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 NeoMatriX Wound Matrix Collagen Dressing Skin Prick Test (NCT03522675), a na na study. The primary outcome is Wheal Formation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03522675 |
| Phase | NA |
| Condition | Allergy Skin, Allergy, Dermatitis, Allergic Contact |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 22 |
| Arms in the primary outcome | n/a |
| Lead sponsor | NeXtGen Biologics, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned healthy volunteers of any sex, as described in its official title. The registry lists enrollment of 22 participants. The number represented in the posted safety counts is 20 for each group; the relationship between those counts and total enrollment is not reported in the registry record.
Intervention
The intervention was NeoMatriX Wound Matrix Collagen Dressing, a device. The registry describes an 8 mm disc and assessment by skin prick test. The study objective was to investigate whether the material could cause an allergic response.
Comparator
The record describes histamine as a positive control and normal saline as a negative control, each listed at 0.1 mL. It also names groups involving NeoMatriX alone, histamine plus NeoMatriX, and saline plus NeoMatriX. Allocation is listed as not applicable, and this is a single-group study; these groups should not be read as a randomized, like-for-like comparison.
Primary question
At 15 minutes, what wheal formation was observed, and did the NeoMatriX response meet the registry’s stated criterion for a positive allergic response: a wheal >3 mm of the positive control, histamine? The primary endpoint is identified, but its numerical result is not reported in the registry record.
3. Trial Design
This was a completed, single-group study of a device, titled “NeoMatriX Wound Matrix Collagen Dressing Skin Prick Test.” Its official title describes skin-prick testing in healthy volunteers of any sex to investigate potential allergy to NeoMatriX Wound Matrix. The registry lists enrollment of 22. The study began on 2018-04-11, and primary completion was recorded as 2018-04-26.
The intervention is named NeoMatriX Wound Matrix Collagen Dressing. The arm description identifies an 8 mm disc and lists histamine positive control and normal saline negative control, each at 0.1 mL. The registry also names three groups: NeoMatriX alone, histamine plus NeoMatriX, and saline plus NeoMatriX. These descriptions provide context for the skin-prick assessment, but they do not establish a randomized comparison. Allocation is recorded as not applicable, and masking is recorded as none.
The study’s listed conditions are Allergy Skin, Allergy, and Dermatitis, Allergic Contact. These registry labels describe the subject area and should not be taken as evidence that participants had those conditions; the official title describes healthy volunteers. The phase is recorded as not applicable, and the study kind is classified as other.
The stated primary outcome is wheal formation, measured in millimetres at 15 minutes. The registry defines a positive response using a comparison with the histamine positive control. However, the numerical primary outcome result is not reported in the registry record. The record lists three outcome measures, but further details about the other measures are not reported in the registry record. No statistical analyses are listed.
The record marks the study completed, but completion status does not itself establish that all planned assessments were reported. The specific protocol, recruitment and analysis details beyond the registry descriptions are 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 | NeoMatriX and Two Comparators |
|---|---|
| STARTED | 22 |
| COMPLETED | 20 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | NeoMatriX and Two Comparators |
|---|---|
| Screen fail | 1 |
| Non-reactive to histamine | 1 |
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 | NeoMatriX and Two Comparators |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 20 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 38.35 (21 to 62) |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 7 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 20 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Wheal Formation, measured over 15 minutes.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | mm |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is wheal formation, recorded as a mean with full range and measured in millimetres at 15 minutes. The registry describes a wheal as a raised, pale, itchy formation on the skin’s surface and treats it as an allergic reaction. Its stated positive-response criterion is a NeoMatriX-associated wheal >3 mm of the positive control, histamine.
A skin-prick endpoint is intended to capture a local skin response following exposure. The timing matters because the registry specifies assessment at 15 minutes; results at another time would not be the same endpoint as defined in this record. Histamine is designated as the positive control and saline as the negative control, giving context for interpreting the test response. The registry’s description does not report the measured wheal values for NeoMatriX or either control.
Reporting a mean and full range can convey both a central summary and the span of observed values. In general, a mean alone can conceal variation between participants, while a range can indicate how dispersed the observed values were. The actual mean and range are not reported in the registry record, so the size and variability of the response cannot be assessed from the posted outcome information.
The endpoint definition states a threshold relative to histamine, but a stated threshold is not itself an observed finding. Without the posted measurements or a reported endpoint conclusion, it is not possible to determine from the registry record whether the criterion was met.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a focused question: whether skin-prick testing with NeoMatriX Wound Matrix produces a wheal response meeting the stated criterion relative to histamine. It identifies the endpoint, its unit, its assessment time, and the response rule. Those details clarify what the study intended to assess, but they do not supply the result. The primary wheal measurement is not reported in the registry record.
Consequently, no estimate of the average response, the range of responses, or the number of participants meeting the stated criterion can be described from the posted outcome information. The record’s endpoint format is mean with full range, but the values themselves are absent. It also does not report a confidence interval, a p-value, or another inferential result. No statistical analyses are listed.
The study includes histamine and saline controls in its arm descriptions. Their inclusion helps explain the intended testing context: one is labelled positive and the other negative. However, the registry labels the study single-group and records allocation as not applicable. It specifically does not describe a randomized, like-for-like control comparison. Therefore the group names should not be interpreted as evidence of randomized allocation or as a basis for a controlled treatment-effect estimate.
The enrollment figure is 22, whereas the adverse-event group entries each list 20 at risk. These are separate posted counts. The registry record does not explain the difference, identify the analyzed population for the primary endpoint, or state whether all enrolled participants completed testing. It would be inappropriate to assume that the primary endpoint was measured for every enrolled participant or to infer why the safety counts use 20.
The posted safety entries report zero serious events, zero other adverse events, and zero deaths in each of the three listed groups, with 20 at risk in each entry. Those counts describe what was entered for the specified groups; they do not replace the missing wheal results and do not establish the frequency of an allergic response under the endpoint definition.
The registry’s completed status indicates the study is marked completed. It does not resolve the absent outcome values or provide a statistical analysis plan. Sample-size justification, interim analyses, analysis populations, and missing-data handling are not reported in the registry record. No conclusion about the observed skin response can be drawn from the endpoint definition or completion status alone.
In general, statistical interpretation depends on both the magnitude of an estimate and its precision. A confidence interval, when reported, describes a range of values compatible with the data under the model and method used; it is not a substitute for the raw endpoint definition. Since no estimate or interval is reported for this primary outcome, its magnitude and precision cannot be characterized. The defensible interpretation is limited to the study question, measurement approach, and posted safety counts.
9. Statistical Methods Explained
The registry describes a mean and full range for the primary wheal endpoint. These are descriptive summaries rather than, by themselves, tests of a statistical hypothesis. A mean condenses observed measurements into a central value, while a full range gives the smallest and largest observations. In general, both can help describe a distribution, although a range does not show how observations are distributed between its endpoints. Neither value is reported for the primary endpoint in the registry record.
What does a confidence interval add?
In general, a confidence interval communicates uncertainty around an estimated quantity under specified statistical assumptions. A narrow interval indicates greater precision than a wide interval for the same kind of estimate. A confidence interval does not make a result clinically or scientifically important by itself, and its interpretation depends on the estimator, data, and method. No confidence interval for the primary endpoint is reported in the registry record, so the precision of a wheal estimate cannot be assessed.
What does the control structure allow?
The arm descriptions include NeoMatriX alone, histamine plus NeoMatriX, and saline plus NeoMatriX. Histamine is identified as a positive control and normal saline as a negative control. These labels describe their intended roles in the test; they do not establish how results compared. The study is recorded as single-group, with allocation listed as not applicable and masking as none. The registry’s own note cautions that the arms are not a like-for-like control comparison. In general, nonrandomized group comparisons can be affected by differences in who receives each condition or how assessments are made. The registry does not report a design that would support interpreting these arms as randomized alternatives.
What can the response threshold establish?
The registry defines a positive allergic response as NeoMatriX producing a wheal >3 mm of the histamine positive control. This is a prespecified-looking operational rule in the outcome description, but the registry does not report whether any participant met it. The wording defines how a response would be classified; it is not evidence that a response occurred or did not occur. The actual wheal measurements and any resulting classification are not reported in the registry record.
How should sample-size illustrations be read?
The methodological note describes a planning illustration based on the observed effect, rather than the trial’s own design. It specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. It also distinguishes participant counts per arm from total event counts for time-to-event settings. No numerical planning outputs or effect fraction are reported in the registry record. These planning assumptions do not establish the study’s original sample-size rationale and must not be interpreted as observed power. The trial’s sample-size justification is not reported in the registry record.
What can a p-value say?
In general, a p-value measures how incompatible the observed data are with a specified null model, under the assumptions of the analysis. It does not measure the probability that the null hypothesis is true, and it does not convey the size or precision of an effect on its own. The registry lists no analyses and reports no p-value for wheal formation. Therefore, there is no posted hypothesis-test result to interpret.
Why can over-dispersion matter?
In general, over-dispersion occurs when variability in the data exceeds what a chosen statistical model expects. If present and ignored, it can make standard errors too small and confidence intervals too narrow, affecting inference. This concept is relevant when a model assumes a particular variance structure, especially for count outcomes. The primary endpoint in this record is described as a mean and full range of wheal measurements, and no model-based analysis is listed. Over-dispersion is not reported as an issue in the registry record, and there is no basis to claim that it was present or assessed.
What analysis details are absent?
The registry lists zero analyses. It does not report a statistical analysis plan, model specification, adjustment variables, subgroup analyses, interim analyses, or a method for handling missing values. In general, these details help readers understand how estimates were generated and which participants contributed to each result. Without them—and without the endpoint measurements—independent interpretation of an estimated treatment or response contrast is not possible. The study’s design and endpoint description can be explained, but no inferential result should be reconstructed from the registry information.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, but details of the two measures beyond the named primary outcome are not reported in the registry record. It does not report whether the outcomes were tested statistically, whether one was designated as primary for analysis beyond the primary outcome label, or whether any multiplicity procedure was planned. In general, when several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase. Multiplicity methods can address that issue, but the appropriate approach depends on the study’s questions and analysis plan. No correction or testing strategy is reported.
The record lists zero analyses. It does not provide an analysis population definition for the wheal endpoint, explain how many participants contributed primary outcome data, or state how missing measurements were handled. It also does not report whether participants with incomplete testing were excluded, retained in a particular analysis set, or handled by another method. These omissions matter because the participants included in an estimate can affect its meaning and precision.
Enrollment is listed as 22, while each adverse-event group lists 20 at risk. The record does not explain this difference or connect those safety counts to the primary endpoint analysis population. It is not possible to infer the number with usable wheal data from either count. The missing-data pattern and reasons for any absent measurements are not reported in the registry record.
In general, missingness can matter when the probability that a measurement is unavailable is related to the response itself or to participant characteristics. The record does not describe missingness, so its direction or impact cannot be assessed. A sample-size justification, interim analysis plan, and prespecified statistical plan are also 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 |
|---|---|---|---|
| NeoMatriX Alone | 0 | 20 | 0.0% |
| Histamine + NeoMatriX | 0 | 20 | 0.0% |
| Saline + NeoMatriX | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| NeoMatriX Alone | 0 of 20 |
| Histamine + NeoMatriX | 0 of 20 |
| Saline + NeoMatriX | 0 of 20 |
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 |
|---|---|
| NeoMatriX Alone | 0 of 20 |
| Histamine + NeoMatriX | 0 of 20 |
| Saline + NeoMatriX | 0 of 20 |
The registry reports three safety group entries: NeoMatriX alone, histamine plus NeoMatriX, and saline plus NeoMatriX. Each lists 20 participants at risk. In every entry, serious adverse events are reported as 0, other adverse events as 0, and deaths as 0. These are the posted counts for those group entries.
Counts of zero mean that no events of the listed categories were entered for the stated at-risk count. They are not a numerical estimate of the primary wheal endpoint, and they do not reveal whether any participant met the registry’s allergic-response criterion. The serious-event counts should also be distinguished from other adverse-event counts and from deaths, which are listed separately.
The registry enrollment is 22, while the safety entries use 20 at risk per group. The reason for that difference is not reported in the registry record. The record does not clarify whether these entries represent distinct participants, overlapping exposures, or another reporting structure, so the counts should not be added together or treated as a total across unique participants.
In general, safety counts are interpreted in light of the duration and completeness of follow-up and the way events were defined and collected. Those details are not reported in the registry record. The posted zero counts should therefore be read narrowly as the reported entries, without extending them into broader claims about safety or the wheal response.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed skin-prick study was intended to investigate the potential for NeoMatriX Wound Matrix to cause an allergic response in healthy volunteers. It specifies a wheal measurement at 15 minutes, reported as a mean with full range, and gives a response criterion relative to histamine. It also describes histamine and saline controls and posts safety counts for three named groups.
What the record does not establish is the observed primary endpoint result. The mean wheal, full range, and number of participants meeting the stated criterion are not reported in the registry record. The study’s statistical analyses are also not listed. As a result, the posted registry information cannot show the magnitude, variability, or precision of the skin response, nor whether it met the registry’s criterion.
The safety entries report zero serious events, zero other adverse events, and zero deaths for 20 at risk in each listed group. Those counts are useful descriptive information, but they do not substitute for the missing endpoint measurements. The record does not explain the difference between enrollment of 22 and the 20 at risk listed in the safety entries.
The study should not be read as a randomized comparison of three alternatives. It is recorded as a single-group study, allocation is not applicable, and masking is none. The named control conditions provide context for the test, but the registry does not support treating the groups as like-for-like randomized arms.
In general, an endpoint definition describes what investigators intend to measure, while results describe what was observed. A completion status indicates that the record marks the study completed; it does not supply missing outcome values. The appropriate conclusion is therefore limited: the registry describes the question and method, but does not report enough primary outcome information to characterize the observed wheal response.
13. Why This Trial Matters Statistically
This study is statistically notable for the distinction between a clearly described endpoint and an unreported endpoint result. The registry gives the measurement time, unit, summary format, and a threshold tied to a positive control. Those elements make the intended assessment understandable. Yet without the measured values, readers cannot judge the response’s size, variation, or precision.
The study also illustrates why design labels matter. Histamine and saline are identified as controls, but the record describes a single-group study, no allocation, and no masking. A control’s presence in an arm description does not by itself create a randomized comparison. Statistical interpretation has to follow the design actually recorded rather than assume a comparison structure that is not documented.
Another issue is the separation between enrollment and the at-risk counts in the adverse-event entries. The record lists enrollment of 22 and 20 at risk in each group, without explaining the relationship. Statistical summaries are interpretable only when the population contributing to each one is clear. The registry does not make that connection for the primary endpoint.
The record also lists three outcome measures but no analyses. In general, multiple outcomes can raise questions about which results were prioritized and how statistical testing was planned. The registry does not provide a multiplicity strategy, analysis plan, or missing-data approach. These are not details that can be reconstructed from the endpoint description alone.
For clinical researchers and biostatisticians, the central lesson is one of reporting completeness: design and endpoint definitions are necessary, but they are not substitutes for numerical outcomes and analysis details. The posted information supports a description of the study’s measurement framework and safety counts, while leaving the primary statistical result unresolved.
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.
A central limitation is that the primary wheal result is not reported in the registry record. Although the endpoint is defined at 15 minutes and specifies mean with full range, the record does not provide the observed mean, range, or participant-level response classification. This prevents assessment of both the response magnitude and its variability.
The registry lists three outcome measures, but the details of the other measures are not reported in the registry record. It lists zero analyses and does not supply inferential estimates, confidence intervals, p-values, or a statistical analysis plan. The absence of these items means there is no posted analysis to evaluate for model choice, adjustment, or precision.
The comparison structure also limits interpretation. The study is single-group, allocation is not applicable, and masking is none. Although histamine and saline appear in the arm descriptions as positive and negative controls, the record cautions that the arms are not a like-for-like control comparison. No randomized contrast should be inferred.
Enrollment is 22, while safety entries list 20 at risk per group. The registry does not explain this discrepancy or identify the primary endpoint analysis population. It also does not report missing-data handling or the completeness of endpoint assessment. These gaps make it difficult to determine exactly which participants contribute to each posted count or intended outcome.
The protocol, sample-size justification, interim analysis plans, and details of follow-up are not reported in the registry record. The safety entries are limited to the listed adverse-event categories and counts; definitions and collection procedures are not provided. These limitations do not change the registry’s stated study question, but they constrain conclusions that can be drawn from the posted record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: NeoMatriX Wound Matrix Collagen Dressing Skin Prick Test — NCT03522675.
- Registry record last updated 2019-05-31; status last verified 2019-05.
- Results first posted 2019-05-31.
- 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
NCT03522675 is a completed, single-group device study titled “NeoMatriX Wound Matrix Collagen Dressing Skin Prick Test.” It concerns skin-prick testing of NeoMatriX Wound Matrix in healthy volunteers of any sex. Enrollment is listed as 22; the study began on 2018-04-11 and primary completion was recorded as 2018-04-26.
The primary endpoint is wheal formation, measured in millimetres at 15 minutes and described as a mean with full range. The registry defines a positive response as a NeoMatriX-associated wheal >3 mm of the histamine positive control. The primary endpoint values and statistical analyses are not reported in the registry record.
The safety entries list 20 at risk in each of three named groups, with zero serious adverse events, zero other adverse events, and zero deaths in each. Allocation is not applicable, masking is none, and the record cautions that the groups are not a like-for-like control comparison. The registry lists three outcome measures, but the other outcome details, analysis plan, sample-size justification, and missing-data handling are not reported in the registry record.