A Phase 3 Study of Efficacy and Safety of Remibrutinib in the Treatment of CSU in Adults Inadequately Controlled by H1-antihistamines: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 3 Study of Efficacy and Safety of Remibrutinib in the Treatment of CSU in Adults Inadequately Controlled by H1-antihistamines (NCT05032157), a randomized phase 3 study. The primary outcome is Mean Change From Baseline in Weekly Urticaria Activity Score (UAS7) at Week 12 (Scenario 1 With UAS7 as Primary Efficacy Endpoint).

2. Clinical Question

The question concerns a symptom score rather than a direct measure of a single symptom. UAS7 combines daily assessments of hives and itch across a week. Its possible range is 0 to 42, with higher scores indicating greater urticaria severity. The trial record describes the Week 12 change from baseline as the primary efficacy endpoint under Scenario 1. It also notes that this endpoint is secondary under Scenario 2, which uses weekly itch severity and weekly hives severity as co-primary endpoints. The statistical interpretation therefore needs to keep the endpoint’s stated scenario context in view, rather than treating every endpoint designation as interchangeable.

The comparison is between randomized groups during the blinded portion of the study. Both groups were scheduled to receive open-label LOU064 after that period, so the Week 12 comparison is distinct from the later open-label follow-up. The registry record describes a study of efficacy, safety, and tolerability; it does not report that every question about those outcomes can be answered by the Week 12 UAS7 comparison alone.

3. Trial Design

This was a multicenter, randomized, double-blind, placebo-controlled Phase 3 study with a parallel-group design. The registry record identifies quadruple masking. Enrollment is listed as 455, and the study status is completed. The recorded study start was 2021-12-01 and primary completion was 2023-12-18.

The treatment schedule had a blinded period followed by an open-label period. The LOU064 25 mg b.i.d. group received blinded LOU064 for 24 weeks and then open-label LOU064 b.i.d. For 28 weeks. The placebo group received blinded placebo for 24 weeks and then open-label LOU064 b.i.d. For 28 weeks. The record describes randomization in a 2:1 ratio of active treatment to placebo. Thus the Week 12 primary comparison occurred during the blinded, placebo-controlled phase, while later follow-up included open-label treatment in both groups.

The primary endpoint analysis population is named as the Full Analysis Set. The posted arm summaries list 297 participants for LOU064 25 mg b.i.d. and 153 for placebo for the primary outcome. These are endpoint group counts, not a substitute for details about participant flow or missing observations. The registry record does not report the specific randomization procedure, stratification factors, or the operational details behind the masking designation.

The record describes 10 outcome measures and 9 analyses. It identifies several secondary outcomes concerning disease activity control, absence of hives and itch, quality of life, angioedema-free weeks, and treatment-emergent adverse events. The listed secondary results include Week 12 and Week 2 UAS7 outcomes. Details of the original design assumptions, including the trial’s own sample-size justification, are not reported in the registry record.

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: Participants underwent a screening period of up to 4 weeks.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS)

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 Mean Change From Baseline in Weekly Urticaria Activity Score (UAS7) at Week 12 (Scenario 1 With UAS7 as Primary Efficacy Endpoint), measured over Baseline, Week 12.

The primary endpoint is mean change from baseline in UAS7 at Week 12. UAS7 assesses hives and itch separately each day. Each daily assessment combines scores on scales from 0, meaning no signs or symptoms, to 3, meaning intense signs or symptoms. Adding the daily scores across 7 days produces a weekly score from 0 to 42. A lower score therefore represents less recorded disease activity on this scale.

Change from baseline describes how the Week 12 score differs from the participant’s baseline score. The posted group means are negative, indicating decreases from baseline in both groups. The comparison of interest is the difference between those mean changes, rather than either group’s change considered in isolation. The reported measure is a least-squares mean, a model-based estimate of a group mean under the analysis model. The registry record identifies the Full Analysis Set as the population for this endpoint.

UAS7 is used because it brings two central CSU symptoms together in a repeated weekly measure. That makes it possible to describe symptom activity over a specified week rather than relying on one day’s assessment. The Week 12 endpoint is an efficacy measure; it does not by itself describe safety, quality of life, or what happened during the subsequent open-label period. The registry record also places this endpoint in two testing scenarios: primary for Scenario 1 and secondary for Scenario 2, where weekly itch and hives scores are co-primary.

7. Results Posted in the Registry

• LOU064 25 mg b.i.d.: mean -19.41 versus -11.73 on control; difference -7.68 (95% CI -9.99 to -5.37), standardized effect d = -0.64; 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.

Number of Participants Who Achieved Disease Activity Control (UAS7 =< 6) at Week 12

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • LOU064 25 mg b.i.d.: 46.8% (139/297) versus 19.6% (30/153) on control; risk difference 27.2 percentage points (95% CI 18.7 to 35.7), risk ratio 2.39 (1.69–3.36); 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 LOU064 25 mg b.i.d. than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number of Participants Who Achieved Complete Absence of Hives and Itch (UAS7 = 0) at Week 12

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • LOU064 25 mg b.i.d.: 27.9% (83/297) versus 6.5% (10/153) on control; risk difference 21.4 percentage points (95% CI 15.0 to 27.8), risk ratio 4.28 (2.29–8.00); 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 LOU064 25 mg b.i.d. than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number of Participants Who Achieved Early Onset of Disease Activity Control (UAS7 =< 6) at Week 2

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • LOU064 25 mg b.i.d.: 30.0% (89/297) versus 5.9% (9/153) on control; risk difference 24.1 percentage points (95% CI 17.7 to 30.5), risk ratio 5.09 (2.64–9.83); 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 LOU064 25 mg b.i.d. than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The posted secondary results cover related but distinct aspects of CSU. They include whether participants met a disease activity control threshold at Week 12, whether hives and itch were completely absent at Week 12, and whether control was achieved by Week 2. The registry record also identifies secondary outcomes concerning dermatology-related quality of life, cumulative weeks of disease activity control, angioedema-free weeks, and treatment-emergent adverse events.

Across the posted Week 12 and Week 2 UAS7 threshold outcomes, the pattern is directionally consistent with the primary result: the LOU064 group had more participants meeting the specified response conditions than the placebo group. These outcomes complement the continuous UAS7 change by focusing on thresholds that may be easier to interpret as defined response states. They are not the same endpoint, and the threshold results do not replace the mean-change comparison.

Secondary findings generally carry less confirmatory weight when the testing strategy and multiplicity control are unclear. Testing several outcomes creates more opportunities for apparently strong results by chance, and the registry record does not report whether these secondary p-values were adjusted or whether a hierarchical testing plan applied. The endpoint descriptions also identify different assessment times and response definitions. Their consistency can add context, but should not be treated as proof that every outcome independently confirms the primary finding.

The registry record lists 7 secondary outcomes, but results described in the posted analyses are not available for every outcome in the record excerpt. For outcomes without posted estimates or analysis details, the result is not reported in the registry record. Interpretation should therefore be limited to the specific posted comparisons and should not assume that unreported outcomes followed the same pattern.

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

• Number of Participants Who Achieved Disease Activity Control (UAS7 =< 6) at Week 12
• Number of Participants Who Achieved Complete Absence of Hives and Itch (UAS7 = 0) at Week 12
• Number of Participants Who Achieved Early Onset of Disease Activity Control (UAS7 =< 6) at Week 2
• Number of Participants Who Achieved Dermatology Life Quality Index (DLQI) = 0-1 at Week 12
• Mean Cumulative Number of Weeks With Disease Activity Control (UAS7 =< 6) up to Week 12
• Mean Cumulative Number of Angioedema Occurrence-free Weeks (AAS7 = 0 Response) up to Week 12
• Number of Participants With Treatment Emergent Adverse Events

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: each participant has a numerical UAS7 change from baseline, and the group result is reported as a least-squares mean. The sponsor’s reported method is Mixed Models Analysis, with the parameter described as a mean difference in final values. A mixed model is a general approach for estimating relationships when data have multiple measurements or grouped structure. The specific model terms, covariance structure, and handling of repeated observations are not reported in the registry record, so those details should not be inferred from the method label alone.

What does a mean difference represent?

A mean difference compares the average outcome in one group with the average outcome in another. For this endpoint, the groups are LOU064 25 mg b.i.d. and placebo, and the outcome is change in UAS7 at Week 12. The reported estimate is -7.68. The negative sign indicates that the estimated change was more negative in the LOU064 group, consistent with a larger mean decrease in UAS7. This comparison is a group-level summary; it does not mean that every participant had a change equal to the group estimate.

The registry record also includes a recalculated comparison based on posted summary statistics. That calculation uses an approximate pooled standard deviation and is explicitly an unadjusted re-calculation. Such a calculation can serve as a check on the broad scale and direction of a contrast, but it does not recreate an analysis using participant-level data or the sponsor’s full model. The approximation is particularly important when comparing its confidence limits with the sponsor’s reported interval.

What do standard errors and confidence intervals describe?

A standard error describes the uncertainty in an estimated quantity, such as a group mean. It is not the same as the spread of individual participant scores. The posted standard errors for the primary group means are 0.702 for LOU064 and 0.948 for placebo. A confidence interval uses an estimate and its uncertainty to describe a range of values compatible with the data under the analysis approach. Its interpretation depends on the model and assumptions; it is not a prediction interval for individual outcomes.

The sponsor reports a 95% confidence interval for the primary mean difference, from -9.91 to -5.46. The recalculation reports a 95% interval from -9.992 to -5.368. The intervals are both centered on the posted contrast to the reported precision, but their limits are not identical. The distinction reflects different analysis approaches and available information, not a reason to combine the intervals.

How should the p-value be read?

The sponsor reports p < 0.001 for the primary comparison. A p-value measures how incompatible the observed data are with a specified null hypothesis under the analysis assumptions. It is not the probability that the null hypothesis is true, nor does it measure clinical importance. The recalculated p-value is also < 0.001. The registry record identifies the sponsor analysis as a superiority analysis, but details of the full testing strategy and any control of error across multiple endpoints are not reported.

How do the secondary binary outcomes differ?

Some secondary outcomes count participants who meet a defined threshold, such as UAS7 at or below 6 or UAS7 equal to 0. These are binary outcomes: each participant either meets the stated condition at the assessment or does not. The reported sponsor analyses use logistic regression and report odds ratios. An odds ratio compares the odds of meeting a condition between groups; it is not the same quantity as a difference in the proportion meeting that condition. The recalculations also report risk differences, which express an absolute difference between group proportions.

Odds ratios and risk differences answer related but distinct questions, and neither should be interpreted without attention to the endpoint definition and analysis population. The registry record does not report the covariates included in the logistic models or the full handling of missing outcome data. The recalculated risk differences are unadjusted summary-statistic comparisons; sponsor-reported odds ratios are model-based results. They are not interchangeable estimates.

Finally, the Full Analysis Set is named for the primary endpoint, but its detailed operational definition is not reported in the registry record. The record also does not describe imputation procedures, sensitivity analyses, model diagnostics, or whether an interim analysis was conducted. Those omissions limit how specifically the modeling assumptions can be evaluated from the posted record alone.

11. Confidence Intervals and Precision

The sponsor’s 95% confidence interval for the Week 12 mean difference is -9.91 to -5.46, around a reported mean difference of -7.68. The interval conveys uncertainty in the estimated difference under the sponsor’s mixed models analysis. It indicates a range of contrasts compatible with the data and model at the stated confidence level; it does not describe the range of individual participant outcomes.

The unadjusted recalculation gives a 95% confidence interval from -9.992 to -5.368 for the same reported estimate of -7.68. These confidence limits come from a different calculation based on posted group summaries and an approximate pooled standard deviation. The recalculated interval is therefore best read as an independent approximation, not as an alternative sponsor analysis. The registry record does not flag a discrepancy.

Both intervals lie on the negative side of zero, consistent with the reported p-values of p < 0.001. This supports a statistically distinguishable group contrast under the analyses’ assumptions. Statistical precision does not answer whether a difference is important to patients, and the confidence interval cannot resolve questions about missing data, model specification, or the generalizability of the enrolled population.

The posted standard errors are 0.702 for the LOU064 group mean and 0.948 for the placebo group mean. They describe uncertainty in those estimated means, not the variability of individual UAS7 changes. The endpoint’s score range is 0 to 42, but the confidence interval for a between-group change is a different quantity and should not be interpreted as a range of UAS7 scores. Precision is also specific to this Week 12 comparison; it should not be carried over to the open-label follow-up or to other outcomes.

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 figures are planning illustrations based on the observed effect, not a reconstruction of the trial’s original design calculation. For these continuous and binary outcomes, the entries mean participants per arm, not total events. The assumptions used for the illustrations are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is set to the stated fraction of the observed effect.

The 80% power column gives the illustrated participants per arm for a design with an 80% chance of detecting the specified effect under those assumptions, if that effect and the other assumptions were true. The 90% power column gives the corresponding per-arm planning figure for 90% power. These are planning probabilities under an assumed effect, not guarantees about a future study. This is not observed power.

Rows using a smaller fraction of the observed effect represent a more modest difference to detect. Detecting a smaller effect generally requires more participants, which is why the planning figures increase as the target effect is reduced. These calculations assume equal allocation for illustration, while the trial record describes randomization in a 2:1 ratio. The registry record does not report the trial’s own sample-size justification or original design assumptions, so the illustrations should not be read as evidence that the completed study was planned using these inputs.

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 = -7.680; pooled standard deviation σ = 11.973.
2. n = 2 × (1.96 + 0.842)² × 11.973² / -7.680² = 38.2, rounded up to 39 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 <- -7.68                      # observed difference in means
sigma <- 11.9731512769195                     # 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(5032157)
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 = 39 (80% power), 52 (90% power)
 75% of observed effect: n per arm = 68 (80% power), 91 (90% power)
 50% of observed effect: n per arm = 153 (80% power), 205 (90% power)
power.t.test: 39.1 
Simulated power at n = 39 per arm: 0.796 (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 reported primary analysis is a Mixed Models Analysis. It estimates a mean difference of -7.68, with a 95% confidence interval from -9.91 to -5.46 and p < 0.001. This is the registry’s reported inferential result for the Week 12 primary endpoint and should be distinguished from the separate recalculation.

The recalculation uses the posted arm-level estimates and standard errors, with an approximate pooled standard deviation. It returns the same mean difference, -7.68, and p < 0.001, but its 95% confidence interval is -9.992 to -5.368. The match in the displayed point estimate does not make the two analyses identical: the sponsor’s result comes from the reported mixed model, while the recalculation is an unadjusted approximation from summary statistics.

The registry record does not flag a discrepancy. The sponsor’s analysis remains the appropriate reference for the trial’s reported inferential result, while the recalculation provides a transparent check using posted summaries. Neither should be used to infer unreported details of model specification, covariate adjustment, or missing-data handling.

15. Multiplicity, Missing Data and Analysis Populations

The registry record identifies 10 outcome measures and 9 analyses, including a primary efficacy endpoint and several secondary outcomes. It describes two testing scenarios: the UAS7 change endpoint is primary for Scenario 1, while weekly itch severity and weekly hives severity are co-primary for Scenario 2, with UAS7 described as secondary in that scenario. The detailed relationship between these scenarios and the final testing hierarchy is not reported in the registry record.

When several outcomes or hypotheses are tested, the chance of at least one apparently strong result can increase. Statistical procedures such as a prespecified hierarchy or multiplicity adjustment can address that issue, but the record does not report whether such procedures were used for the secondary outcomes or how error rates were controlled across scenarios. It is therefore not appropriate to assume that the posted secondary p-values are adjusted, or that they have the same confirmatory status as the sponsor’s primary analysis.

The primary endpoint population is identified as the Full Analysis Set. The operational definition of that set, the treatment of participants with missing Week 12 measurements, and the method used to handle missing data are not reported in the registry record. Nor are sensitivity analyses for missingness described. Missing-data choices can affect estimates when outcomes are unavailable, so the absence of these details limits assessment of robustness.

The registry record reports a mixed models method for the primary result and logistic regression for posted binary secondary analyses, but does not give full model specifications, covariates, diagnostics, or analysis code. It also does not report whether interim analyses were conducted. These are limits on the information available from the record, not evidence that a particular procedure was or was not used. The endpoint’s designation under Scenario 1 and Scenario 2 should be retained when interpreting which comparison was intended to be confirmatory.

16. 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 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: large intestine polyp (0.8%), cholecystitis acute (0.8%), vestibular disorder (0.7%), drug hypersensitivity (0.7%), appendicitis (0.7%).

The safety record lists serious adverse events for the blinded treatment groups and for participants who transitioned to open-label LOU064. There were 12 participants with serious adverse events among 297 at risk in the LOU064 25 mg b.i.d. group, 6 among 153 at risk in the placebo group, and 2 among 129 at risk in the transitioned group. The record lists zero deaths for each of these groups.

These are descriptive counts and denominators. The transitioned group reflects a different treatment period from the blinded comparison, so its count should not be read as a randomized comparison with placebo. The record also lists serious adverse-event terms with percentages, including large intestine polyp and acute cholecystitis at 0.8%, and vestibular disorder, drug hypersensitivity, appendicitis, and pneumonia at 0.7%. The record does not specify in the listed terms which treatment group each percentage corresponds to.

Serious adverse-event counts do not establish that an event was caused by treatment, and they do not summarize every aspect of safety. The registry record reports no deaths in these groups, but the posted counts alone cannot establish comparative safety across the full study without details of exposure, event ascertainment, and analysis.

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

The posted data show a larger mean decrease in UAS7 at Week 12 in the LOU064 25 mg b.i.d. group than in the placebo group. The sponsor’s mean difference is -7.68, with a 95% confidence interval from -9.91 to -5.46 and p < 0.001. The recalculated estimate has the same point estimate and a similar, but not identical, confidence interval. These are group-level estimates for the stated endpoint and time point.

The result does not show that every participant experienced the same decrease, or that every participant met a threshold response. The mean contrast cannot describe the full distribution of individual outcomes. The threshold-based secondary outcomes provide a different kind of information, but their interpretation is limited by the registry’s unreported multiplicity procedures and analysis details.

The result also does not establish a placebo-controlled effect over the entire 52-week treatment schedule. The blinded comparison lasted 24 weeks, and the primary outcome was assessed at Week 12. Both assigned groups were scheduled to receive open-label LOU064 for the following 28 weeks. Later observations therefore answer different questions from the blinded Week 12 contrast.

Nor does the primary efficacy result alone establish safety or tolerability. Serious adverse-event counts and other safety information should be interpreted separately, with attention to the duration of exposure and the distinction between blinded and transitioned participants. The record does not report all details needed to evaluate missing data, the full analysis models, or adjustment across multiple endpoints. The statistical result is evidence about the recorded comparison under its analysis assumptions; it is not medical advice or a guarantee of individual response.

18. Why This Trial Matters Statistically

This study illustrates why the definition and timing of an endpoint matter. UAS7 combines hives and itch over a week, and the primary comparison concerns change from baseline at Week 12. That is different from asking how many participants crossed a response threshold, whether symptoms were completely absent, or how outcomes changed during the open-label period. Each formulation gives a different statistical summary of the trial experience.

The primary result also shows the distinction between a sponsor-reported model analysis and a recalculation from summary statistics. The reported mean difference is -7.68 in both, but the confidence limits differ. A point estimate can agree while the uncertainty calculation reflects different information or assumptions. Keeping those methods distinct helps prevent a summary-statistic approximation from being mistaken for the trial’s full analysis.

Finally, the record highlights the importance of separating statistical evidence from its scope. The Week 12 estimate and its confidence interval address one group comparison at one assessment time. The secondary outcomes can add context, but without reported multiplicity procedures and full missing-data methods, their inferential weight is harder to assess. Clear reporting of analysis populations, model details, testing strategies, and follow-up comparisons is important for judging how far a trial result can be generalized.

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 trial-specific details needed for a full statistical appraisal are not reported in the registry record. The original sample-size justification and design assumptions are not reported, so the planning illustrations based on the observed effect should not be confused with the trial’s original power calculation. The full model specification for the primary mixed models analysis is also not reported, including its covariates and covariance structure.

The primary endpoint is described under two testing scenarios, but the final testing hierarchy and any multiplicity adjustment are not reported. This matters for interpreting the secondary p-values and for understanding the confirmatory status of results across endpoints. The registry record identifies the Full Analysis Set but does not provide its operational definition or describe how missing Week 12 outcomes were handled. Sensitivity analyses for missing data are not reported.

The primary comparison is at Week 12 during the blinded phase. Both groups were scheduled to move to open-label LOU064 after 24 weeks, which limits the scope of later randomized comparisons. Safety counts for participants transitioning to LOU064 are reported separately and should not be combined conceptually with the blinded placebo comparison. The event-term percentages are not mapped to specific groups in the record excerpt.

Finally, the posted summary estimates do not reveal participant-level score distributions or the extent of variation in individual response. The recalculation uses an approximate pooled standard deviation and is not equivalent to the sponsor’s model-based analysis. These limits do not negate the posted estimate, but they constrain how precisely its assumptions, robustness, and applicability can be evaluated from registry information alone.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Phase 3 Study of Efficacy and Safety of Remibrutinib in the Treatment of CSU in Adults Inadequately Controlled by H1-antihistamines — NCT05032157.
• Registry record last updated 2025-04-08; status last verified 2025-04.
• Results first posted 2024-11-01.
• 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

NCT05032157 is a completed, randomized, quadruple-masked, parallel-group Phase 3 study of remibrutinib in adults with chronic spontaneous urticaria inadequately controlled by H1-antihistamines. The registry record lists enrollment of 455 and describes a 24-week blinded comparison of LOU064 25 mg b.i.d. with placebo, followed by 28 weeks of open-label LOU064.

The primary Week 12 endpoint is mean change from baseline in UAS7 in the Full Analysis Set. The sponsor reports a mean difference of -7.68, a 95% confidence interval from -9.91 to -5.46, and p < 0.001. The unadjusted recalculation has the same estimate and a confidence interval from -9.992 to -5.368. The record also includes secondary efficacy outcomes and descriptive safety counts. Details of multiplicity control, missing-data handling, and the original sample-size justification are not reported in the registry record.