This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Safety, Tolerability, and PK of AN2728 in Adolescents With Atopic Dermatitis (NCT01652885), a na phase 1, phase 2 study. The primary outcome is Number of Participants With Local Tolerability Symptoms According to Severity on Baseline.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01652885 |
| Phase | Phase 1, Phase 2 |
| Condition | Dermatitis, Atopic |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 23 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned adolescents with atopic dermatitis. The registry record defines the safety population as participants who were enrolled and had received any amount of study drug. It does not report the age range, disease severity requirements, or other eligibility details, so those aspects of the population cannot be characterized from the registry record.
Intervention
Participants received AN2728 Topical Ointment, 2%, applied twice daily for up to 28 days. The study was intended to investigate safety, tolerability, and systemic exposure. The registry record does not report pharmacokinetic results, so the amount or pattern of systemic exposure cannot be described from these results.
Comparator
The study used a single-group design and had no like-for-like control comparison. It was open-label, with no masking reported. As a result, the registry outcomes do not compare AN2728 with placebo, another treatment, or a concurrent untreated group. Changes over time cannot be separated from other influences using a randomized comparison in this study.
Primary question
The primary outcome was the number of participants classified by the severity of local burning or stinging symptoms at baseline. The categories were none, mild, moderate, and severe, with descriptions ranging from no symptoms to discomfort. The registry record does not report the counts for these categories. Because the measure is explicitly at baseline, it does not itself describe symptoms that began during treatment or a change after treatment.
3. Trial Design
This was an open-label study of AN2728 Topical Ointment, 2%, in adolescents with atopic dermatitis. The registry lists the phases as PHASE1 and PHASE2, a single-group model, and enrollment of 23. The study was sponsored by Pfizer and is recorded as completed. Its registered start was 2012-07 and its primary completion was 2012-10; these dates do not establish the duration of treatment for individual participants.
The intervention description states that the ointment was applied twice daily for up to 28 days. The study purpose was to investigate safety, tolerability, and systemic exposure. The primary outcome concerned the number of participants with local tolerability symptoms, classified by severity at baseline. Two secondary outcomes are listed: treatment success based on Investigator's Static Global Assessment and change from baseline in signs and symptoms of atopic dermatitis at Day 8, 15, 22 and 29. Results for those secondary outcomes are not reported in the registry record.
There was no randomized allocation and no masking. The record identifies a single group receiving the study ointment, rather than a treatment group and a concurrent control group. That design can describe observations among participants who received the ointment, but it cannot provide a randomized estimate of how outcomes compare with a control treatment. The registry record does not report a protocol-level statistical plan, sample-size justification, or details of interim analyses.
The safety population is described as enrolled participants who received any amount of study drug. The record lists 22 outcome measures but no analyses. This distinction matters: an outcome can be named in the registry without its results or an analysis being posted. The available information therefore supports describing the intended measures and the reported safety counts, but not reconstructing missing endpoint results or inferential analyses.
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
| Stage | AN2728 Topical Ointment 2 Percent |
|---|---|
| STARTED | 23 |
| COMPLETED | 22 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | AN2728 Topical Ointment 2 Percent |
|---|---|
| Adverse Event | 1 |
Analysis population for the primary outcome, as defined in the registry: Safety population included all participants who were enrolled and had received any amount of the study drug.
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: Safety population included all participants who were enrolled and had received any amount of study drug.
| Characteristic | Unit | AN2728 Topical Ointment 2 Percent |
|---|---|---|
| Participants analysed | 23 | |
| Age, Continuous | years | 15.0 (SD 1.55) |
| Sex: Female, Male: Female | Participants | 19 |
| Sex: Female, Male: Male | Participants | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Local Tolerability Symptoms According to Severity on Baseline, measured over Baseline.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with local tolerability symptoms according to severity at baseline. The symptoms were burning or stinging. The registry definition distinguishes none, mild, moderate, and severe symptoms, using descriptions that progress from no stinging or burning to a sensation causing definite discomfort. The endpoint is a count classified by symptom severity, not a continuous measurement of symptom intensity.
Local tolerability measures are used to characterize how a topical treatment feels at the application site. Categorizing symptoms by severity can preserve clinically relevant distinctions that a single yes-or-no count would lose. In general, however, the interpretation depends on when the measure is taken and whether the categories are reported consistently. Here the stated timeframe is baseline. That makes the measure a description of symptoms at the starting assessment, not a post-treatment measure or a change from baseline.
The registry record does not report the number of participants in any severity category. It therefore does not allow a reader to characterize the baseline distribution or determine how common each symptom level was in the study population. The endpoint also does not directly measure systemic exposure, treatment success, or change in dermatitis signs and symptoms. Those topics are part of the study purpose or listed secondary outcomes, but the primary endpoint is specifically a baseline local tolerability classification.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study record identifies a single group of adolescents with atopic dermatitis who received AN2728 Topical Ointment, 2%. Its primary outcome is a baseline count classified by local burning or stinging severity. Although the endpoint is defined, the registry record does not report the counts in the severity categories. The primary outcome therefore cannot be interpreted as a numerical finding from the information recorded.
The posted safety figures report 0 participants affected by serious adverse events among 23 at risk. They also report 10 participants affected by other adverse events among 23 at risk. These are descriptive counts for the study group. They do not establish whether an event was caused by the ointment, and they do not compare event frequency with a control group. The registry record lists no serious adverse-event terms. Deaths are not reported in the registry record.
The study purpose includes safety, tolerability, and systemic exposure, but pharmacokinetic results are not reported in the registry record. The listed secondary outcomes include treatment success based on Investigator's Static Global Assessment and change from baseline in signs and symptoms at Day 8, 15, 22 and 29. Their outcome results are not reported in the registry record either. Consequently, the record does not support a numerical account of treatment success, symptom change, or systemic exposure.
The registry lists 22 outcome measures and 0 analyses. An outcome listing describes what was planned or registered; it does not establish that a result was analyzed or posted. No p-values or confidence intervals for the primary endpoint are reported in the registry record. Without those results, it is not possible to assess the precision of a primary estimate or evidence for a difference. In any case, this single-group study has no concurrent randomized comparator from which to estimate a comparative treatment effect.
The enrollment of 23 and the reported safety counts provide the scale of the observations, but not a guarantee that uncommon events would be detected. A count of 0 serious events in the observed group should not be interpreted as proof that serious events cannot occur. Likewise, the count for other adverse events is a descriptive observation, not a causal estimate. The open-label design and absence of a comparator limit attribution and comparative interpretation. Overall, the registry record supports a narrow description of the study design and selected safety counts; it does not report the primary endpoint result or establish comparative efficacy.
9. Statistical Methods Explained
The registry record describes a single-group, open-label study and lists counts as the primary outcome type. It does not report a statistical analysis plan, model, confidence interval, or hypothesis test for the primary endpoint. The explanations below describe general statistical concepts relevant to these measures; they do not imply that a particular method was used in the study.
What does a count measure?
A count records how many participants meet a stated outcome definition. For the primary endpoint, the outcome is not simply whether a symptom occurred: the record specifies classification by severity at baseline. Counts can make the observed frequency of categories easy to describe, but they do not by themselves express uncertainty. Interpretation also depends on the denominator used for each outcome and on whether all eligible observations were available. Outcome-specific denominators are not reported in the registry record for the primary endpoint.
The severity labels are ordered from none through mild and moderate to severe. In general, an ordered classification retains information about levels that would be lost if categories were collapsed into a single yes-or-no measure. But the distance between adjacent categories is not necessarily equal. Treating the categories as if they were equally spaced numerical scores would require justification; no such scoring method is reported in the registry record. The posted primary outcome is described as counts according to severity, not as an average score.
What would a confidence interval add?
In general, a confidence interval describes uncertainty around an estimate under the assumptions of the statistical method. A narrow interval indicates greater precision than a wide interval, while an interval around a count-based proportion can communicate uncertainty that the raw count alone does not show. A confidence interval does not remove limitations from study design, measurement, or selection. No confidence interval for the primary endpoint is reported in the registry record, and there are no category counts from which to interpret such an interval.
A p-value, in general, summarizes how compatible observed data are with a specified statistical hypothesis under a model. It does not measure the size or importance of an effect, and it cannot establish causation. No p-value for the primary endpoint is reported. The registry record also does not identify a primary hypothesis test or adjustment strategy. A reader should not infer an unreported analysis from the fact that outcomes are listed.
Why does the study design matter?
In a randomized comparison, assignment to different groups can support a comparative estimate under the trial's design and analysis assumptions. This study is listed as a single group with allocation recorded as NA, and the arm descriptions do not form a like-for-like control comparison. Descriptive counts can characterize what was recorded among participants receiving the ointment, but they cannot separate treatment effects from changes that might occur without treatment, background variation, or other influences. Open-label assessment can also leave subjective outcomes more open to expectation or assessment effects than masked assessment, although the registry record does not quantify those effects.
For safety counts, the denominator is important: a count without the number of participants at risk is difficult to interpret. The registry safety record gives 23 at risk for serious and other adverse events. In general, a count of no observed serious events does not imply that the underlying risk is zero; precision depends on the amount of information, and uncommon events may not appear in a limited study. No uncertainty interval for the safety counts is reported in the registry record.
What do the planning assumptions mean?
The sample-size assumptions describe planning illustrations based on the observed effect, not the trial's own design. They state a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. These are assumptions for hypothetical planning comparisons, not evidence that this study randomized participants between two arms. The illustrations are not observed power and should not be read as a measure of the probability that this completed study detected an effect. No sample-size justification for the actual single-group study is reported in the registry record.
More broadly, statistical conclusions depend on the match between the question, endpoint, design, and analysis. A baseline severity count can describe starting symptom status, but it cannot answer a question about change after treatment. A single-group safety count can describe observed events, but it cannot estimate a treatment-versus-control contrast. Because the primary endpoint values, analysis details, and pharmacokinetic results are not reported, further statistical reconstruction would go beyond what the registry record supports.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 22 outcome measures and 0 analyses. It names the baseline local tolerability measure as primary and lists treatment success based on Investigator's Static Global Assessment and change from baseline in signs and symptoms at Day 8, 15, 22 and 29 as secondary outcomes. The record does not report results for these secondary measures, nor does it describe how multiple outcomes or repeated time points were handled in analysis.
When a study assesses multiple outcomes, the chance of at least one apparently notable result can increase if each is tested separately without an appropriate plan. General approaches can include specifying a hierarchy, adjusting inference, or treating outcomes as descriptive. Which approach is appropriate depends on the aims and analysis plan. The registry record does not report a multiplicity strategy, so it is not possible to say whether any adjustment was planned or used.
Missing-data handling is also not reported in the registry record. It does not state how missing endpoint assessments were defined, whether participants with unavailable measurements were excluded, or whether any imputation was used. The safety population is defined as enrolled participants who received any amount of study drug. That definition identifies the intended population for safety reporting, but it does not describe missingness for the primary endpoint or secondary outcomes.
The adverse-event figures give 23 at risk for both serious and other events, while endpoint-specific denominators and missingness details are not reported. Readers should not assume that every outcome had the same analysis population simply because the study enrollment is listed. Without the analysis population, outcome values, and missing-data procedures, the completeness and robustness of outcome estimates cannot be assessed from the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| AN2728 Topical Ointment 2 Percent | 0 | 23 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| AN2728 Topical Ointment 2 Percent | 10 of 23 |
Most frequent non-serious adverse event terms
| Event term | Organ system | AN2728 Topical Ointment 2 Percent |
|---|---|---|
| Application site pain | General disorders | 3 of 23 |
| Nasopharyngitis | Respiratory, thoracic and mediastinal disorders | 3 of 23 |
| Application site dermatitis | General disorders | 1 of 23 |
| Application site discomfort | General disorders | 1 of 23 |
| Upper respiratory tract infection | Infections and infestations | 1 of 23 |
| Arthropod bite | Injury, poisoning and procedural complications | 1 of 23 |
| Hand fracture | Injury, poisoning and procedural complications | 1 of 23 |
| Headache | Nervous system disorders | 1 of 23 |
| Migraine | Nervous system disorders | 1 of 23 |
| Dysmenorrhoea | Reproductive system and breast disorders | 1 of 19 |
The registry record reports 0 participants affected by serious adverse events among 23 at risk in the AN2728 Topical Ointment 2 Percent group. It reports 10 participants affected by other adverse events among 23 at risk. These are counts as recorded, not comparative estimates. No serious adverse-event terms are listed. Deaths are not reported in the registry record.
In general, an observed count describes what was recorded during the study; it does not establish that the treatment caused an event or that no unobserved events occurred. A count of 0 serious events is not proof of zero risk, particularly when the study has a limited enrollment. The count of other adverse events likewise cannot be interpreted as a treatment-attributable rate from this single-group, open-label design. There is no concurrent control group for comparison, and no uncertainty intervals or further event details are reported in the registry record.
12. What the Result Does, and Does Not, Mean
The record establishes that an open-label, single-group study of AN2728 Topical Ointment, 2%, was conducted in adolescents with atopic dermatitis, with enrollment of 23. It records a baseline primary endpoint for local burning or stinging symptoms by severity, and safety figures for serious and other adverse events. The available numerical safety information is descriptive and pertains to the study group.
The record does not report the counts for the primary endpoint's severity categories. It also does not report results for the listed secondary outcomes or pharmacokinetic findings. The study purpose included systemic exposure, but that purpose alone is not a result. Without the outcome data, the registry record cannot establish how participants' baseline symptom categories were distributed, whether symptoms changed over time, or what systemic exposure was observed.
The single-group design does not support a randomized comparison with another treatment or no treatment. Any changes observed in a single group could reflect multiple influences, and the registry record does not report the outcome values needed to describe such changes in this case. The record therefore does not establish comparative efficacy, nor does it support a conclusion that the ointment works or does not work.
The serious adverse-event count is an observation, not a guarantee about future risk. The other adverse-event count also does not establish causality. These limits are important when interpreting a study focused on safety and tolerability, especially when no comparator or uncertainty estimates are reported. The findings that can be stated are restricted to the design and the posted counts; broader claims about benefit, harm, or effects in other populations are not established by this registry record.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how the research question and design shape what can be concluded. Its stated aims concern safety, tolerability, and systemic exposure, and its primary endpoint is a baseline classification of local symptoms. Those measures address different aspects of a topical treatment: a baseline symptom count describes the starting assessment, safety counts describe recorded events, and pharmacokinetic outcomes would characterize systemic exposure. The registry record does not report results for all of these aims.
The single-group, open-label design permits descriptive reporting but does not create a randomized contrast. That distinction is central to statistical interpretation: a count observed among treated participants is not the same as an estimate of what would have happened under a comparator. The design can therefore support a limited account of what the registry records, while leaving comparative questions unanswered.
The record also illustrates why endpoint definitions and results must be read together. The severity rubric is detailed, but the counts in its categories are not reported. A carefully defined measure cannot be interpreted as a finding without its observed values. Likewise, listing secondary outcomes does not show what their results were, and a stated study purpose does not substitute for pharmacokinetic results.
Finally, the safety figures convey both the value and the limits of event counts. Reporting participants at risk alongside affected counts makes the descriptive data more interpretable, but the counts alone do not establish causation or precisely characterize uncommon events. The study record is thus useful for understanding the registered design and the boundaries of the reported evidence, rather than for drawing conclusions beyond those observations.
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 registry record does not report the primary endpoint counts by severity, results for the listed secondary outcomes, or pharmacokinetic findings. This prevents assessment of the primary outcome and leaves important parts of the stated study purpose without posted results. It also does not report confidence intervals, p-values, an analysis plan, or a sample-size justification for the actual design.
The study was open-label and single-group, with no randomized control comparison. These features limit the ability to attribute observations to the ointment or to compare outcomes with an alternative. The primary endpoint is measured at baseline, so its stated timeframe does not describe treatment-emergent symptoms or change. The registry record does not provide further measurement timing or analysis details for that endpoint.
Enrollment was 23, and the treatment was applied twice daily for up to 28 days. The record does not provide longer-term observations. It also does not report the age range, detailed eligibility criteria, disease severity requirements, or outcome-specific denominators. The extent to which findings would apply beyond the registered study population cannot therefore be assessed from these details.
For safety, the record gives counts of participants affected, but does not provide detailed event descriptions for other adverse events or uncertainty estimates. The serious-event terms list is empty, and deaths are not reported in the registry record. Missing-data procedures and handling of multiple outcomes are also not reported. Together, these omissions restrict the precision and scope of interpretation; they do not justify filling in unreported findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety, Tolerability, and PK of AN2728 in Adolescents With Atopic Dermatitis — NCT01652885.
- Registry record last updated 2017-04-24; status last verified 2017-03.
- Results first posted 2017-04-24.
- 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.
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18. Record Summary
NCT01652885 is registered as a completed, open-label, single-group study of AN2728 Topical Ointment, 2%, in adolescents with atopic dermatitis. It lists PHASE1 and PHASE2, enrollment of 23, and application twice daily for up to 28 days. The registered start was 2012-07 and primary completion was 2012-10.
The primary endpoint was the number of participants classified by severity of local burning or stinging symptoms at baseline. The registry record does not report the category counts. It reports 0 participants affected by serious adverse events among 23 at risk and 10 affected by other adverse events among 23 at risk. Pharmacokinetic results and results for the listed secondary outcomes are not reported in the registry record. The record lists 22 outcome measures and 0 analyses.