Safety and Efficacy of AL-53817 Nasal Spray Solution: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy of AL-53817 Nasal Spray Solution (NCT01454505), a randomized phase 1 study. The primary outcome is Number of Adverse Events in Stage A.

2. Clinical Question

The clinical questions therefore span two related but distinct stages. Stage A was intended to assess dose tolerance and report adverse events. Stage B compared AL-53817 with vehicle under the stated nasal-spray schedules and an EEC exposure procedure. The record does not identify the tested dose levels or specify which dose was carried forward, so those details are not part of the reported comparison.

The clinical setting matters to interpretation. The listed symptom outcome concerns TNSS during a 6-hour period in the EEC on Day 5, rather than a general measure of symptoms across ordinary daily life. The registry record does not provide the numerical TNSS results, an estimated treatment contrast, or a confidence interval. Consequently, the clinical question can be described from the protocol summary, but the posted information does not establish what the comparative symptom results were.

3. Trial Design

The registry identifies this as a randomized, double-masked, parallel study in Phase 1. It lists an enrollment of 110 and a completed status. The recorded study dates are 2011-10 for the start and 2012-03 for primary completion. Alcon Research is listed as the sponsor. These registry entries establish the broad design and context, but do not explain the randomization sequence, concealment procedures, or how masking was maintained.

The study had Stage A and Stage B. The stated purpose of Stage A was to determine the maximum tolerated dose of AL-53817. Its primary outcome is the number of adverse events on Day 1 among subjects exposed to test article during Stage A. Stage B was intended to evaluate safety and efficacy of AL-53817 for allergic rhinitis. Its listed treatment groups are AL-53817 nasal spray solution and vehicle nasal spray.

In Stage B, each treatment description specifies 1 spray to each nostril twice a day for 4 days, followed on Day 5 by 1 spray to each nostril 60 minutes before entering the EEC. The listed secondary outcome is mean change from baseline in TNSS over a 6-hour period in the EEC at Day 5. The registry does not report the length of follow-up beyond the stated outcome timeframes, the specific details of EEC exposure, or the dose amount of AL-53817.

The record reports group-level safety counts for both stages. The Stage A groups are labeled Stage A/AL-53817 and Stage A/Vehicle; the Stage B groups are labeled Stage B/AL-53817 and Stage B/Vehicle. The number at risk and the reported counts differ by group, but the record does not explain how subjects moved between stages or whether any subjects participated in both. It is therefore important to interpret each group using its own stage label, rather than assume the groups describe separate or identical populations.

Randomization, masking, and a parallel structure can support a fair treatment comparison when implemented as intended. The record does not report enough procedural detail to assess implementation. It also does not provide the treatment allocation ratio, so no allocation ratio should be inferred from the group counts.

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: 50 healthy volunteers were enrolled in Stage A and subsequently exited from the study. 60 unique patients were enrolled in Stage B.

Overall Study

Analysis population for the primary outcome, as defined in the registry: This reporting group includes all subjects exposed to test article during Stage A.

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 Number of Adverse Events in Stage A, measured over Day 1.

The primary outcome is titled “Number of Adverse Events in Stage A,” with a timeframe of Day 1 and a unit of adverse events. The description says adverse events, including serious adverse events and deaths, were reported regardless of their relationship to the test article. The stated population includes all subjects exposed to test article during Stage A. This outcome is intended to capture undesirable events observed during the initial dose-tolerability stage, rather than a symptom-benefit measure.

Counting adverse events can help describe the types and burden of safety events observed during a defined period. It is useful to distinguish the number of events from the number of people who experienced an event: one person can experience more than one event. The registry’s group-level safety fields also include counts of subjects affected, so those figures should not automatically be treated as event totals for the primary endpoint. The record does not provide a detailed event listing or explain how the endpoint count relates to the affected-subject fields.

Adverse events are reported regardless of whether they were considered related to treatment. That approach is useful for an overall safety description because it does not restrict reporting to events judged to have been caused by the study product. At the same time, a count alone does not describe severity, duration, clinical importance, or the basis for attribution. The registry record reports no serious adverse events in the groups, but does not supply a detailed narrative or event categories for the other adverse events.

The TNSS outcome is listed as secondary, not primary. Its stated measure is mean change from baseline over a 6-hour period in the EEC at Day 5. The registry record does not report its result, so the primary safety outcome and the planned symptom measure must be kept distinct when interpreting what the posted results can support.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization assigns participants to treatment groups using a chance-based process. In general, this can reduce systematic differences between groups at the start of a study, although it does not guarantee that every measured or unmeasured characteristic will be balanced. The registry labels this study randomized, but the method for generating or concealing assignments is not reported in the registry record. The group counts alone do not reveal the allocation procedure.

Double masking means that more than one role in the study is intended to remain unaware of assigned treatment. In general, masking can reduce the risk that expectations influence participant reports, clinical assessments, or study conduct. The record identifies the study as double-masked but does not state which roles were masked, how the nasal sprays were made indistinguishable, or whether masking was assessed. Those implementation details are not reported in the registry record.

A parallel design assigns participants to a treatment group and evaluates them in that group rather than having each participant receive every treatment in sequence. In general, parallel comparisons can be interpreted by contrasting outcomes across assigned groups, subject to the assumptions and analysis plan. The study is labeled parallel, but the record does not report the precise analysis population or whether all randomized subjects were included in each outcome analysis.

What does the primary outcome count?

The primary outcome is described as the number of adverse events in Stage A on Day 1. General statistical interpretation distinguishes an event count from a count of participants who experienced at least one event. If a person experiences repeated events, an event total can exceed the number of affected people. The registry safety information contains both numbers at risk and counts of subjects affected by other adverse events, but it does not provide an event-by-event listing that would allow those fields to be reconciled with the primary outcome wording.

When event counts are analyzed, the appropriate method depends on the data structure. General possibilities include models for counts, methods that account for repeated events within the same participant, or simple descriptive reporting. Count data may be more variable than a basic model assumes, a situation often called over-dispersion. In general, accounting for over-dispersion can prevent uncertainty from being understated. The registry record does not report a count model, an over-dispersion assessment, or any statistical analysis for the primary outcome.

How should a treatment estimate be read?

For a comparative outcome, an estimate describes the size and direction of a contrast between groups. A confidence interval describes the range of values compatible with the data and the method used, subject to the model assumptions. A narrow interval indicates greater precision than a wide interval, while an interval that includes values corresponding to no difference may leave the direction or magnitude uncertain. These are general principles; the registry does not report a TNSS estimate or confidence interval for this study.

A p-value is a measure, under a specified statistical model, of how incompatible the observed data are with a null hypothesis. It does not measure the probability that a treatment works, nor does it show the clinical importance of an effect. A p-value is most interpretable alongside an effect estimate, confidence interval, prespecified analysis, and information about multiplicity. No p-value or efficacy estimate is reported in the registry record.

What does the sample-size planning represent?

General planning calculations depend on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. The planning assumptions associated with this study describe a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. For time-to-event calculations, the stated convention is total events; for other calculations, it is participants per arm.

Such calculations are planning illustrations, not observed results or evidence that a study had a particular probability of detecting an effect. They do not establish the original design rationale. The registry record does not report the trial's own sample-size justification or explain whether these planning assumptions match the design decisions made before enrollment. In addition, the posted record does not contain a single analyzed treatment effect on which readers can base an independent assessment of precision for the TNSS outcome.

Why do analysis populations matter?

General trial analyses may include all randomized participants, only participants who received treatment, or a subset meeting defined criteria. These populations answer different questions and may be affected differently by missing outcomes or deviations from assigned treatment. The registry gives the Stage A primary outcome population as all subjects exposed to test article during Stage A, but it does not specify analysis populations for Stage B efficacy outcomes. It also does not report methods for missing data, protocol deviations, or adherence to the scheduled nasal-spray regimen. Those gaps limit assessment of how the observed groups relate to the intended randomized comparison.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary Stage A adverse-event outcome and a secondary Stage B TNSS outcome. It also states that there are three outcome measures, but the additional outcome details are not included in the record information summarized for these results. When a study assesses multiple outcomes, time points, or treatment comparisons, the chance of a seemingly notable result arising by chance can increase. General approaches include defining a primary endpoint in advance, limiting confirmatory tests, or adjusting inference for multiple comparisons. The registry record does not report a multiplicity strategy or identify which analyses, if any, were treated as confirmatory.

The registry lists zero analyses. It does not report a statistical analysis plan, model specifications, treatment contrasts, p-values, confidence intervals, or adjustments for baseline measures. It is therefore not possible to determine how the listed outcome measures were analyzed or whether selective reporting could have affected which results are available. These details are not reported in the registry record.

Missing-data handling is also not described. The record does not state how many participants contributed to the TNSS outcome, whether any Day 5 assessments were unavailable, or how missing measurements were addressed. In general, missing outcomes can affect both an estimate and its precision, and the consequences depend on why values are missing and on the analysis method. No assumptions about missingness or imputation should be inferred.

The Stage A population is described as all subjects exposed to test article during Stage A. For the Stage B outcomes, the analysis population is not reported in the registry record. The registry does not state whether an intention-to-treat, per-protocol, or other population was used. It also does not report how randomized participants who did not receive treatment, did not complete the schedule, or did not enter the EEC were handled. These omissions prevent a full assessment of the analysis populations and the relationship between randomization and the reported outcomes.

11. 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 reports zero serious adverse events in each listed group. The corresponding numbers at risk are 35 for Stage A/AL-53817, 15 for Stage A/Vehicle, 40 for Stage B/AL-53817, and 20 for Stage B/Vehicle. A zero count means that no serious adverse event was reported for that group in the posted results; it does not establish that the underlying risk is zero. With no reported uncertainty interval or detailed event data, the precision of these observations cannot be assessed from the registry record.

The record reports 5 subjects affected by other adverse events in Stage A/AL-53817 and 2 in Stage A/Vehicle. For Stage B, it reports 31 affected in the AL-53817 group and 5 in the Vehicle group. These are counts of affected subjects, not necessarily counts of all events. The record does not give event types, severity breakdowns, event timing, or a statistical comparison. The counts should be read by stage and treatment label rather than pooled across groups.

Death counts are not reported in the registry record. The primary outcome description says adverse events, including serious adverse events and deaths, were reported regardless of test article relationship, but the posted group-level death fields do not provide a count. No conclusion about death occurrence should be drawn from a missing value.

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

The registry record establishes the study's broad purpose, design labels, treatment schedules, outcome descriptions, and group-level adverse-event counts. It documents a Stage A dose-tolerability purpose and a Stage B safety-and-efficacy purpose. It also lists TNSS change over a 6-hour period in the EEC at Day 5 as a secondary outcome. Those details define the questions the study was intended to address.

The posted results do not include an efficacy estimate for TNSS. There is no reported group difference, confidence interval, or statistical test for that symptom outcome. It is therefore not possible from this record to assess the magnitude or precision of a symptom effect, or to determine whether the outcome favored AL-53817 or vehicle. Absence of a reported result is not evidence that there was no effect.

The safety counts show no reported serious adverse events in the listed groups and provide counts of subjects affected by other adverse events. They are descriptive. The record does not report inferential comparisons, adjustment for differences between stages, or sufficient detail on event type and timing to support a causal explanation for the observed counts. A higher or lower count in one listed group cannot, by itself, establish that treatment caused the difference.

The study's randomized, double-masked, parallel labels describe features that can strengthen comparisons when properly implemented. They do not replace reporting of analysis methods, outcome estimates, uncertainty, and participant flow. Those details are not reported in the registry record. The enrollment listed is 110, but that figure alone does not show how many participants contributed to a particular outcome or how complete the outcome data were.

The appropriate conclusion is limited: the registry records an early-stage study with two stages, a listed primary safety outcome, a listed secondary symptom outcome, and descriptive safety results. It does not provide the comparative efficacy results needed to determine the size or precision of an AL-53817 versus vehicle difference. Nor does it justify a treatment recommendation or a claim about treatment effectiveness.

13. Why This Trial Matters Statistically

This trial is statistically notable because its record combines two stages with different purposes. Stage A is framed around maximum tolerated dose and adverse-event reporting, while Stage B is framed around safety and efficacy in an EEC. Treating these as one simple comparison would blur differences in stage, purpose, and possibly exposure. Reading the results within their stage labels is essential to avoid an invalid pooled interpretation.

The study also illustrates why outcome wording matters. The primary endpoint is a number of adverse events, whereas the safety group fields report numbers of subjects affected. Event totals and affected-subject counts answer different questions. Clear definitions and a complete event-level account would help readers understand whether repeated events are represented and how the registry's endpoint description connects to the group-level counts.

A further statistical lesson is that a registered outcome is not the same as a reported estimate. TNSS is listed as a secondary outcome, yet the registry record gives no treatment estimate or uncertainty measure. Without those results, readers cannot judge effect size or precision. A study can document its intended comparison while leaving the quantitative answer unavailable in the record.

Finally, zero observed serious adverse events do not mean zero risk. The reported groups have finite numbers at risk, and the record provides no intervals or fuller event descriptions. This is a useful example of why safety data need both transparent denominators and uncertainty, especially when counts are sparse. The posted information permits cautious description, but not a detailed comparative analysis.

14. 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 main limitation is the absence of reported comparative efficacy results. Although the registry lists mean change from baseline in TNSS over a 6-hour period in the EEC at Day 5 as a secondary outcome, it does not provide an estimate, uncertainty interval, or statistical test. The efficacy question cannot be answered quantitatively from the registry record.

The record also does not report a statistical analysis plan, multiplicity handling, analysis populations for Stage B, or missing-data methods. It is not possible to determine which model was used, whether baseline values were accounted for, how incomplete assessments were treated, or whether analyses followed the randomized assignment. These are not reported in the registry record.

Safety reporting is limited to group counts. The record does not provide event names or severity and timing details for the other adverse events, or explain the relation between the primary endpoint's event-count wording and the group fields describing subjects affected. Death counts are not reported in the registry record. No confidence intervals or statistical comparisons accompany the safety counts.

Important design details are also absent. The dose amount of AL-53817, the Stage A dose levels, the randomization procedure, the masking procedures, the allocation ratio, and the participant flow between stages are not reported in the registry record. The group-level results should therefore not be used to infer those features or to assume that Stage A and Stage B populations can be combined.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety and Efficacy of AL-53817 Nasal Spray Solution — NCT01454505.
• Registry record last updated 2013-05-20; status last verified 2013-03.
• Results first posted 2013-05-20.
• 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.

18. Record Summary

The record describes NCT01454505, “Safety and Efficacy of AL-53817 Nasal Spray Solution,” a completed Phase 1 randomized, double-masked, parallel study sponsored by Alcon Research. The study began in 2011-10, had primary completion in 2012-03, and lists enrollment of 110.

Its stated purpose was to determine the maximum tolerated dose in Stage A and evaluate safety and efficacy in Stage B among ragweed-sensitive subjects in an EEC. The primary outcome is the number of adverse events in Stage A on Day 1. Mean change from baseline in TNSS over a 6-hour period in the EEC at Day 5 is listed as a secondary outcome.

The posted safety information reports zero serious adverse events in each listed group and provides counts of subjects affected by other adverse events. The registry record lists three outcome measures and zero analyses, and does not report a comparative TNSS estimate or its precision. The available results support descriptive safety reading but not a quantitative efficacy conclusion.