Evaluating the Safety and Immunogenicity of Stabilized CH505 TF chTrimer in Healthy, HIV-uninfected Adult Participants.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating the Safety and Immunogenicity of Stabilized CH505 TF chTrimer in Healthy, HIV-uninfected Adult Participants. (NCT04915768), a randomized phase 1 study. The primary outcome is Number of Participants Reporting Local Reactogenicity Events Signs and Symptoms: Erythema and/or Induration.

2. Clinical Question

3. Trial Design

This is a first-in-human Phase 1 trial of the CH505 TF chTrimer vaccine in healthy, HIV-uninfected adults. The record lists the study as completed, with a start date of 2023-01-23, primary completion on 2025-07-15, and enrollment of 51. It describes the study as open-label and lists no masking.

The registry record describes four treatment groups. Group 1 received CH505 TF chTrimer 300 mcg with 5 mcg 3M-052-AF and 500 mcg Aluminum Hydroxide suspension. Group 2 received CH505 TF chTrimer 300 mcg with 3 mcg 3M-052-AF without Alum. Group 3 is described as CH505 cTrimer 300 mcg with 3 mcg 3M-052-AF and 500 mcg Alum. Group 4 received CH505 chTrimer 300 mcg with 5 mcg 3M-052-AF without Alum. Each regimen is described as administered at months 0, 2, 4, 8 and 12.

The registry classifies allocation as randomized but the study model as single-group. It does not explain this combination of classifications or give details of the allocation procedure. The record states that Part B added three groups to assess different dosing and combinations of 3M-052-AF and Alum relative to Part A. It does not report a statistical comparison plan for those groups.

The Group 3 description notes that errors in study injection preparation were identified on October 13, 2023. The remaining explanation of the relevant instructions is incomplete in the registry record, so the exact nature and scope of the preparation issue 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Started (enrolled).

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Reporting Local Reactogenicity Events Signs and Symptoms: Erythema and/or Induration, measured over Measured through 7 days after each study product administration at Study Day 0 (Month 0), Day 56 (Month 2), Day 112 (Month 4), Day 224 (Month 8), and Day 364 (Month 12).

The primary endpoint counts participants reporting local erythema and/or induration, signs of local reactogenicity, after study product administration. The assessment window is through 7 days after each administration at Study Day 0 (Month 0), Day 56 (Month 2), Day 112 (Month 4), Day 224 (Month 8), and Day 364 (Month 12). The record says the number and percentage of participants experiencing each type of sign or symptom were tabulated by severity. For each symptom, a participant was counted once according to the maximum severity across assessments. Severity was graded using the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 [July 2017].

Counting participants gives an interpretable summary of how many people reported a specified local sign, while severity grading distinguishes reports by intensity. Using each participant’s maximum recorded severity avoids counting the same person repeatedly for the same symptom across assessments. These are general features of this kind of endpoint; they do not establish what the results were in this trial.

The registry record does not report the counts or percentages for erythema or induration, by group, severity, or assessment time. It also does not give an overall primary endpoint estimate. Accordingly, the endpoint definition can be described, but the frequency and distribution of these outcomes cannot be interpreted from the registry results recorded.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a binary primary outcome: whether a participant reported local erythema and/or induration. For a binary outcome, the basic descriptive result is a count of participants with the event, usually interpreted in relation to the number assessed. This is a general explanation of binary outcomes, not a claim about the trial’s unreported primary results. The registry supplies an endpoint definition and assessment schedule but no primary outcome counts or analysis estimates.

What does a participant count capture?

The endpoint counts each participant once for a given symptom, using the maximum severity recorded across assessments. In general, this approach describes the number of people who experienced a symptom while avoiding repeated counting of one person for the same symptom at multiple assessments. It does not describe how long a symptom lasted or when it occurred, unless those details are reported separately. Those additional results are not reported in the registry record.

The assessment window is through 7 days after each administration at the listed study visits. A participant’s opportunity to report a symptom is therefore tied to those administration windows. General interpretation of repeated assessments needs to distinguish a participant-level count from a count of events or visits. The registry’s endpoint description specifies a participant-level count for each symptom, but does not provide the underlying observations or separate estimates for each visit.

Why do severity categories matter?

The record says outcomes were tabulated by severity and graded using the DAIDS Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 [July 2017]. In general, severity categories preserve information that a simple yes-or-no count does not: two groups could have similar numbers of participants reporting a symptom but different distributions of severity. Conversely, a severity distribution does not by itself describe the duration of symptoms or establish their cause. No severity-specific primary outcome results are reported in the registry record.

What can group comparisons establish?

In general, a comparison between treatment groups estimates how outcomes differ across the groups under the trial’s design and analysis plan. Random allocation can help balance measured and unmeasured characteristics on average, but the registry record’s combination of randomized allocation and a single-group model is not explained. The record does not give the randomization procedure, planned pairwise comparisons, or an inferential analysis for the four regimens. No group comparison should be inferred from the regimen descriptions alone.

Confidence intervals are a general way to express the precision of an estimated effect: they show a range of values compatible with the data and statistical method, rather than a guarantee that the true value lies in that range. The registry record does not report confidence intervals for the primary endpoint. It also reports no primary analysis estimates, so precision cannot be assessed from those results.

How should planning illustrations be read?

The record describes a sample-size planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. In general, such calculations illustrate the number of participants per arm that a hypothetical design might require under its assumptions. They are not observed power, and they are not evidence that the trial was designed with those assumptions. The record does not report the trial’s own sample-size justification or identify a corresponding two-arm comparison for the four-group study.

For outcomes based on counts, general statistical methods can compare event frequencies, but method choice depends on the estimand, group structure, assessment schedule, and analysis plan. The record does not identify a method for the primary endpoint, explain how repeated assessment times would enter an analysis, or state whether any adjustment for baseline or other factors was planned. Those details are not reported in the registry record. Without reported outcome estimates and methods, the clinical and statistical importance of any group differences cannot be evaluated.

What is known about analysis?

The record lists zero analyses. It names secondary outcomes for serum IgG binding-antibody response rate and magnitude, and serum neutralization response rate and magnitude against heterologous HIV-1 strains, but does not report estimates for them. The stated primary hypothesis concerns expansion of CH103-like B-cell precursors; a corresponding result or analysis is not reported in the registry record. General statistical interpretation requires matching a stated question to its defined outcome, analysis population, estimate, and uncertainty. The available registry information does not provide that complete chain for the study’s primary or immunogenicity questions.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 15 outcome measures, including the primary local reactogenicity outcome and secondary binding-antibody and neutralization outcomes. It does not report a multiplicity strategy. In general, when several outcomes, time points, severity categories, or group comparisons are examined, the chance of at least one apparently notable result can increase. Prespecified testing strategies or clear separation of confirmatory and exploratory aims can help readers interpret multiple analyses. The approach for this trial is not reported in the registry record.

The primary outcome covers erythema and/or induration across five administration visits, with severity categories and participant-level maximum severity. The record does not say whether the outcomes were to be analyzed separately by symptom, severity, visit, or group, or how any resulting comparisons would be handled. It also does not report outcome results that could clarify the pattern of missing observations across visits.

The primary outcome population is described as participants who started, or enrolled. The record does not give a more detailed analysis population definition, such as rules for inclusion in each visit-specific assessment. Missing-data amounts, reasons for missingness, imputation procedures, and sensitivity analyses are not reported in the registry record. In general, missingness can affect both the number of observations contributing to an estimate and how representative those observations are; its consequences depend on why data are absent and how the analysis addresses them.

The registry record reports zero analyses. Consequently, it does not provide a basis for assessing multiplicity control, missing-data handling, or whether analyses followed a prespecified plan. The statistical analysis plan and the trial’s own sample-size justification are not reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: diverticulitis (7.7%).

The registry reports serious adverse-event counts by group. Group 1 has 13 participants at risk and 1 affected; Group 2 has 12 at risk and 0 affected; Group 3 has 14 at risk and 0 affected; and Group 4 has 12 at risk and 0 affected. No deaths are listed in any group. Diverticulitis is listed among the top serious-event terms at 7.7%; the record does not identify a group for that term in the registry record.

These are descriptive counts, not estimates of comparative risk. In general, serious adverse-event counts indicate how many participants were recorded as affected under the registry’s reporting definitions; they do not by themselves establish causation or show whether groups differ reliably. The registry record does not report confidence intervals, statistical tests, event timing, or a causal assessment for these serious-event figures.

The separate counts for other adverse events list all participants at risk as affected in each group. These counts should not be conflated with serious adverse events. The registry information does not give enough event-level detail to characterize the nature or severity of all events in this category.

12. What the Result Does, and Does Not, Mean

The record establishes that a Phase 1, open-label study evaluated CH505 TF chTrimer regimens with differing 3M-052-AF and Alum combinations in healthy, HIV-uninfected adults. It defines a primary outcome focused on local erythema and/or induration and identifies a broader safety and immunogenicity objective. It also records group-level serious adverse-event counts and reports no deaths.

The registry does not report the primary endpoint results, the secondary immunogenicity results, or an analysis of the stated hypothesis about CH103-like B-cell precursors. It therefore does not show how often participants experienced local signs, how severe those signs were, what antibody responses occurred, or whether any outcome differed across groups. The absence of reported analyses is not evidence that an outcome did or did not occur.

General statistical interpretation distinguishes a descriptive observation from a comparative conclusion. A difference in observed group counts, if available, would not by itself show a reliable treatment-group effect; precision, the allocation process, outcome definitions, and analysis plan also matter. In this record, no primary comparison estimates or uncertainty measures are reported. The serious-event counts can be stated as recorded, but they do not establish whether a regimen caused an event or whether groups had different underlying event risks.

The planning framework described in the registry is not a substitute for the trial’s results or design justification. General sample-size illustrations depend on assumptions about allocation, significance level, effect size, and statistical method. They are planning exercises, not observed power and not evidence that a study was adequately sized for a particular question. The registry does not report the trial’s own sample-size rationale.

Accordingly, the registry information supports a limited account of the study design, endpoint definition, and recorded safety counts. It does not support conclusions about the magnitude or precision of reactogenicity or immunogenicity outcomes, nor a conclusion that one regimen is better or worse than another.

13. Why This Trial Matters Statistically

This trial is statistically notable for combining an early-phase safety and immunogenicity objective with multiple vaccine-adjuvant regimens. The registry describes changes in 3M-052-AF dose and Alum use across four groups, while the stated primary endpoint is local reactogenicity. Such a design raises distinct descriptive and comparative questions: how outcomes vary by regimen, how they vary by severity and assessment visit, and whether any immunogenicity measures differ. The registry record does not report analyses addressing those questions.

Clear reporting is especially important when a study has multiple groups and repeated assessments. In general, readers need to know which comparisons were planned, how repeated outcomes were handled, what populations contributed to each analysis, and how uncertainty was quantified. The record does not report these analysis details. It also classifies allocation as randomized while naming a single-group model, without explaining the relationship between those descriptions.

The Group 3 preparation note adds a trial-specific interpretive consideration. The record states that errors were identified in study injection preparation on October 13, 2023, but the associated explanation is incomplete. Without the full details, readers cannot determine the scope of the issue or how it affected the planned or reported analyses. That information is not reported in the registry record.

These features matter statistically because design labels and outcome definitions alone are not enough to evaluate evidence. Estimates, uncertainty, analysis populations, and transparent handling of protocol or preparation issues are needed to understand what the observed data can support. With zero analyses listed, the registry currently offers design and safety-count information rather than a complete statistical account of trial outcomes.

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 of the available registry information is that it reports no primary outcome analyses. Counts and percentages for erythema and induration by group, severity, and visit are not reported in the registry record. Neither are the listed secondary immunogenicity results or an analysis of the stated CH103-like B-cell precursor hypothesis. This prevents assessment of outcome magnitude, between-group variation, and precision.

The study’s allocation and model classifications are not reconciled: allocation is listed as randomized, while the model is listed as single-group, alongside four treatment-group descriptions. The randomization procedure and intended comparisons are not reported in the registry record. The sample-size illustration assumptions are described, but the trial’s own sample-size justification is not reported.

The record identifies Group 3 injection-preparation errors on October 13, 2023, but the associated description is truncated. The scope, affected participants or doses, and any resulting analysis decisions are not reported in the registry record. The Group 3 regimen description also uses “CH505 cTrimer,” while the overall study and other descriptions refer to CH505 TF chTrimer or CH505 chTrimer; the record does not clarify that wording.

Analysis-population details beyond “Started (enrolled),” missing-data amounts and handling, multiplicity procedures, and statistical methods are not reported in the registry record. The serious adverse-event counts are descriptive and are not accompanied by comparative estimates or uncertainty. These limitations are specific to interpreting the registry information and do not establish what may be available in other trial documents.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluating the Safety and Immunogenicity of Stabilized CH505 TF chTrimer in Healthy, HIV-uninfected Adult Participants. — NCT04915768.
• Registry record last updated 2026-04-14; status last verified 2026-03.
• Results first posted 2026-02-27.
• 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.

18. Record Summary

NCT04915768 is a completed, open-label Phase 1 study of CH505 TF chTrimer in healthy, HIV-uninfected adults. The registry lists enrollment of 51, randomized allocation, no masking, and a single-group model. Four groups are described with differing 3M-052-AF doses and Alum combinations, administered at months 0, 2, 4, 8 and 12.

The primary endpoint counts participants reporting local erythema and/or induration through 7 days after each administration, with severity based on maximum severity across assessments. The registry lists 15 outcome measures and zero analyses. Primary and immunogenicity results are not reported in the registry record. Serious adverse-event counts are 1 affected participant in Group 1 and none in Groups 2, 3, or 4; no deaths are listed. The record also notes Group 3 injection-preparation errors and does not provide a complete explanation.