Study of Dupilumab in Adult Participants With Active Eosinophilic Esophagitis (EoE): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Dupilumab in Adult Participants With Active Eosinophilic Esophagitis (EoE) (NCT02379052), a randomized phase 2 study. The primary outcome is Absolute Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 10.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group, placebo-controlled phase 2 study sponsored by Regeneron Pharmaceuticals. The registry record lists triple masking, while the official title describes the study as double-blind. The record does not explain how the masking descriptions relate to one another, so no further detail about who was masked can be inferred.

The trial enrolled 47 adults with active eosinophilic esophagitis. Participants were allocated to dupilumab 300 mg once weekly or matching placebo. Both groups followed a 12-week double-blind treatment phase. The registry describes two injections on day 1 and weekly injections thereafter in each group. The primary endpoint was assessed at Week 10, with additional symptom measures listed at Week 12 and other time points.

The registry record gives the study start as 2015-05-12 and primary completion as 2017-02-17, and lists the study status as completed. Its efficacy population was the Full Analysis Set, defined in the record as all randomized participants. Efficacy was analyzed according to the treatment assigned at randomization. Details such as the randomization ratio, allocation concealment procedures, site count, and the trial’s original 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: After providing informed consent, participants were assessed at screening (to occur between day -35 \& day -1) for eligibility to participate in the study. Participants who met the eligibility criteria underwent day 1 baseline assessments \& randomized in a 1:1 ratio to receive dupilumab or placebo during the 12-week double-blind treatment phase.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS) included all randomized participants. Efficacy analyses were based on the treatment allocated by the interactive voice and web response system (IVRS/IWRS) at randomization (as randomized).

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: The full analysis set (FAS) included all randomized patients. Efficacy analyses were based on the treatment allocated by the interactive voice response system (IVRS)/ interactive web response system (IWRS) at randomization (as randomized).

6. Primary Endpoint

The registry lists the primary outcome as Absolute Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 10, measured over Baseline, Week 10.

The primary endpoint was absolute change from baseline in the Straumann Dysphagia Instrument (SDI) patient-reported total score at Week 10. The SDI asks about dysphagia during a one-week recall period. It combines frequency, graded from 0 to 4, and intensity, graded from 0 to 5. The total score ranges from 0 to 9, with higher scores indicating worsening symptoms.

Change from baseline puts the Week 10 score in context: it describes how much the measure moved relative to each participant’s baseline rather than comparing only the scores at follow-up. The endpoint is patient-reported, so it captures the experience of swallowing difficulty as recorded by participants. The registry identifies symptom relief as the primary objective, making a dysphagia measure relevant to the stated clinical question.

A negative change represents a lower score than baseline and therefore movement in the direction of fewer or less severe symptoms on this scale. The endpoint is a continuous score, and its group summaries are least-squares means with standard errors. The registry record does not report a threshold for what would constitute a clinically important difference, so statistical results alone do not establish the practical importance of a given score change.

7. Results Posted in the Registry

• Dupilumab 300 mg QW: mean -3.00 versus -1.30 on control; difference -1.70 (95% CI -3.23 to -0.17), standardized effect d = -0.64; z-test p = 0.029.

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.

Percent Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 10

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Dupilumab 300 mg QW: mean -45.05 versus -18.59 on control; difference -26.46 (95% CI -50.60 to -2.32), standardized effect d = -0.63; z-test p = 0.032.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Dupilumab 300 mg QW than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Absolute Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 12

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Dupilumab 300 mg QW: mean -2.90 versus -2.20 on control; difference -0.70 (95% CI -2.44 to 1.04), standardized effect d = -0.23; z-test p = 0.431.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Dupilumab 300 mg QW and the control. The interval gives the range of effects that remain compatible with the data.

Percent Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 12

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Dupilumab 300 mg QW: mean -42.83 versus -31.83 on control; difference -11.00 (95% CI -37.83 to 15.83), standardized effect d = -0.23; z-test p = 0.422.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Dupilumab 300 mg QW and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover additional SDI assessments, including percent change and Week 12 results, as well as measures using the weekly reported Eosinophilic Esophagitis Activity Index. This breadth can help describe whether the Week 10 primary finding is reflected in other symptom summaries and follow-up assessments. In the posted SDI results, the Week 10 percent-change comparison points in the same direction as the primary endpoint, whereas the Week 12 comparisons do not show clear evidence of a between-group difference. The overall pattern is therefore not uniform across time points and ways of summarizing the score.

The registry lists 16 secondary outcomes, but numerical results for only three are included in the record details. Numerical results for the other listed secondary outcomes, including the EEsAI outcomes and the SDI responder outcomes, are not reported in the registry record. Their mention in the outcome list is not evidence of a particular result. The secondary outcomes should be interpreted on their own definitions and scales, which need not have the same meaning as the primary SDI change score.

Secondary analyses usually carry less confirmatory weight than a prespecified primary analysis, particularly when many outcomes and time points are examined. Repeated testing creates more opportunities for chance findings. Without a reported multiplicity strategy, an unadjusted secondary p-value does not account for the full set of comparisons. The registry record does not report whether or how the trial adjusted secondary tests for multiplicity. Consequently, the secondary pattern can provide context for the primary result, but should not be treated as a set of independent confirmations or as a replacement for the primary analysis.

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

• Percent Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 10
• Absolute Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 12
• Percent Change From Baseline in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score at Week 12
• Percentage of Participants Achieving a Reduction of ≥ 3 Points in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score From Baseline at Week 10
• Percentage of Participants Achieving a Reduction of ≥ 3 Points in Straumann Dysphagia Instrument (SDI) Patient Reported Outcome (PRO) Total Score From Baseline at Week 12
• Percent Change From Baseline in Weekly Reported Eosinophilic Esophagitis Activity Index (EEsAI) Patient Reported Outcome (PRO) Score at Week 10
• Absolute Change From Baseline in Weekly Reported Eosinophilic Esophagitis Activity Index (EEsAI) Patient Reported Outcome (PRO) Score at Week 10
• Percent Change From Baseline in Weekly Reported Eosinophilic Esophagitis Activity Index (EEsAI) Patient Reported Outcome (PRO) Score at Week 12

9. Statistical Interpretation

10. Statistical Methods Explained

What does a least-squares mean represent?

A least-squares mean is a model-based estimate of the average outcome for a group. Unlike a simple arithmetic mean, it can reflect adjustments included in the statistical model. In this trial, the posted primary comparison is described as ANCOVA, or analysis of covariance, and its reported contrast is a least-squares mean difference. The record does not identify the covariates or give enough detail to reconstruct the model. It is therefore appropriate to describe the reported estimate and its stated method, but not to assume which baseline characteristics were included.

The arm summaries report a least-squares mean and standard error for each group. A standard error describes the uncertainty in estimating a mean, rather than the spread of individual participants’ scores. It generally becomes smaller when an estimate is more precise, although its interpretation depends on the analysis and data.

What does the treatment contrast mean?

The posted primary contrast compares the estimated change in the dupilumab group with the estimated change in the placebo group. Its value of -1.7 is expressed in SDI score points. The negative sign means the estimated change was lower in the dupilumab group. Since the scale defines higher scores as worse symptoms, a more negative change corresponds to a greater average reduction from baseline. This sign interpretation depends on the score direction and should not be confused with a percentage change.

The unadjusted recalculation uses the two posted arm means to estimate a difference. It is called unadjusted because it does not reproduce the ANCOVA model. The results are numerically similar in this case, but similarity does not make the methods identical. Adjusted and unadjusted estimates can differ because their calculations use different information and assumptions. The registry record does not provide the full model specification needed to independently reproduce the ANCOVA.

How should the p-value be read?

A p-value describes how unusual the observed result, or a result more extreme, would be under a specified null model in which there is no between-group difference, assuming the analysis model and its assumptions apply. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of the result. The posted primary p-value is 0.030. It is evidence against the no-difference null in that analysis, but it should be considered alongside the effect estimate, confidence interval, endpoint definition, trial size, and the other outcomes assessed.

The registry labels the comparison as a superiority analysis. That label describes the type of contrast tested; it does not change what the measured endpoint means or independently establish clinical importance. The record does not report whether the primary statistical plan included an adjustment for multiple comparisons.

Why do confidence intervals matter?

A confidence interval expresses uncertainty about an estimated contrast. In repeated use of the same procedure under its assumptions, intervals at a stated confidence level have a long-run coverage interpretation. For an individual trial, the interval gives a range of effect estimates compatible with the data and model, rather than a guarantee that the true value lies within its endpoints. A narrow interval indicates more precision than a wide interval, but precision and clinical importance are different questions.

For the primary ANCOVA estimate, the reported 95% interval ranges from -3.22 to -0.16. Its endpoints are both negative, so the reported interval does not include no difference. The interval still allows a range of possible magnitudes, and the record does not supply a clinical threshold with which to judge those magnitudes.

What does the Full Analysis Set imply?

The registry defines the Full Analysis Set as all randomized participants and says efficacy analyses followed the treatment allocated at randomization. This is an as-randomized approach to group assignment: participants are analyzed according to their original allocation rather than reassigned based on later treatment received. It helps preserve the comparison created by randomization. The record does not describe the handling of missing endpoint observations, protocol deviations, or participants who discontinued treatment, so the details of implementation cannot be assessed from the registry record.

Why can over-dispersion matter in other outcomes?

General statistical context: for count or binary outcomes, some models assume a particular amount of variation. Over-dispersion means the observed variation exceeds that assumed amount. If ignored, uncertainty can be understated and intervals or tests can be too optimistic. The primary endpoint is a continuous SDI score, and the registry describes an ANCOVA analysis; it does not report an over-dispersion assessment. This concept should not be taken as a claim that over-dispersion occurred in this trial.

What can secondary analyses add?

Secondary outcomes can show whether the primary pattern is accompanied by changes in other measures, time points, or ways of expressing symptoms. Each outcome has its own definition and uncertainty. When many outcomes are examined, some results may look persuasive by chance even if there is no real effect for those outcomes. Unless a multiplicity strategy is prespecified and reported, individual secondary p-values should be treated as exploratory rather than as a collection of independently confirmatory tests. The registry record does not report the trial’s multiplicity procedure.

11. Confidence Intervals and Precision

The sponsor-reported primary estimate is a least-squares mean difference of -1.7 SDI points, with a 95% confidence interval from -3.22 to -0.16. The interval is entirely below zero, indicating that the posted ANCOVA analysis is compatible with a negative between-group difference and does not include no difference at the stated confidence level. The breadth of the interval also matters: values across a range of magnitudes remain compatible with the analysis. It does not support treating -1.7 as an exact or certain effect.

The unadjusted recalculation gives a 95% confidence interval from -3.226 to -0.174. Its endpoints are close to those of the posted ANCOVA interval, but the recalculation is based on the arm summaries and is not the same model-based analysis. The two intervals should therefore be distinguished rather than combined or substituted for one another.

Confidence intervals describe statistical uncertainty under the assumptions of the method. They do not measure every source of uncertainty, such as uncertainty about the generalizability of a small phase 2 study, the effects of missing data, or whether an SDI difference is meaningful to participants. The registry record does not report a clinically important difference threshold or sufficient detail to assess all assumptions behind the ANCOVA.

The trial’s arm sizes were 24 for placebo and 23 for dupilumab in the primary analysis. Those counts help explain why the estimate should be read with its interval rather than as a precise fixed value. The interval supports a direction of difference in the Week 10 analysis, while leaving uncertainty about its exact magnitude and practical importance.

12. Planning a Similar Trial: Sample Size

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

The sample-size illustrations describe how many participants per arm would be needed under stated planning assumptions to detect selected fractions of the observed effect. They are planning scenarios, not the trial’s original design calculation. For this continuous endpoint, the figures are participants per arm, not total event counts. The original design assumptions and sample-size justification are not reported in the registry record.

The calculations assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. The rows labelled 100%, 75%, and 50% therefore represent planning for the full observed effect, three-quarters of that effect, and half of that effect, respectively. Smaller effects are harder to distinguish from random variation and require more participants for the same planned power.

The 80% power column means the scenario is designed to have an 80% chance of detecting an effect of the specified size under the assumptions, if that effect is the true one and the model applies. The 90% power column uses a higher chance of detection and consequently calls for more participants. These are prospective design quantities, not measures of what the completed trial achieved.

The illustrations use the observed effect as their starting point, so they should not be interpreted as independent evidence that the observed effect is reliable. This is not observed power. The registry record does not report that these illustrations were the trial’s own planning targets, nor does it report a separate original sample-size justification.

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 = -1.700; pooled standard deviation σ = 2.673.
2. n = 2 × (1.96 + 0.842)² × 2.673² / -1.700² = 38.8, 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 <- -1.7                      # observed difference in means
sigma <- 2.67282705097888                     # 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(2379052)
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 = 69 (80% power), 93 (90% power)
 50% of observed effect: n per arm = 156 (80% power), 208 (90% power)
power.t.test: 39.8 
Simulated power at n = 39 per arm: 0.794 (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 registry’s primary result is the sponsor-reported ANCOVA estimate: a least-squares mean difference of -1.7, with a 95% confidence interval from -3.22 to -0.16 and p = 0.030. The separate recalculation from the posted arm summaries gives a mean difference of -1.7, a 95% confidence interval from -3.226 to -0.174, and p = 0.029. Both estimates point in the same direction and are close in magnitude.

The recalculation is a simple unadjusted comparison. The sponsor’s analysis uses ANCOVA, so its estimate and uncertainty come from a model-based comparison rather than the two arm summaries alone. The registry record does not give the full ANCOVA specification, so the recalculation cannot reproduce or validate every aspect of the sponsor’s model. The small numerical differences are not, by themselves, evidence of an error; different methods can produce slightly different estimates and p-values.

The posted ANCOVA result is the trial’s reported inferential analysis. The recalculation is useful as a transparent comparison based on the available summaries, but it should not be mistaken for a second independent trial result. The record does not indicate a discrepancy between the posted and recalculated primary analyses.

15. Multiplicity, Missing Data and Analysis Populations

The registry record reports a primary endpoint and a substantial set of secondary outcomes, including multiple time points and alternative summaries of dysphagia. When several hypotheses are tested, the chance of at least one apparently positive result can increase. Statistical procedures for multiplicity can control that risk, for example by adjusting tests or by specifying an ordered testing strategy. The registry record does not report whether such a procedure was planned or used, how the secondary outcomes were prioritized, or whether the primary test was protected within a family of analyses.

This absence does not establish that no multiplicity plan existed; it means the plan is not reported in the registry record. The primary result should therefore be distinguished from the collection of secondary results, especially where secondary p-values are considered. The record labels the primary contrast as a superiority analysis but does not supply further detail about the testing hierarchy.

The analysis population is described as the Full Analysis Set, consisting of all randomized participants, with participants analyzed according to their treatment allocation at randomization. That definition is informative about group assignment, but it does not answer how missing Week 10 measurements were handled. The registry record does not report the amount or pattern of missing outcome data, the method used to address missingness, or sensitivity analyses exploring alternative assumptions.

Missing data can affect an estimate if the likelihood of an observed outcome is related to the unobserved value or to participant characteristics. General statistical context: methods for missing data rely on assumptions, and sensitivity analyses can help show whether conclusions depend on those assumptions. No such procedures or findings are reported in the registry record. The record also does not report details of protocol deviations, treatment discontinuation, or a per-protocol analysis. These gaps limit assessment of how robust the posted efficacy estimates are to analysis choices, but do not justify assuming that a particular bias occurred.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: food allergy (4.3%), blood creatine phosphokinase increased (4.3%), abortion spontaneous (4.3%).

The registry reports serious adverse events for 0 of 24 participants in the placebo group and 3 of 23 in the dupilumab 300 mg QW group. It reports zero deaths in both groups. These are counts during the reported safety observation, not estimates of comparative risk that account for uncertainty. With groups of this size, the counts provide a limited description of what was recorded and cannot establish whether a difference between groups is real.

Other adverse events are reported for 14 of 24 placebo participants and 18 of 23 dupilumab participants. These are listed separately from the serious adverse event counts. The registry also lists Food allergy, Blood creatine phosphokinase increased, and Abortion spontaneous among the top serious-event terms, each with 4.3%. The record does not provide enough context in these entries to assign those term percentages to a treatment group or establish causality.

Adverse-event counts are descriptive. They do not show that a treatment caused an event, and these figures alone do not provide a complete assessment of safety, event timing, severity, or exposure. The registry record does not report further detail in the registry record.

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

The posted primary result describes an average difference in change on a specific patient-reported dysphagia scale at Week 10 among randomized adults in this phase 2 study. The ANCOVA estimate is negative, and the reported confidence interval does not include zero. In the context of the SDI scoring direction, this indicates a larger average reduction in the score for the dupilumab group than for the placebo group in that analysis.

The result does not by itself show how individual participants changed. A group mean can coexist with a range of experiences, and the registry does not report the distribution of individual responses in the registry record. Nor does the result establish that a given score difference is important to participants: a clinically important difference threshold is not reported. The finding is specific to the Week 10 endpoint and should not be generalized automatically to every time point or symptom measure.

The Week 12 SDI comparisons do not provide similarly clear between-group evidence in the posted analyses, and numerical results for most listed secondary measures are not reported in the registry record. That limits conclusions about consistency across outcomes and follow-up. The serious adverse event counts are also descriptive and do not establish comparative safety or causation.

As a phase 2, randomized, placebo-controlled study with 47 enrolled participants, the trial offers a controlled comparison in its enrolled population, but the size and scope of the record leave uncertainty about precision and generalizability. The registry result cannot answer questions about longer-term outcomes, populations not represented, or results not reported. It should be read as evidence about the specified study endpoint, not as medical advice or a universal conclusion.

18. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation requires more than checking whether a p-value crosses a conventional threshold. The primary estimate, its confidence interval, endpoint direction, analysis method, and timing all contribute to what the result says. Here the posted ANCOVA estimate and interval point toward a between-group difference in Week 10 SDI change, while later SDI comparisons do not show the same clarity. The time-specific nature of a result matters when a study measures outcomes repeatedly.

It also shows why model-based trial results should be kept distinct from simple recalculations. The posted analysis is ANCOVA; the recalculation uses group summaries without adjustment. Their numerical similarity is reassuring as a descriptive cross-check, but does not erase the methodological distinction or provide the missing model details.

Finally, a registry record can identify the randomized population, outcomes, and selected results while leaving important statistical questions unanswered. The original sample-size justification, missing-data procedures, and multiplicity strategy are not reported in the registry record. These omissions do not prove that the trial lacked appropriate procedures; they limit what can be assessed from the record. Clear reporting of analysis plans and uncertainty is essential to distinguish the primary evidence from exploratory findings and to understand the limits of a small clinical trial.

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.

The primary analysis includes 47 participants across the two reported groups, so estimates may remain imprecise even when the point estimate and p-value suggest a difference. The confidence interval communicates some statistical uncertainty, but it does not address all questions about how well the result applies outside the enrolled study population. The registry describes adults with active eosinophilic esophagitis and does not provide further population detail in the registry record.

The primary endpoint is a patient-reported score with a one-week recall period. That makes it directly relevant to reported dysphagia, but the record does not report a clinically important difference threshold, individual response distributions, or further measurement properties that would help interpret practical importance. The endpoint assessed at Week 10 also does not alone establish whether the pattern continued beyond that assessment.

The Week 12 SDI analyses do not show clear between-group evidence, and results for most of the 16 listed secondary outcomes are not reported in the registry record. This limits assessment of consistency across measures. The record also does not report the original sample-size rationale, the complete ANCOVA specification, how missing data were handled, or the multiplicity procedure. As a result, the registry record is insufficient to evaluate those design and analysis choices in detail.

Safety figures are counts from small groups and lack the fuller context needed to assess event timing, attribution, or comparative risk. The masking descriptors also differ between the registry listing and official title, without an explanation of their relationship. These are limits on interpretation of the record, not evidence that a particular bias or safety problem occurred.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Study of Dupilumab in Adult Participants With Active Eosinophilic Esophagitis (EoE) — NCT02379052.
• Registry record last updated 2020-02-28; status last verified 2020-02.
• Results first posted 2020-02-28.
• 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

NCT02379052 is a completed randomized phase 2 parallel-group study sponsored by Regeneron Pharmaceuticals. It enrolled 47 adults with active eosinophilic esophagitis and compared weekly subcutaneous dupilumab 300 mg with matching placebo during a 12-week double-blind treatment phase. The primary endpoint was absolute change from baseline in the SDI total score at Week 10.

The registry reports an ANCOVA least-squares mean difference of -1.7, with a 95% confidence interval from -3.22 to -0.16 and p = 0.030. The endpoint’s lower scores indicate fewer or less severe dysphagia symptoms. The record also reports selected Week 10 and Week 12 secondary SDI analyses and descriptive adverse-event counts; numerical findings for most listed secondary outcomes are not reported in the registry record.

Important analysis details, including the original sample-size justification, missing-data handling, and multiplicity procedure, are not reported in the registry record. The findings therefore describe the posted analyses and their uncertainty, rather than answering questions beyond the measured outcomes and reported follow-up.