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 Irritation Potential of Omeza Collagen Matrix Using Modified HRIPT (NCT04510675), a non-randomized na study. The primary outcome is Evidence of Erythema During the Challenge Phase for Omeza Collagen Matrix.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04510675 |
| Phase | NA |
| Condition | Erythema, Sensitisation |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 58 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Omeza, LLC |
| Results posted | Yes |
2. Clinical Question
Population
Healthy volunteers were enrolled in a six-week study. The registry reports 58 enrolled and 53 completing the study. It does not report further participant characteristics in the record.
Intervention
The test article was Omeza Collagen Matrix, applied repeatedly to patch sites on the back during an induction period and evaluated again during a challenge phase. The record describes nine induction applications across three weeks.
Comparator
A negative control, identified as 0.9% aqueous sodium chloride, was also applied repeatedly. The registry describes test article and control sites in the same participants, but cautions that this was not a randomized, like-for-like control comparison.
Primary question
The stated objective was to assess sensitization potential by comparing Omeza Collagen Matrix with a negative control using a Modified Human Repeat Insult Patch Test. The primary outcome concerns evidence of erythema during the challenge phase. The registry record does not report the number of participants with erythema or a comparative estimate.
In general, a repeat insult patch test uses repeated exposure followed by a later challenge assessment. The intended statistical question is whether challenge-phase skin reactions are observed after exposure to the test article, and how those observations compare with reactions at negative-control sites. Because the registry describes testing within participants, the comparison conceptually involves paired observations rather than observations from two independent groups. That distinction matters: measurements from the same person may be related, and a suitable analysis would need to account for that relationship.
The record does not report enough outcome detail to determine the frequency or pattern of reactions, whether reactions were more common at test article sites, or how uncertainty around a comparison was quantified. The stated objective and endpoint identify the question of interest, but do not establish an answer to it.
3. Trial Design
The study is titled as a six-week, randomized, evaluator-blinded, in vivo within-subject repeat test in healthy volunteers. However, the registry lists allocation as nonrandomized, masking as none, and the model as a single group. These registry fields do not establish randomized allocation or evaluator blinding. The record does not explain the difference between the title wording and those fields, so the design should be interpreted cautiously.
The study enrolled 58 participants and reports that 53 completed it. Its start date was 2019-12-02, and its primary completion date was 2020-01-11. The interventions were the Omeza Collagen Matrix test article and a negative control identified as 0.9% aqueous sodium chloride. The described procedure involved repetitive, continuous patch applications to the same back sites, approximately 48 hours on weekdays and approximately 72-hour periods over weekends, over three weeks, for a total of nine induction applications. A challenge phase followed 10-17 days later. The available arm descriptions end mid-sentence, so additional procedural detail is not reported in the registry record.
The within-subject arrangement means each participant could contribute observations for both test article and control sites. In general, this can reduce the influence of differences between people when making a paired comparison, because a participant serves as their own reference. It does not by itself guarantee that the test and control sites were allocated randomly, that outcome assessment was masked, or that a paired statistical analysis was used.
The registry explicitly cautions that this was not a randomized comparison and that the arms are not a like-for-like control comparison. The record lists no inferential analyses. It does not report a protocol, a statistical analysis plan, a sample-size justification, or details of any interim analysis. Those design and analysis features should therefore not be inferred from the study title, the intervention descriptions, or the reported enrollment.
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 | Test Article (Omeza Collagen Matrix) and Negative Control (Occlusive Patch of 0.9% NaCl) |
|---|---|
| STARTED | 58 |
| COMPLETED | 53 |
| NOT COMPLETED | 5 |
Reasons for not completing this period:
| Reason | Test Article (Omeza Collagen Matrix) and Negative Control (Occlusive Patch of 0.9% NaCl) |
|---|---|
| Withdrawal by Subject | 5 |
Analysis population for the primary outcome, as defined in the registry: 58 subjects were enrolled with 53 subjects completing 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 | Test Article and Control |
|---|---|---|
| Participants analysed | 58 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 58 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 49.4 (SD 11.4) |
| Sex: Female, Male: Female | Participants | 50 |
| Sex: Female, Male: Male | Participants | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 56 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 36 |
| Race (NIH/OMB): White | Participants | 19 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 58 |
6. Primary Endpoint
The registry lists the primary outcome as Evidence of Erythema During the Challenge Phase for Omeza Collagen Matrix, measured over 24, 48, 72, and 96 Hours.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is titled “Evidence of Erythema During the Challenge Phase for Omeza Collagen Matrix.” It is measured as a count of participants, with assessment scheduled at 24, 48, 72, and 96 hours. The registry describes a numeric reaction scale from 0 - 3: 0 means no visible reaction, + means slight or patchy, 1 means mild, 2 means moderate, and 3 means strong. A score of 1, 2, or 3 is defined in the record as indicating dermal sensitization.
The endpoint is intended to capture whether a reaction is observed after the challenge phase rather than merely describing the repeated induction applications. In general, a prespecified threshold on a reaction scale makes a clinical observation usable as a binary outcome: a participant either meets the threshold or does not. Such an outcome can be summarized as a count, while the scale itself retains the severity categories used to classify the observation.
The registry does not report the number of participants meeting the threshold, the number assessed at each time, or the results for individual time points. It also does not clarify how multiple observations across assessment times were combined into the stated participant count. Consequently, the endpoint definition is available, but its observed value and any comparison with control are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record identifies the question, endpoint definition, study population size, and some safety counts, but it does not report a primary endpoint result. In particular, it gives no count of participants with qualifying erythema, no result by assessment time, and no comparison estimate for test article versus negative control. The registry also lists no analyses. As a result, the posted information does not quantify the observed sensitization outcome or its uncertainty.
The distinction between an endpoint definition and an endpoint result is important. Defining a score of 1, 2, or 3 as indicating dermal sensitization describes how observations are classified. It does not tell the reader how many participants had those scores. Without the observed counts and denominators, neither the frequency of qualifying reactions nor the difference between test article and control sites can be assessed from this record.
The within-subject structure is relevant to interpretation. In general, a paired analysis compares each participant’s response at test and control sites, accounting for the fact that observations from one person may be correlated. Treating paired observations as if they came from unrelated participants can misrepresent uncertainty. The registry does not report which statistical method, if any, was used to account for pairing. It also cautions that this was not a randomized, like-for-like control comparison, limiting the strength of any causal interpretation that might otherwise be drawn from a contrast.
The record reports 58 participants enrolled and 53 completing the study. It does not say how many contributed evaluable challenge-phase data, whether all enrolled participants were included in the endpoint analysis, or how incomplete assessments were handled. Enrollment and completion counts therefore cannot substitute for outcome denominators.
The safety information is limited to a combined group for the test article and negative control. That group lists 58 participants at risk for serious adverse events and none affected, and 58 at risk for other adverse events with one affected. No deaths are reported, and no serious-event terms are listed. These counts describe the registry’s safety entries; they do not supply the missing primary endpoint result.
In general, confidence intervals communicate the range of effect sizes compatible with an estimate under specified assumptions. A p-value addresses compatibility with a statistical null model, not the size or importance of an effect. Neither a confidence interval nor a p-value for the primary outcome is reported in the registry record. Without an estimate and its uncertainty, the available information supports description of the study setup and recorded safety counts, but not a quantitative conclusion about the primary question.
The trial’s completion status is listed as completed. That status means the registry records the study as completed; it does not indicate that the primary result was posted. No interpretation of absent outcome reporting should be taken as evidence of either a positive or negative test result.
9. Statistical Methods Explained
What does a participant count represent?
The primary measure is specified as a count of participants. In general, a binary outcome classifies each participant according to whether a defined event occurred. Here, the registry defines scores of 1, 2, or 3 as indicating dermal sensitization, while a score of 0 is described as no visible reaction. The score + is described as slight or patchy, but the record does not explicitly state how that category contributes to the participant count. The registry does not report the observed count or its denominator for the primary endpoint.
A count alone is not a complete comparison. To interpret a count, readers need to know how many participants were assessed, how the event was defined in practice, and how missing or repeated observations were handled. For a comparison between test and control sites in the same participant, the relationship between paired outcomes also matters. The registry does not report these analytic details.
Why does the within-subject structure matter?
In general, a within-subject design measures more than one condition in the same person. This can help account for stable differences between participants, since each person contributes information under both conditions. However, paired measurements are statistically dependent: an individual’s responses at two sites may be more alike than responses from different people.
For binary paired outcomes, an analysis may use the pattern of agreement and disagreement within participants. The paired pattern contains information that is lost if the two site totals are treated as independent groups. The registry describes test article and negative control applications to the same participants, but it lists no analyses and does not report a method for paired data. It is therefore not possible to determine whether the reported statistical approach, if any, incorporated the within-person structure.
What do randomization and masking contribute?
In general, random allocation can help balance measured and unmeasured factors between comparison conditions. Masking can reduce the chance that knowledge of the assigned condition influences outcome assessment. Those protections depend on the actual procedures, not merely on a study title. The title uses the terms randomized and evaluator-blinded, whereas the registry fields list nonrandomized allocation and no masking. The record does not reconcile these descriptions. The registry also warns that the comparison is not a randomized, like-for-like control comparison, so randomization should not be assumed.
How should uncertainty be understood?
In general, an effect estimate describes the observed contrast between conditions, while a confidence interval conveys uncertainty around that estimate under the chosen model and assumptions. A p-value evaluates how compatible the data are with a specified null model; it does not measure the size, direction, or clinical importance of an effect. For paired binary outcomes, both the estimated contrast and its uncertainty depend on the paired observations and analysis method.
No primary outcome estimate, confidence interval, p-value, or analysis is reported in the registry record. The record therefore does not permit a reconstruction of statistical uncertainty. The sample-size assumptions listed for planning illustrations are not the trial’s own design rationale and do not establish observed power. A planning calculation is hypothetical: it explores sample sizes under stated assumptions, rather than describing how much power the completed study actually had.
Why do outcome time points need a clear rule?
The endpoint lists assessments at 24, 48, 72, and 96 hours. In general, repeated assessment can describe whether reactions emerge, persist, or change over time. But repeated measurements also require a clear summary rule if the endpoint is a single participant count. The analysis might use a prespecified time point, a maximum observed score, or a rule based on any qualifying assessment; these are general possibilities, not reported procedures for this study. The registry does not state how observations across the listed times were combined.
Repeated assessments can also create multiplicity when several time-specific comparisons are tested. Multiplicity refers to the increased opportunity for a chance finding when multiple hypotheses are evaluated. Whether that concern applies depends on the actual analysis plan. The registry record does not report a multiplicity strategy or which, if any, time-specific tests were performed.
What does over-dispersion mean in general?
Over-dispersion occurs when count data vary more than a statistical model assumes. It is relevant to some count-data analyses, where an incorrect variance assumption can make uncertainty estimates too small or too large. The primary measure in this record is described as a participant count for a binary event, and no count-model analysis is reported. Over-dispersion is therefore a general statistical concept, not a feature established for this trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures: the primary erythema outcome and a secondary outcome concerning adverse events deemed related to the test product or study. It does not report a statistical analysis plan, hypothesis-testing procedures, or a strategy for handling multiple comparisons. Multiplicity can arise when several outcomes, time points, subgroups, or comparisons are examined. In general, testing many hypotheses without an appropriate plan can make chance findings more likely. Whether and how that issue affected this study is not reported in the registry record.
The primary outcome includes assessments at 24, 48, 72, and 96 hours. The record does not explain whether each time was analyzed separately, whether a single summary rule was used, or whether any adjustment for repeated testing was planned. The registry lists no analyses, so no multiplicity procedure or unadjusted testing can be confirmed.
The record reports 58 enrolled and 53 completing, but does not report endpoint denominators or the reasons participants did not complete. It also does not describe how missing assessments, withdrawals, or incomplete challenge observations were handled. In general, missing-data methods can affect both the number of evaluable participants and the interpretation of an outcome, particularly if the likelihood of missingness is related to a participant’s reaction or study experience.
Analysis populations are not reported in the registry record. It is not stated whether the primary analysis used all enrolled participants, only completers, or another defined group. There is no reported account of exclusions or protocol deviations. The completion count therefore should not be treated as the analysis denominator, and the available information does not show how missing data or analysis-set choices influenced the posted findings.
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 |
|---|---|---|---|
| Test Article (Omeza Collagen Matrix) and Negative Control | 0 | 58 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Test Article (Omeza Collagen Matrix) and Negative Control | 0 of 58 |
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 |
|---|---|
| Test Article (Omeza Collagen Matrix) and Negative Control | 1 of 58 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Test Article (Omeza Collagen Matrix) and Negative Control |
|---|---|---|
| Influenza | Respiratory, thoracic and mediastinal disorders | 1 of 58 |
The registry safety entry combines the test article and negative control in one group. It lists 58 participants at risk for serious adverse events, with 0 affected, and 58 at risk for other adverse events, with 1 affected. Deaths are listed as 0, and no serious adverse-event terms are listed.
These are counts from the safety record, not a detailed event narrative. The entry does not identify the nature, timing, severity, or attribution of the one other adverse event. The secondary outcome is described as adverse events deemed related to the test product or study, but the registry entry does not provide further event-level information. It also does not separate safety counts for the test article from those for the negative control.
In general, a zero count means no event was recorded in the stated risk group; it does not prove that the underlying event risk is zero. Interpretation also depends on the observation period, completeness of follow-up, event definitions, and the number of participants actually assessed. These details are not reported in the registry record. The counts should therefore be read as the posted safety summary, not as a complete account of all possible harms or as a comparison between treatments.
12. What the Result Does, and Does Not, Mean
The record establishes that a repeat patch test was conducted in healthy volunteers, with Omeza Collagen Matrix and a negative control assessed during a challenge phase. It defines erythema scores and identifies which scores count as dermal sensitization. It also reports enrollment, completion, and a limited combined safety summary. These details describe the trial’s question and some of its conduct.
The record does not report the primary outcome count, endpoint denominators, or a statistical comparison. It therefore does not establish the frequency of qualifying erythema or the degree to which test article and control observations differed. Without an estimate and a measure of uncertainty, the primary question cannot be answered quantitatively from the registry record.
The design information also calls for caution. The title describes randomization and evaluator blinding, while registry fields state nonrandomized allocation and no masking. The record does not resolve that discrepancy and explicitly cautions that the comparison is not randomized or like-for-like. A within-subject design may support paired comparisons in general, but the record does not report whether a paired analysis was conducted.
The safety counts are limited: no serious adverse events or deaths are listed, and one other adverse event is recorded in the combined group. The entry does not provide details about that event or separate counts by intervention. These data should not be expanded into claims about the occurrence or absence of all possible events.
In general, a completed study and a defined endpoint are not substitutes for posted outcome data. The absence of a reported result is not evidence that no reaction occurred, nor evidence that a reaction did occur. The posted information supports a description of study design and recorded safety counts, but not a conclusion about the primary endpoint or a treatment effect.
13. Why This Trial Matters Statistically
This trial illustrates why a clearly defined endpoint is only one part of statistical interpretation. The registry specifies a reaction scale, a threshold for classifying sensitization, and challenge-phase assessment times. Those details make the intended outcome understandable, but they do not reveal how many participants met the threshold or how the test article compared with the negative control.
It also illustrates the importance of matching an analysis to a design. The record describes repeated observations at test and control sites in the same participants, a structure that generally calls for attention to within-person pairing. At the same time, the registry labels allocation nonrandomized and cautions that the comparison is not like-for-like. Together, these details show why readers should distinguish the existence of a control condition from a randomized controlled comparison.
The difference between the study title and registry design fields is another interpretive issue. The title uses randomized and evaluator-blinded language, but the listed allocation and masking fields do not support those descriptions. The registry does not explain the discrepancy. Careful reading means relying on the reported design fields and noting the unresolved conflict rather than assuming a stronger design.
Finally, this record demonstrates the limits of interpreting safety summaries and study completion status. A small set of adverse-event counts does not replace event details or endpoint results, and a completed status does not mean that all planned results are reported. For biostatisticians and clinical researchers, the central lesson is that endpoint definitions, analysis methods, denominators, missing-data handling, and uncertainty estimates are all needed to evaluate what an observed result means. Several of those elements are not reported in the 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 primary limitation for interpretation is that the registry does not report the observed primary endpoint result. No number of participants with qualifying erythema, outcome denominator, time-specific result, or test-versus-control estimate is available. The record also lists no analyses, so there is no reported inferential method or uncertainty measure to assess.
Design descriptions are not fully aligned: the title calls the study randomized and evaluator-blinded, while the registry lists nonrandomized allocation and no masking. The record does not explain this difference. It separately cautions that the comparison is not randomized and that the arms are not a like-for-like control comparison. These limitations make causal interpretation of a between-condition contrast particularly uncertain.
Although the study is described as within-subject, the registry does not report the allocation of sites, the paired outcome patterns, or whether the statistical analysis accounted for pairing. It also does not explain how observations across the challenge assessments at 24, 48, 72, and 96 hours were summarized. The available arm descriptions are truncated during the challenge-phase details, limiting procedural interpretation.
The registry reports 58 enrolled and 53 completing but does not provide reasons for noncompletion, endpoint-specific denominators, missing-data methods, or analysis populations. It does not report a statistical analysis plan, sample-size justification, or interim-analysis information. These omissions prevent assessment of whether the analysis followed a prespecified plan or how incomplete data may have affected results.
Safety reporting is also limited to combined counts for the test article and negative control. The record does not describe the one other adverse event or provide intervention-specific safety summaries. The reported counts should therefore be treated as an incomplete registry summary rather than a detailed safety profile.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Irritation Potential of Omeza Collagen Matrix Using Modified HRIPT — NCT04510675.
- Registry record last updated 2023-05-17; status last verified 2023-02.
- Results first posted 2023-05-17.
- 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
NCT04510675 is a completed study titled “Irritation Potential of Omeza Collagen Matrix Using Modified HRIPT.” It enrolled 58 healthy volunteers, with 53 reported as completing the study. The registry lists Omeza Collagen Matrix as the test article and 0.9% aqueous sodium chloride as the negative control. The described procedure included nine induction applications over three weeks and a later challenge phase.
The primary outcome concerns erythema during the challenge phase, assessed at 24, 48, 72, and 96 hours. Scores of 1, 2, or 3 are defined as indicating dermal sensitization. The registry does not report the primary outcome count or an analysis comparing test and control sites.
Allocation is listed as nonrandomized, masking as none, and the model as single group; the registry cautions that the comparison is not randomized or like-for-like. The combined safety entry lists 0 serious adverse events, 1 other adverse event, and 0 deaths among the stated risk groups. No primary analysis, missing-data approach, or analysis population is reported.