A Study of LY3832479 (LY-CoV016) in Healthy Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of LY3832479 (LY-CoV016) in Healthy Participants (NCT04441931), a randomized phase 1 study. The primary outcome is Number of Participants With One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug.

2. Clinical Question

This is a safety-focused question rather than an efficacy comparison. It asks for a count of participants with at least one qualifying event, not the total number of events and not the number of participants with any event regardless of seriousness or relationship to study drug. The registry record defines serious adverse events by outcomes such as death, hospitalization, life-threatening events, persistent or significant disability, congenital anomaly or birth defect, or other significance determined by the investigator.

The study also lists pharmacokinetic outcomes: area under the concentration-versus-time curve from time zero to infinity and maximum serum concentration. Those measures concern drug exposure, but numerical results for them are not reported in the registry record. The main posted result available for this analysis is therefore the count for the related-serious-adverse-event endpoint, considered across the three LY3832479 dose groups and pooled placebo.

3. Trial Design

The registry describes a Phase 1, randomized, double-masked, placebo-controlled study using a sequential model. Its stated purpose was to evaluate tolerability, safety, pharmacokinetics, and immunogenicity after a single intravenous dose of LY3832479 in healthy participants. The record lists Eli Lilly and Company as sponsor and marks the study as completed.

Participants assigned to LY3832479 received a single intravenous dose of 700 mg, 2800 mg, or 7000 mg; the comparator group received a single intravenous dose of placebo. The posted primary-endpoint results distinguish these three dose groups and pooled placebo. The reported group sizes are 7 for the 700 mg group, 7 for the 2800 mg group, 6 for the 7000 mg group, and 6 for pooled placebo. The record does not describe the details of the randomization sequence, masking procedures, or how the sequential model determined dose progression; those details are not reported in the registry record.

The registry lists enrollment of 26. The study start date is 2020-06-19, and primary completion is dated 2020-10-02. The stated participation period could last up to 16 weeks and may include up to 10 visits to the study center. Those are descriptions of the planned participation period, not evidence that every participant attended the same number of visits or remained in follow-up for the same duration.

The primary safety outcome covers baseline through follow-up at Week 12. The analysis population is described as randomized participants who received at least one dose of study drug. The registry record does not report a separate account of exclusions from that population or the number of participants with missing primary-endpoint information.

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: All randomized participants who received at least one dose of study drug.

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: All randomized participants.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug, measured over Baseline through Follow-up (Week 12).

The primary endpoint counts participants with one or more serious adverse events that the investigator considered related to study drug. It is reported cumulatively from baseline through follow-up at Week 12. A participant is counted if at least one event meets both the seriousness definition and the investigator’s relatedness assessment. The measure is a participant count, not an event count: a participant with multiple qualifying events still contributes to the count of participants with one or more events.

The registry’s seriousness definition includes events resulting in death, initial or prolonged hospitalization, a life-threatening condition, persistent or significant disability or incapacity, congenital anomaly or birth defect, or another event the investigator considers significant. Seriousness and causality are different judgments. An event can be serious without being judged related to study drug, and this endpoint specifically concerns serious events judged related.

This endpoint is used to describe an important safety outcome in a study whose stated aims include evaluating tolerability and safety. A count can convey whether any participants in a group had a qualifying event, but it does not by itself describe event timing, severity beyond the qualifying definition, duration, or all adverse events. The registry directs readers to its reported adverse-events information for a summary of serious events regardless of causality. The primary endpoint results report zero participants with related serious adverse events in each posted group. That finding describes the posted endpoint over its stated observation period; it does not establish that no other adverse events occurred.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is binary at the participant level: each participant either meets the definition of having one or more related serious adverse events during the stated period or does not. The posted outcome is expressed as a number of participants. The primary measure is therefore a count, and its interpretation depends on the endpoint definition, the population assessed, and the observation window. Here, the population is described as randomized participants who received at least one dose of study drug, and the window runs from baseline through follow-up at Week 12.

What does a zero count tell us?

In general, a zero observed count means that no qualifying event was recorded among the participants represented in that group during the specified observation period. It is a description of the observed data, not a guarantee about the event rate in a larger population. Rare outcomes can remain uncertain when no events are observed, because a study with a limited number of participants may not encounter an event even when the event could occur in other settings. This is why a zero count should be read together with the group size, endpoint definition, and follow-up period.

The posted primary results are 0 events for pooled placebo and 0 for each LY3832479 dose group. Their reported group sizes are 6, 7, 7, and 6, respectively. These values do not support a meaningful ranking of groups on this outcome: each group has the same observed count, and the registry marks a two-arm comparison as not estimable for the binary endpoint. No unadjusted re-calculation is reported. No sponsor inferential analysis is reported either; the registry lists 0 analyses.

Why are pairwise comparisons not available?

A comparison between groups for a binary endpoint generally uses the number of participants with the event and the number assessed in each group. When the observed event counts are zero in all groups, a conventional comparison may not yield an estimable effect using the methods intended for an event contrast. The record explicitly states that values are missing or not estimable for a two-arm comparison. That is a limitation of the available comparison, not evidence that the groups are identical in the broader population. It also means there is no posted estimate of a relative or absolute difference, no confidence interval, and no p-value to interpret.

In general, a confidence interval describes the range of values compatible with observed data under a specified statistical method. It helps show precision, not just the direction or size of an estimate. No confidence interval is reported for this endpoint, so the precision of a comparative effect cannot be assessed from the registry results. A confidence interval cannot be recreated from the record without choosing an analysis method, and a newly calculated result would not be part of the sponsor’s posted analysis.

What do the planning assumptions mean?

The registry’s planning illustration is described as a two-sided test at significance level 0.05, with equal allocation between two arms and a normal approximation. It is based on a stated fraction of the observed effect, and the illustration is planning information rather than observed power. For this binary endpoint, the record says values are missing or not estimable for a two-arm comparison, so no usable observed effect is available for that illustration. Any sample-size planning number should not be interpreted as the number enrolled, the number analyzed, or evidence that the completed study had a particular probability of detecting an effect.

In general, a sample-size calculation depends on the effect size to detect, the variability or event frequency assumed, the statistical threshold, allocation, and analysis method. Changing these assumptions changes the resulting planning requirement. The registry record does not report a trial-specific sample-size justification or a complete statistical analysis plan. The listed planning assumptions should therefore not be taken as a full account of how the trial was designed or analyzed.

How should seriousness and relatedness be interpreted?

The endpoint combines two assessments. Seriousness is determined using the registry’s criteria, which include specified consequences and events considered significant by the investigator. Relatedness is the investigator’s judgment about whether the event is related to study drug. The endpoint counts participants only when a serious event is judged related. It is not interchangeable with a tally of serious events regardless of causality, and it does not capture every adverse event. Investigator assessment is part of the outcome definition; the record does not describe an independent adjudication procedure.

The listed secondary outcomes concern pharmacokinetics, not this binary safety endpoint. General methods for continuous concentration measures differ from methods for event counts, but numerical pharmacokinetic findings are not reported in the registry record. Thus, the statistical interpretation is confined to the primary serious-adverse-event counts and the unavailable pairwise comparison.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Pooled Placebo", "700 mg LY3832479 IV", "2800 mg LY3832479 IV", "7000 mg LY3832479 IV")
n      <- c(6, 7, 7, 6)
events <- c(0, 0, 0, 0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Pooled Placebo  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0
ARM  700 mg LY3832479 IV  7  0  0.0  0.0  41.0  0.0  35.4  0.3  36.9
ARM  2800 mg LY3832479 IV  7  0  0.0  0.0  41.0  0.0  35.4  0.3  36.9
ARM  7000 mg LY3832479 IV  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary safety endpoint and two pharmacokinetic secondary outcomes: area under the concentration-versus-time curve from time zero to infinity and maximum serum concentration. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a plan for controlling the chance of false-positive findings across multiple statistical tests. The record lists 0 analyses, so there are no posted inferential tests for which to assess adjustment. The absence of a reported multiplicity method should not be interpreted as evidence that no such considerations were made outside the registry; they are not reported in the registry record.

Missing-data handling is also not reported in the registry record. The endpoint population is described as randomized participants who received at least one dose, but the record does not state how participants with incomplete follow-up, unavailable event assessments, or other missing endpoint information were handled. Nor does it provide a separate count of participants excluded from the endpoint population. The available counts should therefore be read as the posted results, without assuming a particular imputation method or missing-data sensitivity analysis.

The registry reports that values are missing or not estimable for a two-arm comparison of this binary endpoint. This means a comparative estimate is unavailable in the posted results; it does not mean that the observed group counts are missing. The counts themselves are reported for pooled placebo and all three dose groups. No analysis population beyond the stated population of randomized participants who received at least one dose is described for the primary endpoint.

These gaps matter because statistical conclusions depend not only on the observed counts but also on the analysis population, handling of incomplete information, and prespecified approach to multiple outcomes. Those details cannot be reconstructed from the registry record.

12. 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 primary safety result counts participants with one or more serious adverse events considered related to study drug. The posted count is 0 for pooled placebo and 0 for each LY3832479 group: 700 mg, 2800 mg, and 7000 mg. The corresponding group sizes are 6, 7, 7, and 6. The endpoint period is baseline through follow-up at Week 12.

These figures do not mean that no adverse events of any kind occurred. The registry’s broader adverse-event information reports other adverse events for pooled placebo and the 700 mg and 2800 mg groups, while none are reported for the 7000 mg group. It reports zero serious adverse events across the groups and zero deaths. The endpoint highlighted in the primary results is narrower than the broader adverse-event listing because it requires both seriousness and investigator-assessed relatedness.

In general, a participant count records whether a participant had at least one qualifying event; it does not indicate the number of separate events per participant. A zero count also does not establish that the chance of a rare event is zero. These results describe the events recorded under this study’s definition and follow-up, among the participants included in the reported groups. The registry does not provide a comparative confidence interval or an estimable two-arm effect for this binary endpoint.

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

The results support a descriptive statement about the registry record: no participants were reported with one or more serious adverse events considered by the investigator to be related to study drug in pooled placebo or in any of the LY3832479 dose groups. The endpoint covers baseline through follow-up at Week 12, and the reported group sizes are 6 for pooled placebo, 7 for 700 mg, 7 for 2800 mg, and 6 for 7000 mg.

The counts do not demonstrate that the groups have equivalent safety profiles. Equal observed counts, especially when all are zero, are not the same as a precise estimate of no difference. The registry does not report an estimable two-arm comparison, confidence interval, or p-value for this endpoint. The event counts therefore cannot establish that a dose has the same risk as placebo or quantify how much one group’s risk might differ from another’s.

The result also does not mean that no adverse events occurred. The endpoint excludes events that are not serious and serious events not judged related to study drug. The registry separately reports other adverse events in some groups. Nor does the primary result describe events beyond the stated follow-up period, events that may not have been captured, or risks in populations other than the healthy participants enrolled in this study.

The record’s stated aims include pharmacokinetics and immunogenicity as well as safety, but numerical results for the listed pharmacokinetic measures are not reported in the registry record. The primary safety result cannot answer those questions, and it does not establish efficacy. It is a limited observation from a completed Phase 1 study with the reported dose groups, comparator, endpoint definition, and follow-up. The key distinction is between observing no qualifying events in these groups and proving that such events cannot occur.

14. Why This Trial Matters Statistically

This trial illustrates a basic challenge in interpreting safety outcomes: a count of zero is meaningful as a record of what was observed, but it is not a precise estimate of how often a rare outcome occurs beyond the study. The reported group sizes are limited, and the primary endpoint concerns serious events considered related to study drug. Readers need to keep the endpoint definition, group size, and follow-up period together when interpreting a zero count.

The study also shows why descriptive results and comparative inference are not interchangeable. The registry reports the participant counts by dose group and pooled placebo, but it does not report an estimable two-arm comparison for this binary endpoint. No p-value or confidence interval is available. As a result, the record can describe the observed counts but cannot quantify a comparative effect or its precision using posted analyses.

The design places the safety finding in a specific context: a randomized, double-masked, placebo-controlled Phase 1 study in healthy participants, with single intravenous doses across three LY3832479 groups. The primary observation period ends at follow-up at Week 12. These features define what the endpoint can speak to; they do not make the result generalizable to other populations, treatment schedules, or longer observation periods.

Finally, the registry distinguishes this primary outcome from broader adverse-event reporting and lists pharmacokinetic outcomes separately. Keeping those measures separate prevents a common interpretive error: treating the absence of a particular serious, related event as the absence of all adverse events or as evidence about drug exposure. The record is most useful when its narrow outcome and the limits of its posted comparisons remain explicit.

15. 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 endpoint results are counts with no related serious adverse events reported in any group. The group sizes are 6 for pooled placebo, 7 for 700 mg, 7 for 2800 mg, and 6 for 7000 mg. With this pattern, the registry does not provide an estimable two-arm comparison. There is no posted confidence interval or p-value to express comparative precision, and the counts alone cannot rule out uncommon events or establish equivalence between groups.

The endpoint depends on investigator assessment of whether a serious event was related to study drug. The registry defines seriousness but does not report whether relatedness was independently adjudicated or how disagreements were handled. It also does not give event-level details for the primary endpoint beyond the reported zero participant counts. As a result, readers cannot examine timing, duration, or other clinical characteristics of qualifying events from these figures.

The registry describes the primary-endpoint population as randomized participants who received at least one dose. It does not report missing-data handling, a separate accounting of participants excluded from the analysis population, or sensitivity analyses for incomplete follow-up. The record lists 0 analyses and does not report a full statistical analysis plan or trial-specific sample-size justification.

Interpretation is further limited to healthy participants, the single-dose intravenous regimens listed, and the observation period ending at follow-up at Week 12. The listed pharmacokinetic outcomes have no numerical results reported in the registry record. The posted safety counts therefore cannot answer questions about those measures, efficacy, longer-term outcomes, or settings beyond the study as described.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of LY3832479 (LY-CoV016) in Healthy Participants — NCT04441931.
• Registry record last updated 2021-12-06; status last verified 2021-11.
• Results first posted 2021-12-06.
• 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.

19. Record Summary

NCT04441931 is a completed, randomized, double-masked, placebo-controlled Phase 1 study of single intravenous doses of LY3832479 in healthy participants. The registry lists enrollment of 26 and reports three dose groups—700 mg, 2800 mg, and 7000 mg—alongside pooled placebo. The primary safety endpoint counts participants with one or more serious adverse events considered related to study drug from baseline through follow-up at Week 12.

The reported primary endpoint count is 0 for pooled placebo and 0 for each dose group. The registry does not report an estimable two-arm comparison or inferential analysis for this binary outcome. It also lists two pharmacokinetic secondary outcomes, but their numerical results are not reported in the registry record. The primary result should be read as a description of the recorded endpoint in the study groups, not as proof of no risk or evidence of equivalence.