Safety, Tolerability And Efficacy Study Of Topical PF-06763809 In Subjects With Mild To Moderate Chronic Plaque Psoriasis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety, Tolerability And Efficacy Study Of Topical PF-06763809 In Subjects With Mild To Moderate Chronic Plaque Psoriasis (NCT03469336), a randomized phase 1 study. The primary outcome is Change From Baseline in Psoriatic Skin Infiltrate Thickness.

2. Clinical Question

3. Trial Design

This was a randomized Phase 1 study in participants with mild to moderate chronic plaque psoriasis. The registry lists the allocation as randomized and the model as single group. The record says all participants received all six interventions, each applied to a different treatment field. Thus, treatment comparisons were structured around different fields within the same participants, rather than separate participant groups assigned to one treatment each. Details of how treatments were assigned to fields, including any randomization sequence or field allocation procedure, are not reported in the registry record.

The interventions were PF-06763809 at three concentrations, its vehicle, calcipotriene/calcipotriol and betamethasone. The brief summary describes repeated application to six treatment fields for 18 days. It states that participation would last approximately 7 weeks at minimum to approximately 11 weeks at maximum, including the interval from screening to the follow-up phone call. These are descriptions of the planned study course; the record does not report each participant’s actual treatment exposure or time in the study.

The record describes the study as double-blind in its official title and brief summary, while its masking entry is “NONE.” These descriptions are inconsistent, and the record does not explain the difference or specify who was masked. The enrollment was 18. The brief summary anticipated approximately 15 completers, but the actual number who completed the study is not reported in the registry record.

The listed start date was 2018-04-24, the primary completion date was 2019-03-20, and the status is completed. These dates and status do not establish how many participants completed the endpoint assessments. The record identifies safety, tolerability and changes in psoriatic skin infiltrate thickness as study aims, but details of the protocol, recruitment process and treatment-field procedures are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Of 26 participants screened for entry into the study, 4 participants failed at Screening and 4 participants were eligible at Screening but were not randomized in the study, and the remaining 18 participants were assigned to the study treatment.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Analysis population included all participants who had at least one application of the investigational products and had at least one post-baseline assessment of the primary efficacy variable, were included in the Full Analysis Set (FAS).

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 Change From Baseline in Psoriatic Skin Infiltrate Thickness, measured over Baseline, Days 7, 13 and 19.

The primary endpoint was change from baseline in psoriatic skin infiltrate thickness, measured in micrometers (μm). Baseline was defined as the measurement on Day 1, with follow-up assessments at Days 7, 13 and 19. The description identifies the measured feature as skin infiltrate thickness or the echo poor band (EPB) and specifies comparisons of three topical PF-06763809 concentrations with vehicle.

Skin infiltrate thickness is a measured characteristic of psoriatic skin. Tracking its change over scheduled assessments gives a quantitative way to describe how the measured skin feature varies during the treatment period. Comparing the changes associated with active concentrations against vehicle helps distinguish changes observed during active treatment from those observed with the vehicle control, provided that estimates and their uncertainty are reported.

The registry specifies a geometric mean as the summary parameter and standard error as the dispersion measure. The record also identifies a mixed model for repeated measures (MMRM) analysis. These choices concern how repeated measurements and the distribution of the measured outcome are represented; they do not, by themselves, indicate the direction or magnitude of a treatment effect.

Although the endpoint definition and analysis approach are described, numerical outcome estimates are not reported in the registry record. The record therefore does not allow readers to quantify the observed change, compare the PF-06763809 concentrations with vehicle, or judge the precision of those comparisons.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical methods description names an MMRM analysis of changes in skin infiltrate thickness. This is a method intended for outcomes measured repeatedly over time. In general, repeated observations from the same participant tend to be related rather than independent. A repeated-measures model accounts for that structure when estimating changes and comparisons across visits. The registry record does not report the model formula, covariance structure, estimation details or other settings used for the MMRM.

In general, an MMRM can use observed measurements across visits to estimate patterns over time while accounting for their within-participant relationship. It does not mean that every participant has measurements at every visit, nor does naming the method show how missing measurements were handled in practice. The assumptions used for missing outcome data, and any sensitivity analyses, are not reported in the registry record. The reported analysis population required at least one post-baseline primary assessment, but the record does not state the number of participants analyzed or how many observations contributed at each scheduled visit.

The endpoint is summarized using a geometric mean, with standard error as the stated dispersion measure. In general, a geometric mean summarizes values on a multiplicative scale and is often relevant when the distribution is asymmetric or effects are naturally expressed proportionally. A standard error describes the estimated uncertainty of a summary statistic; it is not the same as the spread of individual participant measurements. The registry record does not explain the transformation or exact scale used in the model, so further details should not be inferred from the summary labels alone.

A treatment contrast is the estimated difference or other specified comparison between treatment conditions. For this study, the primary description identifies PF-06763809 at 2.3%, 0.8% and 0.23% compared with vehicle. The outcome description also specifies comparisons of change from baseline with calcipotriene/calcipotriol solution and betamethasone solution as secondary outcomes. The record does not report the contrast estimates, their confidence intervals, or their p-values. Thus, the stated methods cannot be used to reconstruct the results.

Confidence intervals, in general, describe a range of values compatible with an estimate under the analysis assumptions and convey precision. A narrow interval indicates greater precision than a wide interval, while the interval’s position relative to a null value can help interpret a contrast. No confidence intervals for the primary endpoint are reported in the registry record. Standard errors are named as the dispersion measure, but the numerical standard errors are also not reported.

Multiplicity is a concern in general when multiple treatment comparisons or assessment times are considered. Testing several concentrations against vehicle and examining more than one visit can create multiple opportunities to identify an apparently notable result. Appropriate interpretation depends on the prespecified objectives and any adjustment or testing hierarchy. The registry record does not report a multiplicity adjustment, hierarchy, or other method for addressing the number of analyses. The record lists eight outcome measures and twelve analyses, but does not provide enough detail to determine how those analyses were organized or whether any adjustment was used.

In general, over-dispersion means that outcome variability is greater than a model’s assumed distribution allows. If it is present and unaccounted for, standard errors can be too small and inferential results can appear more precise than warranted. The registry record does not state that over-dispersion was assessed or that a particular model was selected to address it. It would therefore be inappropriate to claim that over-dispersion affected these results.

The record includes sample-size assumptions for planning illustrations: 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 fraction of the observed effect. It states that non-time-to-event illustrations are expressed as participants per arm and time-to-event illustrations as total events. These are planning conventions, not observed power. The registry record does not report a protocol sample-size justification, and the single-group, multiple-treatment-field design makes the stated equal-allocation illustration distinct from a report of the actual study design. No sample-size illustration should be read as an observed study result.

In general, randomized allocation can reduce systematic differences between treatment assignments, but the practical meaning depends on how randomization was implemented. Here, the record identifies randomized allocation while stating that all participants received all interventions in separate fields. The assignment procedure for interventions to fields is not reported in the registry record. That missing detail limits assessment of how treatment comparisons were protected against field placement or other systematic influences.

10. Multiplicity, Missing Data and Analysis Populations

The study considered several treatment conditions and repeated assessments. The primary endpoint description names three PF-06763809 concentrations compared with vehicle, while secondary outcomes include comparisons with calcipotriene/calcipotriol and betamethasone. The primary assessment schedule includes baseline and Days 7, 13 and 19. In general, interpreting multiple contrasts and visits calls for clarity about which comparisons were primary, how hypotheses were ordered and whether multiplicity was controlled. Those details are not reported in the registry record.

The record lists eight outcome measures and twelve analyses, but does not describe a testing hierarchy or multiplicity adjustment. It also does not report which analyses were confirmatory or exploratory. Without those details and the numerical results, readers cannot assess the role of multiple testing in interpreting any apparent finding.

The Full Analysis Set included participants with at least one application of an investigational product and at least one post-baseline assessment of the primary efficacy variable. This defines eligibility for that analysis population, but the number analyzed is not reported in the registry record. The record also does not report the number of participants with measurements at each visit, reasons for missing assessments, or whether any participants were excluded after meeting the population definition.

In general, missing data can affect estimates when the likelihood of an unavailable measurement is related to the outcome or treatment response. Statistical handling depends on the reasons for missingness and the analysis assumptions. Although an MMRM is named, the missing-data assumptions, imputation procedures and sensitivity analyses are not reported in the registry record. The anticipated approximately 15 completers in the brief summary is not an observed completion count and does not establish how many participants contributed to the endpoint analysis.

11. Safety Results

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

Deaths

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 safety listing reports 18 participants at risk for serious adverse events, with zero affected, and 18 at risk for other adverse events, with six affected. It also reports zero deaths. No serious adverse-event terms are listed. These figures describe the counts recorded for the combined group titled PF-06763809+Vehicle+Calcipotriene+Betamethasone; they are not broken down by treatment or treatment field.

“Serious” and “other” are separate categories in this listing. The zero count for participants with a serious adverse event does not mean that no adverse events were recorded, because six participants are listed as affected by other adverse events. The record does not report the types, timing, severity or duration of those other events, or whether participants experienced more than one event. It also does not describe the attribution of events to individual interventions.

These counts are descriptive and should be read within the scope of the recorded group and available information. They do not provide a treatment-by-treatment safety comparison. The record does not report additional detail that would clarify how events were collected or classified.

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

The record establishes that a randomized Phase 1 study was conducted in 18 participants with mild to moderate chronic plaque psoriasis, with all participants receiving six interventions in separate treatment fields. It identifies change from baseline in psoriatic skin infiltrate thickness as the primary endpoint and describes an MMRM approach for repeated measurements. It also provides aggregate adverse-event counts.

Those design details do not establish the primary outcome result. Numerical estimates for changes in skin infiltrate thickness, comparisons with vehicle, uncertainty intervals and p-values are not reported in the registry record. Therefore, the record does not show how large any difference was, how precise an estimate might be, or whether observations were consistent across participants and assessment times. It does not support a quantitative conclusion about the primary endpoint.

The safety counts show zero participants with a recorded serious adverse event among 18 at risk, six participants with other adverse events among 18 at risk, and zero deaths. The record does not give enough detail to characterize the other events or compare safety across the interventions. These counts describe the posted information, not every possible aspect of tolerability.

The study’s single-group listing and use of multiple treatment fields are important context. All participants received all listed interventions, so the design differs from a parallel-group trial in which separate groups receive different treatments. The record does not explain the assignment of treatments to fields or resolve its inconsistent descriptions of masking. These gaps limit interpretation of design protections and comparison procedures.

In general, a study’s endpoint definitions and analysis plan describe how investigators intend to evaluate data; they do not replace the estimates and uncertainty needed to interpret the findings. The record supports a description of what was planned and of the posted adverse-event counts, but not a conclusion about the magnitude or precision of the primary treatment comparisons.

13. Why This Trial Matters Statistically

This study is statistically notable for measuring several topical treatments within each participant, using separate treatment fields. That structure is distinct from assigning each participant to one of several parallel treatment groups. In general, within-participant comparisons can account for characteristics shared by the same participant, but interpretation also depends on how treatments are allocated across fields and whether field-specific differences matter. The registry record does not report the allocation procedure, so the safeguards used for those comparisons cannot be assessed from the record.

The endpoint was repeated over time, with baseline and follow-up assessments on Days 7, 13 and 19. Repeated measurement can describe how an outcome changes across visits, but it calls for methods that account for within-participant dependence. The record names an MMRM, making the repeated-measures structure explicit. It does not report the model settings or numerical estimates, so readers cannot evaluate either the implementation or the resulting precision.

The study also raises a reporting distinction between design descriptions and evidence about outcomes. The record gives treatment concentrations, endpoint definitions and an analysis method, yet does not include numerical primary endpoint results. An analysis plan alone cannot establish what the measurements showed. Likewise, enrollment and an anticipated completer count do not reveal the actual analysis sample at each visit.

Finally, the safety listing separates serious from other adverse events and reports aggregate counts, while offering little detail about event type or treatment attribution. This illustrates why counts need context: zero serious adverse events does not mean zero other events, and an aggregate listing does not permit treatment-specific comparisons. The record’s conflicting masking descriptions also show why consistent design reporting matters when readers assess study conduct.

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 primary limitation for interpreting efficacy is that numerical primary endpoint results are not reported in the registry record. Estimates of change, treatment contrasts, standard errors, confidence intervals and p-values are not available. The record therefore does not permit assessment of the magnitude, direction or precision of differences in skin infiltrate thickness.

Several details needed to understand the analysis are also absent. The number included in the Full Analysis Set and the number assessed at each visit are not reported. The record does not describe missing-data assumptions, sensitivity analyses, the MMRM specification or a multiplicity procedure. It identifies eight outcome measures and twelve analyses without explaining how the analyses were structured or prioritized.

The registry describes randomized allocation and a single-group model, with every participant receiving six interventions on separate treatment fields. The procedure for assigning treatments to fields is not reported. The official title and brief summary describe double-blind conduct, whereas the masking entry is “NONE”; the record does not reconcile these descriptions. This leaves uncertainty about how treatment allocation and masking were implemented.

The study enrolled 18 participants, and approximately 15 completers were anticipated in the brief summary, but the actual completion count is not reported. The adverse-event listing gives aggregate counts rather than treatment-specific event data. Types and timing of other adverse events, event severity, attribution and participant-level event counts are not reported in the registry record. These omissions constrain interpretation of both the efficacy analysis and the safety description.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety, Tolerability And Efficacy Study Of Topical PF-06763809 In Subjects With Mild To Moderate Chronic Plaque Psoriasis — NCT03469336.
• Registry record last updated 2020-06-25; status last verified 2020-06.
• Results first posted 2020-06-25.
• 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 registry record identifies NCT03469336 as a completed randomized Phase 1 study of topical PF-06763809 in participants with mild to moderate chronic plaque psoriasis. Enrollment was 18. All participants received six interventions on separate treatment fields, including three PF-06763809 concentrations, vehicle, calcipotriene/calcipotriol and betamethasone. The primary endpoint was change from baseline in psoriatic skin infiltrate thickness, assessed at baseline and Days 7, 13 and 19, with an MMRM analysis described.

Numerical primary endpoint results are not reported in the registry record. The safety listing reports zero serious adverse events among 18 participants at risk, six participants with other adverse events among 18 at risk, and zero deaths. The record does not provide treatment-specific adverse-event details. It describes the study as double-blind in the title and summary but lists masking as “NONE,” without explaining the inconsistency.