A Study of Donanemab (LY3002813) in Healthy Chinese Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Donanemab (LY3002813) in Healthy Chinese Participants (NCT05533411), a randomized phase 1 study. The primary outcome is Number of Participants With One or More Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration.

2. Clinical Question

3. Trial Design

This was a randomized, double-blind, parallel-group Phase 1 study sponsored by Eli Lilly and Company. The official title describes a participant- and investigator-blind study of a single intravenous dose of donanemab compared with placebo in healthy Chinese participants. The registry lists enrollment of 36 and a completed study status.

There were four treatment groups: placebo, 350 mg donanemab, 700 mg donanemab, and 1400 mg donanemab. Each group received a single dose intravenously on Day 1. The registry describes the study as lasting up to approximately 85 days. The primary safety outcome’s timeframe is baseline up to Day 85.

The stated primary purpose was to evaluate the safety and tolerability of donanemab. The study also assessed pharmacokinetics. The listed secondary outcomes are maximum observed concentration (Cmax) and area under the concentration-versus-time curve from zero to infinity (AUC[0-∞]). The registry information does not include numerical results for those pharmacokinetic outcomes.

The study began on 2022-09-14, and its primary completion date was 2023-01-05. These dates describe the registry record and do not, by themselves, explain the conduct of individual visits or the timing of any analyses. Details such as the randomization procedure, allocation concealment, and the specific blinding procedures are not reported in the registry record.

This is a short-duration, early-phase study in healthy participants, not a study of treatment for a disease population. Its stated objectives and outcomes are safety, tolerability, and pharmacokinetics. The registry information does not report a clinical efficacy endpoint or a treatment-effect analysis for clinical benefit.

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 participants randomly assigned to study intervention and who took at least 1 dose of study intervention.

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 Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration, measured over Baseline up to Day 85.

The primary endpoint is the number of participants with one or more treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) considered by the investigator to be related to study drug administration. Its timeframe is baseline up to Day 85, and its unit is participants. A TEAE is described as an untoward medical occurrence that either happens after dosing or was present before dosing and becomes more severe after dosing. The event is considered drug-related when, in the investigator’s opinion, it is possibly related to study drug.

This endpoint is used to describe the frequency of treatment-emergent safety events attributed as possibly related to study drug during the stated observation period. Counting participants rather than event episodes focuses on how many people experienced an event, rather than how often events recurred in the same person. That distinction is useful because participant counts and total event counts answer different descriptive questions.

The registry record does not report the primary endpoint’s result by treatment group. It separately notes that summaries of SAEs and other non-serious adverse events, regardless of causality, are located in the Reported Adverse Event module. Those broader adverse-event counts should not be treated as the primary endpoint’s drug-related count: they use a different causal scope, and the posted information does not identify them as the primary endpoint result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization assigns participants to study groups by chance, with the aim of reducing systematic differences between groups at entry. This is a general statistical principle; the registry identifies the study as randomized but does not report the sequence-generation method, allocation concealment, or implementation details. Those omissions limit assessment of how random assignment was carried out, without changing the fact that the record classifies the design as randomized.

What does double-blind mean?

In general, blinding is intended to reduce the possibility that knowledge of assigned treatment influences participant reporting, investigator assessment, or other study procedures. The registry labels the design double-blind and the official title specifies participant- and investigator-blind. The detailed procedures used to maintain blinding, and whether anyone was permitted to be unblinded under specified circumstances, are not reported in the registry record.

How should event counts be understood?

The primary endpoint is a participant count: it concerns whether a participant had one or more qualifying events during the stated timeframe. A participant count is not the same as a count of every event episode. In general, event counts can be summarized in different ways, and the chosen measure should match the clinical question. Here, the endpoint’s wording centers on affected participants and investigator-assessed relationship to study drug.

The posted safety group information distinguishes serious adverse events from other adverse events. For serious events, it gives the number at risk and the number affected. For other events, it also gives the number at risk and affected. The record describes the other events as non-serious adverse events in its explanation of the adverse-event module. General interpretation should keep severity and causality separate: a serious event is categorized by seriousness, while a judgment that an event is related to treatment addresses attribution. The posted group counts do not state that all other events were judged related.

What can a confidence interval add?

In general, a confidence interval describes the uncertainty around an estimated quantity under a statistical method. It can show which effect sizes are reasonably compatible with the observed data and method, and its width conveys precision. A point estimate alone does not communicate that uncertainty. No confidence interval for the primary endpoint or a treatment contrast is reported in the registry information. The event counts should therefore be read as descriptive observations, not as precise estimates of comparative risk.

Why does sparse data matter?

In general, when events are uncommon and groups are small, estimates of between-group differences can be imprecise, and conventional large-sample approximations may be unreliable. Zero observed serious events in a group does not mean the underlying probability is exactly zero. A study with no observed serious events can still be compatible with a range of underlying risks. This is a general statistical point; no uncertainty estimates are reported for these serious-event counts in the registry record.

What analyses are reported?

The registry lists no analyses. It does not report a statistical model, a method for comparing groups, an approach to repeated or multiple outcomes, or a method for handling missing data. The general choice of a method would depend on the endpoint, study question, and data structure, but the actual statistical plan cannot be inferred from the design description alone. A method should not be attributed to this study unless it is documented in the registry record.

The registry lists Cmax and AUC[0-∞] as pharmacokinetic outcomes. In general, Cmax describes a maximum observed concentration, while AUC represents exposure over a concentration-time curve for the specified interval. The registry information does not give estimates, variability measures, or inferential analyses for these outcomes. No conclusion about pharmacokinetic similarity or differences can be drawn from outcome names alone.

Planning sample sizes and observed results serve different purposes. In general, a sample-size calculation uses assumptions about the effect to detect, variability, significance level, and desired power. Such a calculation is a planning illustration, not observed evidence and not a measure of the probability that a study result is true. The registry record does not report the trial’s sample-size justification or enough outcome analysis detail to assess a study-specific planning calculation.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary safety outcome and secondary pharmacokinetic outcomes, but it does not report a multiplicity strategy. In general, evaluating multiple outcomes or multiple comparisons can increase the chance of at least one false-positive finding if each is tested without adjustment. Whether an adjustment is appropriate depends on the analysis plan and the intended interpretation. Since no analyses are listed, the registry record does not establish whether any adjustment was planned or applied.

Missing-data handling is not reported in the registry record. It does not describe whether participants with incomplete follow-up were excluded from particular summaries, how missing outcome observations were treated, or whether any sensitivity analyses were conducted. These details matter because incomplete observation can affect descriptive counts and comparisons, especially when missingness is related to health status, treatment assignment, or the event being assessed. No such relationship or method can be inferred from the available information.

The primary outcome population is defined as participants randomly assigned to study intervention who took at least one dose. This is the registry’s stated population definition; the information does not describe additional analysis populations or how participants were handled if they did not meet that definition. The number enrolled and the group-specific safety risk sets are reported, but the record does not explain whether these populations differ for any other outcome.

Interim analyses, stopping rules, and a detailed statistical analysis plan are not reported in the registry record. The record also does not report a primary-outcome analysis or a formal comparison. Without these details, the scope of any planned hypothesis testing and the treatment of incomplete or multiple outcome data remain unclear.

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

For serious adverse events, the posted group counts are 0 of 6 for placebo, 0 of 10 for 350 mg donanemab, 0 of 10 for 700 mg donanemab, and 0 of 10 for 1400 mg donanemab. The first number is the number affected, and the second is the number at risk in that group. These counts indicate that no serious adverse events were recorded among the listed participants during the relevant safety observation.

A count of zero is not proof that the underlying risk is zero. In general, a zero count in a limited study can occur even when an event remains possible, and without an uncertainty interval it does not quantify the range of plausible risks. These figures also do not compare serious-event risks with statistical precision, because no inferential comparison or confidence interval is reported.

The other adverse-event counts are distinct from the serious-event counts. The record reports them regardless of causality, and they should not be read as the number of participants with drug-related TEAEs. The primary endpoint’s relationship-to-study-drug criterion requires an investigator judgment that is not identified in these group totals. The registry also states that summaries of SAEs and other non-serious AEs are located in the Reported Adverse Event module.

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

The registry record describes a randomized, double-blind Phase 1 study of a single intravenous dose of donanemab or placebo in healthy Chinese participants. Its main objectives were safety and tolerability, with pharmacokinetic assessment as an additional objective. The posted safety counts show no serious adverse events in the listed groups, alongside other adverse events in each group. These are descriptive observations from this study.

They do not establish that donanemab is safe or unsafe in general, or that one dose group has a higher or lower risk than another. The registry does not provide a primary-outcome result defined by investigator-assessed relatedness, a formal statistical comparison, or uncertainty intervals. The other adverse-event counts include events regardless of causality and therefore do not directly answer the primary endpoint question.

The record also does not report numerical pharmacokinetic results for maximum observed concentration or area under the concentration-time curve. Listing an outcome indicates that it was part of the study’s stated assessment; it does not, by itself, show what the observed concentrations or exposure were.

Interpretation is bounded by the study population, single-dose design, and follow-up timeframe up to Day 85. These findings cannot establish effects in people with a disease, with different participant characteristics, or after longer exposure. The registry information does not provide details of missing-data methods, analysis populations beyond the primary outcome definition, or the statistical plan. Such limitations mean the posted counts are best understood as a record of observed events, not as a comprehensive evaluation of risk or a basis for clinical decisions.

13. Why This Trial Matters Statistically

Early-phase randomized studies can provide structured observations about safety and pharmacokinetics while comparing an investigational treatment with placebo. This study’s four groups include placebo and three single-dose donanemab levels, allowing the registry to present adverse-event counts by group. The randomized, double-blind, parallel-group design is relevant to how such observations are organized, although the registry does not report all operational details needed to evaluate implementation.

Statistically, a key distinction is between a broad count of adverse events and an endpoint that requires an investigator to consider an event related to study drug. The registry’s primary outcome uses the latter definition, while the posted adverse-event group counts are described as covering events regardless of causality. Keeping those measures separate avoids treating general event counts as if they were the primary endpoint.

The record also illustrates why descriptive counts must be interpreted with attention to uncertainty. No serious adverse events are recorded in the listed groups, but the information does not include confidence intervals or a comparative analysis. A zero observed count is a feature of the data, not a guarantee about underlying risk. The registry lists pharmacokinetic outcomes, but numerical outcome estimates are not included in the information used for this analysis.

Finally, the absence of reported analyses, missing-data methods, and multiplicity procedures limits what can be concluded statistically. Transparent reporting of these methods would help readers assess how outcomes were defined, which participants were included, and how uncertainty was quantified. The available record supports a careful description of the study design and posted safety observations, while leaving important inferential questions unanswered.

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 a result for the stated primary endpoint: participants with one or more TEAEs or SAEs considered by the investigator to be related to study drug. The available group counts for serious and other adverse events do not identify drug-related events and therefore cannot be treated as the primary endpoint result.

The record lists no statistical analyses and no inferential results for the safety or pharmacokinetic outcomes. It does not report confidence intervals, p-values, a model, or a formal treatment comparison. Consequently, the precision of observed group differences cannot be assessed from the posted information. The listed Cmax and AUC[0-∞] outcomes have no numerical results in the registry information.

Details of the randomization procedure, allocation concealment, blinding implementation, and statistical analysis plan are not reported in the registry record. The record also does not describe missing-data handling, interim analyses, or multiplicity procedures. These omissions prevent assessment of how those aspects were addressed in the study.

The study concerns healthy Chinese participants receiving a single dose, with safety observation through Day 85. This setting and duration limit how far the observations can be generalized to other populations or longer treatment. The registry reports enrollment and group risk sets, but does not provide additional participant characteristics in the information used for this analysis. These limitations are specific to interpreting this study’s posted record and do not imply that unreported procedures were or were not performed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Donanemab (LY3002813) in Healthy Chinese Participants — NCT05533411.
• Registry record last updated 2024-10-04; status last verified 2024-07.
• Results first posted 2024-10-04.
• 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.

18. Record Summary

NCT05533411 is a completed randomized, double-blind, parallel-group Phase 1 study sponsored by Eli Lilly and Company. It enrolled 36 healthy Chinese participants and compared single intravenous doses of donanemab—350 mg, 700 mg, or 1400 mg—with placebo. The study began on 2022-09-14, and its primary completion date was 2023-01-05.

The primary outcome concerns participants with one or more TEAEs or SAEs considered related to study drug, from baseline up to Day 85. The registry lists Cmax and AUC[0-∞] as secondary pharmacokinetic outcomes. Posted safety counts show no serious adverse events in the listed groups, but the record does not report the primary endpoint result, formal analyses, or numerical pharmacokinetic results.