A Study of Mirikizumab (LY3074828) Injection in Healthy Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Mirikizumab (LY3074828) Injection in Healthy Participants (NCT03053622), a randomized phase 1 study. The primary outcome is Pharmacokinetics (PK): Area Under the Concentration Versus Time Curve From 0 to Infinity (AUC[0-∞]) of Mirikizumab.

2. Clinical Question

The study record describes a single-dose assessment of relative bioavailability, absolute bioavailability, and tolerability. Its secondary outcomes include maximum observed concentration and time of maximum observed concentration. Results for those secondary outcomes are not included in the posted values described in the registry record.

3. Trial Design

This was a Phase 1, randomized, unmasked, parallel-group study of mirikizumab in healthy participants. The registry lists enrollment of 67 and identifies the condition as Healthy. The study is marked completed. Its recorded start date is 2017-04-24, and its primary completion date is 2018-04-03.

Participants were assigned to arms evaluating a 250 mg test formulation delivered subcutaneously as a single injection, the same test formulation delivered as two subcutaneous injections, or the test formulation infused intravenously. A reference formulation was administered as three subcutaneous injections. The registry describes these as single-dose administrations. The available record does not give the number assigned to each arm in the design description; the posted primary endpoint summaries report evaluable group counts separately.

The stated study aim was to compare how much mirikizumab entered the bloodstream and how long it took the body to eliminate it after the different formulation and administration approaches. The study also collected injection side effects. Participants were expected to be in the study for about 18 weeks, including screening, according to the brief summary.

Randomization indicates that assignment to study arms was by chance, but the allocation sequence and concealment procedures are not reported in the registry record. The study was unmasked; further details about who knew each assignment are not reported. The protocol, any planned interim analyses, and the justification for the enrollment target are not reported in the registry record. These details therefore cannot be used to assess design choices beyond the features explicitly recorded.

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

6. Primary Endpoint

The registry lists the primary outcome as Pharmacokinetics (PK): Area Under the Concentration Versus Time Curve From 0 to Infinity (AUC[0-∞]) of Mirikizumab, measured over 0,end of infusion,2,6 hours(h); 24 h; 72 h; 168 h; 240 h; 336 h; 504 h; 672 h; 1008 h; 1344 h; 1680 h; 2016 h, post dose.

The primary endpoint was the pharmacokinetic area under the concentration-versus-time curve from 0 to infinity, abbreviated AUC[0-∞], for mirikizumab. Its unit was microgram*day/milliliter (µg*day/mL). The registry describes the endpoint as a geometric mean with geometric coefficient of variation as the measure of spread. The stated time frame included sampling from 0 through 2016 h post dose, with multiple scheduled measurements in between.

In general, area under a concentration-time curve represents cumulative exposure over the measurement period. Extending the curve to infinity aims to represent total exposure beyond the last observed concentration, using an estimation procedure. The procedure used for that extension is not reported in the registry record.

Exposure is relevant to a bioavailability comparison because it describes the amount of drug reaching systemic circulation over time. Comparing exposure summaries can help characterize how formulation and administration route relate to measured pharmacokinetics. This endpoint alone does not describe every aspect of concentration over time: maximum concentration and the time it occurs are separate pharmacokinetic features. The registry lists those as secondary outcomes, but their results are not reported in the posted results. Nor does an exposure comparison by itself establish clinical benefit or safety in a patient population.

The endpoint population comprised participants who received at least one dose of study drug and had evaluable pharmacokinetic data. The registry does not provide additional detail on how evaluability was defined or how missing concentration measurements were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous pharmacokinetic measure: AUC[0-∞]. The record summarizes each arm with a geometric mean and geometric coefficient of variation, then reports selected pairwise comparisons as ratios of geometric least squares means. The method used to fit the statistical model, the covariates included, and the handling of the repeated concentration measurements are not reported in the registry record. The pairwise ratios therefore can be described as reported analyses, but the precise model assumptions behind them cannot be reconstructed from the record.

Why use a geometric mean?

General statistical explanation: pharmacokinetic measurements are often right-skewed, with some observations much larger than others. A geometric mean summarizes values on a multiplicative scale, typically by transforming values to logarithms, averaging on that scale, and transforming back. This can make relative comparisons more interpretable when proportional rather than absolute differences are of interest. The record identifies geometric means but does not describe the calculations or diagnostics used.

A geometric coefficient of variation describes relative spread rather than spread in the original measurement units. In general, it helps readers assess variability when a multiplicative scale is used. It should not be read as a confidence interval, nor does it show the range of individual participant values. The registry gives no individual-level data or arm-level confidence intervals for the geometric means.

How should the ratios be read?

General statistical explanation: a ratio compares two quantities by expressing one relative to the other. A ratio of 1 corresponds to equal point estimates on that scale. The reported ratios are 0.996, 0.729, 0.422, and 0.307, with the corresponding 90% confidence intervals reported alongside each comparison. The record lists the arms in each comparison, but does not provide a full statistical-method description. The estimates are ratios of geometric least squares means, not simple differences between arithmetic averages.

A confidence interval reflects statistical uncertainty under the model and assumptions used to produce it. It is not a range containing a fixed proportion of individual participants’ results. A 90% confidence interval also does not mean there is a 90% probability that the fixed true value lies in that particular interval. In general, it describes the behavior of the interval-generating procedure over repeated studies under its assumptions. The registry does not report a p-value for these comparisons or specify a decision threshold for interpreting the intervals.

What does variability add?

In general, greater variability can make a comparison less precise, because the observed values provide less concentrated information about the group-level estimate. The reported geometric coefficients of variation are 31.0, 55.0, 36.0, and 22.0 for the reference, two-injection test, single-injection test, and intravenous test arms, respectively. Those summaries contextualize the arm-level means, but they do not replace the confidence intervals for the pairwise ratios.

The outcome was measured at multiple post-dose time points, ending at 2016 h, and summarized as exposure from 0 to infinity. General explanation: extrapolating a measured concentration curve beyond the last observed time can contribute uncertainty to an exposure estimate. The registry does not report how much of the AUC was observed versus extrapolated, the extrapolation method, or related diagnostics. Consequently, that part of the endpoint cannot be independently assessed from the registry record.

The record defines the primary endpoint population as participants who received at least one dose and had evaluable pharmacokinetic data. General explanation: restricting an analysis to participants with usable endpoint data can affect interpretation if the availability of those data is related to treatment assignment or participants’ measured outcomes. The registry does not report reasons for exclusion, missing-data methods, or sensitivity analyses, so the impact of unevaluable data cannot be determined from the record.

The sample-size planning illustration is based on the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; its stated role is planning rather than observed power. General explanation: planning calculations ask what enrollment might be needed under specified assumptions, whereas observed power is not a useful substitute for examining an estimate and its uncertainty after a study. The registry’s own sample-size justification and planning assumptions are not reported in the registry record. No numerical planning results are stated in this account.

10. Analyses Reported by the Sponsor

The registry reports four pairwise analyses as ratios of geometric least squares means with 90% confidence intervals. It does not report p-values or name the statistical method for these comparisons. The posted ratios and intervals are the sponsor-reported analyses; no recalculated comparison values are stated in the registry record. The record does not identify a discrepancy between the posted analysis and a recalculation.

These reported ratios should therefore be read as the registry’s own analysis results, rather than as independent estimates generated from the arm-level summaries. Reconstructing the same model would require details not reported in the registry record, including its model specification and any adjustments. Arm-level geometric means and coefficients of variation alone do not necessarily reproduce adjusted geometric least squares mean ratios.

In general, where a recalculation conflicts with the sponsor’s own analysis, the sponsor’s analysis takes precedence. That issue is not flagged for this record. The useful distinction is that the available comparisons are reported analyses, while the descriptive arm-level means are separate summaries; neither should be mistaken for individual participant data.

11. Multiplicity, Missing Data and Analysis Populations

The registry reports four pairwise comparisons for the primary AUC[0-∞] endpoint. It does not report whether these comparisons were all prespecified, whether a particular contrast was primary among them, or whether any multiplicity adjustment was applied. The statistical plan and any testing hierarchy are not reported in the registry record.

General statistical explanation: when several hypotheses are tested, the chance of at least one false-positive finding can increase if each is assessed independently at the same threshold. Procedures for controlling multiplicity can alter confidence intervals or significance thresholds. Because the record does not describe such procedures and reports no p-values, the pairwise intervals should be interpreted as the reported estimates and uncertainty intervals, not as a documented family-wise testing strategy. No formal claim about multiplicity control can be made.

The registry gives an endpoint population of participants who received at least one dose and had evaluable pharmacokinetic data. Arm-level primary endpoint counts are reported for the reference arm, the two-injection subcutaneous test arm, the single-injection subcutaneous test arm, and the intravenous test arm. The record does not describe how many participants lacked evaluable endpoint data, the reasons for any exclusions, or whether missing measurements occurred at particular time points.

General statistical explanation: excluding participants without evaluable measurements can affect an estimate if missingness is related to exposure or treatment arm. Different missing-data assumptions can produce different interpretations. The registry does not state whether missing measurements were imputed, whether analyses used available observations, or whether sensitivity analyses were conducted. It also does not provide enough information to assess whether endpoint evaluability was determined without knowledge of arm assignment.

Interim analyses, stopping rules, and a detailed statistical analysis plan are not reported in the registry record. The record therefore supports description of the posted estimates and their stated intervals, but not a conclusion about the completeness of the planned statistical safeguards.

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 adverse-event figures distinguish serious adverse events from other adverse events. No serious adverse events are reported in any of the four arms, and deaths are reported as 0 in each arm. The numbers at risk for serious adverse events are 17 for the reference arm, 16 for the two-injection subcutaneous test arm, 17 for the single-injection subcutaneous test arm, and 17 for the intravenous test arm.

For other adverse events, the record reports affected counts of 17 among 17 at risk in the reference arm, 15 among 16 at risk in the two-injection subcutaneous test arm, 17 among 17 at risk in the single-injection subcutaneous test arm, and 15 among 17 at risk in the intravenous test arm. These are counts as recorded, not estimates of comparative risk. The registry does not provide event-specific descriptions in the posted serious-event terms, and no top serious-event terms are listed.

General statistical explanation: observing no serious events in a study does not establish that the underlying risk is absent; rare events may not occur in a study of limited size. The adverse-event figures also do not by themselves establish whether an event was caused by study drug. The record does not report event severity details, duration, or arm-specific event types in the values. These safety observations should be read within the scope of this study rather than as a complete characterization of tolerability.

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

The reported results describe pharmacokinetic exposure after single-dose administration of mirikizumab formulations and routes in healthy participants. AUC[0-∞] summarizes exposure over time; the arm-level geometric means and pairwise ratios provide complementary descriptions of the observed exposure data. The ratios compare geometric least squares means, and their 90% confidence intervals convey uncertainty under the reported analysis.

These findings do not establish a clinical treatment effect. Participants were healthy, the study was Phase 1, and the recorded primary outcome was pharmacokinetic rather than a measure of disease symptoms, function, or clinical events. The registry record does not report outcomes in a patient population or results from repeated dosing. It also does not report results for the listed secondary outcomes of maximum observed concentration and time of maximum observed concentration.

The comparisons do not establish formal bioequivalence or equivalence because the registry does not state a prespecified acceptance margin or testing procedure for that purpose. A ratio near 1 is a descriptive feature of the estimate, not by itself evidence that a criterion was met. Similarly, the intervals should not be treated as proof of equivalence or of a clinically meaningful difference without an applicable decision framework.

The absence of reported serious adverse events in the recorded groups is a description of observed events in this study, not evidence that serious events cannot occur. The other adverse-event counts indicate that events were recorded, but the available record does not give enough detail to characterize each event or attribute it to treatment.

In general, statistical estimates are most informative when considered together with the population, endpoint definition, analysis method, and uncertainty. Here, the population and endpoint are described, but several analysis details are not reported in the registry record. The results can therefore inform a statistical reading of the posted pharmacokinetic comparisons, while leaving questions about analysis assumptions, missing data, and multiplicity unresolved.

14. Why This Trial Matters Statistically

This study is statistically informative because it compares multiple formulation and administration approaches using a pharmacokinetic endpoint suited to describing exposure. The primary measure, AUC[0-∞], summarizes concentration over time rather than relying on a single measurement. The registry also reports geometric means and geometric coefficients of variation, which offer a view of both typical exposure on a multiplicative scale and relative variability.

The parallel randomized design supports comparisons across assigned arms, while the unmasked designation and limited method details are important context for interpreting the record. The pairwise ratios show that the registry’s analysis considered more than the reference formulation against a single test arm: it also reports comparisons among test approaches. That structure makes clear why the overall study cannot be reduced to one comparison.

Confidence intervals matter because the point estimates alone do not show their precision. The reported intervals provide uncertainty information for the ratios, while the arm-level coefficients of variation describe spread in a different way. Reading both types of summaries together is more informative than ranking the arm means alone. At the same time, the absence of a reported equivalence margin, model specification, and multiplicity plan limits what can be inferred from the comparisons.

The record also illustrates a boundary between pharmacokinetic and clinical evidence. Exposure measures can support evaluation of how a product is absorbed and distributed over time, but this study’s posted endpoint does not establish clinical outcomes. The healthy-participant setting and single-dose focus further define the scope of inference. Thus, the statistical value of the record lies in describing measured exposure and its uncertainty, not in answering questions beyond that design and endpoint.

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.

Several trial-specific details needed for a fuller statistical assessment are not reported in the registry record. These include the randomization procedure, allocation concealment, the statistical model used for the geometric least squares mean comparisons, any covariate adjustments, and the method used to estimate AUC beyond the last observed concentration. The record gives no arm-level confidence intervals for the geometric means.

The primary endpoint analysis population is defined as participants who received at least one dose and had evaluable pharmacokinetic data, but the record does not explain evaluability criteria or exclusions. It does not describe missing concentration measurements, their reasons, or sensitivity analyses. Therefore, the possible influence of missing data on the reported estimates cannot be assessed.

The registry does not report whether the four pairwise primary endpoint comparisons were prespecified as a group, how multiplicity was handled, or whether any comparison had a distinct testing priority. It also does not state a formal margin for bioequivalence or equivalence. The confidence intervals alone cannot establish that a formal criterion was satisfied.

The record lists maximum observed concentration and time of maximum observed concentration as secondary outcomes, but does not report their results in the posted values. Event-specific descriptions beyond the serious-event counts are also not provided in those values. The sample-size rationale, protocol, and detailed statistical analysis plan are not reported in the registry record.

Finally, the study concerned healthy participants and single-dose administration. Its findings cannot by themselves establish pharmacokinetic behavior in other populations or under other dosing conditions, and the AUC endpoint is not a clinical efficacy outcome. These limitations define the reach of the reported results rather than invalidate the descriptive comparisons.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of Mirikizumab (LY3074828) Injection in Healthy Participants — NCT03053622.
• Registry record last updated 2024-02-21; status last verified 2024-02.
• Results first posted 2024-02-21.
• 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

The registry record describes a completed Phase 1 randomized, unmasked, parallel study of mirikizumab in healthy participants, with enrollment of 67. The study compared a reference formulation and test formulation administered by subcutaneous injection or intravenous infusion after a single dose.

The primary endpoint was geometric mean AUC[0-∞]. The record reports arm-level exposure summaries and four ratios of geometric least squares means with 90% confidence intervals. The listed secondary outcomes were maximum observed concentration and time of maximum observed concentration, but their results are not reported in the posted values. No serious adverse events or deaths are reported; other adverse events were recorded in the arms.

The registry does not report key details of the statistical model, multiplicity handling, missing-data procedures, or sample-size rationale. The results are therefore best read as the posted pharmacokinetic summaries and comparisons for this healthy-participant, single-dose study.