A Study to Evaluate Efficacy and Safety of Deucravacitinib in Participants With Active Discoid and/or Subacute Cutaneous Lupus Erythematosus (DLE/SCLE): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate Efficacy and Safety of Deucravacitinib in Participants With Active Discoid and/or Subacute Cutaneous Lupus Erythematosus (DLE/SCLE) (NCT04857034), a randomized phase 2 study. The primary outcome is Percentage Change From Baseline in CLASI Activity Score at Week 16.

2. Clinical Question

3. Trial Design

This is a randomized, quadruple-masked, parallel-group Phase 2 study of deucravacitinib compared with placebo in participants with active DLE/SCLE. The registry lists an enrollment of 74. The study start date is 2021-07-12, and the primary completion date is 2024-08-22. Its current registry status is active, not recruiting.

The placebo-controlled period includes two active-treatment groups and a placebo group in the posted primary results. The efficacy results use the labels Treatment 1 and Treatment 2, without dose descriptions in those arm records. The registry separately lists safety groups using dose labels for the placebo-controlled period and for the active-treatment period. The active-treatment-period safety results should not be read as an additional randomized placebo comparison.

The primary outcome is the percentage change from baseline in CLASI activity score at Week 16, with the timeframe described as first dose to Week 16, approximately 16 weeks. Its stated population is all treated participants in the placebo-controlled period with a post-baseline CLASI-A measurement. The registry also lists secondary clinical response outcomes based on CLASI-A and safety outcomes. The original design assumptions, including the intended allocation ratio and the original sample-size justification, are not reported in the registry record. The registry record does not report an analysis count for the posted results.

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: 74 participants randomized and 73 treated in the placebo controlled period. 18 participants who received placebo in the placebo controlled period were randomized into 2 separate treatment arms during active treatment period.

Placebo-Controlled Period

Reasons for not completing this period:

Active Treatment Period

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All Treated Participants in the Placebo Controlled Period with a post baseline measurement in CLASI-A

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 Change From Baseline in CLASI Activity Score at Week 16, measured over From first dose to Week 16 (approximately 16 weeks).

The primary endpoint is percentage change from baseline in the CLASI activity score at Week 16. CLASI is a validated clinical tool for assessing skin involvement in cutaneous lupus erythematosus. It separately assesses disease activity, including features such as erythema, scale, mucous membrane involvement, and alopecia, and damage, including dyspigmentation and scarring. The primary endpoint concerns the activity score rather than the damage score.

A percentage change expresses the change relative to a participant’s baseline activity score. In the posted results, the group means are negative, indicating a reduction from baseline on average. The endpoint is useful for comparing the degree of change in skin disease activity across the study groups at a specified follow-up time. It also retains information about the size of the change, unlike a response outcome that classifies participants according to whether they crossed a threshold.

The registry describes CLASI severity categories as mild for an activity score of 0-9, moderate for 10-20, and severe for 21-70. Those categories provide context for the underlying activity scale; they do not convert the group mean percentage changes into individual severity classifications. The primary outcome population excludes treated participants without a post-baseline CLASI-A measurement, according to the registry description. The effects of missing measurements and the specific analysis handling of those participants are not reported in the registry record.

7. Results Posted in the Registry

• Placebo-Controlled Period: Treatment 2: mean -48.93 versus -48.56 on control; difference -0.37 (95% CI -22.38 to 21.64), standardized effect d = -0.01; z-test p = 0.974.
• Placebo-Controlled Period: Placebo: mean -27.31 versus -48.56 on control; difference 21.25 (95% CI -0.06 to 42.56), standardized effect d = 0.56; z-test p = 0.051.

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.

Percentage of Participants With an Improvement of ≥ 50% From Baseline in the CLASI-A Score (CLASI-50).

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Placebo-Controlled Period: Treatment 2: 54.2% (13/24) versus 60.0% (15/25) on control; risk difference -5.8 percentage points (95% CI -33.5 to 21.8), risk ratio 0.90 (0.55–1.47); unadjusted two-proportion z-test p = 0.680.
  • Placebo-Controlled Period: Placebo: 21.7% (5/23) versus 60.0% (15/25) on control; risk difference -38.3 percentage points (95% CI -63.8 to -12.7), risk ratio 0.36 (0.16–0.84); unadjusted two-proportion z-test p = 0.007.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Placebo-Controlled Period: Treatment 2 and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Placebo-Controlled Period: Placebo than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Percentage of Participants Who Have Disease Improvement as Defined by a Reduction in CLASI-A of ≥ 4 Points From Baseline.

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Placebo-Controlled Period: Treatment 2: 66.7% (16/24) versus 60.0% (15/25) on control; risk difference 6.7 percentage points (95% CI -20.2 to 33.6), risk ratio 1.11 (0.72–1.70); unadjusted two-proportion z-test p = 0.628.
  • Placebo-Controlled Period: Placebo: 39.1% (9/23) versus 60.0% (15/25) on control; risk difference -20.9 percentage points (95% CI -48.6 to 6.8), risk ratio 0.65 (0.36–1.19); unadjusted two-proportion z-test p = 0.149.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Placebo-Controlled Period: Treatment 2 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 Placebo-Controlled Period: Placebo and the control. The interval gives the range of effects that remain compatible with the data.

Mean Change From Baseline in CLASI-A Score.

• 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:
  • Placebo-Controlled Period: Treatment 2: mean -7.50 versus -9.80 on control; difference 2.30 (95% CI -3.21 to 7.81), standardized effect d = 0.23; z-test p = 0.413.
  • Placebo-Controlled Period: Placebo: mean -4.30 versus -9.80 on control; difference 5.50 (95% CI 0.03 to 10.97), standardized effect d = 0.55; z-test p = 0.049.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Placebo-Controlled Period: Treatment 2 and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for Placebo-Controlled Period: Placebo than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The posted secondary outcomes consider several ways of describing CLASI-A change: meeting an improvement threshold, reaching a specified reduction in score, achieving a complete response, and mean change from baseline. Together, these measures offer different views of the same broad clinical domain, but they are not interchangeable. Threshold outcomes emphasize the fraction meeting a criterion; mean change summarizes the magnitude of score changes across the outcome population.

Across these outcomes, the observed pattern is mixed rather than uniformly aligned. The posted percentages and means vary between the two active groups and placebo, and the recalculated comparisons differ in their estimates and uncertainty. This context matters when relating secondary findings to the primary result: secondary outcomes can add descriptive detail, but they do not overturn or independently confirm the primary comparison. In particular, an apparent difference on one endpoint does not demonstrate that the result would persist across other definitions of response or in a prespecified analysis.

The registry record lists secondary outcomes, but reports no secondary analyses. The posted secondary comparisons are therefore simple unadjusted recalculations, not results from a documented multiplicity-controlled testing plan. When several outcomes and contrasts are examined, the chance of at least one apparently unusual result can increase even if there is no underlying difference. Without information about the prespecified testing hierarchy or adjustment procedure, an unadjusted p-value should not be treated as definitive evidence.

The endpoint definitions also affect what can be inferred. A threshold response does not describe how far a participant exceeded the threshold, and a mean can be influenced by the distribution of individual changes. These summaries complement one another, but the registry record does not provide participant-level data or detail on the distribution of outcomes. As a result, the secondary results are best used as context for the primary endpoint and as a basis for questions that would require a reported analysis plan and fuller results to answer.

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

• Percentage of Participants With an Improvement of ≥ 50% From Baseline in the CLASI-A Score (CLASI-50).
• Percentage of Participants Who Have Disease Improvement as Defined by a Reduction in CLASI-A of ≥ 4 Points From Baseline.
• Mean Change From Baseline in CLASI-A Score.
• Percentage of Participants Who Have a Complete Response (CR) on CLASI-A Defined as a Score of "0".
• Number of Participants With Safety Related Events in the Placebo Controlled Period
• Number of Participants With Safety Related Events in the Active Treatment Period
• Number of Participants With Clinically Significant Laboratory Abnormalities in the Placebo Controlled Period
• Number of Participants With Clinically Significant Laboratory Abnormalities in the Active Treatment Period

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is a continuous measure: percentage change from baseline in CLASI activity score. A continuous outcome retains the magnitude of each observation rather than reducing results to a yes-or-no response. The registry reports group means and standard deviations. The mean describes the center of the observed group results, while the standard deviation describes how widely individual results vary around that mean. Neither quantity alone describes the uncertainty in a group comparison.

What does a mean difference represent?

A mean difference compares the observed group means on the endpoint’s scale. For the comparison of Treatment 2 with Treatment 1, the recalculated mean difference is -0.37. For placebo compared with Treatment 1, it is 21.25. The sign depends on the order of the groups in the calculation. A positive value in the placebo comparison is consistent with the placebo group’s less negative mean change. This contrast is an unadjusted calculation from the posted summaries; it is not necessarily the same as a trial model that adjusts for baseline values, stratification variables, or other covariates. Such model details are not reported in the registry record.

How should the p-values be read?

A p-value describes how incompatible the observed result is with a specified null model, under the assumptions of the test. It is not the probability that the null hypothesis is true, nor does it measure the clinical importance of the estimate. The recalculated unadjusted p-values for the primary comparisons are 0.974 and 0.051. These values need to be read alongside the estimates and confidence intervals. They do not account for multiple comparisons, and the original statistical testing procedure is not reported in the registry record.

Why does variability matter?

Observed individual outcomes can vary for reasons that include genuine differences between participants and measurement variability. Standard deviations help describe that spread. Greater variability relative to the group difference generally makes an estimate less precise. The primary outcome standard deviations are 44.68 for Treatment 1, 33.3 for Treatment 2, and 29.72 for placebo. They are descriptive measures of variation within groups, not confidence limits for the group means or differences.

The recalculated mean differences use the posted group means and standard deviations. These comparisons are unadjusted and should not be confused with a sponsor’s fitted analysis. A fitted analysis might use participant-level observations and account for features of the design or data that cannot be reconstructed from group summaries. The registry record does not report a primary analysis model, covariate adjustment, or a sponsor-reported primary estimate. There is no reported discrepancy between the posted summaries and the recalculations, but that does not show that the recalculations reproduce a prespecified analysis.

What do threshold-based secondary outcomes add?

The secondary outcomes include the percentage of participants meeting CLASI-A improvement thresholds, including CLASI-50 and a reduction of at least 4 points, as well as complete response defined as a CLASI-A score of 0. These binary outcomes communicate whether a participant met a defined criterion, but they do not show the full range of changes among participants who did or did not cross the threshold. A participant just below a threshold and a participant with no improvement can fall into the same nonresponse category. Conversely, participants who meet the threshold can have different amounts of improvement.

The secondary results include recalculated risk differences for some outcomes. A risk difference contrasts the observed proportions between groups on an absolute scale. Its confidence interval communicates uncertainty about that contrast. These simple calculations do not adjust for multiple testing. The registry reports no secondary analyses, so no model-based or multiplicity-adjusted result is available for comparison in the registry record.

Why can over-dispersion matter?

Over-dispersion is a general concern for count or binary data when the observed variability is greater than a statistical model assumes. It can make standard errors too small if the model does not account for the extra variability. It is not a reported finding for this trial, and no over-dispersion assessment is reported in the registry record. The primary endpoint is continuous, so an over-dispersion explanation should not be applied to its mean comparison without evidence about the model used.

All recalculated comparisons are based on posted aggregate statistics. They cannot recover participant-level distributions, missing-data patterns, or model diagnostics. Accordingly, they offer a transparent descriptive comparison, but do not replace the analysis plan or detailed trial analysis, which are not reported in the registry record.

11. Confidence Intervals and Precision

A confidence interval gives a range of values compatible with the observed data under the method used to calculate it. It conveys uncertainty about the estimated difference; it is not a range containing a known fixed proportion of individual participant outcomes. A narrower interval indicates greater precision than a wider interval, all else equal. The posted recalculated intervals are unadjusted and should be interpreted as such.

For Treatment 2 compared with Treatment 1 on the primary endpoint, the estimated mean difference is -0.37 and the 95% confidence interval is -22.38 to 21.64. This broad interval includes zero and values favoring either direction of the contrast. The estimate is therefore imprecise relative to the range of differences compatible with these summary data. The p-value of 0.974 is consistent with the interval’s inclusion of zero, but the interval is more informative about the range of possible contrast values than a threshold label alone.

For placebo compared with Treatment 1, the estimated difference is 21.25, with a 95% confidence interval from -0.064 to 42.56. The lower limit is close to zero, and the interval includes zero while extending to a substantially larger positive difference. The p-value is 0.051. The estimate suggests a contrast in the observed group means, but the interval indicates that the size of that contrast is uncertain. A point estimate should not be interpreted as if it were known without error.

The relatively limited group sizes and observed variation are relevant to the breadth of these intervals. A confidence interval does not resolve limitations arising from the endpoint population, missing post-baseline measurements, or the absence of a reported analysis model. The registry record does not report sponsor-derived confidence intervals or a model-based primary estimate. These recalculated intervals are not adjusted for multiple comparisons and do not establish clinical importance.

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 sample-size planning figures are illustrations based on observed effects, not the original design justification for the trial. For the continuous primary endpoint, figures are participants per arm. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and detection of the stated fraction of the observed effect. The trial’s own original design assumptions are not reported in the registry record.

The 80% power column gives the illustrative number of participants per arm needed for an 80% chance of detecting the specified effect under those assumptions, if the assumptions hold. The 90% power column gives the corresponding planning number for a higher target chance of detection. These are prospective planning quantities, not a measure of how likely the completed trial was to detect an effect. The figures are not observed power.

The rows describe planning for the full observed effect and for 75% and 50% of that observed effect. The smaller the effect to be detected, the more participants are generally needed to distinguish it from random variation under the same assumptions. Because the observed primary contrast between the active groups is very small relative to its variability, its illustrative planning figures are much larger than those for the placebo comparison. These calculations are highly dependent on the observed effect and should not be treated as a recommended design for a future study.

The figures correspond to a simple two-arm comparison and do not incorporate all possible features of an actual trial design. The original protocol’s planned allocation, analysis model, attrition allowance, and design effect are not reported in the registry record. The plotted planning curve should be read as a visual representation of the same assumption-dependent relationship between effect size and required participants, rather than as additional trial evidence.

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 = -0.370; pooled standard deviation σ = 39.526.
2. n = 2 × (1.96 + 0.842)² × 39.526² / -0.370² = 179,140.7, rounded up to 179,141 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 <- -0.369999999999997                      # observed difference in means
sigma <- 39.5257444345629                     # 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(4857034)
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 = 179,141 (80% power), 239,819 (90% power)
 75% of observed effect: n per arm = 318,473 (80% power), 426,345 (90% power)
 50% of observed effect: n per arm = 716,563 (80% power), 959,275 (90% power)
power.t.test: 179141.7 
Simulated power at n = 179,141 per arm: 0.801 (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. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates several outcomes, time points, groups, or statistical contrasts. If each is tested separately without adjustment, the chance of at least one small p-value can be higher than the chance attached to any single test. This is a general statistical issue; it does not imply that any particular posted result is false. It does mean that unadjusted results from a collection of analyses should be interpreted with more caution than a single prespecified test.

The registry record lists a primary outcome and multiple secondary outcomes, including several measures of CLASI-A response and safety outcomes. It does not report a multiplicity strategy, a testing hierarchy, or secondary reported analyses. The recalculated comparisons are unadjusted. Their p-values should therefore not be interpreted as if they were protected against the multiplicity associated with examining several outcomes and contrasts. Whether the trial protocol specified a procedure is not reported in the registry record.

The primary outcome population is defined as all treated participants in the placebo-controlled period with a post-baseline CLASI-A measurement. That definition identifies the population included in the posted outcome summary, but the registry record does not explain how missing post-baseline measurements were handled, why measurements were missing, or whether any imputation or sensitivity analyses were used. It also does not report details of a primary analysis model, covariate adjustment, or the handling of intercurrent events.

These omissions limit the ability to assess whether the observed results could be sensitive to assumptions about missing outcomes or analytic choices. They also prevent verification of whether the displayed population and comparisons match the intended analysis population and prespecified plan. Such details are important because analysis choices can affect estimates and uncertainty. The registry record does not report interim analyses, stopping rules, or the original sample-size justification, so no conclusion about those aspects of the study design can be drawn from these results.

15. 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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: humerus fracture (11.1%), covid-19 (6.2%), pyrexia (4.2%), pneumonia (4.2%), stress urinary incontinence (4.2%).

The registry reports serious adverse event counts separately for the placebo-controlled period and the active-treatment period. In the placebo-controlled period, serious events affected 2 participants in the DEUC 3 mg BID group, 2 in the DEUC 6 mg BID group, and 1 in the placebo BID group. The registry lists the corresponding numbers at risk as 25, 24, and 24. In the active-treatment period, the serious-event counts are reported by treatment group, with numbers at risk also listed for each group. These are descriptive counts from the registry, not adjusted comparisons.

No deaths are listed in any of the posted safety groups. The registry also lists serious-event terms and percentages, including humerus fracture, COVID-19, pyrexia, pneumonia, stress urinary incontinence, and oral herpes. The record does not provide enough detail in these summaries to attribute a particular event to treatment or to compare event risks causally across groups. The periods and group labels should be kept distinct, and the figures should not be combined across periods. Safety interpretation requires context about event definitions, follow-up, and participant-level circumstances; those details are not reported in the registry record.

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

The posted results describe changes in CLASI activity during the placebo-controlled period and provide a basis for comparing group summaries. The primary group means were negative, indicating average reductions from baseline, while the recalculated comparisons show considerable uncertainty about the size and direction of between-group differences. These findings characterize the observed data; they do not establish that deucravacitinib causes a particular change or that any observed contrast is clinically important.

The primary endpoint is a measure of skin disease activity, not a complete measure of every aspect of cutaneous lupus or systemic lupus erythematosus. CLASI separately scores activity and damage, and the primary result addresses activity. The results do not establish effects on damage, systemic disease, long-term outcomes, or other outcomes not reported in the posted results. The registry summary describes the target population, but findings from this study should not automatically be extended to people outside that population.

The secondary outcomes offer additional descriptions of improvement, but they are unadjusted and no reported secondary analyses are listed. Their results should be considered alongside the primary comparison rather than treated as independent confirmation. Likewise, the safety summaries are counts and listed event terms; they do not by themselves identify whether an event was caused by treatment or establish comparative safety.

Important analytic details—including the original statistical plan, handling of missing outcome data, and multiplicity procedure—are not reported in the registry record. Those omissions limit how fully the posted summaries can be evaluated. The appropriate interpretation is therefore bounded: the record supplies descriptive outcome and safety summaries and simple recalculated comparisons, with uncertainty that remains substantial for the primary contrasts. It does not provide a basis for medical advice or a definitive statement that treatment does or does not work.

17. Why This Trial Matters Statistically

This study is statistically informative because it evaluates a continuous disease-activity measure alongside threshold-based response outcomes. The primary endpoint preserves information about the magnitude of change, while secondary thresholds can make response easier to describe but discard differences among participants on the same side of a cutoff. Seeing multiple outcome definitions makes it possible to recognize that interpretation may depend on the measure used.

The primary comparison also illustrates why effect estimates and confidence intervals matter together. The active-group means are close, but the uncertainty interval around their recalculated difference is broad. The placebo comparison has a larger estimated contrast, yet its interval includes zero and extends across a wide range. A single p-value cannot communicate all of that information. The posted results therefore provide an example of why precision, not just the direction of a mean or a threshold decision, is central to interpreting a trial.

The registry record also illustrates the boundary between descriptive recalculation and a prespecified clinical-trial analysis. Aggregate means and standard deviations permit simple comparisons, but they do not disclose the full model, data handling, missingness assumptions, or multiplicity approach. Those details are essential to judging whether an analysis was aligned with the planned question and how robust its inference may be.

Finally, planning illustrations based on observed effects show why sample-size requirements depend on the size of the effect a future study aims to detect. Such illustrations are not a substitute for prospective design assumptions, and the registry’s original justification is not reported. Together, these features make the record useful for learning how outcome definitions, uncertainty, analysis transparency, and planning assumptions shape statistical interpretation.

18. 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 efficacy summaries use Treatment 1 and Treatment 2 labels, but the registry does not give dose descriptions for those arms in the primary outcome results. This limits direct linkage between the posted efficacy means and the dose-labelled safety groups. The registry lists different numbers at risk for some safety summaries and primary efficacy groups, reflecting that these are outcome-specific populations; the summaries should not be treated as though they describe identical analysis sets.

The primary endpoint population includes treated participants with a post-baseline CLASI-A measurement. The registry record does not report the number of treated participants missing such a measurement, reasons for missingness, or how missing outcomes were handled. It also does not report participant-level distributions, baseline group summaries, or the original statistical model. Consequently, the recalculated comparisons cannot account for baseline adjustment or other design features that a fuller analysis might use.

Precision is limited: the primary comparison intervals are broad, and one interval includes values on both sides of zero. The estimates are unadjusted recalculations from aggregate summaries. The registry does not report multiplicity handling, a testing hierarchy, the original sample-size justification, or interim analysis details. Secondary results are also unadjusted, with no reported analyses listed. These gaps make it difficult to distinguish planned confirmatory findings from exploratory comparisons.

Safety results are reported as counts and event terms rather than a detailed causal assessment. The registry summaries do not establish whether events were treatment-related, and observations from the active-treatment period are not equivalent to the placebo-controlled comparison. Overall, conclusions should remain specific to the posted outcomes, populations, periods, and available aggregate results.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Study to Evaluate Efficacy and Safety of Deucravacitinib in Participants With Active Discoid and/or Subacute Cutaneous Lupus Erythematosus (DLE/SCLE) — NCT04857034.
• Registry record last updated 2025-09-10; status last verified 2025-08.
• Results first posted 2025-09-10.
• 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.

22. Record Summary

NCT04857034 is a randomized, quadruple-masked, parallel-group Phase 2 study comparing deucravacitinib with placebo in participants with active DLE/SCLE. The registry lists enrollment of 74 and reports a primary endpoint of percentage change from baseline in CLASI activity score at Week 16.

The posted primary group means are -48.56 for Treatment 1, -48.93 for Treatment 2, and -27.31 for placebo. Recalculated unadjusted comparisons have broad confidence intervals, including zero. Secondary outcomes describe threshold-based CLASI-A responses and mean change, while safety summaries report serious events by study period and group. The registry record does not report the original analysis plan, missing-data handling, or multiplicity procedure, so the posted summaries support cautious descriptive interpretation rather than definitive conclusions.