This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Topical Treatment of Recalcitrant Ulcerative Old World Leishmaniasis With WR 279,396 (NCT00657917), a na phase 2 study. The primary outcome is The Appearance of Complete Epithelialization of Ulcerative Lesions Caused by Old World Cutaneous Leishmaniasis With no Relapse.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00657917 |
| Phase | Phase 2 |
| Condition | Cutaneous Leishmaniasis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | U.S. Army Medical Research and Development Command |
| Results posted | Yes |
2. Clinical Question
The study asked whether topical WR 279,396 could be used to treat laboratory-confirmed cutaneous leishmaniasis in military health care beneficiaries. In the study description, cutaneous leishmaniasis meant Old World leishmaniasis acquired in Southwest Central Asia or the Middle East. The primary outcome focused on ulcer healing without relapse, rather than on a comparison between treatments.
Population
Military health care beneficiaries with laboratory-confirmed cutaneous leishmaniasis. The registry describes the study condition as Old World leishmaniasis acquired in Southwest Central Asia or the Middle East, and the title refers to recalcitrant ulcerative disease.
Intervention
WR 279,396, listed as a topical paromomycin plus gentamicin cream. The arm description specifies topical use twice a day for 20 days.
Comparator
No comparator arm is listed. The registry classifies the model as single group and allocation as not applicable, so the study does not provide a like-for-like control comparison.
Primary question
Whether participants met the specified epithelialization criteria for ulcerative lesions and had no relapse by the endpoint follow-up. The registry says the planned statistical analysis could not be performed because only one patient enrolled.
The question is therefore about the clinical course recorded for an individual treated under the study regimen, not about an estimated treatment difference. Without a comparison group, the study cannot separate a treatment-associated outcome from other influences on healing. The registry record does not report an analyzable primary outcome result.
3. Trial Design
This was a phase 2, single-group study with no masking. Allocation is listed as not applicable, consistent with the registry's single-group classification; no randomized or control-arm comparison is described. The listed intervention was topical paromomycin plus gentamicin cream, identified in the arm description as WR 279,396 applied twice a day for 20 days.
The registry lists enrollment as 1 and status as terminated. The recorded study start was 2006-12-20, and primary completion was 2007-06-08. The sponsor was the U.S. Army Medical Research and Development Command. The record does not report why the study was terminated. It also does not report a protocol rationale for the enrollment, a sample-size justification, or the planned statistical methods in enough detail to identify a formal analysis plan.
The primary outcome was intended to capture complete epithelialization, or a staged healing course leading to complete epithelialization, with no relapse. The timeframe is listed as 180 days, with more detailed timing criteria in the outcome description. The listed secondary outcomes were number of relapses and safety and tolerability, including serious and other adverse events. The registry identifies three outcome measures, but lists zero analyses. The primary outcome description explicitly states that the planned statistical analysis could not be performed because only one patient enrolled.
This design can describe the intervention and intended follow-up, but it cannot estimate a comparative treatment effect. The absence of masking also means that the registry does not describe blinded assessment. Whether outcome assessors were otherwise independent or whether any safeguards against assessment bias were used is not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Paromomycin +Gentamicin Topical Cream |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Ultimately, the planned statistical analysis could not be performed because only one patient was enrolled in the study.
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.
| Characteristic | Unit | Paromomycin +Gentamicin Topical Cream |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 1 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as The Appearance of Complete Epithelialization of Ulcerative Lesions Caused by Old World Cutaneous Leishmaniasis With no Relapse, measured over 180 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Surface area in millimeters squared |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint concerns epithelialization of ulcerative lesions caused by Old World cutaneous leishmaniasis, together with the absence of relapse. It was intended to count a lesion as meeting the endpoint if complete epithelialization was present at day 50+2 weeks. It also allowed a staged course: estimated 50%-99% re-epithelialization by day 50+2 weeks, followed by complete epithelialization by day 100+2 weeks. Both routes required no relapse by day 180+30 days. The listed timeframe is 180 days.
The registry gives the unit as surface area in millimeters squared and also says the ulcer was measured in millimeters. The endpoint description does not provide an observed value or an analysis result. It says the planned statistical analysis could not be performed because only one patient enrolled.
As a general statistical point, a healing endpoint can make a clinical outcome explicit by defining what counts as healing and when it must occur. Requiring no relapse adds a durability condition: initial closure alone is not sufficient under this definition. The staged criterion also recognizes that healing may be incomplete at the earlier assessment and complete at the later one. These rules clarify the intended outcome, but they do not establish that the outcome was observed or allow an estimate of how often it would occur across a broader population.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a study with a very limited enrollment and no comparator arm. It lists one enrollee, and its primary outcome description says the planned statistical analysis could not be performed because only one patient enrolled. The record lists zero analyses. Accordingly, there is no reported estimate of the primary endpoint, no treatment-group comparison, and no basis in this record for quantifying a treatment effect.
The endpoint was defined as epithelialization meeting specified timing criteria without relapse by day 180+30 days. That definition describes what the investigators intended to assess; it is not itself evidence that the endpoint was met. The registry record does not report an observed primary outcome value. Nor does it report a relapse count as a result, even though number of relapses is listed as a secondary outcome. Readers should distinguish outcome definitions and planned follow-up from observed results.
In a single-group study, an observed outcome would describe the enrolled participant or participants under the study conditions. It would not by itself show what would have happened under another treatment or without the intervention. General statistical interpretation: comparative effects require a meaningful contrast, and a single group does not supply that contrast. A historical expectation or an assumed benchmark would not substitute for a concurrent comparator unless a suitable design and analysis supported that approach; such a comparison is not reported in the registry record.
The limited enrollment also makes estimates of variability and uncertainty unavailable in a meaningful trial-level sense. A confidence interval is a statistical range expressing uncertainty about an estimated quantity under specified assumptions. No primary-outcome estimate or corresponding interval is reported, so there is no interval to interpret. The absence of an estimate should not be mistaken for a precise estimate of no effect, nor should it be interpreted as proof that the endpoint was or was not achieved.
The record includes safety counts for the listed treatment group: one participant was at risk for serious adverse events and zero were affected; one was at risk for other adverse events and one was affected. These descriptive counts are not comparative safety estimates. With so little information, they cannot characterize the frequency of uncommon events or establish the overall safety profile. The record does not list serious adverse-event terms, and deaths are not reported as a numeric result.
Any planning illustrations associated with the record should be read as hypothetical design calculations, not as evidence about this study's observed power or as a substitute for the missing analysis. General statistical principle: power is a property of a planned design under specified assumptions, not a retrospective measure of whether a result is persuasive. The registry's analysis could not be performed, and the record does not report the underlying effect estimate or a completed inferential analysis.
The most defensible interpretation is therefore descriptive and limited: the registry identifies the intended treatment, endpoint, follow-up, and sparse safety counts, but it does not report an analyzable primary efficacy result. The record does not establish whether the endpoint was met, how the treated participant's outcome compared with an alternative, or how outcomes might vary in a larger group.
9. Statistical Methods Explained
The registry classifies the study as single group and reports allocation as not applicable. These features matter because the usual comparative trial estimate is a contrast between outcomes in intervention and comparator groups. No comparator is listed. Consequently, there is no between-group difference, ratio, or other comparative treatment estimate to interpret from the registry record.
What does a single-group result describe?
General statistical explanation: a single-group study can report what was observed among participants who received the intervention, provided that outcome data are available. Such a description does not by itself identify what caused the outcome. Healing can have multiple influences, and without a comparison group the study cannot estimate how outcomes would differ under another condition. This is a limitation of the design, not a claim about the intervention's effect.
In this record, the enrollment is 1, and the primary outcome description says the planned statistical analysis could not be performed. The registry lists zero analyses. Therefore, the key distinction is between a protocol-defined endpoint and an analyzed outcome: the endpoint is described, but an analyzable primary result is not reported. There is no reported treatment effect estimate, standard error, confidence interval, or hypothesis-test result for that endpoint.
What does the endpoint definition contribute?
General statistical explanation: a well-defined endpoint sets out the event or state that an analysis would count. It can include the type of event, a time window, and conditions for determining whether the event occurred. Here, the endpoint combines epithelialization criteria at specified follow-up times with the absence of relapse by the later follow-up. This makes the planned outcome more specific than a general statement that a lesion improved.
That specificity does not resolve all measurement questions. The record gives a unit of surface area in millimeters squared and also describes the ulcer as measured in millimeters. It does not report a numerical endpoint value, a detailed measurement procedure, or an analysis of the measurement. The registry's phrasing should therefore be read as the stated outcome definition, not as a complete account of how measurements were obtained or evaluated.
How should uncertainty be understood?
General statistical explanation: a confidence interval represents uncertainty around an estimated quantity, conditional on the method and assumptions used. A narrow interval is usually more informative about precision than a wide interval, but an interval does not correct for bias or a weak design. Here, no primary-outcome estimate or interval is reported. It is not possible to infer precision from an analysis that the registry says could not be performed.
A p-value, when reported, measures how compatible data are with a specified null model under stated assumptions. It is not the probability that a treatment works, and it does not measure the size or clinical importance of an effect. No p-value or inferential test result is listed in the registry record. There is therefore no significance test to interpret.
What do the planning assumptions mean?
The sample-size assumptions describe planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They specify that the effect to detect is a stated fraction of the observed effect. These are assumptions for hypothetical planning calculations, not a description of the single-group study's allocation or its actual analysis.
General statistical explanation: a planning calculation asks how much information a future design might need under chosen assumptions about the effect, variability, significance level, and power. Changing those assumptions changes the result. A calculation based on a fraction of an observed effect is especially dependent on the stability and relevance of that effect estimate. The registry record does not report a completed primary analysis from which readers can independently assess an observed effect. Planning outputs should not be read as observed power, proof of adequate design, or evidence that a treatment effect was detected.
The normal approximation is a mathematical approach used in some planning calculations. General explanation: approximations can be useful when their assumptions reasonably represent the design and data, but they do not turn a hypothetical two-arm calculation into evidence from a single-group study. Equal allocation between two arms is likewise a planning assumption for a hypothetical comparison, not the allocation used in this record.
Why can event counts be difficult to analyze?
The primary outcome is expressed as a count-type outcome in the record, and the listed secondary outcomes include relapses and adverse events. General statistical explanation: count outcomes may be analyzed using methods that account for the distribution of counts and the amount of observation time, when appropriate. Some count data show over-dispersion, meaning their variability exceeds what a simple model assumes. Ignoring over-dispersion can make uncertainty look too small. Whether such issues applied cannot be determined because the registry does not report a completed analysis, the relevant outcome data, or the statistical model.
Methods for time-to-event outcomes can also account for when an event occurs and whether observation ends before the event. That is a general option, not a method reported for this trial. The primary endpoint is described through follow-up timing and relapse status, but no time-to-event analysis is listed. The record does not report censoring rules or a statistical method for relapse timing.
Finally, masking is listed as none. General statistical explanation: knowledge of treatment assignment can influence subjective assessments or reporting, although the extent depends on how an outcome is measured and assessed. The registry does not report whether independent assessors or other procedures were used to reduce that risk. No inferential method can recover a missing comparison or missing outcome analysis; the design and available data set the limits on what can be concluded.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, including the primary epithelialization-without-relapse endpoint and secondary outcomes concerning relapses and safety and tolerability. It lists zero analyses. The record does not report a statistical analysis plan, a hierarchy among secondary outcomes, or a multiplicity adjustment. It is therefore not possible to determine whether multiple outcomes or multiple analyses were intended to be handled in a particular way.
General statistical explanation: when several outcomes or statistical tests are examined, the chance of at least one apparently unusual finding can increase. A prespecified outcome hierarchy or an adjustment can help clarify how evidence should be interpreted. These approaches do not create information where the underlying data are unavailable, and their use in this study is not reported in the registry record.
The registry states that the planned statistical analysis could not be performed because only one patient enrolled. It does not report outcome-level missingness, reasons for any missing measurements, or a method for handling missing data. The distinction is important: failure to perform the planned analysis is not the same as a reported analysis in which some observations were missing. The record does not provide enough information to classify outcomes as missing, observed, or imputed at each follow-up.
The record also does not report an analysis population definition, such as which participants would be included in a primary analysis or how deviations from the intervention would be handled. With one enrollee and no reported analysis, there is no basis to assess differences between analysis populations or to evaluate the impact of missing-data assumptions. Any statistical handling of multiplicity, missing data, or analysis populations is not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Paromomycin +Gentamicin Topical Cream | 0 | 1 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Paromomycin +Gentamicin Topical Cream | 1 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Paromomycin +Gentamicin Topical Cream |
|---|---|---|
| Left calf pain | Musculoskeletal and connective tissue disorders | 1 of 1 |
| Flu-like symptoms | General disorders | 1 of 1 |
| Gastroenteritis | Gastrointestinal disorders | 1 of 1 |
| Elevated BP readings | Investigations | 1 of 1 |
| Right gluteal pain | General disorders | 1 of 1 |
| Right groin rash | Skin and subcutaneous tissue disorders | 1 of 1 |
| Left foot edema | Metabolism and nutrition disorders | 1 of 1 |
| Upper respiratory infection | Infections and infestations | 1 of 1 |
| Burning sensation at site | Nervous system disorders | 1 of 1 |
| Worsening pain at ulcer site | General disorders | 1 of 1 |
The listed treatment group has one participant at risk for serious adverse events and zero affected by a serious adverse event. For other adverse events, one participant was at risk and one was affected. These are counts from the registry record, not comparative rates or estimates of risk differences. The study has no listed comparator group against which to compare them.
The zero serious adverse events recorded should be read as a description of the observed registry count, not as proof that serious harms cannot occur. Sparse observation cannot characterize uncommon events or establish how safety might look in a larger group. Likewise, the one other adverse event recorded does not establish that the treatment caused it; the record gives no comparative assessment or event-level details to support that attribution.
The registry's serious adverse-event terms list is empty. Deaths are not reported as a numeric result in the record. The listed secondary outcome includes safety and tolerability, but the record does not provide further event descriptions or a statistical safety analysis. General statistical explanation: adverse-event counts are most informative when interpreted alongside definitions, observation duration, severity, attribution, and a suitable comparison. Those details are not all, so the counts support only a narrow descriptive reading.
12. What the Result Does, and Does Not, Mean
The record establishes that a phase 2 study of topical WR 279,396 was registered as a single-group investigation for cutaneous leishmaniasis, with ulcer epithelialization without relapse as its primary endpoint. It describes topical use twice a day for 20 days and an endpoint extending through the stated follow-up criteria. It also records enrollment of 1 and a terminated status.
The record does not establish whether the primary endpoint was met. The outcome description says the planned statistical analysis could not be performed because only one patient enrolled, and the registry lists zero analyses. No analyzable primary outcome estimate, confidence interval, p-value, or comparative treatment effect is reported. An endpoint definition should not be mistaken for a result.
Because no comparator arm is listed, the study cannot provide a like-for-like estimate of how outcomes differed from another treatment or from no intervention. Even if an individual outcome had been reported, a single-group observation would not by itself identify the cause of that outcome or predict results in a broader group. The registry does not report an alternative benchmark or a statistical method for making a historical comparison.
The safety figures are similarly limited. The record lists no serious adverse events among the one participant at risk, and one other adverse event among the one participant at risk. These counts do not establish comparative safety, rule out uncommon harms, or explain whether the other event was attributed to treatment. The serious-event terms are not listed, and deaths are not reported as a numeric result.
General statistical principle: absence of a reported estimate is not an estimate of no effect. It also cannot be converted into evidence of benefit or harm. The appropriate conclusion is that the registry record documents the intended study question and some descriptive safety counts but does not provide an analyzable efficacy result. It does not support a claim that the treatment works or does not work.
13. Why This Trial Matters Statistically
This study illustrates a central distinction in clinical research: a clearly specified question and endpoint do not guarantee that a study can answer them. The registry describes a specific topical regimen and a primary outcome that requires epithelialization according to timing criteria and no relapse. But it also records enrollment of 1 and states that the planned statistical analysis could not be performed. The endpoint is defined; an analyzable treatment-effect estimate is not available.
The design also makes the limits of comparison visible. A single-group study can record outcomes after treatment, but it cannot directly estimate how those outcomes differ from a comparator. This matters when readers encounter a treatment description alongside an intended clinical outcome: the presence of both is not evidence of a comparative result. Here, the registry lists no comparator arm and no analyses.
There is also a useful lesson about precision. Statistical uncertainty is not something that can be inferred from a treatment label, a planned endpoint, or an enrollment target. It depends on observed outcome data and a suitable analysis. Since the registry says the planned analysis could not be performed and does not report a primary outcome estimate, no meaningful trial-level precision statement can be drawn for efficacy.
Finally, the record shows why safety counts need context. A count of zero serious adverse events is an observation within a very limited record, not a guarantee about rare events or a comparative safety conclusion. Reporting the denominator alongside the count helps readers understand how narrow that observation is, while the absence of detailed event terms and a control group further limits interpretation.
Statistically, the important contribution is transparency about the gap between the intended analysis and the available enrollment. That gap constrains conclusions without changing the stated clinical question. Careful reading separates the protocol's aims, the registry's descriptive data, and the results that were not reported.
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 central limitation is the recorded enrollment of 1. The registry explicitly says the planned statistical analysis could not be performed for this reason. This leaves no reported primary endpoint result and no basis for estimating outcome variability or precision across participants. The record does not explain why recruitment was limited or why the study was terminated, so no explanation for these circumstances should be inferred.
The single-group design provides no concurrent comparator, and masking is listed as none. These features limit comparative interpretation and may leave outcome assessment more vulnerable to knowledge of treatment, depending on how it was conducted. The registry does not describe any independent assessment or other procedures that might address this concern.
The endpoint description includes specific epithelialization and relapse criteria, but no observed result, detailed measurement procedure, or completed analysis is reported. The registry gives both a surface-area unit in millimeters squared and a statement that the ulcer was measured in millimeters. This wording does not provide enough detail to reconstruct the measurement process. The primary outcome is also framed around follow-up timing, but censoring rules and handling of incomplete follow-up are not reported.
The record lists secondary outcomes for relapse and safety and tolerability, yet provides no analysis of those outcomes. The safety information is limited to the listed counts; serious-event terms are absent, and deaths are not reported as a numeric result. The record does not provide enough detail to assess event timing, severity, attribution, or duration of observation beyond the stated outcome timeframe.
Finally, the statistical analysis plan, missing-data approach, analysis populations, and multiplicity strategy are not reported in the registry record. These omissions do not imply that a particular method was or was not used outside the record; they mean the record does not permit readers to evaluate those choices.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Topical Treatment of Recalcitrant Ulcerative Old World Leishmaniasis With WR 279,396 — NCT00657917.
- Registry record last updated 2019-01-22; status last verified 2018-08.
- Results first posted 2019-01-22.
- 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.
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18. Record Summary
This terminated phase 2 study evaluated topical WR 279,396, listed as paromomycin plus gentamicin cream, for cutaneous leishmaniasis. The arm description specifies application twice a day for 20 days. The study was classified as single group, with no masking and no comparator arm. Enrollment is listed as 1.
The primary endpoint was epithelialization of ulcerative lesions without relapse by the specified follow-up criteria. The registry states that the planned statistical analysis could not be performed because only one patient enrolled, and it lists zero analyses. Secondary outcomes included relapse count and safety and tolerability. The safety record lists zero serious adverse events among one at risk and one other adverse event among one at risk. No comparative efficacy estimate is reported.