A Study of LY3314814 in Healthy Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of LY3314814 in Healthy Participants (NCT03222427), a non-randomized phase 1 study. The primary outcome is Absolute Bioavailability of LY3314814.

2. Clinical Question

The clinical question is how much LY3314814 reaches the bloodstream after oral administration, assessed in relation to intravenous administration of a labeled LY3314814 tracer. The registry describes absolute bioavailability as the primary endpoint and says it was assessed using dose-normalized drug exposure measured by the area under the concentration-time curve from zero to infinity.

In general, absolute bioavailability expresses systemic availability after a non-intravenous dose relative to intravenous administration, which serves as a reference for drug entering the bloodstream directly. This study’s registry description identifies a tracer-based method for making that assessment. It does not provide the estimated bioavailability, its uncertainty, or a statistical test result. The study is therefore best read as a pharmacokinetic investigation of drug exposure in healthy participants, rather than as a comparison of clinical outcomes or a test of treatment benefit.

3. Trial Design

This is a completed phase 1 study sponsored by AstraZeneca, listed as a study of LY3314814 in healthy participants. The registry reports an enrollment of 8. The listed study dates are 2018-01-15 for study start and 2018-02-16 for primary completion.

The design is recorded as non-randomized, unmasked, and parallel. The registry lists LY3314814 and labeled [13C415N3] LY3314814 as the drug interventions. The oral intervention is a single 50 milligram dose of LY3314814. The intravenous intervention is a single 100 microgram dose of labeled LY3314814 administered as an infusion. The brief summary describes the infusion as lasting two hours and says the study would last at least two weeks for each participant, not including screening.

Because allocation was non-randomized, the listed interventions should not be treated as randomly assigned groups in a controlled efficacy comparison. The registry itself cautions that the arms are not a like-for-like control comparison. The study’s stated purpose is to measure drug exposure after oral dosing in relation to intravenous tracer administration. That purpose differs from evaluating whether one treatment is superior to another on a clinical outcome.

The primary endpoint is absolute bioavailability, assessed using dose-normalized AUC for oral LY3314814 and intravenously administered labeled LY3314814. A secondary outcome is pharmacokinetic AUC from zero to infinity for both substances. The registry’s description of the primary analysis specifies a mixed-effects analysis of variance model applied to log-transformed values. Details of sequence, allocation procedures, and participant flow beyond the listed enrollment 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: All participants who received at least one dose of study drug and have evaluable PK data.

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 participants who received at least one dose of the study drug.

6. Primary Endpoint

The registry lists the primary outcome as Absolute Bioavailability of LY3314814, measured over Day 1: Predose:0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 8, 12, 24, 48, 72, 96 and 120 hours post-dose.

The primary endpoint is absolute bioavailability of LY3314814. It is expressed in nanogram*hour per milliliter per mg, and the registry identifies the reported summary measure as a geometric mean with geometric coefficient of variation as the dispersion measure. The specified assessment uses dose-normalized area under the drug concentration-time curve from zero to infinity for oral LY3314814 and intravenous labeled LY3314814.

AUC represents drug concentration accumulated over time. In general, comparing dose-normalized exposure after oral and intravenous administration provides a way to estimate the fraction of an orally administered drug that reaches systemic circulation, using intravenous administration as the reference route. Dose normalization is relevant when the administered amounts differ; the registry states that the analysis used dose-normalized AUC.

The endpoint is useful for characterizing pharmacokinetics and route-dependent exposure. It does not directly measure symptom change, disease outcomes, or comparative clinical benefit. The registry lists blood sampling on Day 1 at predose and at 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 8, 12, 24, 48, 72, 96 and 120 hours post-dose. The numerical endpoint estimate and its geometric coefficient of variation are not reported in the registry record. Consequently, the registry description establishes what was intended to be measured, but not the magnitude or precision of the result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a mixed-effects analysis of variance model applied to log-transformed, dose-normalized AUC values. This is a model-based approach for comparing pharmacokinetic measurements while representing variation associated with the study structure. The record does not provide the full model specification, the terms included in the model, or the resulting estimates.

Why use AUC?

In general, drug concentration changes over time after dosing. AUC captures cumulative measured exposure across a specified period, rather than relying on a single concentration at one sampling time. The primary endpoint uses AUC from zero to infinity, which is intended to represent exposure across the observed and extrapolated concentration-time profile. The registry lists sampling times through 120 hours post-dose. It does not report the method used to estimate the portion of AUC beyond the last measured sample, the proportion of AUC extrapolated, or any diagnostics of the concentration-time data.

The secondary outcome also concerns AUC from zero to infinity for LY3314814 and labeled LY3314814. The registry lists 2 outcome measures and 1 analysis, but does not provide the numerical results for either the primary or secondary outcome. The number of outcome measures alone does not establish how many hypotheses were tested or what inferential procedures were used.

Why transform the exposure values?

The primary analysis is described as using log-transformed dose-normalized AUC. In general, pharmacokinetic exposure values are often positive and may be unevenly distributed, with some values farther from the center than others. A logarithmic transformation can make multiplicative differences easier to model and may better align data with model assumptions. After analysis on the log scale, estimates are commonly expressed on the original scale using geometric summaries. The registry identifies a geometric mean and geometric coefficient of variation, but does not report their values.

A geometric mean describes a central value for data analyzed on a logarithmic scale. A geometric coefficient of variation describes relative dispersion around that geometric mean. In general, this type of dispersion measure differs from a standard deviation expressed in the original units. The actual variability in this study cannot be judged because the numerical geometric coefficient of variation is not reported in the registry record.

What does a mixed-effects model contribute?

In general, a mixed-effects model can account for more than one source of variation, using fixed effects for modeled contrasts or conditions and random effects for variation among subjects or other groupings. The registry names a mixed-effects analysis of variance but does not specify the fixed or random effects, covariance structure, degrees-of-freedom method, or model diagnostics. It is therefore possible to describe the stated method, but not to reconstruct the analysis or verify whether its assumptions were met.

For pharmacokinetic comparisons, model estimates and their uncertainty are important alongside the central estimate. A confidence interval, when reported, conveys the range of values reasonably compatible with the data under the specified model and assumptions. A p-value addresses a statistical testing question and does not by itself describe the magnitude or practical importance of an effect. The primary endpoint’s estimate, interval, and test result are not reported in the registry record, so none can be interpreted for this study.

Why does over-dispersion matter in general?

Over-dispersion occurs when observed variability exceeds what a chosen statistical model expects. In general, ignoring it can make estimated uncertainty too small and tests appear more conclusive than warranted. For continuous pharmacokinetic outcomes, the model’s residual variability and distributional assumptions are relevant; for event counts, a model that assumes less variability than the data contain can be misleading. The registry does not report an over-dispersion assessment, and no conclusion about it can be drawn for this study.

The registry’s sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is stated as a fraction of the observed effect. Such illustrations are planning calculations, not observed power and not evidence that the study was designed around a particular target. The trial’s own sample-size justification is not reported in the registry record. No actual planning values are available in the registry information summarized for interpretation, so no sample-size figure or power claim can be assessed.

Because allocation is non-randomized, the listed arms should not be treated as exchangeable groups created by random assignment. The stated endpoint method is aimed at estimating absolute bioavailability using oral and intravenous tracer exposure. That design and analysis are distinct from a randomized test of clinical effectiveness. The registry does not report a full statistical analysis plan or enough model details to evaluate every analytic choice.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures and 1 analysis. It identifies absolute bioavailability as the primary endpoint and AUC from zero to infinity for LY3314814 and labeled LY3314814 as a secondary outcome. These descriptions do not establish whether multiple hypotheses were tested, whether outcomes were analyzed in a hierarchy, or whether any adjustment for multiple testing was applied. Multiplicity procedures are not reported in the registry record.

The primary analysis population is described as participants who received at least one dose of study drug and had evaluable pharmacokinetic data. This definition indicates that evaluable pharmacokinetic data are required for inclusion, but the number meeting that definition is not reported in the registry record. The record does not describe how many participants had missing or unevaluable measurements, why data might have been unavailable, or whether any participants were excluded from a particular outcome analysis.

Rules for handling missing concentration measurements, incomplete profiles, values below quantification limits, or other unavailable data are not reported in the registry record. The registry also does not specify whether the primary analysis used all available observations, any imputation, or a particular approach to incomplete AUC estimates. No conclusion about the effect of missing data on the endpoint can therefore be drawn.

These omissions matter because pharmacokinetic estimates depend on the available concentration-time data and the analysis population. In general, exclusions or incomplete profiles can affect both the estimated exposure and the uncertainty around it. The registry’s stated analysis-population definition is useful, but it is not a substitute for participant flow, missing-data details, or a complete analysis plan.

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 reports 0 serious adverse events among 8 participants at risk in the listed combined group. It also reports 3 participants with other adverse events among 8 at risk, and 0 deaths. These are counts in the registry record, not estimates of comparative safety between randomized groups.

The group is listed as LY3314814 plus [13C415N3] LY3314814. The record does not assign the reported other adverse events separately to oral dosing or intravenous tracer administration. It also does not list the event terms for those other events; the serious adverse event term list is empty. The event descriptions, severity details for the other events, timing, and any assessment of relatedness are not reported in the registry record.

In general, an adverse event is an event recorded during a study, and its occurrence alone does not establish that a study drug caused it. The registry counts should therefore be read as safety observations in this study, not as proof of causation or as a comparison with an untreated group. The available counts also do not answer the primary endpoint question, which concerns pharmacokinetic exposure and absolute bioavailability.

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

The study addresses a focused pharmacokinetic question: the absolute bioavailability of LY3314814 after oral administration, assessed using intravenous labeled LY3314814 as a tracer reference. Its primary endpoint and stated model are described in the registry. However, the estimated bioavailability and its uncertainty are not reported in the registry record. The record therefore does not establish the numerical exposure estimate or how precisely it was measured.

This investigation should not be interpreted as a randomized efficacy comparison. The registry records non-randomized allocation and explicitly notes that the arms are not a like-for-like control comparison. The oral and intravenous interventions are part of a bioavailability assessment, not evidence of a comparison of clinical outcomes. The study population is healthy participants, so the record does not establish results for people with a particular illness.

In general, pharmacokinetic exposure can inform understanding of how a drug is absorbed and reaches systemic circulation. It does not, by itself, show whether a drug improves a health outcome or establish a benefit-risk balance. The registry describes exposure measurement, but does not report a clinical outcome result, a numerical bioavailability finding, or a statistical uncertainty measure for that primary endpoint.

The safety record reports 0 serious adverse events and 0 deaths, alongside 3 participants with other adverse events in the combined group. Those counts provide limited descriptive information and do not establish causation, comparative safety, or the absence of unreported events. Event terms for the other adverse events are not reported in the registry record.

The most defensible reading is that the record documents a completed phase 1 tracer-based pharmacokinetic study and its planned endpoint method. It does not provide the numerical primary result needed to characterize the amount of oral exposure relative to intravenous administration. Any conclusion about the size, precision, or clinical implications of absolute bioavailability would go beyond what the registry record reports.

13. Why This Trial Matters Statistically

This study is statistically distinctive because its primary question concerns absolute bioavailability rather than a clinical outcome comparison. The endpoint uses dose-normalized AUC after oral administration and intravenous tracer administration. That framing makes the choice and interpretation of the exposure measure central: the comparison is intended to characterize drug availability by route, not to test whether a treatment improves an outcome.

The record also illustrates why design labels matter. Non-randomized allocation does not support the same interpretation as random assignment, and the registry explicitly cautions that the arms are not a like-for-like control comparison. Readers should interpret the interventions according to their pharmacokinetic purpose rather than treating them as conventional comparator groups.

Reporting the model and endpoint definition gives useful methodological context. The registry names a mixed-effects analysis of variance applied to log-transformed dose-normalized AUC and identifies a geometric mean with geometric coefficient of variation. At the same time, the numerical estimate, its dispersion, and an uncertainty interval are not reported. This distinction is important: a specified analytical approach does not substitute for the results needed to assess magnitude and precision.

The enrollment of 8 and the stated evaluable-pharmacokinetic-data population also make participant accounting relevant. The number included in the endpoint analysis, missing-data handling, and detailed model specification are not reported in the registry record. Those details would help readers understand how the concentration-time measurements contributed to the estimate.

Finally, the safety counts should be kept separate from the bioavailability result. They describe recorded adverse events, not the primary pharmacokinetic endpoint, and do not establish causation. The trial’s statistical value lies in its focused exposure question and transparent endpoint description, while the missing numerical results limit interpretation of what the analysis found.

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 most important trial-specific limitation for interpretation is that the registry describes the primary endpoint and model but does not report the numerical absolute bioavailability estimate. It also does not report the geometric coefficient of variation, a confidence interval, or a p-value. The magnitude and precision of the primary finding therefore cannot be assessed from the registry record.

The study is recorded as non-randomized, and the registry says the arms are not a like-for-like control comparison. This limits interpretation as a treatment comparison. The described purpose is pharmacokinetic measurement using oral dosing and an intravenous tracer, and should be kept distinct from an efficacy trial.

The registry reports enrollment of 8, but does not report the number of participants included in the primary endpoint analysis. The analysis population is defined by receipt of at least one dose and evaluable pharmacokinetic data; exclusions, incomplete profiles, and missing-data handling are not reported in the registry record. The full model specification and diagnostics are also not reported, limiting independent assessment of the analysis.

The study population is described as healthy participants, which constrains the setting to which the registry’s study description applies. The safety summary reports event counts but does not provide terms for the other adverse events or detailed attribution. The record therefore offers limited information for interpreting the nature of those events.

Finally, the registry’s sample-size assumptions are described as planning illustrations based on an observed effect, rather than as the trial’s own design justification. The trial-specific sample-size rationale is not reported in the registry record. These reporting gaps do not show that the analysis was inappropriate, but they prevent a complete evaluation of its results and assumptions.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of LY3314814 in Healthy Participants — NCT03222427.
• Registry record last updated 2019-10-31; status last verified 2019-10.
• Results first posted 2019-03-22.
• 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

NCT03222427 is a completed phase 1 study sponsored by AstraZeneca, titled “A Study of LY3314814 in Healthy Participants.” The official title describes an absolute bioavailability study using an intravenous tracer method. The registry records study start on 2018-01-15, primary completion on 2018-02-16, and enrollment of 8.

The study used a single oral 50 milligram dose of LY3314814 and a single intravenous 100 microgram dose of labeled LY3314814. The primary endpoint was absolute bioavailability based on dose-normalized AUC, analyzed with a mixed-effects analysis of variance on log-transformed values. The numerical endpoint result is not reported in the registry record.

The registry describes non-randomized allocation and cautions that the arms are not a like-for-like control comparison. Safety counts include 0 serious adverse events, 3 participants with other adverse events, and 0 deaths in the listed combined group. Detailed event terms and primary endpoint estimates are not reported in the registry record.