inferential analyses for the absolute-change endpoint.

In general, multiple secondary outcomes raise the chance of seeing apparently noteworthy results by chance when each is examined separately. Unless an analysis plan specifies which comparisons are confirmatory and how multiplicity is handled, unadjusted secondary results carry less evidential weight than a prespecified primary analysis. The registry does not report a multiplicity strategy or hierarchy for secondary outcomes. These measures can help describe the pattern of recorded outcomes, but the record does not establish that they provide formal, multiplicity-controlled corroboration of the primary result.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Investigator's Global Assessment of Disease Severity
• Participants With "Controlled Disease" According to the Investigator's Global Assessment of Disease Severity
• Participant's Overall Assessment of Treatment Response
• Participant's Assessment of Treatment Preference
• Participants With at Least 75% Reduction in PASI (PASI 75)
• Participants With at Least 50% Reduction in PASI (PASI 50)
• The Absolute Change in PASI (Psoriasis Area Severity Index)

9. Statistical Interpretation

10. Statistical Methods Explained

Several statistical features are needed to read these results carefully. The key distinction is between a paired comparison, which uses the relationship between two measurements from the same participant, and a comparison calculated from separate group summaries. The trial’s treatment description is side-based, and the sponsor reports paired t-tests for the treatment contrasts.

What does a paired t-test estimate?

A paired t-test analyzes within-participant differences. For each participant, it takes the outcome under one treatment and compares it with the outcome under the other treatment. The test then summarizes the average of those individual differences and its uncertainty. Because both measurements come from the same participant, the analysis can account for how strongly the two measurements are related. This is suited to a design in which treatments are applied to different sides of the same person, provided that the analysis uses the intended paired observations.

The registry reports paired t-tests for Group A and Group B, with mean differences in final values, confidence intervals, and p-values. It does not report the individual paired observations, the standard deviation of the paired differences, or further details of the test. The reported entries also do not explicitly state the subtraction order in words. Those omissions limit independent reconstruction of the sponsor’s test and interpretation of the signed differences.

What are the recalculations?

The recalculated comparisons use posted arm means and standard deviations to form simple, unadjusted comparisons. Unlike the sponsor’s paired tests, they do not use the participant-level pairing. They also compare Group A treatment summaries with the Group B vehicle summary. That is a different comparison from the sponsor’s within-group treatment contrasts. The recalculations are useful as a check on what the arm-level summaries suggest, but they do not supersede the sponsor’s own analysis when the two differ.

A mean difference is an estimate of how far apart two averages are on the outcome scale being analyzed. A confidence interval describes a range of values compatible with the estimate under the statistical method and its assumptions. An interval that includes zero indicates that values corresponding to no average difference are among those compatible with the data under that calculation. It does not establish that the treatments are equivalent, and it does not rule out differences elsewhere in the interval.

How should standard deviations and standard errors be read?

The standard deviation describes variability among participant outcomes within a group. The standard error describes uncertainty in an estimated mean or contrast. In general, the standard error depends on both variability and the amount of information available. A larger standard deviation or fewer observations tends to make an estimate less precise. For paired data, the variability of within-participant differences is especially relevant; arm-level standard deviations alone do not show the correlation between the two sides.

Over-dispersion is a general concern when outcome variability is greater than a model assumes. In that situation, uncertainty can be understated if the model does not account for the extra variability. The registry record does not describe a model-based analysis or an over-dispersion assessment for this continuous endpoint. The posted summaries do show standard deviations, but they cannot establish whether every model assumption was checked.

What do the p-values say?

A p-value describes how inconsistent data would be with a specified null hypothesis under the test’s assumptions. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. The sponsor reports p-values from paired t-tests. The recalculated p-values are unadjusted and derive from a different comparison method. The registry record does not report the planned significance threshold for the primary analysis or a multiplicity adjustment, so the p-values should be read as components of the reported analyses rather than as a complete decision rule.

In general, statistical estimates should be interpreted together: the estimated contrast gives a direction and magnitude on its scale, the confidence interval indicates precision, and the analysis method determines which observations and dependence structure were used. In this trial, the paired design and the difference between final-value analyses and the percentage-change primary endpoint are central to that interpretation. The registry does not report enough detail to reconcile those aspects fully.

11. Confidence Intervals and Precision

Confidence intervals communicate uncertainty around estimated treatment differences. The sponsor reports 95% confidence intervals from paired t-tests. For Group A, the interval runs from 5.6 to 25 around a reported mean difference of 15.4. For Group B, it runs from -36.0 to 1.9 around a reported mean difference of -17.1. The Group A interval does not include zero, while the Group B interval does. The latter therefore accommodates a range that includes no difference as well as differences in either direction.

The intervals differ in width, which indicates different precision in the reported contrasts. The Group B estimate is particularly uncertain: its interval covers a broad range of values. That uncertainty should not be reduced to whether a p-value is on one side or another of a cutoff. The registry does not report a prespecified clinical threshold for interpreting these differences, so the interval cannot by itself determine whether any compatible value would be clinically important.

The simple recalculations also have confidence intervals, but they are based on arm-level summary statistics and a different comparison from the sponsor’s paired analysis. Their intervals include zero. Because they do not use the within-participant pairing and do not estimate the sponsor’s within-group contrasts, they should not be used to replace the sponsor’s intervals.

In general, confidence intervals depend on the statistical method and assumptions used. They are not guarantees that the true effect lies within the displayed range, and they do not account for unreported sources of bias or uncertainty. The registry does not provide the paired participant-level data needed to independently reproduce the sponsor’s interval or assess the within-participant variability. The reported intervals are consequently the most direct guide to the precision of the sponsor’s own contrasts, while the recalculations are secondary, method-dependent checks.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect to detect is set at the stated fraction of the observed effect: 100%, 75%, or 50%. These are planning illustrations based on the observed effect, not the trial’s original sample-size assumptions, which are not reported in the registry record.

The 80% power column gives the illustrative number of participants per arm under which the calculation would have an 80% chance of detecting the specified effect, if the planning assumptions and effect were correct. The 90% power column gives the corresponding planning number for a higher probability of detecting that effect. These are design calculations, not guarantees about the result of a future study.

Smaller effects generally require more participants to detect, because a smaller difference is harder to distinguish from the variation in outcomes. That is why the rows planning for 75% or 50% of the observed effect require larger per-arm numbers than planning for the full observed effect. The illustrations also assume equal allocation even though the reported outcome counts in this trial are not equal across its two comparison groups.

These figures are not observed power. Observed power is not a useful substitute for examining the effect estimate and its confidence interval after a study. The planning figures instead show how sample-size requirements can change under stated assumptions about the effect size, allocation, significance level, and desired power. They should not be read as evidence that the trial had adequate or inadequate power under its original design, since that design rationale is not reported.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 5.000; pooled standard deviation σ = 30.868.
2. n = 2 × (1.96 + 0.842)² × 30.868² / 5.000² = 598.3, rounded up to 599 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 5                      # observed difference in means
sigma <- 30.8683941127821                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(764751)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 599 (80% power), 801 (90% power)
 75% of observed effect: n per arm = 1,064 (80% power), 1,424 (90% power)
 50% of observed effect: n per arm = 2,394 (80% power), 3,204 (90% power)
power.t.test: 599.3 
Simulated power at n = 599 per arm: 0.802 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The sponsor’s own reported analyses are paired t-tests, matching the side-based treatment comparisons described in the registry. Group A’s reported mean difference in final values is 15.4, with a 95% confidence interval from 5.6 to 25 and p = 0.003. Group B’s reported mean difference is -17.1, with a 95% confidence interval from -36.0 to 1.9 and p = 0.07.

The simple recalculations use arm-level means and standard deviations rather than paired participant-level differences. They also compare Group A summaries with Group B’s vehicle summary, not the same within-participant contrasts reported by the sponsor. This difference in comparison and method means the recalculations are not a replication of the sponsor’s analysis. The posted recalculated contrasts have confidence intervals that include zero, but they should not be used to overrule the paired results.

The registry record does not report enough detail to independently reproduce the paired tests, including the variability of paired differences and the subtraction order for the reported mean differences. It also reports the sponsor’s contrasts as final values, while the primary endpoint is percentage change from baseline. Because the record does not explain the relationship between these measures, they should not be treated as interchangeable. Given the recorded discrepancy, the sponsor’s own analysis takes precedence over the simple recalculations.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary endpoint and lists secondary outcomes, but it does not report how the family of statistical tests was handled. The approach to multiplicity—whether outcomes or treatment comparisons were prioritized, whether p-values were adjusted, or whether a hierarchy was used—is not reported in the registry record. Without that information, unadjusted secondary results should be regarded as exploratory context rather than as a set of independent confirmatory tests.

The record does not report the statistical analysis plan, the planned significance threshold for the primary analysis, or whether the reported analyses were prespecified. It gives the sponsor’s paired t-test results, but does not describe further model details or state how the final-value contrasts relate to the percentage-change primary endpoint. The subtraction order for the sponsor’s reported mean differences is also not stated in words.

Missing-data handling and analysis populations are not reported in the registry record. It is not stated whether all randomized participants were included, how missing endpoint observations were addressed, or whether any participants were excluded from particular analyses. The outcome records list group counts, but do not explain reasons for those counts or how they relate to enrollment. The registry record also does not report imputation, sensitivity analyses, or rules for handling incomplete paired observations.

The randomization method, allocation concealment, and the identity of the masked parties are not reported. Nor is there information about interim analyses or monitoring of the primary outcome during the trial. These omissions do not establish that such procedures were absent; they mean the registry record does not report them. Consequently, interpretation must rely on the posted outcome definitions and analyses while recognizing that important details needed to assess analysis choices and potential bias are unavailable.

16. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cholecystitis (2.6%).

The registry reports serious and other adverse-event counts by Group A and Group B, rather than by each individual treatment side. In Group A, 1 participant was reported with a serious adverse event among 38 at risk; in Group B, 0 were reported among 12 at risk. Other adverse events were reported for 15 among 38 at risk in Group A and 6 among 12 at risk in Group B. These are group-level counts and do not identify which treatment was associated with an event within a participant.

Cholecystitis is listed as the top serious adverse-event term, with 2.6%. The registry does not provide enough context in this record to interpret that term as a treatment-specific rate or to determine a causal relationship. Death counts are not reported in the registry record.

These figures describe events recorded during the study; they do not establish whether an event was caused by study treatment. The registry does not report event-level timing, severity beyond the serious classification, exposure-adjusted analyses, or a detailed account of how adverse events were collected. The group counts should therefore be read as a limited descriptive safety record, not as a definitive comparison of treatment risks.

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

The results describe short-term changes in modified PASI during treatment for psoriasis vulgaris. The arm summaries show average decreases from baseline across the reported treatment records. The sponsor’s paired analyses estimate within-participant differences in final values for the Group A and Group B comparisons, with different degrees of precision. These are the central statistical observations in the registry record.

Those observations do not, by themselves, establish a treatment effect or a clinically important benefit. The registry does not report a threshold for clinical importance, and the sponsor’s contrasts are reported for final values rather than the percentage-change primary endpoint. The record does not explain the relationship between those analyses. The Group B confidence interval spans values consistent with no difference as well as differences in either direction, while the Group A estimate has a narrower interval that does not include zero under the reported method.

The simple recalculations are not equivalent to the sponsor’s paired comparisons. They use arm-level summaries and compare across Group A and Group B, so they cannot resolve the sponsor’s within-participant treatment contrasts. Because the record identifies a discrepancy, the sponsor’s own analysis takes precedence. Interpretation should not combine the two approaches as though they estimated the same quantity.

The trial was a Phase 2 study with four weeks of treatment. The record does not report longer-term outcomes, a complete analysis plan, multiplicity handling, missing-data methods, or detailed analysis populations. It also does not report results for several named secondary outcomes. These gaps constrain conclusions about durability, robustness, and the consistency of findings across outcomes.

In general, statistical evidence is most informative when the design, estimand, analysis population, and uncertainty estimate align clearly. Here, the paired treatment arrangement and sponsor analysis are relevant, but important analytic details are unavailable. The results should therefore be understood as estimates from the posted short-term data, with uncertainty and reporting limitations, rather than as a final determination about treatment performance.

18. Why This Trial Matters Statistically

This trial illustrates why design structure matters when interpreting clinical results. Although the registry classifies the study as parallel-group, the treatment description compares creams applied to lesions on different sides of the same participant’s body. Such observations are paired: measurements from the same person can be related, and a paired analysis can use that relationship. The sponsor’s use of paired t-tests reflects this feature.

The record also shows why it is important to distinguish an endpoint from the analysis reported for it. The primary endpoint is percentage change in PASI from baseline to Day 28, whereas the sponsor reports mean differences in final values. The registry does not explain their relationship. A result can be statistically precise for one measure without directly answering the question posed by another measure.

A further lesson is that recalculation from group summaries is not always a neutral check. When the design is paired, an analysis that ignores pairing can estimate a different contrast and have different uncertainty. Here, the recalculations also compare arm summaries from different treatment groups, rather than reproducing the sponsor’s within-participant analyses. Recognizing that mismatch prevents a misleading side-by-side reading of estimates and p-values.

Finally, confidence intervals, secondary outcomes, and planning calculations each answer different questions. Intervals describe uncertainty around estimates; secondary outcomes broaden the clinical description but require attention to multiplicity; planning illustrations show how assumptions affect future sample-size requirements. None can replace a transparent account of the original statistical plan, which is not reported in the registry record.

19. 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 are specific to interpreting this record. The primary outcome is percentage change in PASI, but the sponsor’s reported paired analyses concern final values. The registry does not explain whether the paired final-value results correspond to a separate analysis, how they relate to the primary endpoint, or which direction the reported mean differences use. This leaves uncertainty about how directly the sponsor’s tests answer the stated primary question.

The recalculated comparisons do not match the sponsor’s paired design. They use summary statistics and compare Group A arms against Group B vehicle, so they are not within-participant contrasts. The paired participant-level data and variability of paired differences are not reported, preventing independent reproduction of the sponsor’s confidence intervals and tests. In view of the recorded discrepancy, the sponsor’s analysis takes precedence.

The outcome counts reported for the arms do not account for the enrolled number in the registry record, and reasons for the differing counts are not reported. The registry also does not report analysis populations, missing-data handling, or whether all randomized participants contributed to each endpoint. The original sample-size rationale and any planned treatment-effect assumptions are not reported; planning illustrations based on observed effects cannot fill that gap.

Other details that could affect interpretation are not reported in the registry record: the randomization method, allocation concealment, masking roles, body-side assignment procedure, multiplicity strategy, prespecification of the analyses, or interim analyses. Results for several listed secondary outcomes are also not reported. The brief treatment period limits the record to short-term outcomes, and longer-term results are not reported in the registry record.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Efficacy and Safety of LEO 19123 Cream in the Treatment of Psoriasis Vulgaris — NCT00764751.
• Registry record last updated 2025-03-07; status last verified 2018-02.
• Results first posted 2019-05-06.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

23. Record Summary

The registry record describes a completed, randomized, single-masked Phase 2 study sponsored by LEO Pharma, with enrollment of 51 and treatment over four weeks. Participants applied LEO 19123 cream to lesions on one side and either Dovonex® cream or vehicle to the other. The primary endpoint was percentage change in modified PASI from baseline (Day 0) to Day 28.

All posted primary arm means are negative. The sponsor reports paired t-tests for the Group A LEO 19123–Dovonex® comparison and the Group B LEO 19123–vehicle comparison. Simple recalculations from arm summaries do not reproduce those paired contrasts; the sponsor’s analysis takes precedence. The record does not report the original sample-size justification, multiplicity approach, missing-data methods, or enough detail to independently reconstruct the paired analyses. Safety counts are reported by group, not by treatment side.