Study of Effectiveness and Safety of SD-101 in Participants With Epidermolysis Bullosa: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Effectiveness and Safety of SD-101 in Participants With Epidermolysis Bullosa (NCT02014376), a randomized phase 2 study. The primary outcome is Participants With Documented Complete Closure Of The Target Wound Within 1 Month After Initiation Of Treatment.

2. Clinical Question

3. Trial Design

The official title describes a Phase 2b, multi-center, randomized, double-blind, vehicle-controlled study. The registry lists the phase as Phase 2, allocation as randomized, masking as triple, and the model as parallel. The study is marked completed. Its recorded start date is 2014-01-06 and its primary completion date is 2014-06-24. Enrollment is listed as 48; the registry record does not explain how that figure relates to the analysis population or the numbers assigned to each arm.

Participants were assigned to SD-101 cream at 3%, SD-101 cream at 6%, or vehicle cream at 0%. The arm descriptions specify topical application over the entire body once daily for 90 days. Randomized allocation can help balance measured and unmeasured baseline characteristics across groups on average, while masking is intended to limit bias in care, assessment, or reporting. The registry record does not describe the allocation ratio or the roles of the parties included in the triple masking.

The study focused on epidermolysis bullosa and assessed a target wound as its primary endpoint. Secondary outcomes included documented complete closure of the target wound within 2 and 3 months, percentage change in lesional skin based on Body Surface Area Index measurements at Month 3, itching at Day 7, pain at Day 7, and scarring at Week 2, Month 1, Month 2, and Month 3. The record also lists six outcome measures and one analysis, but does not provide a detailed statistical analysis plan or numerical primary endpoint results.

The enrollment figure is not a substitute for arm-specific outcome denominators, and no group allocation counts for the primary analysis are reported. A sample-size justification for the trial itself is not reported in the registry record. Any planning illustrations based on an observed effect should be read as conditional calculations, not as observed power or as evidence about the trial’s design rationale.

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: Intent-to-treat (ITT) Population: Participants who provided informed consent, had been randomized, and had received at least 1 application of study drug.

5. Baseline Characteristics

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

Population: Intent-to-treat (ITT) Population: Participants who provided informed consent, had been randomized, and had received at least 1 application of study drug.

6. Primary Endpoint

The registry lists the primary outcome as Participants With Documented Complete Closure Of The Target Wound Within 1 Month After Initiation Of Treatment, measured over Baseline to 1 Month.

The primary endpoint is the count of participants with documented complete closure of the target wound within 1 month after initiation of treatment. It is a binary participant-level outcome: each participant either meets the stated closure criterion within the specified timeframe or does not. The listed measurement period is Baseline to 1 Month.

Wounds were assessed at study visits using the ARANZ SilhouetteStar wound imaging, measurement, and documentation system. The registry describes photographic images, quantitative measures, and other target-wound assessment information entered by the clinician. The system captured information without contact with the participant’s skin and retained measurement history so serial wound status could be assessed.

Complete closure is a clinically interpretable endpoint because it represents a defined status of the target wound within a specified follow-up period. A participant count can be used to compare the frequency of that status across randomized groups, but interpretation requires the group-specific counts and analysis denominators, along with an appropriate estimate of uncertainty. Those primary outcome results are not reported in the registry record. The endpoint definition therefore explains what was intended to be measured, but does not establish how many participants achieved closure or how the groups compared.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The trial uses a parallel randomized design. In a parallel study, each participant is assigned to a treatment group and outcomes are compared between groups. Randomization is intended to reduce systematic differences at assignment, including differences that may be difficult to measure. It does not guarantee that groups will be identical, especially in a study with limited enrollment. The registry record does not report the method used to generate the allocation sequence, how assignments were concealed, or the allocation ratio.

What does masking contribute?

The registry lists masking as triple and the official title describes the trial as double-blind. These descriptions are both present in the record, but it does not specify which individuals were masked under the registry’s triple-masking classification. In general, masking can reduce the risk that expectations influence treatment, clinical assessment, or outcome reporting. It cannot address every possible source of bias, and the record does not describe how masking was maintained or assessed.

How should the primary endpoint be analyzed?

The primary outcome is a participant count for documented complete target-wound closure within the stated period. For a binary outcome, an analysis commonly compares the number meeting the outcome with the number assessed in each group. An effect estimate can describe the size and direction of a group difference, while a confidence interval conveys the range of values compatible with the data under the analysis assumptions. A p-value addresses compatibility with a specified null hypothesis; it does not quantify clinical importance or the probability that a hypothesis is true.

These are general explanations, not a description of the trial’s actual statistical procedure. The registry record does not report the primary outcome counts, group denominators, effect estimate, confidence interval, or p-value. It also does not report whether an adjusted model was used or whether any assumptions or sensitivity analyses were evaluated. The primary endpoint result therefore cannot be reconstructed from the endpoint description alone.

What can the outcome counts tell readers?

Counts are the basic observed data for a binary participant-level endpoint. To interpret them, readers need to know both how many participants met the endpoint and how many contributed to the analysis in each group. A count without its denominator does not establish the group’s event frequency, and group frequencies alone do not quantify uncertainty. No new proportions or contrasts can be calculated from the available primary endpoint information because those counts are not reported.

The description specifies an intent-to-treat population consisting of participants who consented, were randomized, and received at least one application of study drug. This definition makes treatment initiation part of the analysis-population criteria. It is not enough to determine how participants with missing follow-up were handled, whether outcome assessments were available for everyone in that population, or whether other analysis populations were used.

How should safety counts be read?

The serious adverse event figures report participants at risk and participants affected, separately by treatment group. An affected-participant count is a count of people, not necessarily a count of all events; a participant could potentially experience more than one event. The record does not clarify event-level totals or provide a definition of serious adverse events. The listed other-adverse-event counts are also descriptive. Without further details about ascertainment, follow-up, event coding, and treatment attribution, these figures should not be interpreted as a complete comparative safety analysis.

General statistical principle: uncertainty around safety counts can be substantial when group sizes are limited, and a difference in raw counts does not by itself establish a treatment-related difference. Interpretation also depends on the events’ types, timing, severity, and clinical context, details not fully reported in this record.

What do the planning calculations represent?

The stated planning assumptions use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The target effect is defined as a stated fraction of the observed effect. These are assumptions for planning illustrations, not a report of the original trial’s design calculation. In general, planning estimates indicate how many participants per arm might be needed under specified assumptions. They are not observed power, and they do not change the uncertainty or evidentiary status of the results already observed.

The registry record does not report the trial’s own sample-size justification, the effect size anticipated when the protocol was written, or whether interim analyses were planned or conducted. It also does not report the detailed test procedure, covariate adjustment, handling of repeated measures, or a prespecified hierarchy for outcomes. Those omissions limit the ability to reproduce or fully appraise the statistical analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary wound-closure outcome and several secondary outcomes assessed across different timeframes. Testing multiple outcomes or time points can increase the chance of a chance-positive finding when each is considered separately. A prespecified hierarchy or multiplicity adjustment can help control that risk, but neither the statistical plan nor any multiplicity procedure is reported in the registry record. The listed outcome measures alone do not establish which comparisons were confirmatory or how findings were prioritized.

Missing-data handling is also not reported. The endpoint description defines an intent-to-treat population as participants who consented, were randomized, and received at least one application of study drug. That definition does not explain how participants without an assessable wound outcome were handled, whether missing assessments were imputed, or whether sensitivity analyses were conducted. The number of participants contributing to each outcome and time point is not given in the available primary results.

The record does not provide enough information to assess departures from the intended analysis population, withdrawals, or the completeness of follow-up. It also does not report a detailed analysis plan, so the prespecified status of particular analyses cannot be verified. These gaps matter because selective availability or analysis of outcome data can affect how group comparisons should be understood. The lack of these details should be treated as uncertainty about the analysis, not as evidence that a particular method was or was not used.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cellulitis (6.2%), wound infection (6.2%), feeding disorder (6.2%), bacterial tracheitis (5.9%), catheter site cellulitis (5.9%).

For serious adverse events, the record lists participants at risk and participants affected by group. In the 6% SD-101 group, 15 participants were at risk and 0 were affected; in the 3% group, 16 were at risk and 2 were affected; in the vehicle group, 17 were at risk and 1 was affected. Deaths are listed as 0 in each group. Other adverse events affected 9 participants in the 6% group, 13 in the 3% group, and 12 in the vehicle group.

These counts are descriptive and should not be treated as proof of a treatment-related difference. They do not indicate how many total events occurred if a participant experienced more than one event. The record does not report event-level timing, duration, severity, or causal assessment for each event. It lists cellulitis, wound infection, feeding disorder, bacterial tracheitis, catheter site cellulitis, and pneumonia among the serious-event terms, with percentages of 6.2% or 5.9%. The terms are not assigned to treatment groups in the available record, so they cannot be used to compare groups. Differences in counts require cautious interpretation, particularly without fuller details about event collection and follow-up.

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

The record identifies a randomized, masked, vehicle-controlled study evaluating SD-101 cream in participants with several forms of epidermolysis bullosa. It describes the primary question as whether the target wound achieved documented complete closure within 1 month after treatment began. The wound-assessment method and several secondary outcomes are also specified. These details clarify what the study set out to measure.

However, the numerical primary outcome findings are not reported in the registry record. There is no basis in the available information to state how many participants achieved closure in any group, to estimate a treatment contrast, or to describe the precision of that contrast. This absence should not be interpreted as evidence of benefit or lack of benefit. The secondary outcome names likewise do not establish their results.

The safety information permits a limited description of affected-participant counts and deaths by group. It does not establish that any event was caused by a study cream, and the serious-event terms cannot be assigned to arms from the information available. A complete safety interpretation would require event details and the methods used to collect and assess events.

More broadly, statistical evidence depends on both the observed data and the methods used to analyze them. Randomization and masking are important design features, but they do not replace reporting group-specific results, uncertainty, missing-data handling, and analysis choices. The registry record is useful for identifying the planned question and recorded design, yet its available results are insufficient to judge the primary efficacy comparison. No clinical recommendation follows from these incomplete statistical results.

13. Why This Trial Matters Statistically

This study raises a clear statistical question: whether complete closure of a target wound within a defined follow-up period differed among participants assigned to SD-101 cream or vehicle. A randomized parallel design and masked assessment are relevant because wound status is measured over time and may involve clinical judgment. A documented imaging and measurement system was used to capture target-wound information, including serial measurement history.

The study also illustrates why endpoint definitions and endpoint results must be distinguished. A carefully described measure can make a trial’s question understandable, but interpretation still requires the observed group data and an estimate of uncertainty. Without primary outcome counts or comparative estimates, readers cannot determine the magnitude or precision of any difference. This is a reporting limitation, not a statistical finding of no effect.

The multiple secondary outcomes and timeframes raise questions about prespecification and multiplicity. Since the registry record does not report the analysis plan or adjustment procedures, it is not possible to assess how those outcomes were handled inferentially. Similarly, the absence of missing-data methods and participant flow details makes it difficult to assess how complete outcome ascertainment was.

Safety counts further show why arm-level totals are only a starting point. Counts need context about the events, follow-up, attribution, and whether the unit is participants or events. The record offers some participant counts but not enough detail for a full comparative assessment. Together, these features make the trial statistically informative as a design description while leaving its central outcome comparison unresolved in the available registry record.

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 main limitation is that numerical results for the primary target-wound closure outcome are not reported in the registry record. Without group-specific counts, denominators, and comparative estimates, neither the magnitude nor precision of the primary comparison can be assessed. The available record also does not provide numerical results for the listed secondary outcomes.

Additional methodological details are absent. The registry does not report the randomization procedure, allocation ratio, the identities of those masked, or how masking was maintained. The official title calls the study Phase 2b, while the registry phase listing is Phase 2. The record does not explain that difference in labeling.

The population description does not include baseline characteristics, participant flow, or arm-specific primary endpoint denominators. Although the intent-to-treat population is defined, missing-outcome handling and sensitivity analyses are not reported. The statistical plan, including multiplicity procedures and any interim analyses, is also not reported in the registry record. A sample-size justification for the actual trial is not reported.

The safety figures are limited to participant counts and a list of serious-event terms with percentages. The record does not provide sufficient event-level detail, treatment attribution, or follow-up context to support a complete safety comparison. These limitations constrain interpretation of both efficacy and safety; they do not establish that a particular result or method was absent from the study itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of Effectiveness and Safety of SD-101 in Participants With Epidermolysis Bullosa — NCT02014376.
• Registry record last updated 2020-01-13; status last verified 2020-01.
• Results first posted 2020-01-13.
• 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

NCT02014376 is a completed randomized, parallel, vehicle-controlled study of SD-101 cream in participants with epidermolysis bullosa. The official title describes it as Phase 2b and multi-center; the registry lists Phase 2 and triple masking. Enrollment is recorded as 48. The study compared topical SD-101 cream at 3% and 6% with vehicle cream at 0%, applied once daily over the entire body for 90 days.

The primary endpoint was documented complete target-wound closure within 1 month after treatment initiation. Wound assessment used the ARANZ SilhouetteStar system. The registry record does not report numerical primary endpoint results, comparative estimates, or the detailed statistical analysis plan. It lists secondary outcomes involving later wound closure, lesional skin, itching, pain, and scarring.

Serious adverse events affected 0 participants in the 6% group, 2 in the 3% group, and 1 in the vehicle group; no deaths are listed. The available safety details support descriptive reporting only, not a causal comparison.