A Study of Lasmiditan in Healthy Chinese Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Lasmiditan in Healthy Chinese Participants (NCT04081324), a randomized phase 1 study. The primary outcome is Pharmacokinetics (PK): Area Under the Concentration Versus Time Curve From Time Zero to Infinity AUC(0-∞) of Lasmiditan.

2. Clinical Question

The study examined safety, tolerability, and pharmacokinetics of lasmiditan in healthy Chinese participants. Its primary posted outcome concerns the amount of lasmiditan in the body over time after a single dose on Day 1. The registry record also reports adverse-event counts for placebo and three lasmiditan dose groups. This is a pharmacokinetic and safety study, not a trial of clinical benefit in people with a disease.

The study summary also states that the purposes included evaluating safety and learning more about how the body processes lasmiditan. It was planned to last up to 50 days for each participant. The posted results can describe the reported pharmacokinetic values and adverse-event counts, but they do not establish effects on symptoms or clinical outcomes.

3. Trial Design

This is a completed Phase 1, randomized, double-masked, parallel-group study sponsored by Eli Lilly and Company. The registry record lists 36 participants enrolled. The listed study start date is 2019-11-13, and the primary completion date is 2020-06-15. The record identifies the condition as healthy participants and gives no disease condition for the study population.

Four groups are described: placebo and lasmiditan at 50 mg, 100 mg, and 200 mg. The posted pharmacokinetic results include 10 participants in each of the three active dose groups. Adverse-event risk counts are 6 for placebo and 10 for each active group. The registry record does not state the reason for the difference in group sizes or give further details about the randomization procedure.

For active treatment, the arm descriptions state that participants received a single oral dose on the morning of Day 1 after an overnight fast of at least 8 hours. After at least 72 hours without dosing, participants received once-daily oral doses on Days 4 to 10. The placebo description specifies oral dosing on Day 1 and repeated doses on Days 4 to 10. The registry record says the study could last up to 50 days for each participant.

Randomization is intended, in general, to support comparisons by distributing participant characteristics across assigned groups. Double masking is intended, in general, to limit the influence of treatment knowledge on participant experience and study assessments. These design features do not by themselves show that groups were comparable in every respect or that a particular analysis was unbiased. Details of allocation concealment, masking procedures, and the statistical plan are not reported in the registry record.

The design and reported outcomes are focused on early safety and pharmacokinetics. The registry record does not describe a clinical efficacy endpoint or a disease-treatment comparison. The available arm-level values should therefore be read as descriptive summaries within this study, rather than as evidence of a clinical treatment effect.

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 and had evaluable pharmacokinetic 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 Time Zero to Infinity AUC(0-∞) of Lasmiditan, measured over Predose, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, and 24 hours post-dose.

The primary endpoint is the area under the lasmiditan concentration-versus-time curve from time zero to infinity, abbreviated AUC(0-∞), after a single dose on Day 1. The stated unit is nanogram*hour per milliliter (ng*h/mL). Concentrations were scheduled at predose and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, and 24 hours post-dose.

In general, an area-under-the-curve measure combines concentration measurements across time into an estimate of overall drug exposure during the specified interval. Extending the endpoint to infinity includes an estimated portion beyond the last observed concentration, so the endpoint is not simply a concentration at one scheduled time. The registry record does not describe the calculation method or the extent of any extrapolation.

The endpoint is reported as a geometric mean with geometric coefficient of variation as its dispersion measure. In general, a geometric mean is useful for positive measurements whose distribution may be asymmetric; it summarizes values on a multiplicative scale rather than by ordinary addition. A coefficient of variation describes relative spread around a mean. These summaries communicate the typical reported exposure and its variability, but do not by themselves provide a confidence interval or test of a difference between doses.

The posted geometric means are 385.0 ng*h/mL for 50 mg, 829.0 ng*h/mL for 100 mg, and 1990.0 ng*h/mL for 200 mg. The corresponding geometric coefficients of variation are 48.0, 34.0, and 34.0. Formal comparative estimates are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary result is a descriptive pharmacokinetic summary rather than a posted hypothesis test. The record reports geometric means and geometric coefficients of variation for AUC(0-∞) within each lasmiditan dose group. It gives no p-value, confidence interval, standard error, or estimate of a between-group contrast. Without those comparative quantities, the numeric ordering of the group summaries should not be treated as a formal test of differences.

What the geometric mean describes

In general, the geometric mean summarizes positive measurements after representing them on a logarithmic scale and then returning the summary to the original scale. This can be appropriate when measurements vary multiplicatively or have a right-skewed distribution. It differs from the arithmetic mean, which summarizes values through ordinary addition. The registry record identifies the reported parameter as a geometric mean, but does not specify the transformation, model, or computational details used to obtain it.

The geometric coefficient of variation is reported as the dispersion measure. In general, a coefficient of variation describes spread relative to the scale of the mean, rather than spread in the endpoint’s original measurement units. It is distinct from a confidence interval: a coefficient of variation describes variability among measurements, while a confidence interval would describe uncertainty around an estimated parameter under a specified method. Confidence intervals are not reported in the registry record.

Why AUC is used

In general, the area under a concentration-time curve captures exposure across multiple measurement times rather than relying on one concentration. AUC(0-∞) refers to the interval from the dose time through an estimate extending to infinity. Because the stated endpoint uses an infinite endpoint, its calculation ordinarily involves information beyond the last measured concentration; the specific approach and diagnostics are not reported in the registry record. The time points named for this outcome run from predose through 24 hours post-dose.

Exposure measures such as AUC are used in pharmacokinetic studies to characterize how much drug is present over time. They are not direct measures of symptom change, clinical benefit, or long-term safety. The Day 1 endpoint is specifically described as following a single dose. It should not be conflated with measurements after the repeated dosing period.

How to read the group values

The arm-level geometric means are 385.0, 829.0, and 1990.0 ng*h/mL for the 50 mg, 100 mg, and 200 mg groups, respectively. The corresponding geometric coefficients of variation are 48.0, 34.0, and 34.0. These values allow a descriptive reading of the reported group summaries. No formal contrast, dose-response model, or test of dose proportionality is reported. In general, evaluating dose proportionality requires more than observing that group means rise across dose groups; it requires an analysis that estimates the relationship and its uncertainty.

Randomized allocation can support a causal comparison when a trial prespecifies an appropriate contrast and analysis, and when relevant assumptions are met. Here, the posted primary outcome results are arm-level summaries, not a reported randomized treatment contrast. The registry record does not identify a primary statistical model or state whether the analysis adjusted for any covariates. Therefore, no adjusted or unadjusted inferential result should be inferred from the group summaries.

Why variability and over-dispersion matter in general

In general, greater variability makes an estimate less precise when other design features are held constant. Over-dispersion refers broadly to observed variation exceeding what a chosen statistical model expects. If present, it can make standard errors from an overly restrictive model too small and confidence intervals too narrow. The registry record does not report an over-dispersion assessment or a model for these results, and the geometric coefficients of variation should not be interpreted as proof that a specific model issue was present.

Small group counts also limit the detail available for describing a distribution. A group summary does not reveal the individual measurements, possible outliers, or whether all observations contributed in the same way. Individual-level data and distributional plots are not described in the registry record. The reported sample counts and summary statistics thus provide a compact account, but not a complete assessment of the underlying data.

Planning calculations and observed results

In general, a sample-size planning illustration asks how many participants might be needed under stated assumptions to detect a specified effect with a chosen significance level and power. Such a calculation is not observed power and is not a statement about the actual design rationale. The registry record describes planning assumptions based on a fraction of an observed effect, equal allocation, a two-sided significance level of 0.05, and a normal approximation. These are planning assumptions, not evidence that the trial was designed using that procedure. The actual sample-size justification is not reported in the registry record.

The registry record does not report an estimable two-arm comparison for the other endpoint. A planning illustration based on an effect requires a defined comparison and effect estimate; it cannot replace missing comparative results. Any planning values should be understood only as hypothetical design illustrations, not as trial findings or evidence that the study had adequate power.

Finally, the absence of posted analyses is important. It means the record does not supply a statistical comparison that could answer whether the observed arm-level differences are compatible with chance variation under a specified model. General statistical principles can clarify what the summaries mean, but they cannot fill in an analysis, model, or uncertainty estimate that the registry record does not report.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 4 outcome measures and 0 posted secondary outcomes. It also reports 0 analyses. The primary outcome is the single-dose Day 1 AUC(0-∞) measure. The names, definitions, and statistical handling of the remaining outcome measures are not described in the material available in the registry record.

Multiplicity arises in general when several outcomes, time points, doses, or contrasts are tested. Conducting many tests can increase the chance of at least one apparently unusual result, unless the analysis plan addresses that issue. The registry record does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment. Because formal inferential analyses are not posted, it is not possible to assess how any multiplicity plan was implemented or how it would affect inference.

The stated pharmacokinetic analysis population includes randomized participants who received at least one dose of study drug and had evaluable pharmacokinetic data. The registry record does not give participant-level inclusion or exclusion details, the number excluded from this population, or a comparison between randomized and analyzed participants. It does not describe a missing-data method, imputation, or sensitivity analysis. The extent and handling of missing or nonevaluable measurements are therefore not reported in the registry record.

In general, excluding participants without evaluable measurements can affect interpretation if the reasons for missingness are related to treatment or to the outcome. The available group summaries do not show whether that concern applies. The statistical analysis plan, the method for selecting analysis populations, and any prespecified handling of incomplete data are not reported in the registry record. These gaps limit assessment of how robust the reported summaries are to missingness and analytic choices.

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 serious adverse-event figures are counts of participants affected among the participants listed as at risk. The registry record reports 0 serious adverse events among 6 placebo participants, 0 among 10 participants receiving 50 mg lasmiditan, 0 among 10 receiving 100 mg, and 0 among 10 receiving 200 mg. It also reports 0 deaths in each group. No serious adverse-event terms are listed.

These counts describe what was reported during the study; they do not demonstrate that the risk of a serious event is absent. With small groups, a count of zero still leaves uncertainty about events that might occur in a larger or different population. The registry record does not provide confidence intervals or a formal comparison of serious adverse-event rates.

Other adverse events affected 5 of 6 participants in the placebo group, 9 of 10 in the 50 mg group, 10 of 10 in the 100 mg group, and 8 of 10 in the 200 mg group. These are participant counts, not counts of distinct event types or event episodes. The registry record does not provide the specific non-serious event terms in the registry record reported for this study, nor does it establish whether an event was caused by study treatment.

Because group sizes differ and are small, raw counts are best read descriptively. They do not provide a precise comparative safety estimate, and they should not be converted into an informal ranking of treatment safety.

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

The registry record supports a descriptive account of single-dose lasmiditan exposure in healthy Chinese participants and a summary of adverse-event counts across the study groups. The reported geometric mean AUC(0-∞) values were 385.0 ng*h/mL for 50 mg, 829.0 ng*h/mL for 100 mg, and 1990.0 ng*h/mL for 200 mg. The geometric coefficients of variation were 48.0, 34.0, and 34.0, respectively. These figures characterize the posted summaries, not a formal comparison.

The record also reports 0 serious adverse events and 0 deaths in the listed groups. Other adverse events affected participants in every group, with the counts reported separately by group. These counts describe the observations recorded for this study; they do not establish causation or precisely quantify differences in risk.

The results do not show whether the group differences in exposure are statistically distinguishable, because comparative estimates and their uncertainty are not reported. They do not establish dose proportionality, explain repeated-dose exposure, or provide a clinical efficacy result. The primary endpoint measures pharmacokinetic exposure after a single dose; it is not a measure of symptoms or patient benefit.

The study enrolled healthy participants and was a Phase 1 study. Its results cannot, by themselves, answer questions about use in people with a disease or establish outcomes in broader populations. The record does not report an inferential analysis, a sample-size justification, or a statistical analysis plan. Consequently, the most defensible interpretation stays close to the posted group summaries and avoids treating descriptive differences as confirmed effects.

In general, statistical evidence depends not only on the size and direction of observed estimates, but also on their uncertainty, study design, and the analysis used. Here, the available material documents selected exposure and safety summaries, while leaving important questions about comparative precision and analysis unanswered.

13. Why This Trial Matters Statistically

This study illustrates a common statistical distinction in early pharmacology research: a measured exposure summary is not the same as a clinical outcome, and an arm-level descriptive pattern is not the same as an inferential comparison. The AUC(0-∞) endpoint integrates concentration over time and is reported separately for three lasmiditan dose groups. That makes the result useful for describing pharmacokinetic exposure within the studied groups, while leaving the uncertainty around dose contrasts unresolved.

The use of geometric means and geometric coefficients of variation also highlights how the choice of summary should reflect the data scale. In general, pharmacokinetic measurements are positive and may vary multiplicatively; a geometric summary can therefore be informative. Readers still need information about the calculation, distribution, and uncertainty to judge how stable the summaries are. Those analysis details are not reported in the registry record.

The small group counts make careful interpretation especially important. A zero count of serious adverse events is a useful description of what was observed, but it is not proof that no risk exists. Likewise, counts of other adverse events do not establish a comparative treatment effect. Statistical interpretation should account for the amount of information available and distinguish absence of a reported event from certainty about future outcomes.

The registry record also demonstrates why a registered endpoint and a complete analysis plan matter. A primary outcome can be clearly named and measured, yet still lack posted confidence intervals, formal comparisons, and details of missing-data handling. Those omissions constrain reproducibility and the strength of conclusions that can be drawn from registry results.

For clinical researchers, the key lesson is to separate descriptive pharmacokinetic findings from claims about treatment effects. The study contributes exposure and safety observations in its stated population; comparative precision and broader clinical meaning require evidence that is not reported in this record.

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 main limitation is the lack of posted inferential analyses for the primary pharmacokinetic outcome. The registry record gives group-level geometric means and geometric coefficients of variation, but does not report confidence intervals, p-values, or estimates of between-dose contrasts. The precision of the observed differences is therefore not available.

The reported pharmacokinetic results cover the three lasmiditan groups, while a placebo pharmacokinetic value is not reported in the registry record. The primary outcome is described for a single dose on Day 1, so it does not by itself characterize exposure after the repeated dosing period. The registry record does not report a formal dose-response or dose-proportionality analysis.

The pharmacokinetic analysis population is defined as randomized participants who received at least one dose and had evaluable data, but participant flow into that population and the handling of nonevaluable measurements are not reported. A missing-data method and sensitivity analyses are also not reported. These omissions make it difficult to assess whether the available summaries represent all randomized participants or whether missingness could affect interpretation.

The study groups are small: the reported pharmacokinetic count is 10 participants per active dose group, and the placebo safety risk count is 6. This limits the detail and precision that can be obtained from group summaries, particularly for adverse events. Zero reported serious adverse events should be understood in that context, rather than as evidence that serious events cannot occur.

The registry record does not report the sample-size justification, the statistical analysis plan, masking procedures in detail, or a multiplicity strategy. It also does not provide individual-level results or detailed non-serious adverse-event terms in the information summarized for this study. These specific limitations restrict evaluation of model assumptions, analytic choices, and the comparability of groups.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Lasmiditan in Healthy Chinese Participants — NCT04081324.
• Registry record last updated 2021-07-01; status last verified 2021-06.
• Results first posted 2021-07-01.
• 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, randomized, double-masked, parallel Phase 1 study of lasmiditan in healthy Chinese participants. It lists 36 participants enrolled and a study duration of up to 50 days per participant. The groups received placebo or 50 mg, 100 mg, or 200 mg lasmiditan; active treatment included a single Day 1 dose and repeated once-daily dosing on Days 4 to 10.

The primary posted outcome is single-dose Day 1 AUC(0-∞), reported as geometric means and geometric coefficients of variation for the three lasmiditan dose groups. The record also gives serious and other adverse-event counts. No serious adverse events or deaths are reported among the listed risk counts.

Formal analyses, comparative uncertainty estimates, multiplicity handling, and missing-data methods are not reported in the registry record. The available results are descriptive and concern pharmacokinetics and safety in the study population.