Efficacy and Safety Study Of Short Ragweed Pollen Sublingual-Oral Immunotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy and Safety Study Of Short Ragweed Pollen Sublingual-Oral Immunotherapy (NCT01353079), a randomized phase 3 study. The primary outcome is Scores on a Scale [Net Average Combined Daily Rhinoconjunctivitis Symptom (RSS) and Medication Scores].

2. Clinical Question

3. Trial Design

This was a completed, randomized, parallel-group phase 3 trial sponsored by Greer Laboratories. The registry lists enrollment as 429 and identifies short ragweed pollen allergenic extract and placebo as the study interventions. The official title describes the trial as double-blind, while the registry’s masking designation is quadruple. Which specific roles were masked is not reported in the registry record, so the masking designation cannot be unpacked further from the posted information.

The study objective was to assess pre- and co-seasonal sublingual-oral immunotherapy in relation to rhinoconjunctivitis symptoms over the entire short ragweed pollen season. The primary outcome timeframe is listed as the 2011 ragweed pollen season, 8/2011 -10/2011. The primary outcome description refers to an ITT population defined as subjects with at least one post-treatment efficacy measurement. The posted arm summaries include 196 participants for extract and 193 for placebo; these are the denominators reported for that outcome.

The record lists a start of 2011-04, primary completion of 2011-11, and status of completed. It does not report the trial’s original sample-size justification, detailed allocation procedure, dosing schedule, or a fuller protocol description. Although several secondary measures are posted, the record does not establish whether they were prespecified in a protocol available to readers or how they were prioritized analytically.

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

Analysis population for the primary outcome, as defined in the registry: ITT population includes subjects who had at least one post treatment efficacy measurement

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 Scores on a Scale [Net Average Combined Daily Rhinoconjunctivitis Symptom (RSS) and Medication Scores], measured over 2011 ragweed pollen season, 8/2011 -10/2011.

The primary endpoint was the change from baseline in the average combined daily rhinoconjunctivitis symptom and medication score during the entire ragweed pollen season. It combines symptoms with the use of allergy-relief medication, so the outcome reflects both reported symptom burden and recorded rescue-medication use rather than symptoms alone.

The symptom component summed ratings for eight symptoms: ocular symptoms, nasal symptoms, and ear itching. Ratings ran from 0, absent, to 3, severe. The daily symptom score was formed from morning and evening reports and then averaged across the season. Medication scores were based on use of specified relief medicines; the maximum score depended on cumulative rescue-medication use. The combined score had a stated range of 0 (min) - 51 (max), and lower results were defined as more favorable.

A combined endpoint can represent more than one aspect of the seasonal experience in a single outcome. In general, this can make the endpoint relevant to the study question when both symptoms and medication use matter, but its interpretation depends on how each component is scored and combined. The registry record describes the scoring process, but does not report separate primary conclusions for each component. The posted result should therefore be read as a comparison of the combined measure, not as an isolated estimate of symptom change or medication use.

7. Results Posted in the Registry

• Ragweed Allergenic Extract: mean 0.85 versus 1.69 on control; difference -0.83 (95% CI -1.24 to -0.42), standardized effect d = -0.41; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Scores on a Scale (Net Average Combined Daily Rhinoconjunctivitis Symptom and Medication Scores Reported During the Three Peak Weeks of Ragweed Pollen Season)

• 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 deviations.
• Result:
  • Ragweed Allergenic Extract: mean 1.37 versus 2.23 on control; difference -0.86 (95% CI -1.40 to -0.32), standardized effect d = -0.32; z-test p = 0.002.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Ragweed Allergenic Extract than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Scores of a Scale (Average Daily Rhinoconjunctivitis Symptom Scores During the Entire Ragweed Pollen Season)

• 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 deviations.
• Result:
  • Ragweed Allergenic Extract: mean 0.83 versus 1.60 on control; difference -0.77 (95% CI -1.16 to -0.38), standardized effect d = -0.39; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Ragweed Allergenic Extract than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Scores on a Scale (Average Daily Rhinoconjunctivitis Symptom Scores During the Three Peak Weeks of Ragweed Pollen Season)

• 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 deviations.
• Result:
  • Ragweed Allergenic Extract: mean 1.32 versus 2.10 on control; difference -0.79 (95% CI -1.30 to -0.28), standardized effect d = -0.31; z-test p = 0.003.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Ragweed Allergenic Extract than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes show a consistent directional pattern across measures: the extract group has lower average scores than the placebo group for the posted symptom-only and combined symptom-and-medication outcomes, including outcomes covering the full season and the peak weeks. The sponsor-reported secondary ANCOVA results also give negative mean differences. This broad alignment is compatible with the direction of the primary comparison, but the secondary endpoints describe related, not identical, questions.

The primary endpoint combines symptom and medication scores over the entire season. The secondary set includes a combined score limited to peak weeks and symptom-only scores over the full season and peak weeks. Because the measures and timeframes differ, they should not be treated as repetitions of the primary endpoint. Their common direction supplies context, but does not independently establish the precision or importance of the primary result.

In general, results from multiple secondary tests warrant more caution than a single prespecified primary test. When many outcomes are examined, some may appear statistically notable by chance even if no underlying differences exist for those outcomes. A multiplicity adjustment or a prespecified hierarchy can help address this issue, but whether either was used is not reported in the registry record. Accordingly, unadjusted secondary results carry less inferential weight than the designated primary result and are best read as supportive, exploratory evidence rather than as separate definitive findings.

The record reports three secondary outcomes and their sponsor analyses. It does not report an overall multiplicity strategy, a protocol-defined order of testing, or a separate clinical-importance threshold for these measures. Their consistency in direction is informative descriptively, while the absence of those details limits claims about confirmatory evidence.

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

• Scores on a Scale (Net Average Combined Daily Rhinoconjunctivitis Symptom and Medication Scores Reported During the Three Peak Weeks of Ragweed Pollen Season)
• Scores of a Scale (Average Daily Rhinoconjunctivitis Symptom Scores During the Entire Ragweed Pollen Season)
• Scores on a Scale (Average Daily Rhinoconjunctivitis Symptom Scores During the Three Peak Weeks of Ragweed Pollen Season)

9. Statistical Interpretation

10. Statistical Methods Explained

The main comparison concerns a continuous outcome, the average combined daily symptom and medication score. The registry reports least-squares means for the arm summaries and identifies ANCOVA as the method used in the sponsor’s reported primary analysis. It does not report the full ANCOVA specification, including which covariates were included, how baseline values entered the model, or how missing outcome measurements were handled.

What does a mean difference describe?

In general, a mean difference expresses how far apart the group averages are on the outcome’s original scale. Its sign depends on the order used for the comparison. For this primary comparison, the reported estimate is -0.834 for extract relative to placebo; the endpoint description says that lower scores are more favorable. The estimate is an average contrast, not a statement that every participant had the same score or response.

The arm summaries report 0.853 for extract and 1.687 for placebo. The simple unadjusted recalculation from these posted summaries also gives a mean difference of -0.834. The recalculated uncertainty estimate uses an approximate pooled standard deviation and a simple comparison of the arm summaries. It is not the sponsor’s ANCOVA analysis, which is the analysis reported by the registry for the primary comparison.

Why can analyses differ?

In general, an adjusted analysis can account for variables included in its model, while an unadjusted comparison uses the observed group summaries without such adjustment. Confidence intervals and p-values can also depend on the model, standard-error calculation, and other analysis choices. The registry reports the sponsor’s method as ANCOVA, but does not report enough detail to reconstruct the model. The recalculated interval and p-value are therefore supplementary descriptions of the posted summary statistics, not replacements for the sponsor’s result. Because the record indicates a discrepancy, the sponsor’s own analysis takes precedence.

What does the p-value say?

In general, a p-value measures how incompatible the observed data are with a specified null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor does it measure the size or importance of an effect. The sponsor’s reported primary p-value is p <0.05. The recalculated unadjusted p-value is p <0.001. These statements come from different analyses and should not be collapsed into a single value. The registry does not report the exact p-value for the sponsor’s analysis.

For the primary comparison, the sponsor’s 95% confidence interval ranges from -1.298 to -0.369. In general, a confidence interval describes the uncertainty around an estimate under the method used to construct it. It communicates a range of estimates compatible with the data and method; it is not a guarantee that the true effect lies in the interval. Its width reflects precision as well as the analytic approach. The sponsor interval and recalculated interval differ, reinforcing the need to distinguish the reported analysis from the unadjusted recalculation.

Why can over-dispersion matter?

In general, over-dispersion means that outcomes vary more than a statistical model assumes. If a model understates variability, its standard errors may be too small and its confidence intervals too narrow; if it accounts for variability differently, uncertainty estimates can change. This is a general statistical consideration, not a finding that over-dispersion occurred in this trial. The primary outcome is a continuous score, and the registry describes its standard deviation, but does not report an over-dispersion assessment or a special correction for it.

The analysis population is described as ITT, but with an explicit inclusion condition: subjects had to have at least one post-treatment efficacy measurement. In general, analysis-population definitions and missing-data methods affect what population an estimate represents. The record does not report the number of missing observations, reasons for missingness, imputation procedures, or sensitivity analyses. Thus the extent to which missing measurements could affect the result cannot be assessed from the posted record.

The reported secondary outcomes use related continuous scores. Each has a sponsor-reported ANCOVA result and an unadjusted recalculation is posted for comparison. In general, examining several outcomes increases the chance that at least one result appears notable by chance when each is tested without accounting for the others. The registry record does not report a multiplicity adjustment or a hierarchy for interpreting the secondary outcomes. Their estimates should therefore be treated as supportive descriptions rather than as independent confirmation of the primary result.

11. Confidence Intervals and Precision

The sponsor-reported primary estimate is -0.834, with a 95% confidence interval from -1.298 to -0.369. This interval describes uncertainty around the estimated mean difference under the sponsor’s ANCOVA method. Its endpoints are both negative, consistent with a lower average combined score in the extract group under the stated comparison direction. The interval does not show the range of individual participant scores; it concerns uncertainty in the estimated group difference.

The recalculated unadjusted 95% confidence interval is from -1.243 to -0.425. It shares the sponsor’s point estimate but differs in its endpoints. The distinction matters: confidence intervals depend on the analysis method and its assumptions, and a simple calculation from summary statistics need not reproduce an adjusted ANCOVA interval. Because the registry record flags a discrepancy, the sponsor’s own analysis takes precedence for interpreting the trial’s reported inference.

In general, a narrower confidence interval indicates greater precision for the estimate under the method used, while a wider interval indicates more uncertainty. Precision is not the same as clinical importance. The registry record does not report a threshold for a meaningful difference on the combined score, so the interval cannot be judged against such a threshold from the posted information alone. Nor does the interval describe variation among individual responses.

The primary estimate is presented to three decimal places, while the recalculated upper endpoint is -0.425. These are the rounded values recorded for the respective analyses. The posted arm standard deviations and participant counts help describe the observed summaries, but they do not resolve the methodological difference between the sponsor’s interval and the recalculated interval.

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 planning figures are participants per arm, not total events. The registry record’s planning illustration assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It uses the observed effect as its starting point and considers detecting 100% of the observed effect, 75% of the observed effect, or 50% of the observed effect. These are planning assumptions for the illustration, not reported assumptions from the trial’s original design; the original design assumptions are not reported in the registry record.

The 80% power column gives the estimated participants per arm for a hypothetical study to have an 80% chance of detecting the specified effect under those assumptions, if that effect and the model assumptions were correct. The 90% power column gives the corresponding planning number for a higher chance of detecting that specified effect. These are prospective planning quantities, not outcomes observed in the completed trial.

The figures rise as the target effect becomes smaller: planning for 75% of the observed effect requires more participants per arm than planning for the full observed effect, and planning for 50% requires more still. In general, smaller effects are harder to distinguish from random variation, so more participants are needed to achieve a given target power under otherwise unchanged assumptions. The results are illustrative rather than a reconstruction of the trial’s actual design calculation, and they are not observed power.

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 = -0.834; pooled standard deviation σ = 2.053.
2. n = 2 × (1.96 + 0.842)² × 2.053² / -0.834² = 95.1, rounded up to 96 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 <- -0.834                      # observed difference in means
sigma <- 2.05253482913353                     # 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(1353079)
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 = 96 (80% power), 128 (90% power)
 75% of observed effect: n per arm = 170 (80% power), 227 (90% power)
 50% of observed effect: n per arm = 381 (80% power), 510 (90% power)
power.t.test: 96 
Simulated power at n = 96 per arm: 0.797 (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 reports the sponsor’s primary analysis as ANCOVA, with a mean difference of -0.834, a 95% confidence interval from -1.298 to -0.369, and p <0.05. A simple unadjusted recalculation from the posted group summaries gives the same mean difference, but a different 95% confidence interval, from -1.243 to -0.425, and p <0.001. The identical point estimates do not make the inferential results identical.

The recalculation uses posted summary statistics and an approximate pooled standard deviation. The sponsor’s result comes from the reported ANCOVA analysis. In general, adjustment and model-based uncertainty calculations can change standard errors, intervals, and p-values while leaving a point estimate similar or the same. The record does not describe the ANCOVA model in sufficient detail to reproduce it independently.

The registry record identifies a discrepancy, so the sponsor’s own analysis takes precedence. The recalculated result is useful as a check on the direction and scale of the group contrast, but it should not replace the sponsor-reported analysis or be presented as the trial’s official inferential result. The sponsor’s reported p-value is only given as a threshold, not an exact value.

15. Multiplicity, Missing Data and Analysis Populations

The primary outcome is distinguished from the secondary outcomes in the registry record, but the record does not report whether a formal multiplicity strategy was used. It does not state whether secondary tests were adjusted, whether testing followed a prespecified hierarchy, or whether any interim analyses were planned or conducted. Those details are not reported in the registry record.

In general, multiplicity arises when several hypotheses or outcomes are tested. If each is assessed without accounting for the number of tests, the chance of obtaining at least one apparently notable result by chance can increase. This does not establish that any posted result is spurious; it means that secondary p-values should be interpreted with less certainty when the handling of multiple tests is unknown. The shared direction among secondary outcomes is descriptively relevant, but does not remove this limitation.

The primary population is described as ITT, with inclusion limited to subjects who had at least one post-treatment efficacy measurement. The registry record does not report how many randomized participants lacked post-treatment measurements, why measurements were absent, or how missing values were handled. It also does not report sensitivity analyses evaluating different missing-data assumptions. In general, incomplete outcome data can affect both the estimate and the population to which it applies, depending on the reasons for missingness and the analysis method.

The registry identifies ANCOVA for the sponsor’s primary and secondary analyses but does not give the model specification, covariates, or full statistical analysis plan. The original sample-size justification and the trial’s interim-analysis plan are also not reported in the registry record. These omissions limit independent assessment of whether the reported model and testing strategy followed the intended protocol. The posted results can be described as recorded, but the unavailable details prevent a complete reconstruction of the analysis decisions.

16. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: abdominal pain (0.5%), nausea (0.5%), dehydration (0.5%), vomiting (0.5%), nephrolithiasis (0.5%).

The registry reports serious adverse events affecting 2 participants in the ragweed allergenic extract group, among 218 at risk, and 3 participants in the Glycero-Cocas group, among 211 at risk. Other adverse events affected 28 participants in the extract group, among 218 at risk, and 29 in the Glycero-Cocas group, among 211 at risk. These are counts of participants reported as affected and the corresponding at-risk counts; they do not by themselves describe event severity beyond the serious-versus-other classification.

The registry lists Abdominal pain, Nausea, Dehydration, Vomiting, Nephrolithiasis, and Cardiac failure congestive among the serious adverse-event terms, each at 0.5%. The record does not specify group attribution for those listed terms in the posted summary. Deaths are not reported in the registry record.

In general, safety counts are descriptive and should be interpreted with attention to the definitions, observation period, and completeness of reporting. The registry record does not provide enough detail to assess event timing, relatedness to intervention, or comparative risk. These counts should not be treated as proof of causation or as a complete account of all possible harms.

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

The posted primary analysis estimates a lower average combined symptom-and-medication score in the extract group than in the placebo group during the entire 2011 ragweed pollen season. The sponsor-reported mean difference is -0.834, and its 95% confidence interval from -1.298 to -0.369 lies below zero. That describes the direction and statistical uncertainty of the group-average contrast for the endpoint defined in the registry.

The result does not show that every participant in the extract group had a lower score, nor does it indicate how many participants experienced a particular change. A mean difference can coexist with substantial variation within each arm. The posted summaries include standard deviations, but the registry record does not provide participant-level distributions or response categories that would support conclusions about individual patterns.

The result also does not establish the clinical importance of the estimated difference. The score’s lower-is-more-favorable direction is stated, but a threshold for a clinically meaningful difference is not reported in the registry record. Statistical evidence and clinical importance are different questions; the reported confidence interval addresses uncertainty in the average contrast, not whether that contrast reaches a particular practical threshold.

The finding is tied to the studied population, the specified score, and the season recorded in the trial. It does not establish what would occur in other populations, seasons, or for each separate symptom or medication component. The endpoint combines those components, and the primary analysis concerns their combined score.

Finally, the result should be read alongside limitations in the available record: the full ANCOVA specification, multiplicity strategy, missing-data methods, and original sample-size assumptions are not reported. These gaps do not erase the posted result, but they constrain how completely an independent reader can evaluate the analysis and its broader implications.

18. Why This Trial Matters Statistically

This trial illustrates why the estimand and the direction of a scale should be understood before interpreting a mean difference. The primary endpoint combines symptom severity with medication use, and the registry explicitly states that lower scores are more favorable. That context makes the negative group contrast interpretable as a lower average score in the extract group relative to placebo, rather than as an abstract sign with no clinical direction.

It also illustrates the distinction between a sponsor-reported adjusted analysis and a simple recalculation from group summaries. The point estimate is the same in both, but the confidence intervals and p-value descriptions differ. Reporting both can help readers see how much inferential conclusions depend on analytic choices, while the sponsor’s own ANCOVA result remains the primary reported analysis when the registry identifies a discrepancy.

The trial further shows why related secondary outcomes do not automatically provide independent confirmation. The secondary measures cover different score components and timeframes, and their direction aligns with the primary result. Yet the registry does not report a multiplicity strategy, so the secondary findings have a different evidentiary status from the designated primary endpoint.

Finally, planning calculations based on an observed effect are not a substitute for the original design justification. The posted planning illustration makes visible how the target effect and desired power relate to the number of participants per arm, but the trial’s original assumptions are not reported. Separating a retrospective illustration from an original design plan prevents those quantities from being mistaken for observed power or evidence about the trial’s planning process.

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 registry record gives limited detail about the primary ANCOVA. Its covariates, model form, handling of baseline scores, and standard-error method are not reported, preventing an independent reconstruction of the sponsor’s analysis. The record also flags a difference between the sponsor analysis and the simple recalculation, although their point estimates match; the sponsor’s result takes precedence.

The primary population is defined as ITT participants with at least one post-treatment efficacy measurement. The number and reasons for missing post-treatment observations, methods used to handle missing data, and sensitivity analyses are not reported in the registry record. The record therefore does not permit assessment of how missingness might affect the estimate.

The original sample-size justification, interim-analysis plans, and multiplicity approach are not reported. This is particularly relevant when interpreting the several related secondary outcomes: without a reported testing hierarchy or adjustment, their inferential role is unclear. No clinically meaningful difference threshold for the primary score is reported, limiting interpretation of practical importance.

The score combines symptom ratings and medication use, with the maximum medication score depending on cumulative rescue-medication use. The record describes the scoring approach but does not report separate primary analyses for the symptom and medication components. The safety summary also lacks detail on event timing, relatedness, and group attribution for the serious-event terms listed. These gaps limit the precision of conclusions that can be drawn from the registry record alone.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Efficacy and Safety Study Of Short Ragweed Pollen Sublingual-Oral Immunotherapy — NCT01353079.
• Registry record last updated 2015-02-05; status last verified 2015-01.
• Results first posted 2015-02-05.
• 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

NCT01353079 is a completed randomized, parallel-group phase 3 trial sponsored by Greer Laboratories. It enrolled 429 participants and compared short ragweed pollen allergenic extract with placebo in adults with ragweed-related allergic rhinoconjunctivitis. The official title describes a double-blind trial; the registry lists quadruple masking.

The primary endpoint was change from baseline in the average combined daily symptom and medication score over the 2011 ragweed pollen season. Lower scores were defined as more favorable. The sponsor-reported ANCOVA mean difference was -0.834, with a 95% confidence interval from -1.298 to -0.369 and p <0.05. The simple unadjusted recalculation has the same point estimate but different uncertainty results; the sponsor’s analysis takes precedence.

Three secondary outcomes and safety summaries are posted. The secondary results have a broadly consistent direction, but the multiplicity strategy and several analysis details are not reported in the registry record. The record also does not report the original sample-size justification or missing-data methods.