A Phase 1 Trial to Evaluate CAP256V2LS in Healthy Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 1 Trial to Evaluate CAP256V2LS in Healthy Adults (NCT04408963), a non-randomized phase 1 study. The primary outcome is Number of Participants Reporting Local Reactogenicity Signs and Symptoms Within 7 Days of CAP256V2LS Product Administration.

2. Clinical Question

3. Trial Design

This was a Phase 1, parallel, non-randomized, unmasked trial of CAP256V2LS in healthy adults. The registry record lists an enrollment of 10 and two groups: intravenous infusion and subcutaneous injection. Each group is described as receiving CAP256V2LS at 5 mg/kg on Day 0. Because allocation was non-randomized and both groups received the antibody, the study does not provide a randomized comparison with an untreated or placebo group.

The trial record describes participants as being screened with a medical history, physical examination and blood tests. Some females had a pregnancy test. On the administration day, participants gave blood samples at different time points. The brief summary says they were asked to check their temperature every day for 7 days and to assess redness, swelling or bruising at the administration site. Clinic visits took place at least 2-3 times during the first week, followed by about 9 more visits over the next 6 months; visits included blood tests.

The registry lists the study as completed. The recorded start date is 2022-03-22 and the primary completion date is 2022-11-28. These registry dates describe the recorded study timeline; they do not provide participant-level follow-up information or establish when each outcome was assessed beyond the stated endpoint timeframes.

The primary outcome concerns local signs and symptoms after administration. The listed secondary outcomes concern pharmacokinetic characteristics: maximum observed serum concentration, time to maximum concentration, beta half-life, clearance rate and volume of distribution. Although these outcomes are named, numerical pharmacokinetic results and a detailed 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

Analysis population for the primary outcome, as defined in the registry: Population included all enrolled participants who received CAP256V2LS and provided safety data (via diary card).

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.

Population: Population included all enrolled participants. Weight represents weight at time of enrollment. Age represents age at enrollment day.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Reporting Local Reactogenicity Signs and Symptoms Within 7 Days of CAP256V2LS Product Administration, measured over 7 days after CAP256V2LS product administration, at approximately Week 1.

The primary endpoint is the number of participants reporting local reactogenicity signs or symptoms within 7 days of CAP256V2LS product administration, at approximately Week 1. The outcome description says participants recorded solicited symptoms on a diary card for 7 days and reviewed it with clinic staff at a follow-up visit. A participant was counted once for each symptom at the worst severity reported during that period. The measure called “Any Local Symptom” refers to participants reporting any local symptom at its worst severity.

Severity was graded as Mild, Moderate or Severe using the DAIDS Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1. This endpoint is a count of participants, rather than a measure of symptom duration or a continuous score. Such a count can describe how many participants in a group reported a specified symptom or any local symptom, while the severity grading gives additional descriptive context.

The record identifies the outcome definition and its time window but does not report the observed counts for this primary endpoint. It also does not report uncertainty intervals or a statistical comparison for the endpoint. Therefore, the endpoint’s numerical findings and the precision of any difference between administration groups cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical explanation: the appropriate analysis depends on the outcome being measured. This primary outcome is a count of participants reporting a symptom, not a measurement on a continuous scale. A useful descriptive presentation would state the count in each group and the group denominator, with the symptom definition and observation window made clear. For a comparison, an estimate of the difference or another prespecified contrast would need an uncertainty measure. Those primary numerical results are not reported in the registry record.

What does a participant count represent?

The outcome description specifies that each participant was counted once for each symptom at the worst severity reported during the reporting period. This prevents repeated reports of the same symptom by one participant from being treated as multiple participants with that symptom. It does not mean that the participant could report only one type of symptom. The “Any Local Symptom” measure is defined separately as the count reporting any local symptom at its worst severity. Thus, the count is a participant-level summary under the stated rule, not a tally of every episode or diary entry.

For a binary event such as whether a participant reported a symptom, a proportion can be useful in addition to a count. The denominator must match the endpoint population. The registry defines that population as enrolled participants who received CAP256V2LS and provided safety data through a diary card. The available record does not report the primary symptom counts or the denominators used for those results, so no proportion or comparative estimate can be stated.

Why does severity grading matter?

The endpoint distinguishes Mild, Moderate and Severe symptoms using the named DAIDS grading table. Categorizing severity can make the clinical description more informative than a single all-severity count. However, each category still needs its corresponding count and denominator to be interpreted. The registry provides the grading method but not the primary results by severity. No conclusion about the distribution of severity can therefore be drawn from the posted record.

General statistical explanation: counts in separate severity categories should be interpreted according to the endpoint's rules. If a participant's symptom was recorded more than once at different severities, the stated rule uses the worst severity for that symptom. This is a way to summarize repeated reports, but it does not preserve the timing or duration of each report. Those details would require additional data or outcome summaries, which are not reported in the registry record.

What can be concluded from a comparison?

The two groups received the same antibody by different routes, but the trial is identified as non-randomized and unmasked. A simple contrast between group counts would describe the observed groups; by itself, it would not show that administration route caused a difference. Random allocation is one method for balancing measured and unmeasured characteristics on average, but no such allocation is recorded. The registry also flags that the arms are not a like-for-like control comparison.

General statistical explanation: uncertainty intervals express the imprecision of an estimated effect. A narrow interval generally indicates greater precision than a wide interval, while an interval spanning values compatible with different effects may leave the comparison unresolved. The record does not provide a primary effect estimate or interval. It is therefore not possible to judge precision or statistical compatibility for the primary endpoint from this information.

What do the planning assumptions mean?

The record's sample-size assumptions describe illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms and a normal approximation. The stated approach considers an effect defined as a fraction of the observed effect. These assumptions describe a planning exercise, not the trial's observed outcome and not observed power. “Participants per arm for 80% power” is a planning quantity, not a count of participants who experienced an event in this study.

General statistical explanation: a planning calculation asks how many participants might be needed under specified assumptions to detect a chosen effect with a chosen probability, if those assumptions hold. Its output can change when the target effect, variability, allocation or analysis method changes. A calculation based on an effect observed in a small trial may be particularly sensitive to that estimate. The registry record does not report a sample-size justification or the trial's original planning process, so the planning illustration should not be treated as the protocol's rationale.

What is not available for review?

The registry lists 11 outcome measures and zero analyses. It names pharmacokinetic outcomes, including maximum observed serum concentration, time to maximum concentration, beta half-life, clearance rate and volume of distribution, but the corresponding numerical results are not present in the registry record for this explanation. No detailed statistical model, adjustment strategy or inferential results for the primary outcome are reported in the registry record. Consequently, the methods can be described only at the level of the stated endpoint definitions and planning assumptions; no unreported test or model should be presumed.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures, including the primary local reactogenicity outcome and secondary pharmacokinetic outcomes. It names outcomes for maximum observed serum concentration, time to maximum concentration, beta half-life, clearance rate and volume of distribution. A detailed plan for prioritizing or adjusting analyses across multiple outcomes is not reported in the registry record. Without that information and without the numerical results, it is not possible to assess how multiplicity was handled or whether any reported comparisons were prespecified.

The record lists zero analyses and does not provide numerical results for the primary endpoint. It does not report the number of participants with missing diary data, how missing symptom entries were handled, or whether any sensitivity analyses were performed. The primary endpoint population is described as enrolled participants who received CAP256V2LS and provided safety data through a diary card, but further details about analysis populations are not reported in the registry record.

General statistical explanation: missing outcome data can affect interpretation when the availability of observations is related to symptoms or other participant characteristics. Analysis choices may include defining an evaluable population, making assumptions about missing observations or testing sensitivity to those assumptions. These are general possibilities, not methods that can be attributed to this trial. The record does not report which approach, if any, was used.

The absence of a reported multiplicity strategy, missing-data method or detailed analysis population limits assessment of the statistical safeguards and assumptions behind any outcome interpretation. It does not establish that the trial lacked such procedures; it means they 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry's serious-event summary lists 5 participants at risk and 0 affected in the intravenous group, and 5 at risk and 0 affected in the subcutaneous group. Deaths are recorded as 0 in each group. For other adverse events, the record lists 5 participants at risk and 5 affected in each group. These are counts of participants, not event rates or descriptions of the events themselves.

The registry record does not list serious-event terms. It also does not provide the specific types, severity, duration, timing or assessed relationship to treatment for the other adverse events in this summary. The figures therefore indicate what the registry counted, but they do not supply a full characterization of the events or establish causation. The summary should be read as descriptive safety information from this trial, not as a comparison proving that the administration routes have equivalent safety profiles.

General statistical explanation: observing zero serious events in a group does not demonstrate that the underlying risk is zero. With limited observations, estimates can remain imprecise even when no event is recorded. The registry does not report an uncertainty interval for these serious-event counts. The appropriate interpretation is therefore limited to the recorded counts and the stated at-risk group sizes.

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

This Phase 1 trial examined CAP256V2LS administered as an intravenous infusion or subcutaneous injection in healthy adults. Its primary endpoint was designed to count participants reporting local reactogenicity signs or symptoms during the 7 days after administration, with symptoms graded by severity. The record also names pharmacokinetic outcomes and includes a descriptive adverse-event summary.

The available registry information does not report the primary endpoint counts, the pharmacokinetic results or inferential analyses. As a result, it does not allow a reader to assess the frequency of each local symptom, the pattern of severity, the precision of an arm comparison or the pharmacokinetic estimates. The serious-event summary records 0 affected participants in each group and 0 deaths in each group, while other adverse events are recorded for 5 participants in each group. Those counts do not identify event types or establish why events occurred.

The non-randomized design is also central to interpretation. Since participants were not randomly allocated according to the registry record, and there is no listed untreated or placebo control group, any difference between routes would be descriptive rather than a definitive causal estimate. The record does not report adjusted comparisons that might address differences between groups.

General statistical explanation: a study result is more informative when it includes an effect estimate, its uncertainty and a clear description of the analysis population. A count without a reported denominator or uncertainty may be difficult to compare, and an absence of a reported result must not be mistaken for evidence of no effect. Here, the registry record supports description of the design, outcome definitions and adverse-event counts, but does not support a conclusion about the comparative effect of the two routes or the frequency of the primary endpoint.

The trial's findings should therefore be understood within the scope of the recorded study and its reporting. The record does not establish treatment benefit, does not provide a basis for medical advice, and does not resolve questions that require the missing outcome results or additional comparative evidence.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of how design and reporting shape what can be learned from an early-phase trial. The registry defines a participant-level local reactogenicity endpoint, specifies a 7-day observation window and describes severity grading. Those definitions matter because a count is interpretable only when its event rule, time window and population are clear.

The record also makes a distinction between a descriptive safety summary and a comparative analysis. It reports serious-event counts and counts for other adverse events, but lists no analyses and does not report the primary outcome counts. The presence of event counts alone does not supply an effect estimate or establish the precision of a comparison. Clear outcome reporting is needed to understand both what was observed and how uncertain a comparison may be.

Non-randomized allocation is another key statistical feature. The groups received the same antibody through different administration routes, but the registry cautions that the arms are not a like-for-like control comparison. This illustrates why an observed contrast should not automatically be interpreted as an effect caused by route. The design and the information reported set limits on causal interpretation.

The listed planning assumptions also illustrate a separate distinction: sample-size calculations are prospective planning tools, whereas trial results describe observed data. A planning illustration based on an observed effect is not observed power and cannot fill gaps in unreported outcome results. Keeping those concepts separate prevents planning quantities from being mistaken for evidence about the trial's findings.

Overall, the record highlights the value of complete endpoint results, analysis methods, uncertainty estimates and transparent reporting of missing data. Without them, readers can describe the study design and the safety counts but cannot fully evaluate the primary statistical question.

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 record does not report the numerical results for the primary local reactogenicity endpoint. It describes the symptom collection, severity rules and 7-day period, but the corresponding symptom counts and denominators are unavailable in the record. No primary effect estimate or uncertainty interval is reported.

The study used non-randomized allocation and had no listed placebo or untreated control group. The registry explicitly cautions that the two arms are not a like-for-like control comparison. Therefore, the record does not establish that differences between the route groups, if any, were caused by route of administration. The allocation process and any adjustment for group differences are not reported in the registry record.

The trial included healthy adults ages 18-60 and was a Phase 1 study. The record does not provide details to assess how results might apply to populations outside the stated eligibility group. The posted safety summary also lacks serious-event terms and does not characterize the other adverse events by type, timing, severity or relationship to study product.

The registry lists zero analyses and does not report a detailed statistical analysis plan, multiplicity procedure, missing-data method, or numerical pharmacokinetic results. The primary analysis population is described in general terms as participants who received CAP256V2LS and provided diary-card safety data, but participant-level completeness is not reported. These omissions limit assessment of the outcome estimates and their precision; they do not establish that unreported procedures or data were absent from the trial itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Phase 1 Trial to Evaluate CAP256V2LS in Healthy Adults — NCT04408963.
• Registry record last updated 2024-01-11; status last verified 2023-12.
• Results first posted 2023-12-18.
• 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

The registry record describes a completed Phase 1, parallel, non-randomized, unmasked study of CAP256V2LS in healthy adults. The listed enrollment is 10. One group received 5 mg/kg by intravenous infusion and the other received 5 mg/kg by subcutaneous injection on Day 0. The recorded start date is 2022-03-22, and the primary completion date is 2022-11-28.

The primary endpoint counts participants reporting local reactogenicity signs and symptoms within 7 days, with severity graded using the stated DAIDS table. The record names five pharmacokinetic outcomes. It lists zero analyses and does not report numerical primary-endpoint or pharmacokinetic results. The adverse-event summary records 0 serious events and 0 deaths in each group, and 5 participants with other adverse events in each group. The registry cautions that the non-randomized groups are not a like-for-like control comparison.