A Study of Insulin Peglispro in Healthy Male Japanese Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Insulin Peglispro in Healthy Male Japanese Participants (NCT01995526), a na phase 1 study. The primary outcome is Pharmacokinetics: Observed Maximum Concentration (Cmax) of Insulin Peglispro.

2. Clinical Question

The study’s stated purpose was to evaluate how the body processes insulin peglispro and how the drug affects blood sugar in healthy male Japanese participants. Safety was also to be evaluated. The primary endpoint listed in the registry record is pharmacokinetic: observed maximum concentration, or Cmax. It is not a comparative endpoint between treatments because the record lists one intervention and no control group.

The registry record does not report numerical Cmax results, blood-sugar results, or statistical estimates for the primary endpoint. It therefore does not establish what concentration was observed or how variable the measurements were. The listed endpoint population is limited to participants who received the drug and had evaluable Cmax data; the number meeting that definition is not reported in the registry record.

3. Trial Design

This is a Phase 1 study listed as completed. It used a single-group model, with no allocation to separate treatment groups and no masking. The registry record lists 11 participants as enrolled. The study ran from 2013-12 to primary completion in 2014-01.

All participants in the listed intervention group were assigned a single subcutaneous dose of insulin peglispro at 1.3 Units per kilogram on Day 1. The study was intended to examine pharmacokinetics, glucodynamics, and safety in healthy male Japanese participants. The brief description states that participation could last up to 46 days for each participant, not including screening.

Because the record describes a single group without a control arm, its design cannot estimate a treatment contrast against placebo, usual care, or another active intervention. It can describe measurements collected after dosing, but the absence of a concurrent comparator limits what can be attributed to the drug rather than to other influences or the study context.

The record lists five outcome measures, while the number of analyses is listed as zero. It does not report a statistical analysis plan, an interim-analysis plan, or a sample-size justification. The registry record also does not explain why this enrollment target was chosen. These omissions mean the design description does not establish how outcome data were intended to be analyzed beyond the primary endpoint summary specified in the record.

The record’s completed status and dates describe the study’s administrative course; they do not, by themselves, indicate that numerical results were posted. For the primary endpoint, the registry record states the measure, unit, summary type, dispersion measure, sampling schedule, and analysis population, but it does not report the resulting estimates.

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 insulin peglispro and had evaluable Cmax 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 enrolled participants.

6. Primary Endpoint

The registry lists the primary outcome as Pharmacokinetics: Observed Maximum Concentration (Cmax) of Insulin Peglispro, measured over Predose and 2, 4, 8, 12, 24, 30, 36, 48, 96, 144, and 192 hours postdose.

The primary endpoint is the observed maximum concentration, or Cmax, of insulin peglispro. It is expressed in picomoles per liter (pmol/L). Cmax describes the highest measured concentration over the sampling schedule; it is a pharmacokinetic measure of drug exposure in the blood, rather than a measure of blood-sugar effect or a clinical outcome.

The registry record specifies a geometric mean as the summary measure and a geometric coefficient of variation as the measure of dispersion. In general, a geometric mean is useful for positive measurements whose distribution is asymmetric, since it summarizes values on a multiplicative scale. The geometric coefficient of variation describes relative spread on that scale. These summaries can help readers understand both a typical concentration and variability across participants, but they do not replace the underlying observations or convey the precision of an estimate on their own.

Measurements were scheduled predose and at 2, 4, 8, 12, 24, 30, 36, 48, 96, 144, and 192 hours postdose. The endpoint population is described as all participants who received insulin peglispro and had evaluable Cmax data. The registry record does not report the observed Cmax, its geometric coefficient of variation, a confidence interval, or the number of participants with evaluable Cmax data. Consequently, the endpoint definition is available, but its numerical result and precision cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does Cmax summarize?

Cmax is the maximum observed concentration of a drug in the collected samples. It is a pharmacokinetic summary: it describes measured drug concentration, not by itself the duration of exposure, the total exposure over time, or a clinical effect. The record specifies insulin peglispro concentration in picomoles per liter (pmol/L) and identifies the endpoint as observed maximum concentration.

Sampling time matters because a maximum can only be identified from the measurements collected. The specified schedule begins predose and includes 2, 4, 8, 12, 24, 30, 36, 48, 96, 144, and 192 hours postdose. In general, an observed maximum is the highest measured value among scheduled samples; it need not be the exact concentration at every moment between samples. The registry record does not report individual concentration profiles or the resulting Cmax values.

Why use a geometric mean?

The record specifies a geometric mean. In general, geometric summaries are suited to positive measurements that are asymmetric and are naturally interpreted in relative or multiplicative terms. A geometric mean is not the same as an arithmetic average. It summarizes values after considering their logarithms and then returning the summary to the original measurement scale. This approach can make sense for concentration data when a small number of high values would otherwise pull an arithmetic mean upward.

The record also specifies a geometric coefficient of variation as the dispersion measure. In general, this expresses spread relative to the geometric mean, rather than as an absolute difference in concentration units. It helps describe how variable participant measurements are on a multiplicative scale. Neither a geometric mean nor a geometric coefficient of variation is a substitute for a confidence interval: the former describes a central value, the latter describes dispersion, and an interval conveys uncertainty in an estimate under stated assumptions. No numerical values for these summaries or a confidence interval are reported in the registry record.

What can a single-group study estimate?

The study is listed as single-group, with no allocation to a comparison arm and no masking. It evaluates participants after a single subcutaneous dose of 1.3 Units per kilogram on Day 1. In general, a single-group design can describe measurements within the treated group. It does not directly estimate a between-group treatment difference, because no concurrent comparator is listed. This distinction is important: a postdose measurement is not itself evidence of a contrast against an untreated or differently treated group.

Allocation and masking are listed as NA and NONE, respectively. The record does not state a randomized comparison. Thus, comparative effect estimates, randomization-based balance between treatment groups, and masked outcome assessment between groups should not be inferred from this design description.

How should planning illustrations be read?

Any sample-size illustrations associated with the results are planning exercises, not outcomes observed in this study. The stated assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. Such calculations answer a hypothetical design question: how many participants per arm might be needed under those assumptions to detect a chosen effect size. They are not observed power and do not show that the study had a particular probability of detecting an effect.

The record describes this trial as single-group, so the two-arm planning assumptions should not be mistaken for the actual study design. The registry record does not report the observed primary endpoint estimate or the numerical outputs of those planning illustrations. No sample-size justification for the study itself is reported in the registry record.

What can be concluded from the listed analyses?

The registry record lists five outcome measures and zero analyses. It gives the primary endpoint’s summary type, dispersion measure, time points, and analysis population, but not the corresponding estimates. A specified method tells readers how a quantity is characterized; it does not disclose the data or the result. The record does not report model details, adjustment variables, tests, confidence intervals, or a full statistical analysis plan.

These distinctions prevent overinterpretation. General statistical methods explain how summaries may be understood, but they cannot recover absent trial results. With no numerical Cmax result, no uncertainty estimate, and no comparator, the posted record cannot support a quantitative claim about the size of a treatment effect or its precision.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists five outcome measures, but it does not report how they were prioritized beyond identifying the primary endpoint. It also lists zero analyses. A statistical analysis plan describing testing order, multiplicity adjustment, or how conclusions would account for multiple outcomes is not reported in the registry record.

In general, multiplicity arises when several outcomes or statistical tests are considered: the chance of at least one apparently notable result can increase if each is assessed without a plan for handling multiple comparisons. That general concern does not establish that a particular adjustment was necessary or used in this study. The registry record does not provide enough analysis detail to determine how multiplicity was addressed.

The primary endpoint population is defined as participants who received insulin peglispro and had evaluable Cmax data. The record lists 11 enrolled participants, but it does not report how many had evaluable Cmax data, whether any measurements were missing, how missing observations were handled, or whether participants were excluded from endpoint analyses. Details on imputation, sensitivity analyses, and the handling of protocol deviations are not reported in the registry record.

The record’s population definition should therefore be read as an endpoint-specific description, not as evidence that every enrolled participant contributed to the primary analysis. The absence of reported missing-data methods also limits assessment of potential bias if measurement availability was related to participant characteristics or observed concentrations. These matters cannot be resolved from the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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 record lists 11 participants at risk for serious adverse events, with zero participants affected. For other adverse events, it lists 11 participants at risk and one participant affected. These are event-category counts, not estimates of a comparison between treatment groups; the study has no listed comparator group.

The record does not list terms among the top serious adverse events. It does not identify the term for the other adverse event in the registry record for this study. Deaths are not reported in the registry record. These distinctions matter: a zero count for the listed serious adverse event category is not equivalent to a complete account of every safety outcome, and an unspecified other-event count does not reveal the event’s nature or severity.

The counts describe what the registry record reports for this study. They do not establish the frequency of events in a broader population or provide a comparative estimate. The record does not report additional detail on event timing, duration, outcome, or relationship to treatment. Those safety details are not reported in the registry record.

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

This study addresses a defined early-phase pharmacokinetic question: the observed maximum concentration of insulin peglispro after a single subcutaneous dose in healthy male Japanese participants. The registry record specifies the concentration unit, geometric summary, dispersion measure, sampling times, and endpoint population. These details make the intended measurement clear.

However, the registry record does not report the numerical Cmax result, its geometric coefficient of variation, or an interval expressing uncertainty. It also does not report numerical glucodynamic results. Consequently, the posted results do not allow readers to judge the magnitude or precision of the primary concentration estimate, or to assess the blood-sugar findings described as a study aim.

The single-group design does not provide a randomized comparison against another treatment or a control. The study can be understood as a description of measurements in the treated group, not as an estimate of comparative effectiveness. No claim that insulin peglispro works or does not work follows from the endpoint definition alone.

The safety figures record zero participants with a serious adverse event and one participant with an other adverse event, each among 11 at risk. These counts are limited to what is listed in the registry record. The event term and further safety details are not reported there, and deaths are not reported in the registry record.

In short, the record explains what the study was designed to measure and how its primary pharmacokinetic endpoint was to be summarized. It does not provide enough numerical outcome information to assess the primary result’s size or precision, support a treatment comparison, or characterize the full safety profile. Those limits apply to the available registry information and should not be mistaken for evidence that unreported analyses or measurements had a particular result.

13. Why This Trial Matters Statistically

This study is a useful example of why a clear endpoint definition and a reported result are separate parts of statistical interpretation. The registry record identifies Cmax, its measurement unit, the geometric mean, the geometric coefficient of variation, the sampling schedule, and the endpoint population. Together, those details describe what the investigators intended to summarize.

At the same time, the record does not report the numerical endpoint estimate or its uncertainty. Without those, readers cannot evaluate the concentration level, variability, or precision. A well-defined measure is not a substitute for a result, and a summary statistic cannot be interpreted quantitatively when its estimate is absent.

The single-group design also illustrates the difference between describing an outcome and estimating a comparative effect. The record lists one intervention and no comparator. Thus, the study can describe postdose pharmacokinetic measurements in the study population, but it does not supply a between-treatment contrast. This is a design limitation for comparative questions, not a flaw in describing the study’s stated pharmacokinetic objective.

Finally, the safety counts and the primary endpoint population show why denominators and analysis populations matter. The registry lists participants at risk for adverse events and separately defines who is eligible for the primary endpoint analysis. It does not report the evaluable Cmax count or additional safety details. Readers therefore need to distinguish the design and count information that is recorded from results and methods that are not reported.

The statistical lesson is restrained interpretation: distinguish a measurement definition from its observed value, a within-group description from a comparative estimate, and planning assumptions from observed study evidence.

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 interpreting this trial is that the registry record does not report numerical results for the primary Cmax endpoint. It gives the planned summary and sampling schedule, but no geometric mean, geometric coefficient of variation, or confidence interval. The number of participants with evaluable Cmax data is also not reported in the registry record.

The study is single-group, and no comparator is listed. Accordingly, the record cannot support a direct comparison with another treatment or control condition. The sample comprises healthy male Japanese participants, so the registry description does not establish how findings would apply to other populations. The trial’s stated aims include glucodynamics and safety, but numerical glucodynamic results and detailed safety findings are not reported in the registry record.

The record lists five outcome measures and zero analyses, but does not provide a full analysis plan. It does not report how missing data were handled, whether any participants were excluded from endpoint analyses, or whether sensitivity analyses were conducted. These omissions limit assessment of how robust the endpoint summaries would be to incomplete observations or analytic choices.

Safety reporting is also limited in the available information. The record lists zero serious adverse events and one other adverse event among 11 at risk, but does not give the other event’s term or additional event details. Deaths are not reported in the registry record.

Finally, the trial’s completed status does not supply the absent numerical findings. The study dates and design details contextualize the record, but do not resolve the uncertainty created by missing outcome estimates and analysis information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Insulin Peglispro in Healthy Male Japanese Participants — NCT01995526.
• Registry record last updated 2018-10-19; status last verified 2018-03.
• Results first posted 2018-10-19.
• 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

NCT01995526 is a completed Phase 1, single-group study titled “A Study of Insulin Peglispro in Healthy Male Japanese Participants.” The registry record lists Eli Lilly and Company as sponsor and 11 participants as enrolled. The study ran from 2013-12 to primary completion in 2014-01.

Participants received a single subcutaneous dose of insulin peglispro at 1.3 Units per kilogram on Day 1. The primary endpoint was observed maximum concentration, summarized as a geometric mean with geometric coefficient of variation over predose and postdose sampling times through 192 hours. The endpoint population was participants who received the drug and had evaluable Cmax data.

The record lists five outcome measures and zero analyses. It reports zero serious adverse events among 11 at risk and one other adverse event among 11 at risk. Numerical primary endpoint results, detailed glucodynamic results, and further safety details are not reported in the registry record.