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 and Efficacy Study of a Novel Ointment to Treat Plaque Type Psoriasis (NCT01029405), a randomized phase 2 study. The primary outcome is Percentage of Participants With Greater Decrease In Overall Target Plaque Severity Score (OTPSS): Ointment (2% Twice Daily), Vehicle.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01029405 |
| Phase | Phase 2 |
| Condition | Psoriasis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 145 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with plaque type psoriasis. The registry record describes the intent-to-treat population for the primary outcome as all randomized participants who received study medication. Enrollment was 145. The record does not report further eligibility details or demographic characteristics, so the population cannot be characterized more specifically from this information.
Intervention
The study evaluated AN2728 Ointment B at 2% and 0.5%, applied once or twice daily. The primary outcome description focuses on the 2% ointment applied twice daily. The registry record also lists ointment regimens at both strengths and frequencies, together with Ointment B Vehicle.
Comparator
The primary outcome compares an ointment-treated target plaque with a vehicle-treated target plaque. The official title describes a bilateral study, and the outcome description reports the percentage of participants with reduced OTPSS in each of these plaque conditions. How plaques were assigned to treatment, and whether assignment was randomized by side or another method, is not reported in the registry record.
Primary question
At Day 42, what percentage of participants had a greater decrease in Overall Target Plaque Severity Score for the plaque treated with AN2728 Ointment B 2% twice daily than for the vehicle-treated plaque, and what percentage had a greater decrease in the reverse comparison? The registry record defines this comparison but does not report the corresponding percentages or their uncertainty.
3. Trial Design
This was a randomized, quadruple-masked, Phase 2 study with a parallel model. The official title describes a 12 Week bilateral study of AN2728 Ointment B at 2% and 0.5% versus Ointment B Vehicle. The brief summary says treatment was applied once or twice daily for 12 weeks. The registry record lists five arm descriptions: 2% twice daily, vehicle, 2% once daily, 0.5% twice daily, and 0.5% once daily. It does not provide a fuller account of how participants or plaques were assigned among these regimens.
The bilateral feature is relevant to the primary outcome, which compares target plaques treated with ointment and vehicle within the outcome description. The record does not explain how the bilateral comparison relates operationally to the parallel model, or describe the assignment of treatment to body sites. Randomization and quadruple masking are recorded, but the randomization sequence, concealment procedures, and identities of the masked groups are not reported in the registry record.
Enrollment was 145. The study started in 2009-11, reached primary completion in 2010-05, and is listed as completed. Pfizer is the sponsor. The record does not give the number of participants in each efficacy arm, the number who completed treatment, or the number contributing to the primary outcome. The adverse-event group counts are reported separately and should not be treated as a substitute for arm-specific efficacy denominators.
The primary outcome was assessed at Day 42, while the overall treatment period was 12 weeks. The registry record identifies a secondary outcome concerning greater OTPSS decrease for 0.5% once daily, 0.5% twice daily, and 2% once daily compared with vehicle. Numerical results for that outcome 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.
Overall Study
| Stage | AN2728 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily |
|---|---|---|---|---|
| STARTED | 36 | 37 | 35 | 37 |
| COMPLETED | 34 | 34 | 31 | 32 |
| NOT COMPLETED | 2 | 3 | 4 | 5 |
Reasons for not completing this period:
| Reason | AN2728 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily |
|---|---|---|---|---|
| Withdrawal by Subject | 0 | 1 | 2 | 0 |
| Protocol Violation | 0 | 0 | 0 | 1 |
| Adverse Event | 0 | 0 | 1 | 1 |
| Lost to Follow-up | 2 | 1 | 1 | 2 |
| Other | 0 | 1 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Intent-to-treat population included all randomized participants who received study medication.
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: Intent-to-treat population included all randomized participants who received the study medication.
| Characteristic | Unit | AN2728 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 36 | 37 | 35 | 37 | 145 | |
| Age, Categorical: <=18 years | Participants | 0 | 1 | 0 | 0 | 1 |
| Age, Categorical: Between 18 and 65 years | Participants | 36 | 31 | 34 | 33 | 134 |
| Age, Categorical: >=65 years | Participants | 0 | 5 | 1 | 4 | 10 |
| Gender: Female | Participants | 6 | 4 | 4 | 4 | 18 |
| Gender: Male | Participants | 30 | 33 | 31 | 33 | 127 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With Greater Decrease In Overall Target Plaque Severity Score (OTPSS): Ointment (2% Twice Daily), Vehicle, measured over Day 42.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percenatge of participants |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percentage of participants with a greater decrease in Overall Target Plaque Severity Score (OTPSS) for the plaque treated with AN2728 Ointment B 2% twice daily compared with the vehicle-treated plaque, with the reverse comparison also described. OTPSS is an investigator assessment of target-plaque severity. Each plaque receives a score from 0 (no plaque) to 8 (very severe plaque); a higher score indicates greater severity. A decrease therefore represents a lower recorded severity score for the assessed plaque.
Expressing the outcome as a percentage of participants makes the endpoint a participant-level comparison of which treated plaque had the greater score decrease. It is not a report of the average OTPSS score, and it does not by itself show the size of the score change for each participant. The bilateral comparison is intended to distinguish the relative change between the ointment-treated and vehicle-treated plaques, while the score scale describes plaque severity.
The endpoint is assessed at Day 42. Its registry description does not state how a tie, unchanged scores, missing plaque assessments, or other incomplete observations were handled. Nor does it report the percentages, counts, confidence intervals, or test results. The endpoint definition and timing are reported, but the numerical result and its precision are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a planned clinical comparison, not a numerical estimate of its outcome. It describes the percentage of participants with greater OTPSS decrease in the ointment-treated plaque than in the vehicle-treated plaque, and the percentage with the reverse pattern, at Day 42. The corresponding percentages are not reported in the registry record. As a result, the direction and magnitude of the observed efficacy comparison cannot be described from this record.
The scale itself has a clear direction: higher OTPSS indicates greater plaque severity, and a decrease means a lower score than before. However, the outcome is based on which plaque had the greater decrease, not on the average amount of score change. A participant-level directional comparison does not tell the reader whether the difference between the two plaques was small or large. The registry description supplies no change values or distribution of changes to clarify that distinction.
Statistical precision also cannot be assessed. Confidence intervals and p-values for the primary comparison are not reported in the registry record. In general, a confidence interval communicates the uncertainty around an estimated effect, while a statistical test assesses compatibility of the data with a specified null hypothesis under its assumptions. Neither can be reconstructed from the endpoint description alone, and no analysis approach should be assumed.
The randomized and quadruple-masked design features are relevant to how treatment comparisons may be protected from systematic differences and observer expectations. They do not, by themselves, establish the size or precision of an effect. The registry record does not detail the randomization procedures, masking roles, or statistical model used for the primary outcome. The official title calls the study bilateral, and the primary outcome description compares ointment-treated and vehicle-treated plaques, but the registry record does not explain the assignment and analysis of plaque pairs.
The enrollment figure of 145 is not an efficacy denominator. The primary analysis population is defined as randomized participants who received study medication, but the number who met that definition and contributed data at Day 42 is not reported in the registry record. No efficacy conclusion should be inferred from enrollment or from the adverse-event counts, which address safety reporting in listed groups rather than the primary efficacy outcome.
Overall, the posted results do not provide the numerical primary endpoint result, an uncertainty estimate, or enough analysis details to independently assess the treatment contrast. The outcome definition indicates what the study sought to compare; it does not establish the result of that comparison.
9. Statistical Methods Explained
The design and endpoint permit some general statistical interpretation, but the specific primary-outcome method is not reported in the registry record. The concepts below explain what the recorded design features mean without assuming which calculations the investigators used.
What does randomization contribute?
In general, randomization assigns treatment according to a chance-based process. Its purpose is to reduce systematic differences between treatment groups at the time of assignment, including differences that may be known or unknown. Randomization is not a guarantee that groups will be identical, particularly in a study with limited enrollment. Interpretation also depends on how the sequence was generated, concealed, and implemented. Those procedural details are not reported in the registry record.
The record classifies the study as randomized and parallel. It also describes a bilateral study and an endpoint comparing ointment-treated and vehicle-treated plaques. In general, when two sites from the same participant are compared, their outcomes may be statistically related because they share participant characteristics. An analysis should account for the design and unit of assignment. The registry record does not state whether or how the primary analysis accounted for within-participant pairing, or how the bilateral feature was reconciled with the parallel model.
What does quadruple masking mean for interpretation?
Masking is intended to limit the influence of treatment knowledge on care, assessment, or reporting. The registry record labels masking as quadruple, but does not identify the roles covered by that label or describe how masking was maintained. In general, masking can be especially relevant when an outcome includes investigator scoring, as OTPSS does. It can reduce the risk that expectations affect assessment, but it cannot remove all possible measurement error or other sources of bias.
How should a percentage endpoint be understood?
The primary outcome is expressed as the percentage of participants whose plaque-score decrease was greater for one treatment condition than the other, with the reverse pattern also described. In general, such a participant-level percentage is based on classifying each participant according to a comparison of their two plaque changes. It differs from comparing mean score changes: it describes the frequency of a direction of difference, not the average size of that difference. The registry record does not describe the handling of equal changes, absent assessments, or other cases that might not fit a directional classification.
For a percentage estimate, the number of participants meeting the outcome and the relevant analysis denominator are important for interpretation. The registry record defines the primary population as randomized participants who received study medication but does not report the primary outcome counts or denominator. The percentage estimates therefore cannot be checked or recalculated from the record.
What can uncertainty measures tell readers?
In general, a confidence interval describes a range of estimates compatible with the observed data and the method's assumptions. It helps readers judge how precisely an effect is estimated; it is not a guarantee that the true effect lies within that range. A p-value, when reported, summarizes how unusual data at least as extreme as those observed would be under a specified null hypothesis and model. It does not measure the probability that a treatment effect is true, nor does it describe the clinical importance of a difference.
No confidence interval, p-value, or test method for the primary comparison is reported in the registry record. It is therefore not possible to judge the statistical precision of the primary result or to identify the evidence threshold used for interpretation. The outcome definition alone does not supply those missing details.
What do the planning assumptions mean?
The registry record describes sample-size planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not observed outcomes or proof of the trial's design rationale. The actual effect fractions and numerical planning results are not reported in the registry record.
In general, a planning calculation estimates the sample size needed under stated assumptions about the target effect, variability, allocation, and statistical procedure. Changing those assumptions can change the resulting sample-size estimate. A planning illustration based on an observed effect is not observed power and does not establish that the original study was adequately powered. The registry record does not report the trial's own sample-size justification or the assumptions used when the study was designed.
The record further distinguishes time-to-event calculations, which use total events, from other calculations, which use participants per arm. No time-to-event primary outcome is described for this study. The primary outcome is a participant percentage at Day 42. The statistical method used to analyze it, and whether the planning illustration corresponds to its analysis, are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies a primary outcome concerning the percentage of participants with greater OTPSS decrease for the 2% twice-daily ointment compared with vehicle at Day 42. It also names a secondary outcome concerning the 0.5% once-daily, 0.5% twice-daily, and 2% once-daily regimens compared with vehicle. Numerical results for these outcomes are not reported in the registry record.
When a study assesses multiple outcomes, treatment regimens, time points, or comparisons, the chance of at least one apparently notable result can increase if no adjustment or prespecified hierarchy is used. In general, a multiplicity strategy may control the overall error rate, prioritize a primary comparison, or identify analyses as exploratory. The registry record does not report a multiplicity procedure, a testing hierarchy, or whether the primary and secondary comparisons were adjusted.
The primary outcome population is defined as all randomized participants who received study medication. This describes who was intended to be included, but the number of participants analyzed is not reported. The handling of missing Day 42 assessments, incomplete treatment, protocol deviations, or participants without a usable bilateral comparison is not reported in the registry record. No imputation method, sensitivity analysis, or missing-data assumption is described.
The registry record does not report whether analysis followed the original randomized assignment regardless of treatment received, whether exclusions were made, or which covariates were included. Thus, the stated population definition should not be taken as a complete analysis plan. Without the numerical endpoint results and details of missing-data and multiplicity methods, readers cannot assess how those choices may have affected the estimates or their uncertainty.
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 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | 0 | 36 | 0.0% |
| AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | 0 | 37 | 0.0% |
| AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | 0 | 34 | 0.0% |
| AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily | 0 | 37 | 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 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | 9 of 36 |
| AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | 14 of 37 |
| AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | 12 of 34 |
| AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily | 16 of 37 |
Most frequent non-serious adverse event terms
| Event term | Organ system | AN2728 Ointment B 0.5 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 0.5 Percent +Ointment B Vehicle, Twice Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Once Daily | AN2728 Ointment B 2 Percent + Ointment B Vehicle, Twice Daily |
|---|---|---|---|---|---|
| Pruritus | Skin and subcutaneous tissue disorders | 1 of 36 | 2 of 37 | 1 of 34 | 6 of 37 |
| Influenza | Infections and infestations | 3 of 36 | 3 of 37 | 0 of 34 | 1 of 37 |
| Pharyngitis | Infections and infestations | 2 of 36 | 1 of 37 | 1 of 34 | 1 of 37 |
| Dermatitis contact | Skin and subcutaneous tissue disorders | 1 of 36 | 0 of 37 | 1 of 34 | 3 of 37 |
| Pharyngotonsillitis | Infections and infestations | 1 of 36 | 0 of 37 | 2 of 34 | 0 of 37 |
| Hypertension | Vascular disorders | 0 of 36 | 1 of 37 | 1 of 34 | 1 of 37 |
| Excoriation | Injury, poisoning and procedural complications | 1 of 36 | 0 of 37 | 0 of 34 | 1 of 37 |
| Dyslipidaemia | Metabolism and nutrition disorders | 0 of 36 | 1 of 37 | 0 of 34 | 1 of 37 |
| Back pain | Musculoskeletal and connective tissue disorders | 1 of 36 | 0 of 37 | 0 of 34 | 1 of 37 |
| Pain in extremity | Musculoskeletal and connective tissue disorders | 1 of 36 | 0 of 37 | 1 of 34 | 0 of 37 |
The registry record lists four safety groups, each with a count at risk and counts for serious and other adverse events. For AN2728 Ointment B 0.5% plus Ointment B Vehicle once daily, 36 participants were at risk; 0 had a serious adverse event and 9 had other adverse events. For the twice-daily 0.5% regimen, 37 were at risk; 0 had a serious adverse event and 14 had other adverse events. For 2% once daily, 34 were at risk; 0 had a serious adverse event and 12 had other adverse events. For 2% twice daily, 37 were at risk; 0 had a serious adverse event and 16 had other adverse events.
These are counts, not estimates of comparative risk. The record does not give definitions or event-term detail for the reported other adverse events, and the death entries are not reported. A recorded zero serious adverse events in a group means none were reported among those listed at risk; it does not establish that an event is impossible or characterize risks beyond the study observations. The registry record does not report a comparative safety analysis or uncertainty estimates for these counts.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, quadruple-masked Phase 2 study evaluated AN2728 Ointment B at 2% and 0.5%, at once- or twice-daily frequencies, against Ointment B Vehicle in plaque type psoriasis. The treatment period was 12 weeks, and the primary outcome description focuses on a Day 42 bilateral plaque-severity comparison for 2% ointment applied twice daily versus vehicle. These details identify the clinical question and the outcome being assessed.
The record does not report the primary outcome percentages, counts, or uncertainty estimates. It therefore does not show which plaque condition more often had the greater decrease, how large any difference was, or how precisely it was estimated. The endpoint definition is not itself evidence of a favorable or unfavorable result. No conclusion about the efficacy comparison can be drawn from the design description alone.
The listed safety data report zero serious adverse events in each of the described groups, alongside counts of other adverse events. Those observations describe the safety reporting recorded for the listed groups; they do not provide a complete comparative safety analysis. The registry record does not report death counts, event-term detail, or uncertainty around group comparisons.
Enrollment of 145 describes the study's recorded enrollment, not the number contributing to the primary endpoint. The primary population is defined, but the primary outcome denominator and missing-data handling are not reported. The results therefore cannot be independently reproduced or evaluated for sensitivity to analysis choices from the registry record alone.
In short, the record documents a study design, a plaque-severity outcome, and selected adverse-event counts. It does not report the numerical efficacy result, the statistical analysis method, or enough information to assess efficacy precision, multiplicity, or missing-data effects. The scope of interpretation should remain limited to what is actually recorded.
13. Why This Trial Matters Statistically
This trial raises statistical issues that are important when interpreting dermatology studies with site-level assessments. The primary outcome compares plaque changes within the bilateral study description, while the record also labels the model parallel. In general, measurements from two sites on the same participant may be correlated. The assignment structure and analysis need to reflect the actual design; otherwise, uncertainty can be mischaracterized. The registry record does not explain the assignment of treatment to plaques or the method used to account for paired observations.
The endpoint also illustrates the distinction between the direction and magnitude of change. Reporting the percentage of participants whose score decreased more under one condition identifies how often a comparison favors one side in direction. It does not reveal how large the score differences were. A score-change summary and a participant-level directional summary answer different questions, and the registry record describes the latter.
Assessment is based on investigator-rated OTPSS. Masking can help limit assessment influenced by treatment knowledge, but interpretation still depends on assessment procedures, outcome definitions, and the statistical handling of incomplete observations. The record identifies quadruple masking and defines the score scale, but does not report the masking roles or missing-data methods.
Finally, the absence of numerical primary results sharply limits what can be learned from the posted record about effect size and precision. The study design and endpoint are useful for understanding the planned comparison, while the missing estimates prevent readers from evaluating its statistical evidence. This distinction between a documented question and a reported result is central to responsible trial interpretation.
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 central limitation for interpretation is that the registry record does not report numerical results for the primary efficacy outcome. It also does not report the primary analysis denominator, confidence intervals, p-values, or the statistical method used. The endpoint definition is available, but readers cannot assess the estimated comparison, its precision, or reproduce it from the record.
The bilateral study description and parallel model are both recorded, but the operational relationship between them is not explained. The registry record does not specify how target plaques were selected, how treatment was assigned to plaques or sides, or how within-participant dependence was handled in analysis. These details matter for understanding both the comparison and its uncertainty.
Details needed to assess analysis populations and incomplete observations are also absent. The primary population is described as randomized participants who received study medication, but the number analyzed at Day 42, the number with missing assessments, and the handling of missing or tied plaque comparisons are not reported. The record does not provide a full statistical analysis plan, a multiplicity strategy, or the trial's sample-size justification.
The safety information is limited to group-level counts of participants at risk and adverse events. Serious-event counts are recorded as zero for the listed groups, but death counts are not reported, and event-term detail and comparative uncertainty are absent. These limitations mean the recorded safety counts cannot be treated as a comprehensive comparative assessment.
Enrollment was 145, but enrollment alone does not establish the amount of information available for any particular outcome. The study is Phase 2 and completed, yet those labels do not replace the missing efficacy estimates and analysis details. Any interpretation should be confined to the design and safety counts actually described in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy Study of a Novel Ointment to Treat Plaque Type Psoriasis — NCT01029405.
- Registry record last updated 2017-03-07; status last verified 2017-01.
- Results first posted 2017-03-07.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01029405 is a completed, randomized, quadruple-masked Phase 2 study sponsored by Pfizer. It enrolled 145 participants and is described as a 12 Week bilateral study of AN2728 Ointment B at 2% and 0.5%, applied once or twice daily, compared with Ointment B Vehicle. The recorded study model is parallel.
The primary outcome concerns the percentage of participants with greater OTPSS decrease for 2% ointment twice daily versus vehicle, and the reverse comparison, at Day 42. OTPSS rates target-plaque severity from 0 (no plaque) to 8 (very severe plaque), with higher scores indicating greater severity. The primary numerical results and statistical analysis details are not reported in the registry record.
The registry record lists four safety groups with 0 serious adverse events in each and reports other adverse-event counts. It does not report death counts. The study started in 2009-11 and reached primary completion in 2010-05.