Vascular Inflammation in Psoriasis - Apremilast: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vascular Inflammation in Psoriasis - Apremilast (NCT03082729), a na phase 4 study. The primary outcome is Change in Total Vascular Inflammation of the Aorta as Measured by FDG-PET/CT Between Baseline and Week 16..

2. Clinical Question

The study asked whether aortic vascular inflammation changed between baseline and week 16 during treatment with apremilast in people with moderate-to-severe psoriasis. It also planned to examine cardiometabolic biomarkers, body composition, psoriasis severity, and patient-reported outcomes. The registry record identifies the primary measure as total aortic vascular inflammation assessed with FDG-PET/CT.

This is a question about change over time in one treated group, not a randomized comparison of apremilast with another treatment or with no treatment. Such a design can describe what happened to participants with measurements at the specified visits. Without a concurrent control group, it cannot by itself separate a treatment-associated change from other influences on measurements over time.

3. Trial Design

This was a Phase IV, open-label, single-group study sponsored by the University of Pennsylvania. The registry record lists enrollment of 70 and a completed status. The study began on 2017-04-24, and primary completion was recorded as 2021-08-17. The record describes apremilast as a 30mg oral tablet taken twice per day for 52 weeks. It does not describe a randomized allocation or a masking procedure; masking is listed as none.

The primary endpoint concerned change in total vascular inflammation of the aorta from baseline to week 16. Its stated timeframe was after all study participants had completed the week 16 visit. The planned measurement used FDG-PET/CT and a tissue-to-background ratio based on standardized uptake value. The registry says the number analyzed reflects availability of analyzable samples, so enrollment should not be read as the number with usable endpoint data.

The record also lists secondary outcomes involving visceral and subcutaneous adipose tissue, psoriasis severity assessed by PASI and PGA, dermatology quality of life, itch measured by visual analog scales, vascular inflammation in five aortic segments, and total aortic vascular inflammation at other time points. It lists 145 outcome measures and 221 analyses. Those counts indicate a broad set of registered measurements and analyses; they do not establish which results were reported or how multiplicity was handled.

Because the study had one open-label group, the primary comparison is a before-and-after comparison within that group. There is no concurrent control arm against which to assess the change. The registry record does not report a protocol-level explanation of the design, a sample-size justification, or a detailed statistical analysis plan. The study is completed, but the numerical primary-endpoint estimate and its uncertainty 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The number of subjects analyzed reflect availability of analyzable samples.

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 in Total Vascular Inflammation of the Aorta as Measured by FDG-PET/CT Between Baseline and Week 16., measured over After the completion of week 16 visit by all study participants..

The primary endpoint was change in total vascular inflammation of the aorta between baseline and week 16. It was assessed with FDG-PET/CT using a tissue-to-background ratio, or TBR, derived from standardized uptake value. The registry describes TBR as assessing aortic inflammation relative to the venous blood pool, which serves as the background reference.

In general, a ratio comparing tissue uptake with a reference background can help express the measured signal in relation to a reference rather than as an isolated tissue value. FDG-PET/CT combines a functional imaging signal with anatomical imaging. The registry’s description identifies the aortic measure and its reference, but does not report the numerical baseline or week 16 values, the observed change, or a confidence interval.

The endpoint is a continuous measure, and the registry identifies the planned summary as a mean with standard error. A mean describes the average measured value in the analyzed group. A standard error describes the precision of that estimated mean, rather than the spread of individual participants’ measurements. The record does not report the number of analyzable observations for this endpoint, so the precision of the primary estimate cannot be assessed from the registry record.

The endpoint is an imaging measure of vascular inflammation, not a clinical event or a direct measure of cardiovascular disease occurrence. Its role in this study was to assess change in an imaging-based biological measure over time. The registry record does not report a numerical result that would show the direction, magnitude, or precision of that change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary measurement was a continuous imaging endpoint: total aortic vascular inflammation assessed by FDG-PET/CT. The registry describes the measure as a tissue-to-background ratio based on standardized uptake value, with the venous blood pool serving as the background reference. The planned comparison was between baseline and week 16, and the planned summary was a mean with standard error.

What does the mean describe?

In general, a mean is the arithmetic average of the observed values in the analysis group. For a before-and-after endpoint, the relevant analysis could summarize measurements at each visit or summarize participant-level changes; the precise statistical procedure used for this study is not reported in the registry record. The distinction matters because estimates based on paired observations use the within-participant relationship between visits, while summaries of separate visit groups do not express that pairing in the same way.

What does the standard error describe?

In general, a standard error describes the precision of an estimated quantity, such as a mean. It is not a description of how widely individual observations vary. A confidence interval is a range constructed to express uncertainty around an estimate under a specified statistical method. The registry record identifies standard error as the planned dispersion summary, but does not report a standard error or confidence interval for the primary result. The level and method for any confidence interval are not reported in the registry record.

What is the role of the imaging ratio?

The record states that TBR uses standardized uptake value to assess aortic signal relative to venous blood-pool background. In general, using a reference can provide context for interpreting a tissue signal. The record does not give details about image processing, reader procedures, quality control, or how values were combined across aortic locations for the primary endpoint. Those procedural details are not reported in the registry record.

What does a single-group comparison estimate?

In general, a single-group before-and-after analysis estimates change over time among the analyzed participants. Because this study had no separate comparator group, it does not estimate a difference in change between treated and untreated groups. A change over time can be described, but the design alone cannot establish how much of that change is attributable to treatment rather than other time-related or measurement-related influences. Open-label status also means treatment masking was not used; whether that affected measurement or participation is not reported in the registry record.

How should missing measurements be considered?

The registry states that the number analyzed reflects availability of analyzable samples. In general, analyses with missing or unusable measurements can represent a selected subset if availability is related to participant characteristics or outcomes. The registry record does not report the number analyzed at each visit, reasons measurements were unavailable, methods for handling missing values, or sensitivity analyses addressing missing data. It therefore does not establish whether the analyzed participants represent everyone enrolled.

What do the planning illustrations represent?

The planning illustrations are described as calculations based on the observed effect, not as the trial’s original design justification. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. For non-time-to-event outcomes, the illustrations are expressed as participants per arm for 80% power or other stated power levels; time-to-event illustrations use a total number of events. These are hypothetical planning quantities, not observed power and not the number enrolled or analyzed in this single-group trial. The registry record does not report the trial’s own sample-size justification. The numerical planning results are not reported in the registry record.

The statistical test, model, adjustment variables, treatment of repeated measurements, and procedures for outliers are not reported in the registry record. General statistical principles can explain what such choices mean, but they cannot identify which methods were actually used in this study. The primary numerical result and its uncertainty are also not reported, so statistical significance or the precision of the observed change cannot be assessed from the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Apremilast")
n   <- c(57)
m   <- c(-0.017)
sp  <- c(0.033)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Apremilast  57  -0.017  0.249  -0.083  0.049

11. Multiplicity, Missing Data and Analysis Populations

The registry lists many secondary outcomes, including body composition, psoriasis assessments, patient-reported measures, and vascular imaging at multiple time points or aortic segments. It records 145 outcome measures and 221 analyses. When many outcomes or analyses are examined, the chance of at least one apparently notable result can increase. In general, multiplicity procedures can control or otherwise address that issue. Whether any such procedure was prespecified or used is not reported in the registry record.

The record identifies one primary endpoint, but does not report a detailed statistical analysis plan, a hierarchy for secondary outcomes, or which analyses were confirmatory versus exploratory. The registry record also does not report whether the primary analysis used a paired method, adjusted for covariates, or included sensitivity analyses.

The primary endpoint description says that the number analyzed reflects availability of analyzable samples. The number with usable baseline and week 16 measurements is not reported in the registry record. Reasons for missing or unusable samples, the number excluded, and any method used to handle missing data are also not reported. In general, missing-data methods matter because conclusions can depend on whether participants with missing measurements differ from those with observed measurements.

The record does not report a defined analysis population beyond the statement about analyzable samples. It is therefore not possible to determine from the registry record whether the primary analysis included all enrolled participants, only participants with paired measurements, or another group. The registered enrollment of 70 should not be treated as the primary-endpoint analysis count.

12. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hospitalization due to fall (2.9%), stroke (1.4%), acute kidney injury (1.4%), soft tissue mass (1.4%), fracture due to fall (1.4%).

The registry record lists 70 participants at risk for serious adverse events and 6 participants affected. For other adverse events, it lists 70 at risk and 31 affected. It reports 0 deaths. These are the posted safety counts; the record does not give a concurrent control group for comparison.

The listed serious event terms and registry percentages are hospitalization due to fall, 2.9%; stroke, 1.4%; acute kidney injury, 1.4%; soft tissue mass, 1.4%; and fracture due to fall, 1.4%. These entries describe reported terms and percentages in the registry record. They do not indicate, by themselves, that an event was caused by treatment, nor do they establish comparative risk.

In general, adverse-event counts are descriptive unless the study design and analysis support a comparison. Interpretation also depends on how events were collected, coded, and attributed, and on the observation period. Those details are not reported in the registry record beyond the listed treatment duration and safety counts. The counts should therefore be read as registry-reported safety information, not as evidence of a causal relationship or a comparison with another treatment.

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

The registry record establishes that this completed Phase IV study was designed to examine change in an imaging measure of aortic vascular inflammation during apremilast treatment in people with moderate-to-severe psoriasis. It describes a single-group, open-label design, a baseline-to-week-16 primary comparison, and a treatment course described as 52 weeks. It also lists several secondary imaging, clinical-assessment, and patient-reported outcomes.

However, the numerical primary result is not reported in the registry record. There is no reported estimate of change, standard error, confidence interval, or p-value. The number of participants with analyzable primary measurements is also not reported. Consequently, the direction, magnitude, and precision of the primary endpoint change cannot be characterized from the registry information.

Even if a within-group change were available, a single-group before-and-after design would describe change over time rather than isolate a treatment effect through a randomized comparison. Other time-related influences cannot be separated from treatment effects using this design alone. The open-label design and the lack of a separate comparator are relevant when considering what the study can establish.

The registered safety counts provide descriptive information about serious and other adverse events and deaths among participants at risk. They do not establish whether treatment caused an event, and they do not provide a controlled safety comparison. The record also does not report how multiplicity across the numerous listed outcomes was handled.

In short, the registry record describes the question and design but does not report enough numerical primary-endpoint information to assess the observed change or its uncertainty. It cannot support a conclusion about the magnitude or causal interpretation of an effect on aortic inflammation.

14. Why This Trial Matters Statistically

This study is statistically notable for combining an imaging-based biological endpoint with a single-group longitudinal design. The primary question concerns change in aortic FDG-PET/CT TBR from baseline to week 16. That focus makes clarity about the measurement, analysis population, and within-participant comparison important: the registry describes the measure but does not report the numerical estimate or the number analyzed.

The design also illustrates the difference between observing change and estimating a comparative treatment effect. A before-and-after result can describe the analyzed group’s measurements over time. Without a concurrent control group, it cannot distinguish treatment-associated change from other influences on measurements over time. This is a design limitation, not a claim about what the unreported results might show.

Multiplicity is another relevant statistical issue. The registry lists a broad set of secondary outcomes and a large number of analyses. In general, examining many outcomes can complicate interpretation of isolated findings, so the analysis hierarchy and any multiplicity approach are useful context. Those details are not reported in the registry record.

Finally, the record notes that analyzable samples determine the number analyzed. That makes the reporting of endpoint-specific sample counts and missing-measurement handling especially relevant to judging precision and possible selection in the analysis. Those details are not reported. The record’s safety counts are also descriptive and lack a control comparison. Together, these features show why statistical interpretation depends not only on the endpoint definition, but also on the analysis population, uncertainty estimates, comparator structure, and transparent reporting.

15. 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 the registered findings is that the numerical primary-endpoint result is not reported in the registry record. The record does not give the estimated change, the standard error, a confidence interval, or a p-value. The number of participants with analyzable baseline and week 16 measurements is also not reported, although the record states that analysis counts reflect availability of analyzable samples.

The study used a single-group, open-label design with no separate control group. Any reported within-group change would not, by itself, distinguish treatment-associated change from other changes over time. The record does not describe masking of endpoint assessment or provide enough detail to assess whether image evaluation was independent of treatment knowledge.

Specifics of image acquisition, processing, quality control, and the construction of the total aortic measure are not reported in the registry record. Neither are the statistical test or model, handling of repeated measurements, adjustment variables, outlier procedures, or confidence-interval method. The record does not report reasons for missing or unusable samples or sensitivity analyses for missing data.

The registry lists numerous outcomes and analyses, but does not report a multiplicity strategy or a hierarchy for interpreting secondary endpoints. It also does not report the trial’s own sample-size justification. The planning illustrations are described as based on the observed effect and are not the original design rationale; they should not be confused with observed power. Finally, safety counts are reported without a concurrent comparator, limiting comparative interpretation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Vascular Inflammation in Psoriasis - Apremilast — NCT03082729.
• Registry record last updated 2022-11-10; status last verified 2022-10.
• Results first posted 2022-11-10.
• 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.

19. Record Summary

NCT03082729, titled “Vascular Inflammation in Psoriasis - Apremilast,” is a completed Phase IV, open-label, single-group study sponsored by the University of Pennsylvania. The registry lists enrollment of 70, a start date of 2017-04-24, and primary completion on 2021-08-17. Apremilast is described as a 30mg oral tablet taken twice per day for 52 weeks.

The primary endpoint was change in total aortic vascular inflammation from baseline to week 16, measured with FDG-PET/CT using a tissue-to-background ratio. The registry record does not report the numerical primary result or the number analyzed. It lists secondary imaging, psoriasis, and patient-reported outcomes, along with 6 participants affected by serious adverse events, 31 affected by other adverse events, and 0 deaths among 70 at risk.