Safety and Efficacy Study of DSC127 in Treating Subjects With Diabetic Ulcers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy Study of DSC127 in Treating Subjects With Diabetic Ulcers (NCT00796744), a randomized phase 2 study. The primary outcome is The Primary Efficacy Parameter Will be the Proportion of Ulcers Healed by 12 Weeks as Defined as 100 % Epithelialized With no Drainage..

2. Clinical Question

3. Trial Design

This was a phase 2, randomized, parallel-group, placebo-controlled study of DSC127 for diabetic ulcers. The registry lists US Biotest, Inc. as sponsor and the study status as completed. Enrollment is listed as 78. The study had a placebo vehicle control group and two active-treatment groups: 0.03% DSC127 and 0.01% DSC127 in vehicle control. The brief summary says the study was intended to assess safety, tolerability, and the effect of different doses on chronic foot-ulcer healing.

The registry describes the trial as randomized and parallel-group. Its masking entry is triple, while the official title calls it double-blind. Which groups of people were masked, and how masking was implemented, are not reported in the registry record. Allocation procedures, stratification, and any other details about randomization are also not reported in the registry record.

The primary efficacy outcome was the number of ulcers healed within 12 weeks of first treatment, with healing defined as 100% epithelialized with no drainage. The primary population is identified as the Intent-to-Treat Population. The posted primary group counts are 8 healed ulcers with placebo, 14 with 0.03% DSC127, and 8 with 0.01% DSC127. The posted results also include ulcer-area re-epithelialization over 12 weeks and time to re-epithelialization over 24 weeks. Adverse events were another stated secondary outcome.

The trial's detailed protocol, recruitment procedures, sample-size justification, and analysis plan are not reported in the registry record. Its start and primary-completion dates are listed as 2008-10 and 2010-12. These dates describe the registry record, but do not provide details about the timing of individual assessments or analyses.

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: Intent-to-Treat Population

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 The Primary Efficacy Parameter Will be the Proportion of Ulcers Healed by 12 Weeks as Defined as 100 % Epithelialized With no Drainage., measured over Healing to occur within 12 weeks of first treatment.

The primary endpoint counts ulcers that met the registry's definition of healing within 12 weeks of first treatment. An ulcer qualified as healed when it was 100% epithelialized and had no drainage. The posted measure is a number of ulcers healed, and the registry identifies the Intent-to-Treat Population as the population for this outcome.

This endpoint focuses on a clearly defined healing state by a specified assessment window. Counting ulcers that meet the definition can make the clinical outcome easier to interpret than a change in an intermediate measurement alone. The time limit also makes the question explicit: whether the ulcer reached the defined healing state within the stated period. These are general features of a binary healing endpoint, not claims about the trial's rationale beyond the registry description.

The posted counts are 8 for placebo, 14 for 0.03% DSC127, and 8 for 0.01% DSC127. Group sizes listed with these results are 24, 26, and 27, respectively. The registry record does not report an estimable two-arm comparison for this count outcome. It also does not explain the interval bounds listed with the primary counts, so those bounds should not be interpreted as a particular kind of interval without further information. The counts alone do not establish the precision of a treatment comparison or explain how missing endpoint observations were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods are most informative when they connect each estimate to its outcome, population, and uncertainty. The registry identifies a primary count outcome and continuous secondary outcomes. Those outcome types call for different summaries and analyses. The record does not report the full statistical analysis plan, so the methods below describe the posted results and general statistical concepts rather than reconstructing the trial's unreported plan.

What does a count endpoint show?

The primary outcome is the number of ulcers healed by the specified time, under a definition requiring complete epithelialization and no drainage. A count says how many qualifying events were recorded in each group. To compare randomized groups, an analysis would ordinarily need to express the difference or relative frequency with an uncertainty estimate, using an approach suited to the outcome and its denominator. The registry record does not report an estimable two-arm comparison for this outcome. It is therefore not appropriate to infer a formal treatment contrast from the three counts alone. The record also does not explain the interval bounds attached to those counts, so their construction and interpretation are not reported in the registry record.

How should a mean difference be read?

The secondary continuous outcomes are reported as group means, with a mean difference calculated for each active group against placebo. A mean difference is the estimated average outcome in one group minus the average in the comparison group, using the contrast direction represented in the posted result. A value below zero therefore points in the negative direction of that contrast; whether that direction is favorable depends on the outcome's definition. For time to re-epithelialization, a smaller time has a different practical interpretation than a higher rate of re-epithelialization. The contrast should be read alongside the outcome unit, not as a direction that has the same meaning across measures.

A confidence interval describes a range of values compatible with the estimate under the analysis assumptions and method. It communicates precision as well as direction. When the interval includes zero for a difference, the data do not distinguish the estimated contrast from no difference at the level represented by that interval. A wide interval also means that materially different effects remain compatible with the posted data. The registry record does not state the confidence level used for the continuous-outcome intervals, so no particular level should be assumed from the record.

Why do standard deviations matter?

A standard deviation describes variation among individual observations around a group mean. It is not the same as a standard error, which describes uncertainty in an estimated mean. The rate outcome is reported with standard deviations; time to re-epithelialization is reported with standard errors. These dispersion measures cannot be substituted for each other without additional information. In general, high variability among participants makes a mean difference harder to estimate precisely, particularly when group sizes are modest. If outcome data are strongly skewed or contain influential values, a mean and standard deviation may not fully describe their distribution. The registry record does not report distributional checks or alternative analyses.

Over-dispersion is a general concern for count data when the observed variability exceeds what a simple count model assumes. In that situation, a model that assumes too little variation can produce uncertainty estimates that are too small. This is a general statistical issue, not a finding about this trial: the registry record does not report a count model, an over-dispersion assessment, or a model-based primary comparison.

What are the recalculated secondary comparisons?

The continuous-outcome comparisons are unadjusted re-calculations from posted summary statistics. They are not listed as sponsor-reported analyses. Such calculations can provide a transparent way to describe a simple contrast, but they may not reproduce a prespecified analysis that accounts for trial design features, covariates, missing observations, or other modeling choices. The registry record does not report whether the sponsor used adjusted analyses or whether these re-calculations align with the original analysis plan. Because the stated discrepancy flag is false, there is no noted conflict between the posted results and these recalculations; if the sponsor's own analysis differs, that analysis takes precedence.

What do the planning illustrations mean?

The registry includes planning illustrations based on the observed secondary-outcome effects, not the trial's design justification. They use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects set to stated fractions of the observed effect. For example, for the rate comparison with 0.03% DSC127, planning for 100% of the observed effect gives 327 participants per arm for 80% power and 438 participants per arm for 90% power; planning for 75% of the observed effect gives 582 participants per arm for 80% power and 778 participants per arm for 90% power. These figures are illustrations of assumed future-study sizes under the stated conditions. They are not observed power, are not the actual trial's enrollment target justification, and do not establish that the observed effect is a stable estimate of the effect a future study would encounter.

Planning numbers can change substantially when the assumed effect changes. Smaller assumed effects require larger sample sizes to detect under otherwise fixed assumptions. That relationship is general, and the illustrations should be read as conditional: they depend on the chosen effect, model assumptions, allocation, and error rate. The registry record does not report the trial's original sample-size calculation, the anticipated effect used for its design, or whether any adjustment for multiple comparisons was included.

The posted planning values for time-to-event-style summaries are described as total numbers of events, using a Schoenfeld approach; the other planning values are participants per arm. This distinction matters because an event total is not interchangeable with an enrollment target. The registry reports time to re-epithelialization as a mean in weeks, and does not provide a sponsor-reported time-to-event analysis. The planning approach should therefore be understood as an illustration in the record, not as evidence that the trial conducted a time-to-event analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary efficacy outcome and several secondary outcomes, including adverse events, rate of re-epithelialization, and time to re-epithelialization. The posted continuous results include comparisons of each active concentration with placebo. The registry record does not report a multiplicity strategy, such as a prespecified hierarchy, adjustment of significance thresholds, or a plan to control the overall false-positive rate. The secondary comparison p-values are unadjusted re-calculations. They should therefore be interpreted as individual, exploratory comparisons rather than as evidence adjusted for the full set of outcomes and contrasts.

Missing-data procedures are not reported in the registry record. The primary population is identified as Intent-to-Treat, but this label alone does not explain how participants without an outcome assessment were handled, whether every randomized participant was included in the posted endpoint counts, or whether imputation or sensitivity analyses were used. Details of missingness, exclusions after randomization, and the populations used for the secondary outcomes are also not reported in the registry record.

The registry lists enrollment as 78, while group sizes reported for the primary and continuous secondary outcomes differ across outcome records. The adverse-event groups also have their own at-risk counts. The record does not explain these differences or state whether they reflect outcome availability, analysis-population definitions, or another reason. It would be inappropriate to infer the cause from the counts alone.

The primary result is a count, and the registry says a two-arm comparison was not estimable for that outcome. The record does not report whether this was due to data limitations, analysis choices, or another issue. No interim analyses, stopping rules, or detailed analysis plan are reported in the registry record. Those omissions limit assessment of whether the observed outcomes were analyzed according to a prespecified strategy and how robust the conclusions would be to alternative handling of missing data or multiple testing.

11. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cellulitis (8.3%), chest pain (7.7%), osteomyelitis (7.1%), oedema peripheral (4.2%), pain in extremity (4.2%).

The posted safety counts distinguish serious adverse events from other adverse events. Serious adverse events were reported for 5 of 24 participants in the placebo vehicle control group, 4 of 26 in the 0.03% DSC127 group, and 4 of 28 in the 0.01% DSC127 group. Other adverse events were reported for 16 of 24, 15 of 26, and 18 of 28 participants in those respective groups. These are group-level counts; they do not describe the timing, duration, severity profile beyond the serious/non-serious distinction, or causal relationship of each event to treatment.

The registry lists serious-event terms including Cellulitis, Chest Pain, Osteomyelitis, Oedema Peripheral, Pain in Extremity, and Syncope, with percentages ranging from 4.2% to 8.3%. The record does not provide further detail in the listed terms about event counts by treatment group, repeated events in an individual, or attribution. Deaths are not reported in the registry record. Safety counts should be read descriptively: they do not by themselves establish whether an event was caused by an intervention or whether differences between groups are meaningful.

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

The posted data describe a randomized comparison of placebo vehicle control with two DSC127 concentrations in people with diabetic ulcers. The primary outcome was defined as healing by 12 weeks, requiring 100% epithelialization and no drainage. The registry lists 8 healed ulcers with placebo, 14 with 0.03% DSC127, and 8 with 0.01% DSC127. These are observed counts, not a reported estimate of the difference between treatment groups. The registry record does not provide an estimable two-arm comparison for this primary count outcome.

The secondary continuous outcomes provide unadjusted contrasts with intervals that include zero. Those results leave uncertainty about the direction and size of any group differences. The estimates are based on posted summary statistics, and sponsor-reported analyses are not listed. They should not be taken as proof of no difference, nor as proof of a meaningful difference. The safety figures similarly describe how many participants were reported with events, without establishing causation or comparative risk.

The registry does not report its sample-size justification, multiplicity plan, missing-data procedures, or detailed analysis plan. Those omissions restrict how fully the results can be judged. The planning illustrations are based on observed effects and stated assumptions; they are not evidence of power achieved in this trial, and they are not the original design rationale. In particular, an illustration that assumes an observed effect does not show that the same effect would be expected in another study.

Thus, the registry record supports a description of group outcomes and their uncertainty, but does not provide a precise reported primary comparison. It does not establish a treatment effect or its absence. These statistical results should not be interpreted as medical advice or as a conclusion about treatment use.

13. Why This Trial Matters Statistically

This trial is statistically informative because it illustrates how a clearly defined clinical outcome can still be difficult to interpret when the registry reports group counts but not an estimable comparison. A primary endpoint framed around a specific healing state and time window is understandable, but comparative inference requires an estimate of the difference and its uncertainty. Without that estimate, readers cannot tell how precisely the observed group counts distinguish the treatment groups.

The record also illustrates why secondary outcomes should be read in context. Measures of healing rate and healing time may add useful description, but multiple outcomes and contrasts raise questions about multiplicity. The posted secondary comparisons are unadjusted recalculations, and the registry does not describe an analysis hierarchy or multiplicity adjustment. Individual p-values in that setting are not equivalent to a single confirmatory test of the trial's main question.

Another statistical lesson is the distinction between an observed effect and a planning assumption. The registry's sample-size illustrations use observed secondary effects and explicit hypothetical assumptions. They can show how planning numbers depend on the effect chosen, but they cannot tell readers what the trial's original sample-size calculation was or what power it achieved. The original rationale is not reported in the registry record.

Finally, the record demonstrates the importance of documenting analysis populations, missing-data methods, and safety denominators. The primary population is named, but the handling of missing outcomes is not described. Different posted group counts appear across outcomes, without explanation. These details affect how estimates are interpreted and reproduced. In statistical reporting, transparency about these decisions is necessary to assess precision, comparability, and the limits of the evidence.

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.

Several limitations specific to this registry record affect interpretation. The primary outcome is posted as counts of ulcers healed, but a two-arm comparison is not estimable. The record does not say why this comparison is unavailable, and the interval bounds associated with the count results are not explained. Consequently, the primary outcome cannot be interpreted through a posted comparative effect estimate and uncertainty interval.

The reported group sizes vary by outcome. The primary outcome lists 24, 26, and 27 participants; the adverse-event groups list 24, 26, and 28 at risk. Enrollment is recorded as 78. The registry does not explain how these figures relate, whether they reflect missing outcome data or different analysis populations, or how individual ulcers relate to participants. No further assumptions should be made from these figures.

For the continuous outcomes, the available comparisons are unadjusted recalculations from summary statistics, and no sponsor-reported analyses are listed. The registry does not report the complete analysis plan, confidence level for the intervals, multiplicity handling, distributional checks, or methods for missing data. The rate outcome is reported with standard deviations, whereas time to re-epithelialization is reported with standard errors; the record does not provide a unified account of the analysis choices behind the two measures.

The registry also does not explain the difference between its triple-masking entry and the official title's double-blind wording, or identify who was masked. The protocol and original sample-size justification are not reported. These gaps do not erase the posted observations, but they limit independent assessment of the methods, the risk of bias, and the precision and reproducibility of the comparative results.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety and Efficacy Study of DSC127 in Treating Subjects With Diabetic Ulcers — NCT00796744.
• Registry record last updated 2012-09-27; status last verified 2012-08.
• Results first posted 2012-09-27.
• 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

NCT00796744 is a completed, randomized, parallel-group phase 2 trial of DSC127 in subjects with diabetic ulcers. The registry describes placebo vehicle control and active groups receiving 0.03% DSC127 or 0.01% DSC127. Its primary efficacy outcome was the number of ulcers healed within 12 weeks, defined as 100% epithelialized with no drainage, in the Intent-to-Treat Population.

The posted primary counts are 8, 14, and 8 for placebo, 0.03% DSC127, and 0.01% DSC127, respectively. A two-arm comparison for that count outcome is not estimable in the registry record. Secondary results include rate and time to re-epithelialization; the posted comparisons are unadjusted recalculations with intervals including zero. Safety counts are reported by group, but deaths are not reported in the registry record.

The registry does not report the detailed analysis plan, multiplicity procedures, missing-data methods, or original sample-size justification. The findings should therefore be read as descriptive posted results with important limits on comparative interpretation.