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Allergy, Peanut Phase 3 Binary Endpoint NCT04984876

Efficacy and Safety of QGE031 (Ligelizumab) in Patients With Peanut Allergy: Complete Statistical Analysis

This analysis examines the Week 12 peanut-protein challenge outcome in a randomized Phase 3 ligelizumab trial, alongside the registry’s secondary outcomes, safety figures and sponsor-reported analyses. The trial record is marked terminated.

Trial start: 2021-12-07  ·  Enrollment: 211  ·  Sponsor: Novartis Pharmaceuticals
Scope of this record

This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.

1. Trial at a Glance

This page covers the registry results for Efficacy and Safety of QGE031 (Ligelizumab) in Patients With Peanut Allergy (NCT04984876), a randomized phase 3 study. The primary outcome is Percentage of Participants Who Tolerated a Single Dose of >= 600 mg (1044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12.

211
Enrollment
Phase 3
3
Arms
In the primary outcome
+40.3 pts
Risk difference
Ligelizumab 240 mg
23.9 to 56.8 pts
95% CI
Two-sided
FeatureRegistry value
ClinicalTrials.gov identifierNCT04984876
PhasePhase 3
ConditionAllergy, Peanut
AllocationRandomized
Design modelParallel
MaskingTriple
Enrollment211
Arms in the primary outcome3
Lead sponsorNovartis Pharmaceuticals
Results postedYes

2. Clinical Question

Population

Participants had a medically confirmed diagnosis of immunoglobulin E (IgE)-mediated peanut allergy. The primary outcome applied to the Full Analysis Set. The registry describes the primary population as including the ligelizumab 120 mg arm, the ligelizumab 240 mg arm and the placebo-to-ligelizumab arm, with the latter labelled as placebo for efficacy estimands.

Intervention

The study assessed two ligelizumab regimens: 120 mg and 240 mg by subcutaneous injection every four weeks. The primary Week 12 result compares each dose arm with placebo; it does not report a direct randomized comparison between the two ligelizumab doses.

Comparator

The primary outcome record identifies the placebo group as the comparator. The arm descriptions also include staged regimens in which placebo was given before ligelizumab. For the primary efficacy estimands, the placebo-to-ligelizumab arm is labelled as placebo. The registry record does not give further detail on how that estimand label was applied in the analysis.

Primary question

At Week 12, what proportion of participants tolerated a single peanut-protein dose of >= 600 mg, corresponding to a cumulative tolerated dose of 1044 mg, without dose-limiting symptoms during the double-blind placebo-controlled food challenge? The outcome is a challenge-based measure of the amount of peanut protein tolerated under the trial’s assessment conditions. It is not, by itself, a measure of reactions outside the study challenge or of longer-term outcomes.

3. Trial Design

The registry describes NCT04984876 as a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study of ligelizumab in participants with peanut allergy. Masking is recorded as triple. The study’s official title describes a 52-week assessment of clinical efficacy and safety; the brief summary identifies subcutaneous ligelizumab regimens of 240 mg and 120 mg every four weeks. Enrollment is recorded as 211.

The listed treatment arms include ligelizumab 120 mg or 240 mg throughout the treatment period, as well as groups that began with placebo and later received ligelizumab. In the staged regimens, placebo was given for the first 8 or 16 weeks, followed by ligelizumab for the remainder of the described treatment period. For the primary outcome, the registry identifies the 120 mg and 240 mg arms and the placebo-to-ligelizumab arm labelled as placebo for efficacy estimands. The posted primary counts compare each active-dose group with the placebo comparator; they do not establish a direct comparison between the two active doses.

The study start is recorded as 2021-12-07 and primary completion as 2023-11-27. The current status in the registry record is terminated. The reason for termination, the number who completed follow-up, and the relationship between termination and the planned treatment schedule are not reported in the registry record. The original design’s sample-size justification, allocation ratio, detailed analysis plan and any interim-analysis plan are also 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.

Overall Study

StageLigelizumab 240 mgLigelizumab 120 mgPlacebo 8 Weeks and Ligelizumab 240 mgPlacebo 8 Weeks and Ligelizumab 120 mgPlacebo 16 Weeks and Ligelizumab 240 mgPlacebo 16 Weeks and Ligelizumab 120 mg
STARTED475146441112
Randomized Analysis Set (RAS)475146441112
Full Analysis Set (FAS)475146441112
Safety Set (SAF)475146441112
COMPLETED44404137811
NOT COMPLETED3115731

Reasons for not completing this period:

ReasonLigelizumab 240 mgLigelizumab 120 mgPlacebo 8 Weeks and Ligelizumab 240 mgPlacebo 8 Weeks and Ligelizumab 120 mgPlacebo 16 Weeks and Ligelizumab 240 mgPlacebo 16 Weeks and Ligelizumab 120 mg
Subject decision2103330
Guardian decision010201
Lost to Follow-up001100
Physician Decision100100
Adverse Event001000

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS). This outcome measure applies to ligelizumab 120 mg arm, ligelizumab 240 mg arm, and placebo 16-week to ligelizumab 120/240 mg arm (labelled as placebo for efficacy estimands).

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.

Only the first 6 of 7 groups are shown.

CharacteristicUnitLigelizumab 240 mgLigelizumab 120 mgPlacebo 8 Weeks and Ligelizumab 240 mgPlacebo 8 Weeks and Ligelizumab 120 mgPlacebo 16 Weeks and Ligelizumab 240 mgPlacebo 16 Weeks and Ligelizumab 120 mg
Participants analysed475146441112
Age, ContinuousYears19.5 (SD 7.50)18.8 (SD 6.27)18.7 (SD 6.95)20.0 (SD 7.75)17.4 (SD 4.57)16.1 (SD 3.58)
Age, Customized: 12 - 17 yearsParticipants2729252468
Age, Customized: 18 - 55 yearsParticipants2022212054
Sex: Female, Male: FemaleParticipants2525192036
Sex: Female, Male: MaleParticipants2226272486
Race (NIH/OMB): American Indian or Alaska NativeParticipants000000
Race (NIH/OMB): AsianParticipants8102122
Race (NIH/OMB): Native Hawaiian or Other Pacific IslanderParticipants000000
Race (NIH/OMB): Black or African AmericanParticipants631200
Race (NIH/OMB): WhiteParticipants31364239710
Race (NIH/OMB): More than one raceParticipants110210
Race (NIH/OMB): Unknown or Not ReportedParticipants111010
Time to diagnosis of peanut allergyYears16.287 (SD 7.9393)16.381 (SD 6.9248)15.556 (SD 7.5799)17.748 (SD 7.8969)15.598 (SD 5.3525)14.971 (SD 3.5291)
Number of participants with at least one food allergy: 1 food allergyParticipants1215131153
Number of participants with at least one food allergy: 2 food allergiesParticipants1058411
Number of participants with at least one food allergy: 3 food allergiesParticipants552531
Number of participants with at least one food allergy: 4 food allergiesParticipants876401
Number of participants with at least one food allergy: 5 food allergiesParticipants044312
Number of participants with at least one food allergy: > 5 food allergiesParticipants1215131714
Peanut specific Immunoglobulin E (IgE)IU/mL109.021 (SD 147.9877)80.644 (SD 117.6312)131.948 (SD 189.7757)116.198 (SD 128.9151)51.606 (SD 48.6951)262.136 (SD 543.7764)
Total Immunoglobulin E (IgE)IU/mL524.35 (SD 444.009)482.25 (SD 478.047)455.38 (SD 397.960)436.31 (SD 335.113)325.15 (SD 208.482)635.42 (SD 535.099)
MTD (maximum tolerated dose) of peanut protein (mg) - n (%): < 1 mgParticipants252210
MTD (maximum tolerated dose) of peanut protein (mg) - n (%): 1 mgParticipants446912
MTD (maximum tolerated dose) of peanut protein (mg) - n (%): 3 mgParticipants1414111111
MTD (maximum tolerated dose) of peanut protein (mg) - n (%): 10 mgParticipants91471145
MTD (maximum tolerated dose) of peanut protein (mg) - n (%): 30 mgParticipants1814201144
Peanut Skin Prick Test (SPT) (undiluted): Size of mean wheal diametermm13.83 (SD 5.720)14.61 (SD 6.007)13.23 (SD 6.414)16.82 (SD 8.262)14.45 (SD 4.845)12.17 (SD 3.664)
Peanut Skin Prick Test (SPT) (average across dilutions): Size of mean wheal diametermm7.232 (SD 2.8339)7.273 (SD 2.7253)7.508 (SD 2.7624)7.907 (SD 2.8866)6.575 (SD 2.3809)7.743 (SD 2.3547)
Poly-sensitized to food: YesParticipants2927222788
Poly-sensitized to food: NoParticipants1824241734
Poly-allergic to food: YesParticipants3536333369
Poly-allergic to food: NoParticipants1215131153
History of anaphylactic reaction to food: YesParticipants3236293298
History of anaphylactic reaction to food: NoParticipants1415161224
History of anaphylactic reaction to food: UnknownParticipants101000

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Who Tolerated a Single Dose of >= 600 mg (1044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12, measured over Week 12.

ElementRegistry entry
Result typeCount Of Participants
Measure of spreadnot applicable
UnitParticipants
Endpoint classificationBinary Endpoint

The primary endpoint is the percentage of participants who tolerated a single dose of >= 600 mg of peanut protein without dose-limiting symptoms at Week 12. The registry also expresses that threshold as a cumulative tolerated dose of 1044 mg. Cumulative tolerated dose is defined as the sum of tolerated doses and does not include the dose that caused a reaction. The assessment took place during a double-blind placebo-controlled food challenge.

A dose-limiting symptom was defined as a true allergic reaction during administration of a single peanut-protein dose that, in the investigator’s view, should prevent further doses. Symptoms requiring rescue medication also counted as dose-limiting. This definition makes the endpoint a threshold-based responder outcome: each participant is classified according to whether the specified challenge dose was tolerated under the study criteria.

This type of endpoint is used to summarize challenge performance in a clinically defined form rather than only reporting a continuous dose measurement. The responder rate can be compared between randomized groups, while the threshold makes clear what level of challenge tolerance counts as a response. The endpoint does not describe all symptoms, all exposures, or experiences outside the food challenge. The registry’s stated rule also classified participants as non-responders if they discontinued treatment or missed more than 1 doses before Week 12 for reasons other than operational complications caused by a public health emergency.

7. Results Posted in the Registry

Risk difference: Ligelizumab 240 mg

+40.3

95% CI: 23.9 to 56.8 percentage points

Recalculated from the posted summary statistics

Primary outcome by arm, with 95% confidence intervals
Primary outcome by arm with 95% confidence intervals0.012.925.838.751.664.6Ligelizumab 240 mg (n=47)Ligelizumab 120 mg (n=51)Placebo (n=23)% of participants (95% CI)
Treatment effect versus the control arm
Forest plot of risk difference (percentage points) vs control (95% CI)Ligelizumab 240 mgLigelizumab 120 mg-6.347.2221344861risk difference (percentage points) vs control (95% CI)

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.

Secondary outcomeTypeEffect measureEstimate (95% CI)Planning size, 80% power
Percentage of Participants Who Tolerated a Single Dose of >= 1000 mg (2044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12Binary EndpointRisk difference+25.4 pts (9.9 to 40.9)34 per arm
Percentage of Participants Who Tolerated a Single Dose of 3000 mg (5044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12Binary EndpointRisk difference+10.5 pts (-2.6 to 23.7)122 per arm
Percentage of Participants Who Tolerated a Single Dose of >= 1000 mg (2044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12 After 4 Weeks of TreatmentBinary EndpointRisk difference-15.1 pts (-26.9 to -3.3)60 per arm

Percentage of Participants Who Tolerated a Single Dose of >= 1000 mg (2044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12

Treatment effect versus the control arm
Forest plot of risk difference (percentage points) vs control (95% CI)Ligelizumab 240 mgLigelizumab 120 mg-8.392.2113233445risk difference (percentage points) vs control (95% CI)

Percentage of Participants Who Tolerated a Single Dose of 3000 mg (5044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12

Treatment effect versus the control arm
Forest plot of risk difference (percentage points) vs control (95% CI)Ligelizumab 240 mgLigelizumab 120 mg-8.60-1.665.28121926risk difference (percentage points) vs control (95% CI)

Percentage of Participants Who Tolerated a Single Dose of >= 1000 mg (2044 mg Cumulative Tolerated Dose) of Peanut Protein Without Dose-limiting Symptoms at Week 12 After 4 Weeks of Treatment

Treatment effect versus the control arm
Forest plot of risk difference (percentage points) vs control (95% CI)Placebo 8 Weeks and Ligelizum…Placebo-29-23-16-9.90-3.482.93risk difference (percentage points) vs control (95% CI)

Across the posted Week 12 secondary challenge outcomes, the broad pattern is that the number meeting the more demanding tolerance thresholds is smaller than for the primary threshold. The comparisons do not all point to equally clear differences, and the pattern varies across doses and outcome definitions. Other secondary measures extend the assessment to later challenge tolerance, maximum symptom severity, changes in maximum tolerated dose, and peanut-specific IgE and IgG4.

These outcomes add context to the primary responder result by considering different challenge thresholds, timing and laboratory measures. They do not constitute a single, interchangeable measure of treatment response. A result for one threshold does not establish the same effect at another threshold or on a biomarker, and the secondary outcomes should be interpreted according to their separate definitions and analysis populations. The registry posts 14 secondary outcomes, but detailed results are not available for every listed measure in the record described.

Unadjusted secondary findings carry less weight when many outcomes and comparisons are examined. The chance of seeing a seemingly notable result can increase across multiple tests, even when each individual test uses a conventional significance threshold. The registry record does not report a multiplicity-control procedure for the secondary results. Consequently, isolated secondary p-values should be treated as exploratory unless the analysis plan establishes otherwise; such a plan is not reported in the registry record.

The overall secondary pattern can be considered alongside the primary endpoint, but it should not be used to resolve uncertainty in the primary analysis or to imply a broad conclusion across outcomes. The trial’s terminated status and the absence of full reporting for all listed secondary endpoints further limit how comprehensively the full outcome pattern can be assessed.

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

9. Statistical Interpretation

Clinical Biostats interpretation

At Week 12, the posted counts show 21 participants in the ligelizumab 240 mg arm, 8 in the 120 mg arm and 1 in the placebo arm meeting the primary responder definition. The corresponding group sizes were 47, 51 and 23. These are observed counts for this endpoint, not estimates of what would occur in a different population.

The unadjusted recalculation expresses each active-dose comparison as a risk difference against placebo. For 240 mg, the estimated difference is 0.403, with a 95% confidence interval from 0.239 to 0.568 and an unadjusted p-value of <0.001. For 120 mg, the estimated difference is 0.113, with a 95% confidence interval from -0.017 to 0.243 and an unadjusted p-value of 0.167. The interval for the 240 mg comparison is above zero, while the interval for 120 mg includes zero. These are simple unadjusted recalculations from the posted summary counts; the sponsor’s own analysis takes precedence because the registry record flags a discrepancy.

The sponsor reported logistic-regression odds ratios of 25.83 for 240 mg versus placebo and 5.10 for 120 mg versus placebo. The corresponding 95% confidence intervals are 4.34 to 506.78 and 0.80 to 100.98; reported p-values are 0.002 and 0.073. The sponsor’s analyses therefore also distinguish between the two dose-versus-placebo comparisons in their reported p-values, but the confidence intervals are broad, especially for the odds-ratio estimates. The adjusted odds ratios and the unadjusted risk differences are different statistical measures and should not be read as interchangeable effect estimates.

There were few responders in the placebo group, and the number of events was limited across the groups. With sparse outcomes, effect estimates can be sensitive to a small number of participants, and odds-ratio intervals can be especially wide. The observed pattern is informative about the registered Week 12 responder outcome, but uncertainty remains about the size of the effect, particularly for the lower dose comparison. A p-value does not state the probability that a treatment effect is true, and a confidence interval does not cover every source of uncertainty, such as early termination or the limits of the recorded analysis.

The trial status is terminated, but the reason and implications for interpretation are not reported in the registry record. The reported endpoint results should therefore be read as the posted Week 12 findings, not as evidence about all planned outcomes or the complete intended follow-up. The data do not answer whether the two doses differ directly, because the reported primary comparisons are each against placebo.

10. Statistical Methods Explained

The primary outcome is binary: a participant either met the Week 12 tolerance threshold without dose-limiting symptoms or did not. The registry posts counts by group. A useful way to compare binary outcomes is the risk difference, which subtracts the observed proportion in the comparator group from the observed proportion in the active-treatment group. A positive difference means the observed responder proportion was higher in the active group; a negative difference means it was lower. The recalculated differences are unadjusted and use the posted summary counts.

What does an unadjusted comparison tell the reader?

An unadjusted comparison describes the observed groups without accounting for other variables through a regression model. Random assignment is intended to create comparable groups, but an unadjusted estimate is still a summary of the observed data. It does not establish that every prognostic factor was balanced, and the posted counts do not allow those factors to be examined. The record’s stated analysis population and missing-response rule also matter when interpreting the counts.

The registry’s sponsor-reported primary analyses use logistic regression and report odds ratios. An odds ratio compares the odds of response between groups, rather than subtracting the probabilities. Odds ratios and risk differences answer related but distinct questions, and their numerical values are not directly comparable. The registry record does not report the full regression specification or covariates, so the extent and details of adjustment are not reported in the registry record. Because the record flags a discrepancy, the sponsor’s own analysis takes precedence over the simple unadjusted recalculation.

How should the p-values be read?

A p-value describes how compatible the observed data are with a specified null model, under the assumptions of the analysis. A small p-value is not the probability that the null hypothesis is true, nor does it measure the clinical importance of an effect. The unadjusted p-values accompanying recalculated risk differences are not the same as the p-values from the sponsor’s logistic-regression analyses. They arise from different analyses and may differ for that reason as well as because of the discrepancy noted in the registry record. No multiplicity adjustment is described in the posted results.

For the primary outcome, the sponsor reports a p-value of 0.002 for the 240 mg comparison and 0.073 for the 120 mg comparison. The associated intervals show substantial uncertainty in the estimated odds ratios. In general, a result should be read using its effect estimate and interval as well as its p-value. A threshold-based distinction between p-values does not itself show that the two dose effects differ from each other; a direct dose-to-dose comparison is not reported.

Why do sparse counts matter?

When events are uncommon, each observed response has a relatively large influence on the estimated group contrast. This can make estimates unstable and intervals wide. Logistic regression can also produce imprecise odds-ratio estimates when event counts are limited. That is relevant to these results because the posted responder counts are small, particularly in the placebo group. The sponsor’s broad confidence intervals reflect limited precision in the effect estimates, even where a reported p-value is small.

General statistical explanation: a confidence interval describes a range of values reasonably compatible with the data and the method used to calculate it. It is not a guarantee that the true value lies within the interval, and it does not include every possible source of uncertainty. Here, uncertainty also concerns the study’s terminated status, details of the analysis that are not reported, and the applicability of a food-challenge response to outcomes not measured by this endpoint.

What is and is not described about the analysis?

The record identifies the Full Analysis Set for the primary outcome and gives a specific non-responder rule for treatment discontinuation or missing more than 1 doses before Week 12, with an exception for operational complications caused by a public health emergency. It does not provide further details on other missing-data handling, sensitivity analyses, the model specification, or adjustments for multiple comparisons. Those features are not reported in the registry record and should not be inferred from the posted estimates.

The sample-size figures are planning illustrations based on the observed effect, not a reconstruction of the original trial design. They use the assumptions stated in the sample-size material. They do not explain the study’s actual enrollment target or provide observed power. Interpretation of the observed trial results should remain separate from those hypothetical planning calculations.

11. Confidence Intervals and Precision

The confidence intervals show how much uncertainty surrounds the estimated comparisons under the stated calculation method. For the unadjusted primary risk difference comparing 240 mg with placebo, the 95% interval is 0.239 to 0.568. It does not include zero, the value corresponding to no difference in responder proportions. For the 120 mg comparison, the interval is -0.017 to 0.243 and includes zero. This means the posted counts are compatible with a range of values that includes no difference as well as positive differences.

The sponsor’s reported odds-ratio intervals are much wider: 4.34 to 506.78 for 240 mg and 0.80 to 100.98 for 120 mg. The breadth indicates limited precision in the odds-ratio estimates. The interval for 120 mg includes the value 1, which represents equal odds in the groups, while the 240 mg interval does not. These sponsor analyses take precedence over the unadjusted recalculations because the registry record identifies a discrepancy. The risk-difference intervals and odds-ratio intervals use different effect scales and should be interpreted separately.

General statistical explanation: a confidence interval reflects sampling uncertainty under the analysis method; it is not a range of outcomes for individual participants and does not account automatically for every design or reporting limitation. Sparse event counts tend to make intervals wider, and a small comparator group can contribute to imprecision. The posted counts and wide sponsor intervals warrant caution about the exact magnitude of the association, even when the direction of the estimate is clear.

The intervals do not resolve questions about the termination, unreported analysis details, missing data beyond the stated rule, or the effects of multiple testing. Nor do they establish whether ligelizumab doses differ from one another. The posted primary analyses compare each dose with placebo.

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.

Effect to detectParticipants per arm, 80% powerParticipants per arm, 90% power
100% of the observed effect1722
75% of the observed effect2634
50% of the observed effect4762
Sample size needed versus the size of the effect to detect
Sample size needed versus size of effect to detect205010040%60%80%100%80% power90% powersize of effect to detect, as % of the effect observed (log vertical scale: participants per arm)
Method and assumptions. Two-sided α = 0.05, 1:1 allocation, pooled-variance normal approximation for two proportions (control proportion held at the observed value). Calculated for the comparison: Ligelizumab 240 mg.

The sample-size figures are planning illustrations based on the observed effect, not the original trial’s documented design assumptions. For these binary outcomes, the figures are participants per arm, rather than total events. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to be detected is a stated fraction of the observed effect. The original trial’s own sample-size assumptions are not reported in the registry record.

The 80% power column gives the number of participants per arm estimated to be needed for 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 planning number for a higher chance of detection. These are design calculations for hypothetical future studies, not a measure of the evidential strength of the completed trial.

Each row considers a different fraction of the observed effect. Planning for 75% or 50% of the observed effect represents a smaller effect to detect than planning for 100% of it. Smaller effects generally require more participants to distinguish them from random variation under otherwise similar assumptions. The figures can therefore be used to understand how the assumed effect size influences planning, not as a recommended enrollment target for a future study without further design work.

This is not observed power. Observed power is not a useful substitute for reading the effect estimate, confidence interval and study limitations after results are known. The original trial’s design rationale, including the reason for its enrollment target, 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 z1−α/2 = 1.960) and the desired power (z1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n = [ z1−α/2 √(2p̄(1−p̄)) + z1−β √(p0(1−p0) + p1(1−p1)) ]2 / (p1 − p0)2

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 = 0.043; treatment proportion p1 = 0.447; average p̄ = 0.245.
  2. First term: z1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6084 = 1.1924.
  3. Second term: z1−β × √[p0(1−p0) + p1(1−p1)] = 0.842 × 0.5374 = 0.4523.
  4. n = (1.1924 + 0.4523)2 / (0.4033)2 = 16.6, rounded up to 17 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 <- 0.0434782608695652                          # control proportion
p1 <- 0.446808510638298                          # 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(4984876)
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 = 17 (80% power), 22 (90% power)
 75% of observed effect: n per arm = 26 (80% power), 34 (90% power)
 50% of observed effect: n per arm = 47 (80% power), 62 (90% power)
power.prop.test: 16.6 
Simulated power at n = 17 per arm: 0.843 (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.

Very small required sample. The formula gives a very small requirement because the observed effect is very large relative to the variability. Normal-approximation formulas are unreliable at such sizes, and the simulation above shows the power actually achieved. An exact or simulation-based design would be needed in practice.

14. Analyses Reported by the Sponsor

MethodEstimate95% CIP-value
Regression, LogisticOdds Ratio (OR) 25.834.34 to 506.780.002
Regression, LogisticOdds Ratio (OR) 5.100.80 to 100.980.073
Where the two analyses differ, rely on the sponsor's. The simple re-calculation above reaches a different conclusion from the sponsor's analysis, usually because the sponsor adjusts for covariates, stratification or repeated measures, or (for event rates) uses a negative binomial model that allows for over-dispersion and so gives wider intervals.

The registry reports sponsor analyses using logistic regression. For the primary comparison of ligelizumab 240 mg with placebo, the reported odds ratio is 25.83, with a 95% confidence interval of 4.34 to 506.78 and p = 0.002. For 120 mg versus placebo, the reported odds ratio is 5.10, with a 95% confidence interval of 0.80 to 100.98 and p = 0.073.

The recalculated results use the posted group counts to estimate unadjusted risk differences and p-values. They are not the same estimand or model as the sponsor’s logistic-regression odds ratios. The registry record flags a discrepancy between the recalculated and reported analyses, so the sponsor’s own analysis takes precedence. The recalculation can still help describe the observed responder proportions and their unadjusted contrasts, but it should not replace the reported sponsor analysis.

The registry does not report enough detail to reconstruct the sponsor’s full model or determine the source of the discrepancy. Covariates, model specification, and any additional analysis details beyond the reported method are not reported in the registry record. The sponsor’s intervals are broad, so the point estimates should not be treated as precise measures of the size of the effect. The reported comparisons are each against placebo; they do not directly test whether the two ligelizumab doses differ.

15. Multiplicity, Missing Data and Analysis Populations

The record identifies the Full Analysis Set for the primary endpoint and defines a non-responder rule for participants who discontinued treatment or missed more than 1 doses before Week 12 for reasons other than operational complications caused by a public health emergency. This gives some information about how particular cases were classified for the primary outcome. The registry record does not report a fuller account of missing-data methods, the number of missing Week 12 assessments, sensitivity analyses, or whether other missing observations were handled differently.

The primary endpoint has two active-dose comparisons against placebo, and the registry lists numerous secondary outcomes. Testing several hypotheses can increase the chance of at least one apparently notable result arising by chance. The posted record does not report whether a family-wise error procedure, hierarchical testing strategy, or other multiplicity adjustment was used. The protocol’s and statistical analysis plan’s multiplicity approach is not reported in the registry record. Without that information, unadjusted secondary results should be viewed cautiously, and the nominal p-values should not be treated as if they necessarily control the overall false-positive risk.

The sponsor’s primary analyses are reported as logistic regression, but the model specification and covariates are not reported in the registry record. The reason for the discrepancy between the reported analyses and the unadjusted recalculations is also not reported. No interim-analysis plan, stopping rule, or original sample-size justification is reported in the registry record. The record’s terminated status does not explain whether stopping affected enrollment, follow-up, or the analysis set.

These gaps do not invalidate the results that are posted, but they limit independent assessment of how robustly the analysis addressed missingness, multiplicity and model choices. Interpretation should distinguish what the record explicitly states—the endpoint definition, the primary analysis population and the stated non-responder rule—from analysis details that remain unreported.

16. Safety Results

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

ArmParticipants with serious adverse eventsParticipants at riskPercentage
Placebo Controlled Period (Up to Week 8) Ligelizumab 240 mg SCq4w0470.0%
Placebo Controlled Period (Up to Week 8) Ligelizumab 120 mg SCq4w0510.0%
Placebo Controlled Period (Up to Week 8): Placebo01130.0%
Placebo Controlled Period (Up to Week 16) Ligelizumab 240 mg SCq4w0470.0%
Placebo Controlled Period (Up to Week 16) Ligelizumab 120 mg SCq4w0510.0%
Placebo Controlled Period (Up to Week 16): Placebo0230.0%
Any Ligelizumab 240 mg SCq4w (Subcutaneous Injection Every 4 Weeks) - Up to Week 680990.0%
Any Ligelizumab 120 mg SCq4w (Subcutaneous Injection Every 4 Weeks) - Up to Week 6811011.0%
Participants with at least one serious adverse event
Serious adverse events by armPlacebo Controlled Period (Up…0.0%Placebo Controlled Period (Up…0.0%Placebo Controlled Period (Up…0.0%Placebo Controlled Period (Up…0.0%Placebo Controlled Period (Up…0.0%Placebo Controlled Period (Up…0.0%Any Ligelizumab 240 mg SCq4w …0.0%Any Ligelizumab 120 mg SCq4w …1.0%% of participants with at least one serious adverse event

Deaths

ArmDeaths (participants affected of at risk)
Placebo Controlled Period (Up to Week 8) Ligelizumab 240 mg SCq4w0 of 47
Placebo Controlled Period (Up to Week 8) Ligelizumab 120 mg SCq4w0 of 51
Placebo Controlled Period (Up to Week 8): Placebo0 of 113
Placebo Controlled Period (Up to Week 16) Ligelizumab 240 mg SCq4w0 of 47
Placebo Controlled Period (Up to Week 16) Ligelizumab 120 mg SCq4w0 of 51
Placebo Controlled Period (Up to Week 16): Placebo0 of 23

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

ArmParticipants affected of at risk
Placebo Controlled Period (Up to Week 8) Ligelizumab 240 mg SCq4w21 of 47
Placebo Controlled Period (Up to Week 8) Ligelizumab 120 mg SCq4w17 of 51
Placebo Controlled Period (Up to Week 8): Placebo27 of 113
Placebo Controlled Period (Up to Week 16) Ligelizumab 240 mg SCq4w26 of 47
Placebo Controlled Period (Up to Week 16) Ligelizumab 120 mg SCq4w20 of 51
Placebo Controlled Period (Up to Week 16): Placebo9 of 23

Most frequent serious adverse event terms

Event termOrgan systemPlacebo Controlled Period (Up to Week 8) Ligelizumab 240 mg SCq4wPlacebo Controlled Period (Up to Week 8) Ligelizumab 120 mg SCq4wPlacebo Controlled Period (Up to Week 8): PlaceboPlacebo Controlled Period (Up to Week 16) Ligelizumab 240 mg SCq4wPlacebo Controlled Period (Up to Week 16) Ligelizumab 120 mg SCq4wPlacebo Controlled Period (Up to Week 16): Placebo
Post procedural complicationInjury, poisoning and procedural complications0 of 470 of 510 of 1130 of 470 of 510 of 23

Most frequent non-serious adverse event terms

Event termOrgan systemPlacebo Controlled Period (Up to Week 8) Ligelizumab 240 mg SCq4wPlacebo Controlled Period (Up to Week 8) Ligelizumab 120 mg SCq4wPlacebo Controlled Period (Up to Week 8): PlaceboPlacebo Controlled Period (Up to Week 16) Ligelizumab 240 mg SCq4wPlacebo Controlled Period (Up to Week 16) Ligelizumab 120 mg SCq4wPlacebo Controlled Period (Up to Week 16): Placebo
Injection site erythemaGeneral disorders5 of 477 of 510 of 1136 of 478 of 510 of 23
NasopharyngitisInfections and infestations4 of 472 of 515 of 1138 of 473 of 513 of 23
Upper respiratory tract infectionInfections and infestations1 of 473 of 517 of 1133 of 474 of 512 of 23
HeadacheNervous system disorders2 of 473 of 515 of 1134 of 474 of 511 of 23
Injection site painGeneral disorders2 of 473 of 514 of 1133 of 473 of 510 of 23
COVID-19Infections and infestations1 of 472 of 512 of 1135 of 475 of 510 of 23
UrticariaSkin and subcutaneous tissue disorders5 of 471 of 511 of 1137 of 471 of 510 of 23
Injection site swellingGeneral disorders2 of 474 of 510 of 1132 of 474 of 510 of 23
Injection site oedemaGeneral disorders3 of 471 of 510 of 1134 of 472 of 510 of 23
CoughRespiratory, thoracic and mediastinal disorders1 of 470 of 513 of 1134 of 470 of 512 of 23

Serious events with the highest arm-level rate: post procedural complication (1.0%).

Do not overextend the safety comparison. Serious-adverse-event counts are safety observations, not efficacy outcomes, and should not be combined with the primary result into a single benefit-risk number.

The safety record separates serious adverse events from other adverse events and reports groups for different exposure periods. In the placebo-controlled period up to Week 8, no serious adverse events were reported in the listed ligelizumab 240 mg, ligelizumab 120 mg or placebo groups. The corresponding other-adverse-event counts were 21, 17 and 27. For the placebo-controlled period up to Week 16, no serious adverse events were reported in the listed active-dose groups or placebo group; other-adverse-event counts were 26, 20 and 9.

For the broader exposure categories reported up to Week 68, no serious adverse events were reported in the 240 mg group, while 1 was reported in the 120 mg group. No deaths were reported in the listed safety groups. The registry identifies “Post procedural complication” as a top serious-event term, at 1.0%.

These are descriptive counts across groups and periods, not adjusted comparisons of safety risk. The categories cover different exposure windows and may not be mutually exclusive; counts should not be added across periods or groups. The record does not provide enough information to assess event timing, causality, severity for all other events, or the impact of termination on safety follow-up. Absence of a reported serious event in a group does not establish absence of risk.

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

The posted primary outcome describes whether participants met a defined peanut-protein challenge threshold at Week 12. In the observed data, more participants in the 240 mg arm met that threshold than in placebo, while the estimate for 120 mg was less precise and its confidence interval included no difference. The sponsor’s own logistic-regression analyses take precedence over the unadjusted recalculations because the registry record flags a discrepancy. Those sponsor results also have broad confidence intervals, so the exact magnitude remains uncertain.

This result does not establish that either regimen changes a participant’s everyday experience of peanut exposure. The endpoint was measured during a controlled food challenge, using a particular dose threshold and a specified definition of dose-limiting symptoms. It does not answer questions about all possible doses, symptoms outside the challenge, long-term outcomes, or outcomes not recorded in the registry.

The primary comparisons are each against placebo. They do not show whether the 240 mg dose is better than the 120 mg dose, because a direct dose-to-dose analysis is not reported. The registry’s other listed outcomes may add context, but their multiplicity handling and complete result pattern are not reported in the registry record.

The record marks the study terminated but does not state why. The reason for termination, its effect on follow-up and the completeness of all planned analyses are not reported in the registry record. The results therefore need to be understood within the limits of the posted Week 12 findings, group sizes, sparse responder counts, uncertainty intervals and incomplete reporting of some analysis details. They describe the data recorded for this trial; they do not provide a complete answer to every question about ligelizumab, peanut allergy or longer-term safety.

18. Why This Trial Matters Statistically

This trial illustrates several important statistical issues in clinical research. First, a binary responder outcome can be easy to communicate because it ties the result to a defined threshold, but the choice of threshold matters. The primary endpoint concerns tolerance of a single challenge dose of >= 600 mg and a cumulative tolerated dose of 1044 mg. Secondary thresholds and other challenge measures ask related but distinct questions.

Second, the observed responder counts are limited, particularly in the placebo group. Sparse counts make effect estimates sensitive to individual outcomes and can produce wide intervals. The sponsor’s odds-ratio intervals make that imprecision visible: the estimated association is not known with the same precision as the point estimate alone might suggest. Reporting both the estimate and its interval is therefore central to interpreting the result.

Third, the record juxtaposes sponsor-reported logistic-regression analyses with simple unadjusted recalculations that do not agree exactly. The registry flags the discrepancy, and the sponsor’s analysis takes precedence. This is a useful reminder that analysis method and estimand matter: an odds ratio from a regression model is not equivalent to a crude risk difference from group counts.

Finally, multiple outcomes, a terminated status and incomplete reporting of analysis details shape the strength of conclusions. The record gives enough information to describe the primary endpoint and several posted results, but does not report the original sample-size rationale, multiplicity plan or reason for termination. Statistical interpretation must account for both the numbers reported and the limits of the record.

19. Limitations

The registry record marks the trial terminated, but the reason is not reported. It is therefore not possible from the record to determine whether termination affected planned enrollment, treatment exposure, follow-up completeness or the timing of analyses. Although the study title describes a 52-week assessment, the primary endpoint is a Week 12 food-challenge result; the later study period should not be assumed to be fully represented by that endpoint.

The primary responder counts are small, including only 1 responder in the placebo group. This contributes to broad uncertainty, especially for odds-ratio estimates. The record’s reported primary analyses and the unadjusted recalculations differ, and the full model specification needed to independently reproduce the sponsor analysis is not reported. The sponsor analysis takes precedence, but the source of the discrepancy is not reported in the registry record.

The endpoint is specific to a controlled food challenge and a defined dose threshold. It does not encompass all clinically relevant outcomes or exposures. The primary comparisons do not directly compare the two active doses. Although the registry lists several secondary outcomes, the multiplicity approach and detailed results for every listed outcome are not reported. Missing-data handling beyond the stated primary non-responder rule, the number of missing observations and sensitivity analyses are also not reported in the registry record.

Safety counts are presented across multiple exposure periods and categories. They are descriptive and do not, by themselves, establish comparative safety. The record does not explain the relationship between overlapping exposure groups, or give full event-level detail in the information posted. These limitations constrain interpretation of the size, generality and completeness of the findings.

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23. Record Summary

NCT04984876 is a terminated Phase 3 randomized, double-blind, placebo-controlled, parallel-group study of ligelizumab in participants with medically confirmed IgE-mediated peanut allergy. The primary Week 12 endpoint assessed tolerance of a single peanut-protein dose of >= 600 mg without dose-limiting symptoms during a controlled food challenge. The posted counts were 21 of 47 for ligelizumab 240 mg, 8 of 51 for 120 mg and 1 of 23 for placebo.

The sponsor reported logistic-regression odds ratios for each active dose versus placebo. The registry record flags a discrepancy with simple unadjusted recalculations, so the sponsor’s analysis takes precedence. Confidence intervals are broad, and the 120 mg estimate is particularly uncertain. Secondary outcomes cover additional challenge thresholds and other measures; the multiplicity approach is not reported. The reason for termination and several analysis details are not reported in the registry record.

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