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 Ivermectin and Human Immunity (NCT03459794), a randomized early/phase 1 study. The primary outcome is The Number of Cytokines Showing Statistically Significant Changes From Pre-treatment Levels Will be Recorded..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03459794 |
| Phase | EARLY/Phase 1 |
| Condition | Ivermectin |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 12 |
| Arms in the primary outcome | 4 |
| Lead sponsor | University of Georgia |
| Results posted | Yes |
2. Clinical Question
Population
Participants in a completed early-phase study of ivermectin and human innate immunity. The registry lists an enrollment of 12. Blood samples were used to measure serum cytokines and other immune-related outcomes.
Intervention
A single oral ivermectin dose of 150mcg/kg. Blood was collected before treatment and at 4 and 24 hours after treatment.
Comparator
A single oral placebo. The study used randomized allocation and a parallel-group model; the registry describes masking as triple, but does not specify which groups of people were masked.
Primary question
How many cytokines in a panel of 41 showed statistically significant changes from pre-treatment levels at the post-treatment measurements in each group? The study description frames this as an investigation of whether ivermectin interacts with human innate immunity.
The primary outcome is a count of cytokines meeting a statistical significance threshold in comparisons with baseline. It is not a count of participants who changed, and it does not by itself quantify the size or biological importance of a change. The posted results list zero cytokines with statistically significant changes for the ivermectin groups at 4 and 24 hours and for the control groups at those times.
The broader study description also refers to comparing blood cell types, immune-related chemicals, and white blood cell gene expression. The posted primary outcome focuses on serum cytokines. A complete set of numerical results for those other measurements is not reported in the registry record.
3. Trial Design
The registry identifies this as an early-phase 1 study with randomized allocation, a parallel-group model, and triple masking. It is marked completed, with an enrollment of 12. The study began on 2018-02-12, and primary completion is recorded as 2018-04-09. The sponsor is the University of Georgia.
Participants were allocated to ivermectin or an oral placebo. The ivermectin arm description specifies a single oral dose of 150mcg/kg; the control arm description specifies one oral placebo administration. The brief study description says that blood was collected before treatment and after treatment, with cytokine measurements at 4 and 24 hours. It also describes measurements of blood cell types, immune-related chemicals, and white blood cell gene expression at 4 and 24 hours.
The outcome records list 8 participants in each ivermectin time group and 4 in each control time group. These are the counts associated with the two post-treatment time points; they should not be added as if they were separate participants. The registry's total enrollment is 12. The details of the randomization sequence, allocation concealment, and which people were masked are not reported in the registry record.
The primary endpoint is the number of cytokines with statistically significant changes from pre-treatment levels, based on comparisons of group mean levels. The registry also lists complete blood counts as a secondary outcome and records three outcome measures and three analyses. The specific methods and results for the other analyses are not reported in the registry record. A detailed protocol, sample-size justification, and prespecified statistical analysis plan 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 | Ivermectin | Control |
|---|---|---|
| STARTED | 8 | 4 |
| COMPLETED | 8 | 4 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Cytokines were measured in sera using the HCYTOMAG-60K-PX41 kit from EMD Millipore. The numbers reported are the number of cytokines with statistically significant changes ( p = \<0.05) from pre-treatment levels.
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 | Ivermectin | Control | Total |
|---|---|---|---|---|
| Participants analysed | 8 | 4 | 12 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 | 4 | 12 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 5 | 4 | 9 |
| Sex: Female, Male: Male | Participants | 3 | 0 | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 | 1 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 6 | 3 | 9 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 7 | 4 | 11 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 1 |
| Region of Enrollment: United States | participants | 8 | 4 | 12 |
6. Primary Endpoint
The registry lists the primary outcome as The Number of Cytokines Showing Statistically Significant Changes From Pre-treatment Levels Will be Recorded., measured over Pre-treatment, 4 hours and 24 hours post-treatment.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Cytokines changed from t=0 |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint counts how many cytokines in a panel of 41 had a statistically significant change from the pre-treatment level. Serum cytokines were measured with the HCYTOMAG-60K-PX41 kit from EMD Millipore. The stated comparison is between mean levels in each group and pre-treatment levels, with p < 0.05 used to identify a statistically significant change. The endpoint is therefore a count of cytokines meeting that criterion, not a participant-level response count.
This kind of endpoint can give a compact account of whether measured markers crossed a specified statistical threshold. It does not show the size, direction, or clinical meaning of each marker's change. The registry explicitly says that no threshold for biological significance was prespecified. Statistical significance and biological importance are different concepts: a threshold for statistical testing alone does not establish that a change is meaningful in biological terms.
The posted counts are zero at 4 hours and 24 hours in both treatment groups. The registry does not give the individual cytokine estimates, their uncertainty, or the full testing procedure used to obtain the counts. Those omissions limit interpretation of what the zero counts say about the underlying measurements.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome is zero cytokines with statistically significant changes from pre-treatment levels for the ivermectin group at 4 hours and at 24 hours. The control group also has a count of zero at both time points. These are the reported counts under the endpoint definition; they do not establish that every cytokine level was unchanged. A cytokine could have changed without crossing the stated statistical threshold, and the record does not provide the underlying estimates needed to assess such changes.
The endpoint description says that significance was assessed using comparisons of group mean levels, not at the level of individual participants. Accordingly, zero significant cytokines should not be read as evidence that no participant had a change, or that the group's measurements were identical before and after treatment. The result is a threshold-based summary across a panel, rather than a description of each marker's direction and magnitude.
The record does not report a numerical treatment-versus-control contrast, confidence interval, p-value for such a contrast, or a named statistical test. Its analysis entry has no method or numerical estimate. The counts in the four groups do not substitute for a direct comparison between treatment and control. No conclusion about the relative group effects can be drawn from the counts alone, beyond noting that the reported counts are the same.
Interpretation also depends on how the 41 cytokines and the time points were handled analytically. The registry states the significance threshold but does not report whether adjustments were made for multiple testing, whether analyses were prespecified in detail, or how missing measurements were treated. Without those details and the marker-level results, the precision and robustness of the findings cannot be evaluated from the registry record.
The study is small, with enrollment of 12, and its posted outcome counts reflect the groups listed for the two post-treatment times. The registry does not provide confidence intervals or other measures of uncertainty for the counts. The absence of reported statistical significance is therefore not equivalent to a demonstration of no effect. It means only that the posted outcome count is zero under the stated criterion for each listed group and time.
The brief summary describes an exploratory question about ivermectin and innate immunity. The posted endpoint is one way of examining that question, but it is not a direct measure of anti-parasitic effects or clinical outcomes. The registry record does not report evidence connecting these cytokine counts to parasite outcomes or patient benefit. The interpretation should remain bounded to the measurements and results recorded.
9. Statistical Methods Explained
What does a significance count represent?
The primary outcome reduces measurements from a panel of 41 cytokines to a count: how many meet a statistical criterion for change from pre-treatment levels. In general, a statistical test assesses how compatible observed data are with a specified null model. A p-value below the chosen threshold is treated as statistically significant under that rule. Here, the stated threshold is p < 0.05. A count built from these decisions is easy to summarize, but it discards information about the size and direction of each cytokine's change.
For example, the same count can arise from different patterns of marker-level results. That general point matters because the registry does not post the individual cytokine estimates or their uncertainty. A zero count therefore describes the number crossing the stated threshold; it does not show that all measured concentrations were exactly stable or that the data rule out changes of interest.
Why distinguish within-group changes from a treatment comparison?
The endpoint description says that the reported significance counts come from comparisons of mean levels in each group, rather than from comparisons at the level of individual participants. A change-from-baseline analysis within a group asks whether measurements at a follow-up time differ from that group's baseline under the chosen method. A treatment comparison asks a different question: whether the change in the ivermectin group differs from the change in the control group.
In general, a result in one group and a result in another group should not be treated as a direct test of the difference between those groups. Here, all four posted counts are zero, but that equality of counts is not a treatment-effect estimate. The registry does not report a numerical between-group contrast or the test used to estimate one.
What does the parallel randomized design contribute?
Randomized allocation is intended, in general, to support fair comparison of groups by reducing systematic differences at assignment. A parallel-group design assigns participants to a group that receives its assigned intervention rather than describing a crossover between interventions. In this study, the registry lists ivermectin and oral placebo arms, and labels the allocation randomized and the masking triple.
Those design labels do not provide all implementation details. The randomization sequence, concealment process, and identities of the masked groups are not reported in the registry record. Nor does the record explain whether the primary analysis followed an intention-to-treat approach or another analysis population. These are relevant details because they help readers understand how assignment and participant inclusion were handled.
Why is multiplicity relevant?
When many markers or time points are examined, repeated testing can increase the chance of one or more nominally significant findings even if there are no true effects. This is a general statistical concern, not a claim that a particular error occurred in this study. The primary outcome covers 41 cytokines and describes measurements at 4 and 24 hours. The registry states a p-value threshold but does not report whether the testing procedure adjusted for the number of comparisons or how the family of tests was defined.
Because the posted count is zero at each listed time and group, the main interpretive issue is not an excess of positive counts. Still, the testing strategy affects what a count means and how it should be compared across groups or times. The exact procedure, including any adjustment, is not reported in the registry record.
What can be said about precision and planning?
A confidence interval, in general, describes a range of values compatible with data and a specified method, conveying uncertainty around an estimate. No confidence interval is reported for the primary outcome or a treatment contrast. The registry's analysis entry also does not supply a test method, estimate, or p-value. Thus, the posted counts alone do not quantify precision.
Sample-size calculations are planning tools, not measures of what a completed trial has demonstrated. The stated planning assumptions describe illustrations based on an observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. These assumptions do not establish the trial's original design rationale. The sample-size justification is not reported in the registry record, and the numerical planning results are not part of the posted endpoint details. Such illustrations should not be described as observed power.
How should sparse count data be approached?
In general, count outcomes may need methods that account for their distribution and variability. Over-dispersion occurs when count variability exceeds what a chosen model expects; ignoring it can make standard errors too small and tests too optimistic. Whether over-dispersion is relevant depends on the data and model. The registry record does not identify a model for the cytokine count, report a dispersion estimate, or provide enough information to assess that issue. No specific count-data method can therefore be attributed to this analysis.
The outcome itself is a count of markers crossing a threshold, not a conventional count of independent clinical events. Its construction from statistical tests also means its behavior depends on the underlying marker measurements and testing procedure. Without marker-level values and a documented analysis method, the count is best read descriptively as posted rather than as a fully specified inferential estimate.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome concerns a panel of 41 cytokines and reports changes at 4 and 24 hours after treatment relative to pre-treatment levels. Testing many markers across more than one time point raises a general multiplicity question: whether the analysis controlled the overall chance of false-positive findings across the set of tests. The registry states p < 0.05 as the statistical significance criterion and says no biological-significance threshold was prespecified. It does not report a multiplicity adjustment, the test family, or a detailed analysis plan. No adjustment should be assumed.
Missing-data handling is not reported in the registry record. The outcome entries give group counts for the listed time points, but the record does not say whether all planned cytokine measurements were available, how incomplete measurements were treated, or whether any imputation or sensitivity analysis was used. The numbers attached to the outcome groups do not, by themselves, establish completeness of all assays.
The analysis population is also not reported in the registry record. There is no description of whether all randomized participants were included, whether exclusions were made, or how participants with unavailable measurements were handled. The record does not specify whether the analysis was intention-to-treat, per-protocol, or based on another rule.
These details matter because the reported outcome is a count derived from multiple tests, and both the set of analyzable measurements and the testing procedure can affect that count. With no reported participant-level analysis population, missing-data method, or multiplicity strategy, the counts can be stated as posted, but their inferential context remains incomplete.
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 |
|---|---|---|---|
| Ivermectin | 0 | 8 | 0.0% |
| Control | 0 | 4 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ivermectin | 0 of 8 |
| Control | 0 of 4 |
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 |
|---|---|
| Ivermectin | 1 of 8 |
| Control | 1 of 4 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ivermectin | Control |
|---|---|---|---|
| Minor gastrointestinal upset | Gastrointestinal disorders | 1 of 8 | 1 of 4 |
The registry reports serious adverse events for 0 of 8 participants at risk in the ivermectin group and 0 of 4 participants at risk in the control group. It reports no deaths in either group. These figures describe serious adverse events recorded in the registry; they do not establish that no other health events occurred.
For other adverse events, the registry records 1 affected participant among 8 at risk in the ivermectin group and 1 among 4 at risk in the control group. The event terms and details are not reported in the registry record. The record lists no serious adverse-event terms among the top reported terms.
These are small groups, and the counts should be read descriptively. A zero count does not prove that an event is impossible or establish comparative safety. The registry does not provide event-level descriptions, timing, severity details for the other events, or a statistical comparison between groups. These safety figures do not answer the primary cytokine question, which concerns changes in serum markers.
12. What the Result Does, and Does Not, Mean
The posted results show zero cytokines meeting the stated statistical-significance criterion for change from pre-treatment levels in each of the ivermectin and control groups at 4 and 24 hours. This is a summary of threshold crossings, not proof that every cytokine measurement stayed constant. Nor does it indicate the direction or magnitude of any changes that did not meet the criterion.
The result does not establish that ivermectin had no effect on innate immunity. A non-significant count can reflect several possibilities, including small or variable changes, limited precision, or an analysis that does not identify changes under its chosen threshold. The registry does not report enough marker-level data or uncertainty estimates to distinguish among such explanations. The record also does not provide a direct treatment-versus-control estimate for the primary outcome.
Similarly, the result does not show that ivermectin changed cytokines in a way that matters biologically. The registry says that no threshold for biological significance was prespecified. Statistical significance is a property of a testing procedure and data; it is not itself a measure of biological importance. The count should not be interpreted as a clinical outcome or as evidence about parasite treatment effects.
The registry describes a study of immune measurements after a single dose of ivermectin or placebo, with blood sampling before treatment and at 4 and 24 hours. It also describes other planned or measured domains, including blood cell types, immune-related chemicals, gene expression, and complete blood counts. Numerical results for all of those outcomes are not reported in the registry record. Conclusions should therefore remain limited to the posted cytokine counts and the available safety counts.
In general, small early-phase studies can be useful for examining measurements and generating questions, while often providing limited precision for comparative effects. That general observation does not substitute for missing study-specific estimates. The record's total enrollment is 12, and confidence intervals and a detailed analysis are not reported. The results are consequently descriptive rather than a precise estimate of a treatment effect.
13. Why This Trial Matters Statistically
This trial raises a statistical question that appears in many biomarker studies: how should results from many measurements be condensed without losing the information needed to interpret them? The primary endpoint counts cytokines that cross a significance threshold. That format is concise, but the count does not retain each marker's direction, magnitude, or uncertainty. The posted value can therefore be reported accurately while leaving important scientific detail unresolved.
The distinction between a within-group change and a treatment comparison is also central. A change from baseline in each arm is not the same as an estimate of whether the treatment group's change differs from the control group's change. The registry reports counts for the groups and times but does not report a direct contrast. Recognizing that distinction prevents a descriptive summary from being mistaken for a comparative treatment estimate.
The panel of 41 cytokines and two follow-up times makes multiplicity a relevant general consideration. The registry gives a significance threshold but does not describe a correction or testing hierarchy. That gap illustrates why a prespecified analysis plan is valuable: it makes clear how many tests are interpreted together, how findings are prioritized, and how uncertainty is quantified.
Finally, the study's small enrollment and absence of reported confidence intervals emphasize the difference between an observed result and its precision. Zero significant-marker counts are the posted result, but they do not establish that meaningful changes were ruled out. For biostatisticians and clinical researchers, the record is a useful example of why endpoint definition, multiplicity, missing-data handling, and between-group estimation all shape what a concise biomarker result can support.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation for interpretation is the sparse statistical reporting. The registry gives counts of cytokines with statistically significant changes but does not give marker-level estimates, variability, confidence intervals, or the statistical test used. Its reported-analysis entry has no method or numerical result. A direct comparison of ivermectin with placebo is not reported in the registry record.
The outcome is a threshold-based count across 41 cytokines. The registry says no biological-significance threshold was set, and does not report whether the statistical testing accounted for multiple markers and time points. The direction and magnitude of individual changes cannot be recovered from the posted counts.
Information about missing measurements and the analysis population is not reported in the registry record. The record does not describe whether all randomized participants contributed data at each time, how missing measurements were handled, or what inclusion criteria were applied to the analysis. Randomization and triple masking are stated, but implementation details and masked roles are not reported.
The study enrolled 12 participants, and the primary endpoint provides no uncertainty interval. The safety counts are also small and do not include event descriptions for the other adverse events. Further, numerical results for the other immune measurements described in the study summary are not reported in the registry record. These limitations restrict the interpretation to the posted endpoint counts and prevent a detailed assessment of comparative effects, precision, or consistency across outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Ivermectin and Human Immunity — NCT03459794.
- Registry record last updated 2019-07-12; status last verified 2019-04.
- Results first posted 2019-07-12.
- 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
The registry record describes a completed early-phase 1 randomized, triple-masked, parallel-group study sponsored by the University of Georgia, with enrollment of 12. Participants received a single oral ivermectin dose of 150mcg/kg or a single oral placebo. The study summary describes blood collection before treatment and at 4 and 24 hours after treatment.
The primary endpoint counts cytokines with statistically significant changes from pre-treatment levels in a panel of 41. The posted count is zero for the ivermectin and control groups at both listed times. Complete blood counts are listed as a secondary outcome. The record also reports no serious adverse events and no deaths in either group, with 1 other adverse event recorded in each group.
Marker-level results, a direct treatment comparison, confidence intervals, detailed statistical methods, multiplicity handling, missing-data methods, and the sample-size justification are not reported in the registry record.