A Study to Assess Treat-to-Target and Dosing Flexibility of Oral Upadacitinib Tablets in Adult Participants With Moderate to Severe Atopic Dermatitis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Assess Treat-to-Target and Dosing Flexibility of Oral Upadacitinib Tablets in Adult Participants With Moderate to Severe Atopic Dermatitis (NCT05507580), a randomized phase 4 study. The primary outcome is Percentage of Participants Achieving ≥ 90% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 90) at Week 24.

2. Clinical Question

This is a treat-to-target and dose-flexibility question rather than simply a comparison of two unchanged doses. The first treatment period was randomized in a 1:1 ratio to 15 mg or 30 mg, but the subsequent single-blind dose was allocated according to the Week 12 EASI response. Thus, the Week 24 groups represent treatment sequences shaped by both initial randomized dose and response-guided reassignment. The posted Week 24 outcome describes the proportion reaching the specified EASI threshold within each sequence. The primary comparison estimates how the reported response proportion in each sequence differs from the 15 mg-to-15 mg reference pathway. It does not, by itself, isolate the effect of changing dose for otherwise identical participants, because the pathway groups were determined in part by response at Week 12.

3. Trial Design

This completed phase 4 trial is described as randomized, blinded, and sequential. It enrolled 461 participants with atopic dermatitis. The registry summary describes a 35-day screening period, a 12-week double-blind period, a 12-week single-blind period, and a follow-up visit 30 days after the last study visit. It also describes an expected enrollment of approximately 454 participants and participation at up to 160 sites worldwide; these are summary descriptions, while the record lists enrollment of 461.

During the double-blind period, participants were randomized in a 1:1 ratio to receive oral upadacitinib 15 mg or 30 mg once daily for 12 weeks. At Week 12, participants entered one of four single-blind treatment pathways. Participants who achieved at least a 90% reduction in EASI continued or moved to 15 mg; those below the EASI 90 threshold received 30 mg. The four pathways therefore combine the initial assigned dose with the Week 12 response-guided dose.

The primary Week 24 endpoint population is described as participants allocated to an assigned dose at Week 12 for the single-blind period, with available data analyzed as observed. This population definition is important: it is not simply every participant enrolled at the beginning of the trial. The registry record reports outcome percentages and confidence intervals for the four pathways. It does not report the trial's original sample-size justification, detailed statistical analysis plan, or a full account of how randomization was implemented beyond the stated 1:1 allocation.

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: The study comprised of a 35-day Screening Period, a 12-week Double-Blind Treatment Period and a 12-week Single-Blind Treatment Period. During the Single-Blind Period, participants were blinded to the upadacitinib dose and Eczema Area and Severity Index (EASI) score evaluations.

Double-Blind Treatment Period

Reasons for not completing this period:

Single-Blind Treatment Period

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT\_2) Population: all participants who were allocated to an assigned dose at Week 12 for the Single-Blind Treatment Period; participants with available data, as observed analysis

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.

Population: ITT\_1 Population: all participants who were randomized in the Double-Blind Treatment Period

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Achieving ≥ 90% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 90) at Week 24, measured over Baseline and Week 24.

The primary endpoint is the percentage of participants achieving EASI 90 at Week 24, defined as at least a 90% reduction from baseline in the Eczema Area and Severity Index score. EASI is a composite measure of atopic dermatitis severity and affected body area. The record describes four disease characteristics—erythema, thickness, scratching, and lichenification—rated from 0 (absent) through 3 (severe). It also assesses affected area across the head, trunk, upper extremities, and lower extremities, with regional area converted to a score from 0 to 6. The overall EASI score ranges from 0 to 72.

A threshold endpoint such as EASI 90 expresses whether a participant crossed a prespecified response level, rather than how much the score changed on average. This makes the result interpretable as a proportion reaching a substantial reduction from baseline. It also discards some information: participants just below and just above the threshold are classified differently even if their underlying changes are similar. For that reason, this endpoint is best read alongside the other posted response thresholds and their uncertainty, rather than as a complete account of disease activity.

The timeframe is baseline to Week 24. The registry describes the primary population as participants allocated to an assigned dose at Week 12 for the single-blind period, using available data in an observed analysis. The endpoint therefore pertains to the post-reassignment treatment pathways and the participants with available Week 24 data, as defined in the record.

7. Results Posted in the Registry

• UPA 15 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period: 48.1% (64/133) versus 74.6% (53/71) on control; risk difference -26.5 percentage points (95% CI -39.7 to -13.3), risk ratio 0.64 (0.52–0.81); unadjusted two-proportion z-test p = <0.001.
• UPA 30 mg Double-Blind Treatment Period --> UPA 15 mg Single-Blind Treatment Period: 68.5% (89/130) versus 74.6% (53/71) on control; risk difference -6.2 percentage points (95% CI -19.1 to 6.7), risk ratio 0.92 (0.77–1.10); unadjusted two-proportion z-test p = 0.357.
• UPA 30 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period: 29.3% (24/82) versus 74.6% (53/71) on control; risk difference -45.4 percentage points (95% CI -59.5 to -31.3), risk ratio 0.39 (0.27–0.56); unadjusted two-proportion z-test p = <0.001.

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 Achieving ≥ 75% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 75) at Week 24

• 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:
  • UPA 15 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period: 69.2% (92/133) versus 97.2% (69/71) on control; risk difference -28.0 percentage points (95% CI -36.8 to -19.3), risk ratio 0.71 (0.63–0.80); unadjusted two-proportion z-test p = <0.001.
  • UPA 30 mg Double-Blind Treatment Period --> UPA 15 mg Single-Blind Treatment Period: 88.5% (115/130) versus 97.2% (69/71) on control; risk difference -8.7 percentage points (95% CI -15.4 to -2.0), risk ratio 0.91 (0.85–0.98); unadjusted two-proportion z-test p = 0.034.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for UPA 15 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for UPA 30 mg Double-Blind Treatment Period --> UPA 15 mg Single-Blind Treatment Period than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Percentage of Participants Achieving a 100% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 100) at Week 24

• 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:
  • UPA 15 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period: 7.5% (10/133) versus 33.8% (24/71) on control; risk difference -26.3 percentage points (95% CI -38.2 to -14.4), risk ratio 0.22 (0.11–0.44); unadjusted two-proportion z-test p = <0.001.
  • UPA 30 mg Double-Blind Treatment Period --> UPA 15 mg Single-Blind Treatment Period: 21.5% (28/130) versus 33.8% (24/71) on control; risk difference -12.3 percentage points (95% CI -25.3 to 0.8), risk ratio 0.64 (0.40–1.01); unadjusted two-proportion z-test p = 0.058.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for UPA 15 mg Double-Blind Treatment Period --> UPA 30 mg Single-Blind Treatment Period than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between UPA 30 mg Double-Blind Treatment Period --> UPA 15 mg Single-Blind Treatment Period and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Participants Achieving ≥ 75% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 75) at Week 12

• 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:
  • UPA 30 mg Double-Blind Treatment Period: 79.3% (180/227) versus 64.4% (143/222) on control; risk difference 14.9 percentage points (95% CI 6.7 to 23.1), risk ratio 1.23 (1.09–1.39); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for UPA 30 mg Double-Blind Treatment Period than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes extend the Week 24 response picture with EASI 75 and EASI 100, and include EASI response measures at Week 12. The registry also lists combined EASI and itch response outcomes and an investigator global assessment outcome. Across these measures, the pattern is broadly consistent with the primary endpoint in showing that response proportions differ across the reported treatment pathways or initial dose groups. These outcomes add information about response thresholds and timepoints, but they do not replace the primary Week 24 EASI 90 result.

These endpoints are related because they assess different thresholds or aspects of atopic dermatitis response. A lower EASI threshold captures a broader set of responses than EASI 90, while EASI 100 represents complete reduction from baseline as defined by the score. Week 12 outcomes precede the response-guided dose assignment, whereas Week 24 outcomes follow it. That timing distinction is important: Week 12 results describe the double-blind treatment period, while the later measures reflect the subsequent treatment pathways.

The registry posts 17 secondary outcomes, but not all have reported analysis records. The numerical secondary endpoint results should be read in their tables rather than treated as a single confirmatory body of evidence. Each additional outcome and comparison creates another opportunity to observe an apparently notable result by chance. The posted secondary p-values are unadjusted, and a multiplicity procedure or prespecified hierarchy is not reported in the registry record. Consequently, secondary findings carry less inferential weight than a result supported by a clearly reported, prespecified multiplicity strategy.

In general, consistency across related measures can help describe the overall pattern, but it does not remove the need to account for multiplicity, missing data, and the response-guided structure. The secondary outcomes provide context for the primary endpoint; they should not be used selectively to make stronger claims than the registry's analysis details support.

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

• Percentage of Participants Achieving ≥ 75% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 75) at Week 24
• Percentage of Participants Achieving a 100% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 100) at Week 24
• Percentage of Participants Achieving ≥ 75% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 75) at Week 12
• Percentage of Participants Achieving ≥ 90% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 90) at Week 12
• Percentage of Participants Achieving a 100% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 100) at Week 12
• Percentage of Participants Achieving a ≥ 90% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 90) and Worst Pruritus Numerical Rating Scale of 0 or 1 (WP-NRS 0/1) at Week 12 Among Those With WP-NRS > 1 at Baseline
• Percentage of Participants Achieving a ≥ 90% Reduction From Baseline in Eczema Area and Severity Index Score (EASI 90) and Worst Pruritus Numerical Rating Scale of 0 or 1 (WP-NRS 0/1) at Week 24 Among Those With WP-NRS > 1 at Baseline
• Percentage of Participants Achieving Validated Investigator Global Assessment for Atopic Dermatitis (vlGA-AD) of 0 or 1 at Week 12

9. Statistical Interpretation

10. Statistical Methods Explained

The posted primary endpoint is binary: each participant either met the EASI 90 threshold at Week 24 or did not. The group results are percentages of participants meeting that threshold, accompanied by 95% confidence intervals. Comparisons are expressed as risk differences, with the 15 mg-to-15 mg pathway as the reference. The registry also posts unadjusted p-values for these comparisons.

What a percentage represents

For each pathway, the percentage summarizes the observed frequency of the endpoint among participants included in the stated analysis population with available data. It is not an average change in EASI score. A percentage can be useful for communicating how common the threshold response was in a group, but its precision depends on how many participants contribute data and how outcomes are distributed. The group sizes are included in the results display so readers can see the basis of the estimates.

What the confidence intervals show

In general, a confidence interval gives a range of values compatible with the observed data under the statistical method used. A narrower interval indicates greater precision; a wider interval indicates greater uncertainty. For a group percentage, the interval concerns the underlying response proportion for that pathway. For a risk difference, it concerns the difference between the reference pathway's response proportion and the comparison pathway's proportion, with the sign indicating direction according to the displayed comparison. A confidence interval is not a guarantee that the true value lies within the particular interval, and it does not address whether the comparison is free from bias.

How to read a risk difference

A risk difference compares two proportions by subtracting one from the other. Here the posted estimates are on a proportion scale, and negative estimates indicate that the comparison pathway's observed response proportion was lower than the reference pathway's. The interval indicates the uncertainty around that contrast. If the interval includes zero, the posted data are compatible with no difference as well as with differences in either direction at the interval's stated confidence level. This interpretation is statistical, not a statement about clinical importance.

Unadjusted p-values

A p-value describes how unusual data at least as discrepant as those observed would be under a specified null hypothesis and statistical model. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The primary comparison p-values are explicitly unadjusted in the posted calculations. Since multiple outcomes and comparisons appear in the record, unadjusted p-values do not account for the possibility of false-positive findings arising from examining many results. Whether the sponsor used a planned multiplicity strategy is not reported in the registry record.

Why the design affects interpretation

The initial dose was randomized, but the subsequent dose was allocated according to Week 12 EASI response. This sequence makes the Week 24 pathway groups response-selected. A comparison between pathways can reflect the dose history and differences associated with meeting the Week 12 response rule. It should not be treated as a clean randomized contrast of single-blind doses alone. The registry describes a sequential model, but further details of the statistical model or any adjustment for baseline or Week 12 characteristics are not reported.

Analysis population and missing observations

The primary endpoint population is described as participants allocated to an assigned dose at Week 12 for the single-blind period, with available data analyzed as observed. An observed-data analysis uses the recorded endpoint values rather than filling in missing values through an imputation procedure. The record does not report the amount or pattern of missing Week 24 outcome data, reasons for missingness, or sensitivity analyses addressing missing outcomes. Thus, the percentages should be understood in the context of the stated available-data population.

Details of the trial's original statistical plan, including model specifications, covariate adjustment, and planned handling of multiple comparisons, are not reported in the registry record. The results can therefore be described from their posted estimates, intervals, and unadjusted p-values, but readers should not infer unreported design or analysis choices.

11. Confidence Intervals and Precision

The results display gives 95% confidence intervals for each pathway's Week 24 EASI 90 percentage and for the risk differences against the 15 mg-to-15 mg reference. These intervals are important complements to the percentages: the point estimate is the center of the reported result, while the interval shows the range of uncertainty under the method used. The intervals differ in width across pathways and comparisons, so the estimates are not equally precise.

For the primary percentages, the posted intervals are 64.5 to 84.8 for 15 mg-to-15 mg, 39.6 to 56.6 for 15 mg-to-30 mg, 60.5 to 76.4 for 30 mg-to-15 mg, and 19.4 to 39.1 for 30 mg-to-30 mg. These ranges should be considered when comparing the apparent ordering of the point estimates. They describe uncertainty in each group proportion, not uncertainty in a direct contrast between two groups.

The risk-difference intervals directly address the contrasts. For 15 mg-to-30 mg, the interval is -0.397 to -0.133; for 30 mg-to-15 mg, -0.191 to 0.067; and for 30 mg-to-30 mg, -0.595 to -0.313. The interval for the 30 mg-to-15 mg contrast includes zero, while the other two listed intervals do not. This is consistent with the reported unadjusted p-values, but does not account for multiplicity or the response-based reassignment.

In general, confidence intervals reflect sampling variability under the analysis assumptions; they do not capture every source of uncertainty. In this trial, the available-data definition, response-guided allocation, and lack of reported details about missing-data sensitivity analyses matter in addition to interval width. The intervals do not remove those design and analysis limitations, and they do not establish the clinical importance of a difference.

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 section is a planning illustration based on the observed effect, not a report of the trial's original sample-size design. For these binary endpoints, figures are participants per arm, rather than total events. The listed assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The assumed effect to detect is the stated fraction of the observed effect. The trial's own original sample-size justification and design assumptions are not reported in the registry record.

The column for 80% power gives the illustrated number of participants per arm for a study with an 80% chance of detecting the specified effect under those assumptions, if that effect were real. The 90% power column describes the corresponding planning target for a 90% chance. These are prospective planning quantities. They do not tell us the probability that this completed trial's finding is true or whether the trial had adequate power after it was conducted; this is not observed power.

Rows that plan for a smaller fraction of the observed effect require more participants per arm. That is because smaller differences are generally harder to distinguish from random variation. The table and curve should therefore be read as sensitivity illustrations: the required group size changes as the assumed effect changes. They are not recommendations for a future study unless the assumptions are considered suitable for that separate design question.

The trial itself used a 1:1 randomized allocation during the double-blind period, but the planning illustration's equal allocation assumption does not establish that these calculations reproduce the original design. The original sample-size rationale, including any assumptions about endpoint rates or attrition, is not reported in the registry record.

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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.746; treatment proportion p₁ = 0.481; average p̄ = 0.614.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6885 = 1.3495.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6625 = 0.5576.
4. n = (1.3495 + 0.5576)² / (-0.2653)² = 51.7, rounded up to 52 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
p0 <- 0.746478873239437                          # control proportion
p1 <- 0.481203007518797                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(5507580)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 52 (80% power), 69 (90% power)
 75% of observed effect: n per arm = 90 (80% power), 120 (90% power)
 50% of observed effect: n per arm = 193 (80% power), 258 (90% power)
power.prop.test: 51.7 
Simulated power at n = 52 per arm: 0.816 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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

The record lists a primary endpoint and multiple secondary outcomes, with comparisons across treatment pathways for several measures. Testing or estimating many outcomes can increase the chance of observing a seemingly notable result even when there is no underlying effect for some comparisons. A multiplicity adjustment or a prespecified sequence for interpreting endpoints is not reported in the registry record. The posted comparison p-values are unadjusted, so they should be interpreted as individual comparisons rather than as multiplicity-controlled evidence.

The record describes the primary analysis population as all participants allocated to an assigned dose at Week 12 for the single-blind period, with available data analyzed as observed. This identifies the population and indicates that the displayed endpoint analysis uses observed data. However, the amount of missing Week 24 data, reasons for missingness, and the assumptions about why data may be unavailable are not reported in the registry record. Imputation methods and sensitivity analyses for missing outcomes are also not reported.

Missing outcomes can affect an observed-data percentage if participants with unavailable results differ from those with observed results. Without details on missingness and sensitivity analyses, the extent to which the reported percentages might be affected cannot be assessed from this record alone. The pathway group sizes in the results display should therefore be read together with the stated available-data analysis population.

The protocol's full statistical analysis plan, model details, and any interim analysis plan are not reported in the registry record. The record does not specify whether additional adjustment was used for baseline factors or for the response-based reassignment at Week 12. These gaps do not change the posted values, but they limit assessment of how fully the reported comparisons correspond to the intended confirmatory analysis.

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: acute myocardial infarction (1.4%), humerus fracture (0.8%), pyelonephritis (0.7%), coronary artery disease (0.4%), toxic nodular goitre (0.4%).

The safety display reports counts of participants with serious adverse events and counts with other adverse events, together with the group at risk. During the double-blind period, serious adverse events were reported for 8 of 229 participants in the 15 mg group and 0 of 232 in the 30 mg group. In the single-blind pathway groups, the corresponding serious adverse event counts were 1 of 72, 1 of 144, 1 of 133, and 0 of 91. The display reports 0 deaths in each listed group.

These are descriptive counts. The groups represent different treatment periods and pathways, and the registry excerpt does not provide a detailed account of exposure time or a statistical comparison of safety outcomes. The counts should not be used to rank the pathways or establish that a difference is due to dose. A serious adverse event is also distinct from the broader category of other adverse events; the table reports these separately.

The listed serious event terms include acute myocardial infarction, humerus fracture, pyelonephritis, coronary artery disease, toxic nodular goitre, and epididymitis. The posted safety counts are not a substitute for the full adverse-event record or a comparative safety analysis.

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

The posted data show the proportions achieving EASI response thresholds in the specified treatment pathways and the uncertainty around those estimates. For the primary Week 24 outcome, the reference pathway had a higher observed EASI 90 percentage than the 15 mg-to-30 mg and 30 mg-to-30 mg pathways; the 30 mg-to-15 mg pathway's estimate was also below the reference, but its risk-difference interval included zero. These are descriptions of the posted results, not medical advice or a conclusion about what an individual should receive.

The trial's sequence is central to what the comparisons mean. Initial treatment was randomized, but the single-blind dose was chosen according to whether participants reached EASI 90 at Week 12. As a result, the four Week 24 groups reflect both earlier dose assignment and response-based allocation. The comparisons cannot be interpreted as though participants were randomized at Week 12 to each later dose regardless of their response.

The record does not report a multiplicity adjustment, missing-data sensitivity analyses, or the full statistical analysis plan. The primary results are based on available observations in the stated Week 12 allocation population. These features affect how confidently the estimates can be generalized beyond the observed data and how the unadjusted comparisons should be weighed.

In general, a statistical difference and a clinically important difference are not interchangeable. The posted risk differences and p-values describe statistical evidence under the calculations shown; they do not establish the importance of a difference to patients. Nor do the endpoint results alone describe every aspect of disease activity, durability, safety, or treatment burden. The secondary and safety displays provide additional descriptive context, but their interpretation also depends on their populations, timing, and analysis details.

The most defensible reading is therefore a limited one: the registry reports differing observed Week 24 response proportions across response-guided dose pathways, with varying precision. It does not establish the causal effect of changing the single-blind dose or settle all questions about comparative benefit and risk.

17. Why This Trial Matters Statistically

This trial is statistically interesting because its treatment pathways combine randomization with response-guided reassignment. Randomization supports comparisons of the initial 15 mg and 30 mg groups during the double-blind period. At Week 12, however, participants were allocated to a subsequent dose according to EASI response. The Week 24 comparisons consequently address complete treatment sequences, not an isolated randomized contrast of later doses.

The endpoint is also a threshold response. EASI 90 gives a clear proportion-based outcome, but converting a continuous score into a threshold means that the precise score changes are not represented in the primary endpoint. The registry's additional response thresholds help give context, although their interpretation is tempered by multiple outcomes and the absence of a reported multiplicity strategy.

The primary results illustrate why point estimates, confidence intervals, population definitions, and design details need to be read together. Some contrasts have intervals that exclude zero, while another is less precise and includes zero. Yet neither statistical significance nor the apparent ranking of percentages resolves the response-selection issue. The analysis population and observed-data approach also matter when interpreting the scope of the estimates.

More broadly, this record demonstrates how a treat-to-target design can make simple group labels misleading if the later treatment assignment depends on an earlier outcome. A transparent account of the estimand, missing-data approach, multiplicity plan, and model would help readers understand exactly which causal or descriptive question the primary analysis was designed to answer. Those details are not reported in the registry record, so interpretation should stay close to the estimates and design features that are posted.

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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several trial-specific features limit what can be concluded from the posted endpoint results. First, the Week 24 pathways were formed using the Week 12 EASI response rule. Pathway comparisons therefore combine dose history with response-based selection and are not equivalent to an unrestricted randomized comparison of the later doses. The registry record does not report a statistical adjustment designed to address this feature.

Second, the primary population is restricted to participants allocated to an assigned dose at Week 12, and the analysis uses available observed data. The record does not report the number or pattern of missing Week 24 outcomes, reasons for missingness, imputation, or sensitivity analyses. The resulting percentages should not automatically be interpreted as estimates for every participant initially enrolled.

Third, the results include multiple secondary outcomes and comparisons, while the reported p-values are unadjusted. A multiplicity plan or hierarchy is not reported in the registry record. The analysis model, covariate adjustments, and original sample-size justification are also not reported, limiting independent assessment of the planned inferential framework.

Finally, the posted results focus on threshold response percentages. They do not, by themselves, convey the full distribution of EASI changes or establish clinical importance. Safety counts are descriptive, and the excerpt does not provide a comparative safety model or details needed to interpret differences in exposure across periods. These limitations do not invalidate the posted estimates, but they constrain causal and confirmatory interpretations.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Study to Assess Treat-to-Target and Dosing Flexibility of Oral Upadacitinib Tablets in Adult Participants With Moderate to Severe Atopic Dermatitis — NCT05507580.
• Registry record last updated 2025-07-29; status last verified 2025-07.
• Results first posted 2025-07-29.
• 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

This completed phase 4 study evaluated treat-to-target and dose flexibility of oral upadacitinib in adults with moderate to severe atopic dermatitis. The registry describes randomized 15 mg or 30 mg treatment during a 12-week double-blind period, followed by a 12-week single-blind period in which dose allocation depended on Week 12 EASI response. The record lists 461 enrolled participants.

The primary endpoint was the percentage achieving EASI 90 at Week 24. The posted results report response percentages, confidence intervals, and unadjusted comparisons for four treatment pathways. The primary analysis population comprised participants allocated to a Week 12 single-blind dose, with available data analyzed as observed. The record also includes secondary outcomes and descriptive adverse-event counts.

Multiplicity handling, missing-data sensitivity analyses, the complete statistical plan, and the original sample-size justification are not reported in the registry record. The response-guided allocation is important when interpreting pathway comparisons.