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 Safety and Immunogenicity Study of Na-GST-1 With or Without CpG (NCT02143518), a randomized phase 1 study. The primary outcome is Vaccine-related Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02143518 |
| Phase | Phase 1 |
| Condition | Hookworm Infection, Hookworm Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 24 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Baylor College of Medicine |
| Results posted | Yes |
2. Clinical Question
Population
Healthy adult volunteers participated in a Phase 1 study concerning Na-GST-1, a protein associated in the registry summary with the adult stage of the hookworm life cycle. The condition fields list hookworm infection and hookworm disease. The registry record reports total enrollment of 24.
Intervention
The study included a high-dose Na-GST-1/Alhydrogel formulation administered alone, a low-dose Na-GST-1/Alhydrogel formulation with 500 µg CpG 10104, and a high-dose Na-GST-1/Alhydrogel formulation with 500 µg CpG 10104. The record describes the study as evaluating safety and immunogenicity.
Comparator
The registry lists three parallel groups: 100 µg Na-GST-1/Alhydrogel alone, 30 µg Na-GST-1/Alhydrogel plus CpG 10104, and 100 µg Na-GST-1/Alhydrogel plus CpG 10104. The design permits comparisons among these formulations, but the registry record does not identify a single designated comparator for every analysis.
Primary question
The primary outcome concerns the frequency of immediate, systemic, and local injection-site adverse events, graded by severity, for Na-GST-1/Alhydrogel administered alone or with CpG 10104. The stated observation timeframe is up to study day 470. The record also lists IgG antibody response on study day 126 and an exploratory cellular immune response as secondary outcomes.
3. Trial Design
The registry describes NCT02143518 as a randomized, quadruple-masked, parallel Phase 1 study. It enrolled 24 participants and is marked completed. The recorded start was 2014-10, and primary completion was 2016-06. Baylor College of Medicine is listed as sponsor.
The parallel design assigned participants to one of three listed formulations: 100 µg Na-GST-1/Alhydrogel alone; 30 µg Na-GST-1/Alhydrogel plus 500 µg CpG 10104; or 100 µg Na-GST-1/Alhydrogel plus 500 µg CpG 10104. The adverse-event summary lists 8 participants at risk in each group. The registry record does not describe the randomization sequence, allocation concealment, or the specific roles masked under quadruple masking.
The stated objective was to evaluate safety and immunogenicity in healthy adult volunteers. The primary outcome focuses on vaccine-related adverse events, including immediate, systemic, and local injection-site events, graded by severity, through up to study day 470. The listed secondary outcomes concern IgG antibody response to Na-GST-1 on study day 126 and exploratory cellular immune response to Na-GST-1.
Although the registry identifies the study as randomized and masked, those design labels do not by themselves describe how outcomes were analyzed. Statistical methods, analysis populations, handling of missing observations, and a protocol-based sample-size justification are not reported in the registry record. The posted registry results also contain no statistical analysis results. Consequently, the available description supports an account of the planned groups and outcomes, but not a reconstruction of the trial’s full analysis plan.
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 | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|
| STARTED | 8 | 8 | 8 |
| COMPLETED | 8 | 6 | 7 |
| NOT COMPLETED | 0 | 2 | 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 | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 | Total |
|---|---|---|---|---|---|
| Participants analysed | 8 | 8 | 8 | 24 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 | 8 | 8 | 24 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Continuous | years | 26.5 (24.75 to 30.5) | 31.0 (26.0 to 45) | 32 (28.5 to 41.75) | 29 (25.5 to 41.75) |
| Sex: Female, Male: Female | Participants | 5 | 2 | 3 | 10 |
| Sex: Female, Male: Male | Participants | 3 | 6 | 5 | 14 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 2 | 0 | 0 | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 1 | 0 | 1 |
| Race (NIH/OMB): Black or African American | Participants | 1 | 5 | 4 | 10 |
| Race (NIH/OMB): White | Participants | 5 | 1 | 4 | 10 |
| Race (NIH/OMB): More than one race | Participants | 0 | 1 | 0 | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 8 | 8 | 8 | 24 |
6. Primary Endpoint
The registry lists the primary outcome as Vaccine-related Adverse Events, measured over Up to study day 470.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the frequency of vaccine-related adverse events among participants. The record specifies immediate, systemic, and local injection-site events, graded by severity, for Na-GST-1/Alhydrogel administered alone or in combination with CpG 10104. The timeframe is up to study day 470. The registry lists the outcome unit as participants and the measure as a count of participants.
General statistical context: safety endpoints are used to describe the types and frequency of events observed during a study. Recording severity and event category can distinguish the occurrence of an event from its clinical classification, while a defined follow-up timeframe indicates the period covered by the endpoint. Counts of affected participants are descriptive; they do not, by themselves, establish whether a formulation caused an event or whether event frequencies differ between formulations.
The registry record does not provide a single reduced comparison for this outcome because it encompasses several event categories and time points. Detailed results by event type, severity, or time point are not reported in the registry record. The adverse-event summary does give group-level counts for serious and other events, but those counts do not reproduce the full primary endpoint description.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted adverse-event summary lists 8 participants at risk in each of the three groups. In every group, 0 participants are listed as affected by a serious adverse event, and 8 are listed as affected by other adverse events. The summary also lists 0 deaths in each group. These are descriptive counts, not estimates from a reported statistical comparison.
The serious-event counts therefore show no serious adverse events recorded in the listed groups. That observation should be read within the scope of the registry summary: it does not establish that serious events cannot occur, nor does it provide a comparative estimate with a confidence interval. The other-event counts indicate that each participant at risk in each group was listed as affected by an other adverse event. The registry summary does not give the event terms, grades, timing, recurrence, or participant-level details needed to characterize those other events further.
The primary outcome is broader than the serious-event summary. It covers immediate, systemic, and local injection-site events, graded by severity, through up to study day 470. The record does not provide the detailed category-by-category results or a statistical analysis of those results. The listed counts should therefore not be treated as a complete account of all primary-endpoint findings.
The registry describes the study as assessing immunogenicity and lists an IgG response outcome on study day 126 and an exploratory cellular immune response. Numerical immune-response results are not reported in the registry record. No effect estimates, confidence intervals, p-values, or other inferential results are reported. Thus, the record supports a descriptive reading of the adverse-event counts, but it does not support a statistical conclusion about differences among the formulations or a quantified immune response.
General statistical context: a count summarizes how many participants met a stated event definition, while a comparative analysis estimates how event occurrence differs between groups and communicates uncertainty around that estimate. Without the event definitions and analysis details for the posted counts, and without comparative estimates, interpretation should remain limited to what the registry lists for each group.
9. Statistical Methods Explained
The record identifies a randomized, quadruple-masked, parallel design and gives counts of participants at risk and affected in three groups. It does not report the statistical analysis methods used for the primary endpoint or secondary outcomes. No statistical analysis results are reported in the registry record. The concepts below explain how such methods are generally interpreted; they do not describe an analysis documented for this study.
What does a participant count describe?
For a binary outcome, each participant is classified according to whether the specified event occurred during the stated observation period. A count of affected participants records how many met that definition. It is a direct descriptive summary, but it does not convey the event’s timing, duration, severity, or recurrence unless those features are separately tabulated. The registry’s adverse-event summary distinguishes serious events from other events, while the primary outcome description also names immediate, systemic, and local injection-site categories and severity grading.
A count can be compared across groups, but the count alone is not a complete estimate of a treatment contrast. A comparative analysis needs a defined outcome, a specified contrast, and a method for representing uncertainty. The registry record does not report such an analysis for these adverse-event outcomes. It also does not state whether comparisons were adjusted or unadjusted, or identify a model for the primary endpoint.
How should uncertainty be understood?
General statistical context: a confidence interval describes a range of estimates compatible with the data and the method used, under the assumptions of that method. A narrow interval indicates greater precision than a wide interval. An interval around a group difference can help show whether the observed data are compatible with a range of possible differences. No confidence intervals are reported for this study’s listed adverse-event counts, so precision cannot be assessed from an interval estimate in the registry record.
A p-value, when reported, measures how unusual the data would be under a stated statistical model and a specified null hypothesis. It is not a measure of the size or importance of an effect. The registry record does not report p-values or hypothesis tests. The absence of such results should not be replaced by a calculation from the event counts and presented as the trial’s own analysis.
What is the status of the sample-size illustrations?
The planning description characterizes sample-size calculations as illustrations based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It explicitly distinguishes these illustrations from the trial’s own design. Such calculations are planning scenarios: they describe a hypothetical sample size under chosen assumptions, not the number of participants actually observed and not the probability that this completed study detected an effect.
The record does not report a protocol-based sample-size justification. Nor does the planning description establish that the three-group trial was designed around the equal allocation between two arms assumed in the illustrations. Sample-size illustrations should therefore not be interpreted as evidence of observed power or as a description of the actual group allocation. The registry record’s enrollment is 24, and the adverse-event summary lists 8 participants at risk in each group.
Why do outcome definitions and dispersion matter?
General statistical context: an analysis must match the form of the outcome. A participant-level event count differs from a rate based on repeated events or person-time. If participants can experience repeated events, a method that assumes independent events may understate uncertainty when events cluster within participants. Over-dispersion means that observed variation is greater than a model expects; when present, methods that account for it can produce more appropriate uncertainty estimates. The registry describes the primary measure as a count of participants, but does not report repeated-event analyses or a dispersion model.
In this study, the primary endpoint includes several event categories and time points. Combining or selecting among such categories can affect what a summary means. The registry record does not report a statistical plan specifying how categories, severity grades, or timing were to be combined or compared. The result listing also indicates no reduced single comparison for the primary outcome. As a result, a reader cannot infer a prespecified analysis from the endpoint description alone.
Randomization supports a planned comparison among study groups, while masking can reduce some forms of influence on assessment or reporting. General statistical context: these design features do not remove the need to define outcomes, analysis populations, missing-data handling, and statistical methods. The registry record does not report those analysis details, so the descriptive counts should not be treated as adjusted or causal estimates.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety outcome and secondary outcomes concerning IgG antibody response to Na-GST-1 on study day 126 and exploratory cellular immune response to Na-GST-1. It reports three outcome measures overall, but the complete details for every measure are not reported in the registry record. Statistical analyses are not reported.
Multiplicity arises when several outcomes, event categories, time points, or group comparisons are considered. General statistical context: testing many hypotheses can increase the chance of finding an apparently notable result by chance. Analysis plans may address this by defining a primary comparison, controlling error rates, or treating additional findings as exploratory. The registry record does not report a multiplicity strategy, a hierarchy of tests, or a prespecified set of pairwise comparisons. Because the primary endpoint covers multiple event categories and time points, the absence of those details limits interpretation of any isolated comparison.
Missing-data methods and analysis populations are also not reported in the registry record. The adverse-event summary gives the number at risk in each group, but it does not describe withdrawals, missed assessments, exclusions, or whether every randomized participant contributed to each outcome. It is therefore not possible to determine from the record how missing observations were handled or whether the analyses followed an intention-to-treat, per-protocol, or other population definition.
These omissions do not show that the trial lacked such procedures; they mean the procedures are not reported in the registry record. Without the analysis plan and population definitions, the listed group counts can be read descriptively, but their relationship to a prespecified inferential analysis cannot be established.
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 |
|---|---|---|---|
| 100 µg Na-GST-1/Alhydrogel | 0 | 8 | 0.0% |
| 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 0 | 8 | 0.0% |
| 100 µg Na-GST-1/Alhydrogel + CpG 10104 | 0 | 8 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| 100 µg Na-GST-1/Alhydrogel | 0 of 8 |
| 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 0 of 8 |
| 100 µg Na-GST-1/Alhydrogel + CpG 10104 | 0 of 8 |
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 |
|---|---|
| 100 µg Na-GST-1/Alhydrogel | 8 of 8 |
| 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 8 of 8 |
| 100 µg Na-GST-1/Alhydrogel + CpG 10104 | 8 of 8 |
Most frequent non-serious adverse event terms
| Event term | Organ system | 100 µg Na-GST-1/Alhydrogel | 30 µg Na-GST-1/Alhydrogel + CpG 10104 | 100 µg Na-GST-1/Alhydrogel + CpG 10104 |
|---|---|---|---|---|
| Injection site pain | General disorders | 7 of 8 | 8 of 8 | 7 of 8 |
| Headache | Nervous system disorders | 5 of 8 | 5 of 8 | 5 of 8 |
| Upper respiratory tract infection | Infections and infestations | 4 of 8 | 5 of 8 | 6 of 8 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 1 of 8 | 2 of 8 | 6 of 8 |
| Myalgia | Musculoskeletal and connective tissue disorders | 1 of 8 | 3 of 8 | 5 of 8 |
| Nausea | Gastrointestinal disorders | 1 of 8 | 1 of 8 | 4 of 8 |
| Haemoglobin decreased | Investigations | 2 of 8 | 1 of 8 | 2 of 8 |
| Systolic hypertension | Vascular disorders | 0 of 8 | 3 of 8 | 2 of 8 |
| Abdominal Pain | Gastrointestinal disorders | 0 of 8 | 3 of 8 | 1 of 8 |
| Body temperature increased | Investigations | 1 of 8 | 1 of 8 | 2 of 8 |
The registry’s serious-event summary lists 0 affected participants among 8 at risk in each group. It lists 0 deaths in each group. These counts describe the events recorded in the registry summary; they do not establish that the risk of a serious event is absent or that the groups are equivalent.
For other adverse events, the summary lists 8 affected participants among 8 at risk in each group. This is a participant count, not a count of individual event episodes. The record does not provide event terms, severity, onset, duration, recurrence, or a breakdown by immediate, systemic, or local injection-site category for these figures. It also does not clarify in this summary how the other-event category maps onto the full primary endpoint description.
General statistical context: when event counts are small, estimates of event frequency can be imprecise, and a zero observed count does not mean the underlying event probability is zero. A registry count is also not, by itself, a causal assessment of whether an event was related to an intervention. The primary outcome is described as vaccine-related adverse events, but the displayed serious and other event counts do not provide enough detail to assess relatedness or compare severity patterns. They should be read as limited descriptive summaries, not as a complete safety analysis.
12. What the Result Does, and Does Not, Mean
The record documents a randomized, quadruple-masked, parallel Phase 1 study in healthy adults, with three Na-GST-1/Alhydrogel formulations, with or without CpG 10104. Its primary focus was the frequency and severity of vaccine-related adverse events through up to study day 470. The adverse-event summary reports no participants affected by serious adverse events and no deaths in the listed groups, while all participants at risk in each group are listed as affected by other adverse events.
These summaries do not establish that one formulation is safer than another. The record does not provide comparative estimates, confidence intervals, hypothesis tests, detailed adverse-event terms, or event severity and timing for the reported other events. The listed counts therefore support description of the registry entries, not a definitive estimate of differences among formulations.
The record also does not provide numerical results for the listed immune-response outcomes. It cannot, on the basis of these posted results, quantify an IgG response or an exploratory cellular response. Nor does the registry summary establish an effect on hookworm infection or disease. The study description and condition fields provide context, but no clinical infection outcome results are reported.
General statistical context: an observed result in a small early-phase study is interpreted in light of its outcome definitions, follow-up, precision, and analysis methods. A descriptive count is not equivalent to evidence of a treatment effect. Here, the record supports a limited account of group-level adverse-event counts and the study’s stated objectives. It does not support claims about efficacy, a complete comparison of safety profiles, or the magnitude and precision of immune responses.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of the distinction between a registered study design and a reported analysis. The registry identifies randomization, quadruple masking, a parallel structure, three formulations, and a primary safety outcome. Those design features define the setting for comparisons, but they do not supply the estimates or uncertainty needed to interpret a comparative result.
The study also illustrates why endpoint detail matters. The primary outcome includes immediate, systemic, and local injection-site adverse events, graded by severity, over a stated follow-up timeframe. A compact count of serious and other adverse events cannot replace category-specific results when the endpoint spans multiple types of events and time points. Without those details, the reader cannot determine how the broader endpoint was summarized or analyzed.
Another statistical issue is the distinction between actual enrollment and hypothetical planning calculations. The planning description identifies assumptions for sample-size illustrations and explicitly separates those calculations from the trial’s design. That distinction prevents a planning scenario from being mistaken for observed evidence or a justification documented in the protocol. The registry does not report a protocol-based sample-size justification or statistical analysis results.
Finally, the record names immunogenicity outcomes but does not provide their numerical results. This makes clear that listing an outcome is not the same as reporting its estimate. For clinical researchers, the record offers useful information about design and outcome intent while also showing how missing analysis details constrain what can be concluded from registry results.
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 registry record does not report detailed results for the primary endpoint’s immediate, systemic, and local injection-site categories, severity grades, or time points. The serious and other adverse-event counts do not supply those details, and the record does not report the event terms or timing behind the other-event counts. This limits interpretation of the broad safety outcome.
No statistical analysis results are reported. Comparative effect estimates, confidence intervals, p-values, analysis models, and prespecified contrasts are not reported in the registry record. The randomization and masking labels are present, but the methods for sequence generation, concealment, and implementation of masking are not described.
The record does not report a protocol-based sample-size justification, the analysis populations, or methods for missing observations. It also does not report a multiplicity strategy for the multiple event categories, time points, and listed outcomes. The planning description refers to hypothetical sample-size illustrations, but those assumptions are not a substitute for the trial’s statistical plan.
Numerical results for the IgG and exploratory cellular immune-response outcomes are not reported in the registry record. The registry also does not provide clinical results for hookworm infection or disease. These limitations mean the available information is mainly descriptive: it gives group-level adverse-event counts and study objectives, but not a full safety analysis, an immune-response estimate, or a clinical efficacy comparison.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Immunogenicity Study of Na-GST-1 With or Without CpG — NCT02143518.
- Registry record last updated 2025-07-04; status last verified 2025-07.
- Results first posted 2025-07-04.
- 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
NCT02143518 is a completed, randomized, quadruple-masked, parallel Phase 1 study sponsored by Baylor College of Medicine. It enrolled 24 healthy adults and evaluated 100 µg Na-GST-1/Alhydrogel alone, 30 µg Na-GST-1/Alhydrogel plus 500 µg CpG 10104, and 100 µg Na-GST-1/Alhydrogel plus 500 µg CpG 10104. The primary outcome concerned vaccine-related adverse events through up to study day 470.
The adverse-event summary lists 8 participants at risk in each group, 0 affected by serious adverse events in each group, 8 affected by other adverse events in each group, and 0 deaths in each group. Detailed event results, statistical analyses, and numerical immune-response results are not reported in the registry record. The listed secondary outcomes concern IgG antibody response on study day 126 and exploratory cellular immune response to Na-GST-1.