Oral Immunotherapy for Peanut and Mammalian Meat Allergies: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Oral Immunotherapy for Peanut and Mammalian Meat Allergies (NCT02350660), a non-randomized na study. The primary outcome is The Level of Allergen Consumed Post-oral Immunotherapy.

2. Clinical Question

3. Trial Design

This was a pilot study titled “Oral Immunotherapy for Peanut and Mammalian Meat Allergies,” sponsored by the University of Virginia. The registry lists the study as completed, with a start date of 2012-03 and primary completion in 2014-09. Enrollment is listed as 24. The phase is recorded as NA.

The design is parallel and non-randomized, with no masking. The record describes one arm as daily cow’s milk consumption for alpha-gal allergic participants and the other as peanut oral immunotherapy using peanut powder. Because the arms concern different allergens and populations, differences between them cannot be read as a treatment effect from a controlled comparison. The record itself cautions that the arms are not a like-for-like control comparison.

The study summary describes a pilot assessment of oral immunotherapy’s effect on specific immunoglobulin E levels and antigen consumption in two food allergies. The registered primary outcome measure, however, is the level of allergen consumed at an open challenge. The record does not report an outcome result for immunoglobulin E levels.

Following 36 months of maintenance oral immunotherapy, participants completed an open challenge at month 37. The primary endpoint is a single time-point assessment rather than repeated measurement. Allocation procedures, eligibility criteria, dose schedules, adherence assessment, and the rationale for the enrollment target 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: Due to changes in funding structure, the study was unable to be completed with the designed number of participants and was therefore closed to enrollment

Overall Study

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 The Level of Allergen Consumed Post-oral Immunotherapy, measured over Following 36 months of maintenance oral immunotherapy, participants completed an open challenge at month 37.

The primary endpoint is the amount of cow’s milk or peanut flour consumed at an open challenge following oral immunotherapy. It is recorded in milligrams and described as a mean with standard deviation. The assessment took place after 36 months of maintenance treatment, at an open challenge at month 37. The record specifies that this is a single time-point measurement, not a repeated series of measurements.

In general, an allergen-consumption challenge can provide a direct measure of how much of the relevant food was consumed under the challenge conditions. A mean describes the group’s average measured amount, while a standard deviation describes how spread out individual measurements are around that average. These summaries answer different questions: the mean concerns the typical level in the group, and the standard deviation concerns variability among participants.

The registry record does not report the mean or standard deviation for either arm. It also does not provide an inferential comparison, confidence interval, or other numerical result for the endpoint. Without those values, the direction, size, and precision of the observed endpoint cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the design permit?

The study is described as parallel, non-randomized, and unmasked. In a parallel design, participants are followed in the arm to which they belong rather than switching between interventions. Random allocation, when used, can help balance known and unknown participant characteristics between comparison groups. Because this study was not randomized, that protection against systematic group differences is absent. The record also identifies the arms as different allergy and intervention settings, rather than like-for-like alternatives.

In general, masking can reduce the influence of expectations on care, outcome assessment, or reporting. This study is listed as having no masking. The primary outcome was assessed during an open challenge, and the record does not describe a blinded assessment process. The consequences of this design for any measured result cannot be quantified from the registry record.

What does the endpoint summary mean?

The endpoint is continuous: it measures an amount in milligrams. The record specifies a mean and standard deviation. In general, the mean is the arithmetic average of measurements, and the standard deviation describes how dispersed measurements are around that average. The standard deviation is not the same as the uncertainty in the estimated mean. A confidence interval for the mean would address that uncertainty, but no confidence interval is reported in the registry record.

The endpoint is a single assessment after maintenance therapy, not a repeated outcome measured over time. A single time-point measure can describe consumption at that challenge, but it does not by itself show a trajectory or change over repeated assessments. The record does not report a baseline value for this endpoint or a within-participant change analysis.

How should a comparison be interpreted?

General statistical interpretation distinguishes an observed association from a causal effect. In a randomized comparison, allocation can support a causal interpretation when the design and analysis are appropriate. In a non-randomized comparison, group differences may be entangled with differences in who entered each arm or in the intervention context. Here, the arms also concern different allergens and populations. The record cautions against treating them as a like-for-like control comparison. It does not report an adjusted analysis that would address potential differences between groups.

For a continuous outcome, a comparison might report a difference in means with an uncertainty interval, or a suitable model-based estimate. Such summaries could indicate the estimated contrast and how precisely it was measured. The registry record reports no analyses and gives no numerical result for the primary endpoint, so no such contrast or precision estimate can be interpreted.

What is over-dispersion, in general?

Over-dispersion is a general issue for statistical models that assume a particular amount of variability, especially models for counts or binary outcomes. It occurs when the observed variability is greater than the model’s assumptions allow. If ignored, standard errors may be too small and uncertainty may appear overstated in precision. The primary endpoint in this record is a continuous amount, and no model or distributional analysis is reported. There is therefore no basis for saying that over-dispersion was assessed or affected the trial’s endpoint analysis.

What do the planning assumptions mean?

The registry describes sample-size illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. These are planning assumptions for hypothetical designs, not the trial’s own design justification. The registry record does not report the numerical planning illustrations, the observed effect used, or the original sample-size rationale.

In general, a sample-size calculation asks how many participants would be needed under specified assumptions to detect a chosen effect with a chosen error rate and power. Its answer depends on the assumed effect, outcome variability, analysis, and allocation. A calculation based on an observed effect is especially dependent on that estimate and should not be presented as observed power. The planning illustrations do not establish what power this completed study achieved.

What analysis details are unavailable?

The registry record lists no analyses. It does not report the statistical model, hypothesis test, handling of missing values, analysis population, adjustment variables, or confidence intervals. These details matter because they define which participants and measurements contribute to an estimate and how uncertainty is calculated. They are not recoverable from the endpoint description alone.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Cow's Milk for Alpha-gal Allergics", "Peanut Powder")
n   <- c(7, 17)
m   <- c(6, 300)
sp  <- c(1.3, 57)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Cow's Milk for Alpha-gal Allergics  7  6.000  1.300  4.798  7.202
CARM  Peanut Powder  17  300.000  57.000  270.693  329.307

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and no analyses. It does not report whether additional outcomes were measured, whether multiple hypotheses were planned, or whether any adjustment for multiple testing was used. Multiplicity arises when several outcomes, time points, or comparisons are tested; in general, without an appropriate plan, the chance of a false positive across a family of tests can increase. The record does not provide enough analysis detail to determine whether this issue arose.

The primary endpoint is described as a single time-point assessment at the open challenge following maintenance therapy. The record does not report missing outcome counts, reasons for missingness, or methods for handling missing measurements. It also does not describe whether all enrolled participants completed the challenge. Missing-data assumptions and their effect on an estimate therefore cannot be assessed.

The record does not define an intention-to-treat, per-protocol, or other analysis population, and it lists no analyses. The enrollment figure alone does not establish how many participants contributed to the endpoint result. No outcome denominator or participant flow is reported in the registry record.

In general, analysis populations and missing-data methods should be specified because they affect which observations inform the result and the interpretation of the estimate. These elements, along with any multiplicity strategy, are not reported in the registry record.

12. Safety Results

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

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry lists serious adverse events by arm. In the cow’s milk for alpha-gal allergic participants group, 0 serious adverse events are reported among 7 at risk. In the peanut powder group, 0 serious adverse events are reported among 17 at risk. The record lists 1 other adverse event among 7 at risk in the cow’s milk group and 3 among 17 at risk in the peanut powder group.

These are descriptive registry counts. They do not establish that the interventions caused or prevented events, and the non-randomized arms are not a like-for-like safety comparison. The record does not provide event descriptions for the serious-event category; the list of top serious-event terms is empty. Death counts are not reported in the registry record, so they should not be interpreted as zero.

In general, safety counts need context, including how events were defined, how they were collected, the observation period, and whether counts refer to events or affected participants. Those details are not reported in the registry record. The listed counts should therefore be read as the recorded summaries, not as a complete characterization of safety or as a comparative risk estimate.

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

The registry record documents a completed pilot study of oral immunotherapy in two food-allergy settings. It identifies the interventions, the non-randomized parallel design, and a primary endpoint based on allergen consumption at an open challenge after maintenance therapy. It also reports adverse-event counts for the two arms.

It does not report the numerical primary endpoint results. The mean and standard deviation for allergen consumption are not reported in the registry record, nor are confidence intervals, p-values, or analyses. Therefore, the posted results do not allow the reader to quantify the amount consumed, the precision of a group estimate, or a statistical contrast.

The study cannot be read as a controlled comparison between cow’s milk and peanut interventions. The interventions and allergy groups differ, and allocation was not randomized. The record itself says the arms are not a like-for-like control comparison. Even a numerical difference between these groups would not, by itself, isolate an intervention effect.

In general, a pilot study can be used to explore procedures and generate information for further research, but its label alone does not establish the study’s purpose or the adequacy of its design for a particular inference. The registry does not report a sample-size justification, and enrollment should not be treated as proof of sufficient precision.

The planning assumptions are not trial outcomes or observed power. They are described as illustrations based on an observed effect, but the effect and numerical planning results are not reported in the registry record. The appropriate interpretation is therefore limited to the documented design and event counts, while the main outcome question remains quantitatively unanswered in the record.

14. Why This Trial Matters Statistically

This study is statistically notable for the gap between a clearly described primary measurement and the absence of numerical outcome results in the registry record. The endpoint is specified as a mean amount of allergen consumed, with a standard deviation, following a challenge at month 37. Yet the record does not report either summary value or an analysis. Knowing the intended measurement does not reveal its observed level or precision.

The design also illustrates why comparisons need a clear comparator. The arms address different allergies and interventions, and allocation was non-randomized. The registry cautions that the arms are not a like-for-like control comparison. This makes it important to avoid interpreting the groups as if they were randomized alternatives or using their safety counts as comparative risk estimates.

The record’s sample-size assumptions distinguish planning from the trial’s actual design. The stated illustrations use a two-sided significance level of 0.05, equal allocation, and a normal approximation, but the numerical illustrations and effect used are not reported in the registry record. Such planning calculations cannot fill the gap left by missing endpoint results, and they are not observed power.

More broadly, the trial demonstrates that a registry entry can specify an outcome’s unit, summary measure, and timing while leaving key analysis details unavailable. Without the outcome estimate, its uncertainty, analysis population, and missing-data information, readers cannot evaluate the primary result statistically. The record supports careful description of the study, but not a quantitative assessment of the primary endpoint.

15. 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 most immediate limitation for interpretation is that the registry record does not report numerical results for the primary endpoint. Although the measure is defined as allergen consumption in milligrams and the summary as a mean with standard deviation, neither value is reported for either arm. No confidence interval, p-value, or analysis is listed.

The design is non-randomized and unmasked. The arms involve different allergy settings and interventions, and the record explicitly warns that they are not a like-for-like control comparison. This limits the interpretation of any between-arm contrast and makes causal attribution inappropriate on the basis of the design description alone.

The record does not report baseline characteristics, detailed eligibility criteria, dosing schedules, adherence, participant flow, or the number contributing to the primary endpoint. Missing outcome data and their handling are not reported. The record also does not define an analysis population or describe an analysis model.

The study summary refers to specific immunoglobulin E levels and antigen consumption, but the registry lists one outcome measure and no analyses. Numerical results for immunoglobulin E levels are not reported in the registry record. A sample-size justification and the numerical planning illustrations are also not reported. These omissions prevent assessment of precision, attrition, analytic choices, and whether the enrollment target was appropriate for the intended question.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Oral Immunotherapy for Peanut and Mammalian Meat Allergies — NCT02350660.
• Registry record last updated 2020-11-03; status last verified 2020-11.
• Results first posted 2020-11-03.
• 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.

19. Record Summary

NCT02350660 is a completed, non-randomized, unmasked, parallel pilot study sponsored by the University of Virginia. The registry lists enrollment of 24, a start date of 2012-03, and primary completion in 2014-09. The interventions were daily cow’s milk consumption for alpha-gal allergic participants and peanut oral immunotherapy using peanut powder.

The primary endpoint was allergen consumption in milligrams at an open challenge at month 37, following 36 months of maintenance oral immunotherapy. It was a single time-point measure summarized as a mean and standard deviation. Numerical endpoint results and analyses are not reported in the registry record. The registry lists 0 serious adverse events among 7 at risk in the cow’s milk group and among 17 at risk in the peanut powder group; it also lists 1 and 3 other adverse events, respectively. The record cautions that the arms are not a like-for-like control comparison.