Safety and Efficacy Study of PF-06473871 to Reduce Hypertrophic Scars From Recurring Post-Revision Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy Study of PF-06473871 to Reduce Hypertrophic Scars From Recurring Post-Revision Surgery (NCT01730339), a randomized phase 2 study. The primary outcome is Physician Global Assessment Using Physician Overall Opinion Question of Patient and Observer Scar Assessment Scale (POSAS).

2. Clinical Question

The registry describes a study of PF-06473871 for reducing hypertrophic skin scarring following revision surgery of existing breast scars. Its primary endpoint was a physician’s global assessment of scar severity. The scale runs from 1, normal skin, to 10, the worst imaginable scar, so a lower score corresponds to a rating closer to normal skin.

The within-subject design means the treatment regimens were compared within participants rather than by treating every observation as coming from a separate participant group. The registry states that within-participant treatment differences were assessed between the regimens each participant received. It does not describe the precise treatment sequence or allocation procedure beyond identifying the study as randomized.

The study enrolled 103 participants. The primary endpoint was evaluated at Week 24, with 43 participants evaluable in each listed Group 1 regimen and 53 in each listed Group 2 regimen. Those endpoint-specific counts are not the same as the enrollment count. The registry record does not report a more detailed account of the population’s characteristics or the original rationale for the enrollment target.

3. Trial Design

This was a Phase 2, randomized, double-blind, within-subject, placebo-controlled study. The registry lists Pfizer as the sponsor and gives the status as completed. The recorded start was 2012-12, and primary completion was 2014-10. Enrollment was 103.

The study compared PF-06473871 with placebo for hypertrophic skin scarring after revision surgery of existing breast scars. The registry lists two groups and two dosing descriptions: Group 1 received PF-06473871: 4* 5 mg/cm and placebo 4* 5 mg/cm; Group 2 received PF¬06473871: 3* 5 mg/cm and placebo 3* 5 mg/cm. The arm descriptions themselves are blank, and the registry does not give a more detailed explanation of the regimen notation.

In a within-subject study, the treatment comparison is made among measurements from the same participant, rather than relying only on a comparison of independent groups. This design can account for participant-level differences, but its analysis must reflect the relationship between measurements from the same person. The sponsor’s posted primary-outcome analyses are identified as repeated-measures models.

The primary endpoint was assessed at Week 24. The registry identifies the modified Intent To Treat population as randomized participants who received at least one dose of investigational product; for this endpoint, the participant count means those evaluable for the outcome. The listed evaluable counts were 43 for each Group 1 regimen and 53 for each Group 2 regimen. The registry record does not report the randomization details, treatment sequence, masking procedures, or the original sample-size justification.

Four secondary outcomes are listed: physician scar assessment using the complete POSAS, patient global assessment using the overall-opinion question of the POSAS, PR-SEQ symptoms and appearance domain scores, and a physician and participant photoguide scar assessment score. The registry lists 10 outcome measures and 88 analyses, but this summary focuses on the primary physician global assessment.

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: A total of 103 participants were randomized into the study. Of these, 100 participants received at least 1 dose of study drug and were included in the modified intent to treat (mITT) and safety population.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Modified Intent To Treat (mITT) population included all participants who were randomized and received at least 1 dose of investigational product. Here, N (number of participants analyzed) signifies those participants who were evaluable for this outcome measure.

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: Modified Intent To Treat (mITT) population included all participants who were randomized and received at least 1 dose of investigational product.

6. Primary Endpoint

The registry lists the primary outcome as Physician Global Assessment Using Physician Overall Opinion Question of Patient and Observer Scar Assessment Scale (POSAS), measured over Week 24.

The primary endpoint was the physician’s global assessment of scar severity using the overall-opinion question of the Patient and Observer Scar Assessment Scale, or POSAS. Physicians rated the participant’s scar compared with normal skin. The scale ranges from 1 for normal skin to 10 for the worst imaginable scar. As a result, lower scores represent assessments closer to normal skin, while higher scores represent more severe ratings on this scale.

The endpoint was measured at Week 24 and summarized as a least-squares mean with a standard error for each regimen. A least-squares mean is a model-based estimate, not simply a raw average; in this trial, the sponsor’s analyses used repeated-measures models. The registry says that the within-participant treatment difference was assessed between the regimens received by each participant.

A physician assessment provides a structured observer rating rather than a direct measure of a participant’s own experience. That distinction matters because scar appearance and symptoms can be assessed from different perspectives. The registry lists patient-reported and other observer-assessed outcomes as secondary measures, but the primary question concerns physician-rated global scar severity. The registry record does not give a detailed justification for selecting this endpoint or explain how it was prioritized relative to the secondary outcomes.

7. Results Posted in the Registry

• Group 1: PF-06473871: 4* 5 mg/cm: mean 4.00 versus 4.68 on control; difference -0.68 (95% CI -1.47 to 0.11), standardized effect d = -0.36; z-test p = 0.092.
• Group 2: PF¬06473871: 3* 5 mg/cm: mean 4.61 versus 4.68 on control; difference -0.07 (95% CI -0.85 to 0.71), standardized effect d = -0.04; z-test p = 0.860.
• Group 2: Placebo 3* 5 mg/cm: mean 4.86 versus 4.68 on control; difference 0.18 (95% CI -0.58 to 0.94), standardized effect d = 0.09; z-test p = 0.644.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a repeated-measures model do?

In a within-subject trial, observations from the same participant are related. A repeated-measures model is designed to account for that dependence when estimating treatment differences. It can use the paired structure of the data rather than treating each regimen’s observations as though they came from entirely separate participants. That distinction matters because differences between participants can contribute substantial variation to a comparison, while a within-participant analysis focuses on changes across regimens for the same participant.

The registry identifies the sponsor’s method as a repeated-measures model and reports least-squares mean differences. A least-squares mean is an estimate from a statistical model, and the reported difference summarizes the model’s comparison. The registry record does not describe the model formula, covariance structure, included terms, or handling of any other design features. Those details should not be inferred from the method label alone.

What is a mean difference?

A mean difference expresses the distance between two estimated means in the original measurement units. Here, the unit is units on the scar-assessment scale. The direction depends on which regimen is subtracted from which; the registry does not provide that subtraction convention for the sponsor’s reported estimates. The scale interpretation is clear independently of that convention: lower scale values correspond to ratings closer to normal skin, and higher values correspond to more severe scar ratings.

The sponsor’s Group 1 least-squares mean difference is 0.68 and the Group 2 difference is 0.24. These are model-based comparisons, not simple differences that should be reconstructed from the displayed endpoint means without knowing the model and contrast convention. The approximate recalculations use a different approach and should not be read as replacements for those model estimates.

What do standard errors and confidence intervals describe?

A standard error describes the uncertainty in an estimate due to sampling variability under the statistical method used. It is not the same quantity as the spread of individual participant scores. The registry reports standard errors for the group-level endpoint estimates. The sponsor also reports confidence intervals for treatment differences, giving a range of values compatible with the model and its assumptions at the stated confidence level.

A confidence interval that includes zero is compatible with no difference as well as with differences in either direction within the interval. An interval that does not include zero indicates that zero is outside the reported interval under that method, but it does not on its own establish clinical importance. The sponsor’s intervals are 90% confidence intervals. The recalculated intervals are 95% confidence intervals and come from approximate unadjusted calculations, so the two sets should not be compared as if they were produced by the same analysis.

Why can the recalculation differ from the sponsor result?

The posted recalculations are simple, unadjusted calculations from summary statistics. The calculations use the posted means, standard errors, and participant counts, and an approximate pooled standard deviation is used. They do not recreate the participant-level repeated-measures analysis. In a within-subject design, the variation of paired differences depends on the relationship between measurements from the same participant. Summary means and marginal standard errors do not fully describe that relationship.

The Group 2 recalculations also use the Group 1 placebo summary as the reference for the comparisons. The sponsor’s Group 2 result instead reports a comparison between the Group 2 PF-06473871 and placebo regimens. This difference in comparison definition is another reason the recalculated Group 2 estimates do not reproduce the sponsor’s estimate. The registry record flags a discrepancy; the sponsor’s own analysis takes precedence.

Why can over-dispersion matter?

Over-dispersion is a general statistical issue that arises when observed variability is greater than a model’s assumed variability. When that happens, standard errors may be too small if the extra variation is not accommodated, making confidence intervals too narrow and tests appear more decisive than warranted. This is a general explanation, not a claim that over-dispersion was assessed or present in this study. The registry record does not report an over-dispersion assessment.

What do p-values say?

A p-value describes how unusual data at least as incompatible with a specified null hypothesis would be under the model and its assumptions. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The sponsor reports p = 0.022 for Group 1 and p = 0.404 for Group 2. The recalculated unadjusted p-values are different because the recalculations use a different analysis. The registry record does not report whether the sponsor adjusted these tests for multiple comparisons.

All these methods depend on design and analysis choices. The registry record does not report enough detail to independently reproduce the sponsor’s model or determine how missing endpoint observations were handled. The distinction between the sponsor’s model-based findings and the approximate summary-statistic calculations is therefore important when interpreting the posted results.

10. Confidence Intervals and Precision

Precision concerns how narrowly an estimate is localized by its uncertainty interval. The sponsor reports 90% confidence intervals for the repeated-measures treatment differences. For Group 1, the interval is 0.19 to 1.16 around a reported difference of 0.68. For Group 2, it is -0.24 to 0.72 around a reported difference of 0.24. The registry does not specify the subtraction order for these model-based differences, so the intervals should be read as uncertainty around the reported contrasts rather than assigned a direction not stated in the record.

The Group 1 sponsor interval excludes zero, while the Group 2 interval includes zero. This describes the intervals’ relationship to zero; it does not establish whether a difference is clinically important. The registry record does not report a minimum clinically important difference for the physician assessment scale.

The approximate recalculations have 95% confidence intervals: -1.471 to 0.111 for the Group 1 treatment comparison, -0.847 to 0.707 for the Group 2 PF-06473871 comparison, and -0.582 to 0.942 for the Group 2 placebo comparison. Each includes zero. These intervals are not direct alternatives to the sponsor’s intervals: they use a different confidence level and approximate, unadjusted calculations rather than the sponsor’s repeated-measures model. Their disagreement with the sponsor’s posted results is flagged in the registry record, and the sponsor’s own analysis takes precedence.

Participant counts for the endpoint were 43 in each Group 1 regimen and 53 in each Group 2 regimen. Those counts convey the amount of endpoint information but do not, by themselves, determine precision. Variability, the within-participant relationship, and the analysis method also matter. The registry record does not report the paired-difference variability or enough model detail to independently assess the sponsor intervals’ precision.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size estimates are planning illustrations based on the observed effect, not the trial’s original design calculation. The registry record does not report the original sample-size justification or its assumptions. These estimates use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect.

The 80% power column gives the estimated participants per arm for a design with an 80% chance of detecting the specified effect under those assumptions if that effect is real. The 90% power column gives the participants per arm for a 90% chance under the same type of assumptions. These are planning targets, not counts of participants who were observed or analyzed. The figures are participants per arm, not total enrollment and not total events. The event-count convention applies only to time-to-event calculations, which are not the outcome considered in this analysis.

Estimates are shown for planning around 100%, 75%, and 50% of the observed effect. Smaller effects require more participants to detect, because a smaller difference is harder to distinguish from random variation. This is especially consequential when the observed difference is close to zero: planning directly from such an estimate can yield extremely large sample-size targets and is highly sensitive to uncertainty in the estimate itself.

The Group 1 treatment comparison and the Group 2 comparisons have very different observed effect estimates, so their planning figures differ substantially. The Group 2 PF-06473871 comparison is particularly close to zero in the recalculation, and its corresponding illustrative targets are very large. These figures should not be interpreted as recommendations for a future trial without a justified target effect and an appropriate design model for the within-subject structure. This is not observed power; it is a planning illustration based on the observed effect and the stated assumptions.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.680; pooled standard deviation σ = 1.871.
2. n = 2 × (1.96 + 0.842)² × 1.871² / -0.680² = 118.9, rounded up to 119 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.68                      # observed difference in means
sigma <- 1.87145665191583                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1730339)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 119 (80% power), 160 (90% power)
 75% of observed effect: n per arm = 212 (80% power), 283 (90% power)
 50% of observed effect: n per arm = 476 (80% power), 637 (90% power)
power.t.test: 119.9 
Simulated power at n = 119 per arm: 0.798 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Analyses Reported by the Sponsor

The sponsor’s posted primary-outcome results come from repeated-measures models and are reported as least-squares mean differences. For Group 1, the sponsor reports 0.68, a 90% confidence interval from 0.19 to 1.16, and p = 0.022. For Group 2, the sponsor reports 0.24, a 90% confidence interval from -0.24 to 0.72, and p = 0.404.

The approximate recalculations use posted summary statistics and are unadjusted. They do not reproduce the paired repeated-measures analysis. In addition, the Group 2 recalculations use the Group 1 placebo mean as their reference, while the sponsor’s Group 2 analysis compares the Group 2 PF-06473871 and placebo regimens. The difference in method and comparison definition explains why the recalculated values should not be treated as replications of the sponsor estimates.

The registry record flags a discrepancy between the sponsor results and the recalculations. Under that circumstance, the sponsor’s own analysis takes precedence. The recalculated results remain useful as a transparent check on posted summary statistics, but they do not supersede the trial’s reported model-based analysis. The registry record does not provide enough detail to independently reconstruct that analysis.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures, four secondary outcomes, and 88 analyses. That is a broad set of reported endpoints and analyses, making multiplicity an important interpretive issue. When many hypotheses are tested, the chance of finding at least one apparently notable result by chance can increase. Statistical approaches can address multiplicity, but the registry record does not report whether the sponsor adjusted for multiple comparisons, which outcomes were included in any adjustment, or how the primary endpoint was protected within the analysis plan.

The sponsor reports p-values for the two primary-outcome regimen comparisons, but the registry record does not state whether these comparisons were treated as a family or whether their p-values were adjusted. The posted p-values should therefore be read as reported results, without assuming a multiplicity procedure. The record also does not report whether an analysis hierarchy or a prespecified order for interpreting the secondary outcomes was used.

The registry defines the primary endpoint population as randomized participants who received at least one dose of investigational product and were evaluable for this outcome. It reports 43 evaluable participants for each Group 1 regimen and 53 for each Group 2 regimen. The meaning of those counts is endpoint-specific; they do not indicate that every enrolled participant contributed an evaluable Week 24 score.

The registry record does not report the missing-data strategy, reasons for missing endpoint observations, assumptions about missingness, or sensitivity analyses. It also does not state whether participants with incomplete repeated measurements were included in the sponsor’s model or how such observations were handled. These details matter because conclusions can depend on how incomplete data are treated, especially when the analysis relies on repeated observations.

The record does not report an interim analysis plan, stopping boundaries, or the original detailed statistical analysis plan. These omissions do not establish that such procedures were absent; they mean they are not reported in the registry record. Without those details, the reported results can be described, but the full prespecification and multiplicity context cannot be independently assessed.

15. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events by combined PF-06473871/placebo regimen group. For the 4* 5 mg/cm group, 0 of 45 participants at risk were reported as affected by serious adverse events. For the 3* 5 mg/cm group, 0 of 55 participants at risk were reported as affected. These are the posted serious-adverse-event counts; they do not establish that no serious events occurred outside the registry’s reported accounting.

The registry also lists other adverse events affecting 30 of 45 participants in the 4* 5 mg/cm group and 35 of 55 in the 3* 5 mg/cm group. These are reported separately from serious adverse events and should not be conflated with the serious-event counts. The groups combine PF-06473871 and placebo exposure, so these figures do not isolate events by treatment.

Death counts are not reported in the registry record. The serious-event summary is not a complete account of event types, timing, severity, or treatment attribution. It should be read as the registry’s posted count, not as a standalone assessment of comparative safety.

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

The posted primary endpoint describes physician ratings of scar severity at Week 24 on a scale from 1, normal skin, to 10, the worst imaginable scar. The sponsor’s repeated-measures analysis reports a difference of 0.68 for Group 1 and 0.24 for Group 2. The Group 1 90% confidence interval excludes zero, while the Group 2 interval includes zero. These are findings from the sponsor’s stated model; the registry does not report the contrast direction, so the sign should not be translated into a treatment-favoring direction without that information.

The raw Group 1 endpoint means are 4.0 for PF-06473871 and 4.68 for placebo. The Group 2 means are 4.61 for PF¬06473871 and 4.86 for placebo. On the scale’s stated interpretation, smaller scores correspond to ratings closer to normal skin. However, a difference in mean scores does not by itself show whether a change would be noticeable or meaningful to participants or clinicians. The registry record does not report a threshold for clinical importance.

The approximate unadjusted recalculations differ from the sponsor’s repeated-measures findings. They are based on summary statistics, do not model the within-participant relationship, and use the Group 1 placebo mean as the reference for the Group 2 comparisons. The registry record flags a discrepancy, so the sponsor’s own analysis takes precedence. The recalculations should be understood as checks on summaries, not as independent confirmation of the sponsor result.

These results do not settle questions about the other listed outcomes, the handling of missing measurements, or multiplicity across analyses. Nor do they establish findings beyond the participants and setting recorded in this study. The registry record identifies the study as completed and reports the endpoint results, but it does not provide the full analysis plan or enough participant-level information to independently reproduce the sponsor model.

17. Why This Trial Matters Statistically

This trial presents a useful statistical example of why the design and analysis must be interpreted together. A within-subject study produces related observations from the same participant. A repeated-measures model is intended to reflect that relationship, while a simple calculation from separate group summaries may not. The difference is not a minor technical detail: it can affect the estimated uncertainty and the treatment contrast being reported.

The trial also illustrates why two results with similar labels may not be directly comparable. The sponsor’s Group 2 result compares the Group 2 PF-06473871 and placebo regimens using a repeated-measures model. The approximate Group 2 recalculations instead use the Group 1 placebo mean as the reference. The analysis method and comparison definition both matter when a reader encounters different estimates from the same registry record.

Uncertainty also deserves attention alongside point estimates. The sponsor’s Group 1 interval excludes zero, whereas the Group 2 interval includes zero. Neither observation supplies a threshold for clinical importance, and the registry record does not report one. The record’s many listed analyses also make multiplicity and prespecification relevant questions, while leaving those details unreported.

Finally, the illustrative sample-size calculations show why observed effects should not be treated as stable design targets without care. Calculations based on an estimate near zero can imply very large participant requirements, and smaller target effects require more participants. The estimates are planning illustrations, not observed power or evidence that a particular future design is appropriate. Together, these features make the study a case for reading model-based results, confidence intervals, comparison definitions, and planning assumptions as connected parts of statistical interpretation.

18. 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 include enough detail to reproduce the sponsor’s repeated-measures analysis. It does not report the model specification, covariance structure, contrast coding, or the subtraction order for the sponsor’s least-squares mean differences. This makes it difficult to reconcile the reported estimates fully with the endpoint summaries.

The approximate calculations are not a substitute for that model. They are unadjusted recalculations from summary statistics, rely on an approximate pooled standard deviation, and do not account for the within-participant correlation. For the Group 2 recalculations, the reference is the Group 1 placebo summary rather than the Group 2 placebo regimen used in the sponsor’s reported comparison. The registry flags the discrepancy, and the sponsor’s own analysis takes precedence.

The available endpoint counts are evaluable participant counts, not the enrollment total. The record does not report why some enrolled participants may not have contributed an evaluable Week 24 outcome, how missing data were handled, or whether sensitivity analyses were conducted. It also does not report the original sample-size justification, interim analysis procedures, or a detailed multiplicity strategy.

The registry lists four secondary outcomes and many analyses, but the primary endpoint results alone do not describe those other outcomes. The safety figures are grouped across PF-06473871 and placebo exposure and therefore do not isolate adverse events by treatment. Death counts are not reported in the registry record.

The design and outcome descriptions also leave some practical details unclear. The regimen notation is reproduced as recorded, but the arm descriptions are blank, and the randomization sequence and treatment order are not reported. The record does not provide a clinical-importance threshold for the scar-assessment scale. These limitations constrain interpretation of direction, precision, completeness, and generalizability without negating the results that are posted.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Safety and Efficacy Study of PF-06473871 to Reduce Hypertrophic Scars From Recurring Post-Revision Surgery — NCT01730339.
• Registry record last updated 2016-02-17; status last verified 2016-01.
• Results first posted 2015-11-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT01730339 is a completed Phase 2, randomized, double-blind, within-subject, placebo-controlled study sponsored by Pfizer. It enrolled 103 participants and evaluated PF-06473871 for hypertrophic skin scarring following revision surgery of existing breast scars. The primary endpoint was physician global scar assessment using the POSAS overall-opinion question at Week 24, on a scale from 1 for normal skin to 10 for the worst imaginable scar.

The sponsor reported repeated-measures least-squares mean differences of 0.68 for Group 1 and 0.24 for Group 2. Approximate unadjusted calculations from posted summary statistics differ; the registry record flags the discrepancy, so the sponsor’s analysis takes precedence. The record lists four secondary outcomes and reports serious adverse events affecting 0 of 45 and 0 of 55 participants in the combined regimen groups. The original sample-size justification, missing-data approach, and multiplicity strategy are not reported in the registry record.