StrataGraft Safety, Tolerability and Efficacy in Pediatric Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for StrataGraft Safety, Tolerability and Efficacy in Pediatric Subjects (NCT05517902), a non-randomized phase 3 study. The primary outcome is Percentage of Participants Who Achieved Confirmed Complete Closure of StrataGraft Treatment Sites Without Autograft Within 12 Weeks of StrataGraft Application.

2. Clinical Question

The study was intended to evaluate safety, tolerability, and efficacy in pediatric subjects. Its stated purpose included evaluating whether StrataGraft treatment eliminates or reduces the need for autografting and promotes wound closure. These are the study questions, not conclusions about the treatment. The registry record does not report the primary endpoint result, so it does not establish what percentage achieved the defined closure outcome.

3. Trial Design

The registry identifies this as a Phase 3, multicenter, single-arm, open-label study. Allocation is non-randomized, and the registered model is parallel. The two cohorts are defined by age: 2 to under 12 years and 12 to 17 years. They are not described as treatment and control arms; both cohort descriptions specify StrataGraft.

The planned treatment was a single application to burn sites on Day 1. Each cohort description specifies treatment of 0.5% to 10% total body surface area. The study summary describes up to 3 non-contiguous deep partial thickness burn areas located on the same extremity or plane of the torso. The registry identifies the relevant condition as including skin wounds, burns, and trauma-related wounds.

Enrollment is listed as 1. The record gives a start date of 2023-04-28, a primary completion date of 2024-05-09, and a status of completed. These entries describe the registered study, but do not supply a participant flow or show how many participants contributed to each endpoint analysis.

In an open-label study, participants and study personnel are not masked to the assigned treatment. Here, there was no randomized treatment assignment or concurrent control arm. That design can describe outcomes observed after treatment, but it does not provide a randomized comparison that separates treatment effects from other explanations for the outcomes. The registry record does not report a protocol, a sample-size justification, or further detail about how the study design was selected.

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

Analysis population for the primary outcome, as defined in the registry: Safety population included all participants who were enrolled and received StrataGraft.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Safety population included all participants who were enrolled and received StrataGraft.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Who Achieved Confirmed Complete Closure of StrataGraft Treatment Sites Without Autograft Within 12 Weeks of StrataGraft Application, measured over Up to Week 12.

The primary endpoint is the percentage of participants who achieved confirmed complete closure of StrataGraft treatment sites without autograft within 12 weeks of StrataGraft application. The registry defines complete closure as complete skin re-epithelialization confirmed at 2 consecutive visits at least 2 weeks apart, with confirmation no later than Week 20. The stated endpoint timeframe is up to Week 12.

This is a binary outcome at the participant level: a participant either meets the defined closure criterion without autograft or does not. Reporting the percentage expresses how common that outcome was in the endpoint population. It does not, by itself, describe the time to closure, the size of a wound, or outcomes beyond the specified closure and autograft criteria.

In general, a closure endpoint can be useful because it gives a defined clinical event and a stated assessment window. Requiring confirmation at separate visits is a way to distinguish confirmed closure from a finding at a single assessment. The registry also lists secondary outcomes concerning the percentage of treatment sites closed without autograft, the number of confirmed complete wound closures, and the mean of averaged treatment-site area autografted by Week 12. These measure related but distinct aspects of wound closure and autograft use.

The primary endpoint result is not reported in the registry record. Its participant count, percentage, and uncertainty interval are also not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-arm design estimate?

This study is registered as non-randomized and single-arm. The registered intervention is StrataGraft, and no concurrent comparator is listed. In general, a single-arm study can report the outcomes observed among participants receiving the intervention. It cannot make a randomized, like-for-like comparison between intervention and control groups because such groups are not part of the registered design.

The absence of a control group also limits causal interpretation. Outcomes can be influenced by factors other than the intervention, including the underlying condition and care received. A before-and-after observation or comparison with a historical expectation would require information about those methods and assumptions. Such a comparison is not reported in the registry record.

What does the primary endpoint count?

The primary outcome is a participant-level binary measure: confirmed complete closure of treatment sites without autograft within 12 weeks. The registry’s definition requires complete skin re-epithelialization confirmed at 2 consecutive visits at least 2 weeks apart, with confirmation no later than Week 20. The result would ordinarily be expressed as the percentage meeting the criterion in the defined population. The registry record does not report the number meeting the criterion, the endpoint denominator, or the resulting percentage.

In general, a binary endpoint reduces a complex clinical course to whether a prespecified event occurred. This can make the result straightforward to communicate, but it does not show all details of the course. For example, the primary endpoint does not itself report the timing of closure within the stated window or the area of each treatment site. The listed secondary outcomes address some related site-level and autograft measures, but their results are not reported in the registry record.

How should uncertainty be assessed?

In general, an estimate is more informative when accompanied by an uncertainty measure such as a confidence interval. A confidence interval represents a range of values compatible with the data under a statistical procedure and its assumptions. It is not a guarantee, and its width helps readers assess precision. The primary endpoint estimate and confidence interval are not reported in the registry record, so precision cannot be assessed from the posted results.

A p-value, in general, assesses how compatible data are with a specified null model; it does not measure the size or clinical importance of an effect. No p-value or inferential test for the primary endpoint is reported in the registry record. There is no basis in the posted information to characterize the result as statistically significant or not statistically significant.

What do the analysis fields establish?

The registry lists zero analyses. This does not provide a statistical analysis plan or identify a model, adjustment strategy, confidence-interval method, or hypothesis test. The registry record does not report whether interim analyses were planned or performed. It also does not report a sample-size justification. These details should not be inferred from the Phase 3 designation or from the fact that the study is marked completed.

In general, analysis choices should match the outcome and design. A binary participant-level endpoint may be summarized as a proportion, while site-level outcomes may require methods that account for multiple sites within the same participant. This is a general statistical consideration, not a description of methods used in this study. The registry record does not report an analysis addressing clustering of treatment sites, adjustment for covariates, or handling of repeated assessments.

What can be concluded from the posted figures?

The posted information describes enrollment as 1 and defines the primary population as enrolled participants who received StrataGraft. It does not provide endpoint-level counts or a primary result. The safety figures list one participant at risk in the 2 to under 12 years cohort and no participants at risk in the 12 to 17 years cohort for the displayed adverse-event categories. These safety entries do not supply an efficacy estimate.

In general, sample-size planning depends on assumptions about the target effect, variability or event rate, significance level, and desired power. The registry record does not report the trial’s own sample-size justification or planning assumptions. Any sample-size illustration elsewhere should be read as a planning exercise, not as a description of the number enrolled or as observed power. No such calculation can establish the study’s observed result.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("2 to < 12 Years Age Group Cohort")
n      <- c(1)
events <- c(1)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  2 to < 12 Years Age Group Cohort  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and identifies a primary endpoint and three secondary outcomes. The listed secondary measures concern treatment-site closure without autograft, confirmed wound closures, and treatment-site area autografted by Week 12. The record does not report a multiplicity strategy for interpreting several outcomes. It does not state whether any outcome hierarchy, adjustment, or other approach was specified.

In general, evaluating multiple outcomes can increase the chance of a false-positive finding if each is treated as a separate confirmatory test. Adjustments or a prespecified hierarchy can address that issue, but the registry record does not report whether either was used. With no posted endpoint analyses, there are no reported statistical tests to interpret in light of multiplicity.

The record defines the primary population as the safety population, including participants enrolled and treated with StrataGraft. It does not report the number analyzed for the primary endpoint, the number with missing endpoint assessments, reasons for missing data, or a method for handling missing outcomes. It also does not report whether participants who received treatment but lacked confirmation were counted as not meeting the endpoint.

In general, missing-data methods can affect results when outcome status is unavailable, and the assumptions behind those methods matter. No missing-data approach is reported in the registry record, so it cannot be assessed. The record also does not describe a separate intention-to-treat population, a per-protocol population, or endpoint-specific exclusions.

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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists safety figures by age cohort. For the 2 to under 12 years cohort, 1 participant is listed as at risk for serious adverse events and 0 as affected; for other adverse events, 1 is listed as at risk and 1 as affected. Deaths are listed as 0. For the 12 to 17 years cohort, 0 participants are listed as at risk and 0 as affected for both serious and other adverse events; deaths are listed as 0.

These entries should be read with their at-risk counts in view. A cohort with 0 participants at risk does not provide an observation of zero events among treated participants; the registry lists no participant at risk in that cohort. The displayed counts are not a detailed account of event type, timing, duration, severity, or relationship to treatment.

The registry lists no top serious adverse-event terms. The safety figures do not establish that an adverse event cannot occur, and they do not by themselves characterize safety in a broader pediatric population. The registry record does not report additional detail about adverse-event definitions or collection and analysis methods.

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

The posted record establishes that a completed Phase 3, multicenter, open-label, single-arm study was registered to evaluate StrataGraft in pediatric subjects with deep partial thickness thermal burns. It describes the intended application, age-based cohorts, primary endpoint definition, enrollment entry, and selected safety counts. These details clarify what the study set out to assess.

The posted record does not report the primary endpoint result or results for the listed secondary outcomes. It therefore does not show how many participants achieved confirmed closure without autograft, the percentage who did so, or how precise any estimate would be. It also does not provide a comparative treatment effect. The stated study purpose is not evidence that the intended outcomes occurred.

In general, an observed outcome in a single-arm study describes what happened among participants in that study, not what would have happened to the same participants under another treatment. Without a concurrent comparator, differences from usual care cannot be directly estimated through random assignment. The record’s discussion of autografting as usual treatment provides context for the research question, not a control-group result.

The enrollment entry is 1, and the safety figures list participants at risk by cohort. Those entries do not replace an endpoint-specific analysis. They should not be used to infer an unreported closure percentage or an unreported uncertainty interval. Likewise, the zero serious adverse events listed in the younger cohort is a registry count, not proof of absence of risk.

Accordingly, the record supports a description of the study’s design and intended outcome, but not a conclusion about the magnitude, precision, or comparative effect of StrataGraft. Those conclusions would require outcome data and analysis details that are not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a clearly defined statistical question: whether participants achieve confirmed complete closure of StrataGraft treatment sites without autograft within the specified period. The endpoint combines a clinical event, confirmation at separate visits, and an explicit restriction on autograft use. That definition makes clear what would count as meeting the primary outcome.

The design also illustrates why the structure of a trial matters when interpreting results. The registry describes a single-arm study with age-based cohorts rather than a randomized comparison. Such a study can provide descriptive evidence about outcomes observed in the enrolled participants, but it cannot directly estimate a randomized contrast with usual care. This distinction remains important even when the study is Phase 3.

The enrollment entry of 1 makes clear why the endpoint-specific denominator and uncertainty would be essential to interpretation. The registry record does not provide the primary result, its denominator, or an interval describing precision. Without those items, readers cannot assess the observed closure outcome or how much uncertainty surrounds it. Statistical significance is not a substitute for an estimate and its precision, and no inferential result is posted.

The record also shows the value of complete reporting. A defined endpoint alone is not enough to judge the findings; readers need results, analysis populations, missing-data handling, and methods for uncertainty and multiplicity. Those details are not reported in the registry record. The distinction between registered questions and posted findings is therefore central to reading the study responsibly.

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 this trial is that the registry record does not report the primary endpoint result. It also does not report the result for any listed secondary outcome, an endpoint-specific denominator, or a confidence interval. As a result, no efficacy estimate or assessment of its precision can be made from the posted information.

The study is single-arm and non-randomized, with no concurrent comparator. Consequently, its design does not support a direct randomized comparison with autografting or another treatment. Although the study summary describes the rationale for seeking an alternative to autografting, the registry does not report an autograft control group.

Enrollment is listed as 1, and the safety entries show no participants at risk in the older cohort. The record does not provide a participant flow or explain cohort enrollment. It also does not supply detailed eligibility criteria, baseline characteristics, or endpoint-specific population counts. These omissions limit assessment of who contributed to the outcomes and how representative the study participants were.

Statistical methods that could affect interpretation are not described: the registry record does not report the primary analysis method, handling of missing outcome data, multiplicity approach, or sample-size justification. It does not report whether interim analyses were planned or performed. The listed safety counts also lack details about event types and collection methods. These limitations are specific to what the registry record reports and should not be filled by assumption.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: StrataGraft Safety, Tolerability and Efficacy in Pediatric Subjects — NCT05517902.
• Registry record last updated 2025-03-18; status last verified 2025-02.
• Results first posted 2025-03-18.
• 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

The registry record describes NCT05517902, titled “StrataGraft Safety, Tolerability and Efficacy in Pediatric Subjects.” It is a completed Phase 3, multicenter, open-label, non-randomized, single-arm study sponsored by Stratatech, a Mallinckrodt Company. The registered dates are 2023-04-28 for study start and 2024-05-09 for primary completion. Enrollment is listed as 1.

The study evaluates a single application of StrataGraft in pediatric subjects with deep partial thickness thermal burns. Its primary endpoint is the percentage of participants achieving confirmed complete closure of treatment sites without autograft within 12 weeks. The primary endpoint result, statistical analysis, and results for the listed secondary outcomes are not reported in the registry record.