This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study of Insulin Peglispro and Glargine on Fats in Participants With Type 1 Diabetes (NCT01771250), a randomized phase 1 study. The primary outcome is Very Low Density Lipoprotein-Triglyceride (VLDL-TG) Concentrations.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01771250 |
| Phase | Phase 1 |
| Condition | Diabetes Mellitus, Type 1 |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 15 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Eli Lilly and Company |
| Results posted | Yes |
2. Clinical Question
Population
Participants with type 1 diabetes who were randomized and received at least one dose of study drug. The registry reports enrollment of 15 and specifies this treated randomized group as the primary endpoint population.
Intervention
Daily subcutaneous insulin peglispro during one treatment period. The dose was stable and based on prestudy basal insulin dosing; the registry describes a range of 0.2 to 0.8 units per kilogram.
Comparator
Daily subcutaneous insulin glargine during the other treatment period, also at a stable dose based on prestudy basal insulin dosing and within the reported range of 0.2 to 0.8 units per kilogram.
Primary question
What were the average VLDL-triglyceride concentrations at steady state during the specified post-dose interval for each treatment? The registry posts separate geometric means, but not a paired treatment contrast or its uncertainty.
The study focused on triglyceride metabolism rather than a clinical outcome. Its primary endpoint was the average total concentration of very low density lipoprotein-triglyceride (VLDL-TG), measured from 240 to 420 minutes on Day 22 while participants were receiving each treatment. The stated unit is micromole per Liter (μmol/L).
Because the design was crossover, participants received both treatments in separate periods. In principle, this allows each participant’s result on one treatment to be compared with that participant’s result on the other. The registry’s posted endpoint summaries, however, give treatment-specific geometric means and variability, not the within-participant differences needed to describe that comparison directly. The record does not report a formal test of whether the treatments differed.
3. Trial Design
The registry describes a randomized, open-label, phase 1 crossover study of insulin peglispro and insulin glargine in participants with type 1 diabetes. Each participant was to receive a daily injection of each study drug, one in each treatment period. The brief description says each period lasted 3 to 4 weeks and was followed by procedures examining how the body uses or stores fats during treatment. The arm descriptions specify stable daily subcutaneous doses for at least 21 days in each period, within a range of 0.2 to 0.8 units per kilogram. Dose selection was based on the prestudy basal insulin dosing regimen.
Randomization applies to the treatment allocation or order in this crossover design; the registry does not report the sequence details. Masking is listed as none. The record does not report whether a washout period separated the treatments, how long any such interval lasted, or how period and sequence effects were handled. Those details matter when interpreting crossover studies because measurements in one period may be influenced by period conditions or by the preceding treatment.
The registry lists enrollment of 15. For the primary endpoint, it defines the population as all participants who were randomized and received at least one dose. The posted treatment-specific results each list 14 participants. These figures should not be treated as a complete account of participant flow: reasons for differences between enrollment, endpoint population, and posted summaries are not reported in the registry record.
The study status is completed. The record lists a start in 2013-10 and primary completion in 2014-12. It reports four outcome measures, but only the primary result is described in the endpoint information; other endpoint values are not available for a two-treatment comparison.
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.
Before assignment: Insulin treatments were transitioned by gradual tapering/titration as required at the start of each period and the end of Period 2 based on the participants individual randomization and pre-study therapy.
Period 1
| Stage | Insulin Peglispro (LY2605541) Then Insulin Glargine | Insulin Glargine Then Insulin Peglispro |
|---|---|---|
| STARTED | 8 | 7 |
| Received at Least One Dose of Study Drug | 7 | 7 |
| COMPLETED | 7 | 7 |
| NOT COMPLETED | 1 | 0 |
Reasons for not completing this period:
| Reason | Insulin Peglispro (LY2605541) Then Insulin Glargine | Insulin Glargine Then Insulin Peglispro |
|---|---|---|
| Met exclusion criteria | 1 | 0 |
Period 2
| Stage | Insulin Peglispro (LY2605541) Then Insulin Glargine | Insulin Glargine Then Insulin Peglispro |
|---|---|---|
| STARTED | 7 | 7 |
| COMPLETED | 7 | 7 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants who were randomized and received at least one dose of study drug.
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 who received at least one dose of study drug.
| Characteristic | Unit | All Study Participants |
|---|---|---|
| Participants analysed | 14 | |
| Age, Continuous | Years | 35.3 (22 to 62) |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 8 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 14 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: Denmark | Participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Very Low Density Lipoprotein-Triglyceride (VLDL-TG) Concentrations, measured over Day 22: 240 minutes (min) to 420 min.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | Geometric Coefficient of Variation |
| Unit | micromole per Liter (μmol/L) |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the average total concentration of VLDL-TG at steady state, measured from 240 to 420 minutes on Day 22 during dosing with each study drug. VLDL-TG refers to triglyceride carried in very low density lipoprotein particles. The concentration is reported in micromole per Liter (μmol/L), with a geometric mean as the summary measure and geometric coefficient of variation as the dispersion measure.
In general, measuring a circulating lipid-related concentration over a defined interval can characterize an aspect of metabolism during treatment. The endpoint’s scheduled interval makes clear which post-dose measurements contribute to the summary; it is not an assessment of triglyceride levels at all times or of a long-term clinical outcome. The registry describes the endpoint as an average concentration calculated at steady state, not as a change from baseline.
A geometric mean is commonly used for positive measurements whose distribution is skewed: it summarizes values after a logarithmic transformation and then returns the summary to the original scale. A geometric coefficient of variation describes relative spread on a multiplicative scale. These summaries describe the observed measurements; neither one by itself estimates a treatment effect. The record does not provide confidence intervals or a paired treatment contrast for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry posts a geometric mean VLDL-TG concentration of 0.27 μmol/L for insulin peglispro and 0.17 μmol/L for insulin glargine. The corresponding geometric coefficients of variation are 55.0% and 66.0%. Each treatment-specific result lists 14 participants. These figures describe the posted summaries for the specified measurement interval; they do not establish the size or precision of a treatment contrast.
The design is crossover, so the comparison of interest would ordinarily use measurements from the same participants under both treatments. Separate geometric means do not show how each participant’s measurement changed between periods. The registry does not post a paired estimate, confidence interval, p-value, or other formal comparative analysis. As a result, the posted summaries do not establish whether the observed treatment-specific values are distinguishable beyond sampling variation.
The geometric coefficients of variation indicate dispersion around each geometric mean on a relative scale. They are not confidence intervals and should not be read as uncertainty in the treatment contrast. Without the participant-level paired data or a reported model-based comparison, the amount of uncertainty around the difference between treatments is not reported in the registry record.
The endpoint captures a metabolic measure at a particular time under study conditions. It does not by itself describe longer-term lipid patterns, clinical outcomes, or effects outside the specified interval. The record also does not report baseline endpoint values or change-from-baseline estimates, so the treatment summaries should not be interpreted as changes from participants’ starting values.
The registry indicates that values for another endpoint were missing or not estimable for a two-arm comparison. It also lists four outcome measures but reports no secondary outcomes. Accordingly, the available result should be interpreted as a narrow description of the posted primary endpoint summaries, rather than as a complete account of all planned or collected measurements.
There is no basis in the registry record to infer why the treatment-specific groups list 14 participants while enrollment is 15, or to infer which participants contributed to each measurement. Likewise, no conclusion about treatment benefit or harm follows from the endpoint summaries alone. They are descriptive statistics for VLDL-TG in this study, with the comparative analysis and its precision not reported.
9. Statistical Methods Explained
The registry presents the primary endpoint as a geometric mean with geometric coefficient of variation. It does not report a formal analysis comparing the two treatments. The following concepts are general explanations of these statistical summaries and of what a crossover comparison ordinarily requires.
What does a geometric mean describe?
In general, the geometric mean summarizes positive values by taking their logarithms, averaging on that scale, and transforming the average back to the original measurement scale. This approach can be useful when values are right-skewed or when relative rather than absolute variation is meaningful. It is not the same as an arithmetic average. For this endpoint, the registry reports geometric means of 0.27 μmol/L during insulin peglispro and 0.17 μmol/L during insulin glargine. These are treatment-specific summaries, not a direct estimate of the within-participant treatment effect.
What does geometric coefficient of variation mean?
In general, a coefficient of variation expresses spread relative to the scale of the measurements. A geometric coefficient of variation is defined on a multiplicative scale and is associated with analysis of log-transformed values. The reported values are 55.0% for insulin peglispro and 66.0% for insulin glargine. They describe variability among measurements; they are not confidence limits, a range containing a specified proportion of participants, or a measure of uncertainty in the difference between treatments.
Why does crossover structure matter?
In general, a crossover design exposes participants to each treatment in separate periods. Since the same participant contributes observations under both conditions, an analysis can account for within-participant pairing. A paired comparison often removes some variability attributable to stable differences between participants, but it must also consider period and sequence effects where appropriate. The registry does not report the treatment sequence, washout details, or methods for handling period effects.
Separate treatment summaries do not preserve the pairing information. Even when both treatment groups list the same number of participants, that alone does not reveal whether all participants contributed both endpoint measurements or how their paired values were distributed. The record does not provide a paired estimate, standard error, confidence interval, or test statistic. It therefore does not quantify the uncertainty of a treatment contrast.
What would a confidence interval add?
In general, a confidence interval gives a range of values compatible with an estimate under a specified statistical procedure. It conveys precision: a narrower interval indicates greater precision for that estimate, while a wider interval indicates less. An interval for a paired treatment contrast would help readers assess both the estimated direction and the plausible magnitude of the difference. No such interval is reported for the primary endpoint. The geometric coefficients of variation cannot substitute for it, because they describe spread in endpoint measurements rather than uncertainty in the estimated contrast.
What is not available about the analysis?
The registry record does not report the model, test, significance threshold, handling of missing endpoint values, or adjustment for period or sequence. It does not report a statistical analysis plan or a formal primary comparison. The record lists no analyses and no posted secondary outcomes. These absences prevent reconstruction of the sponsor’s intended or completed comparative method. They should not be filled in by assuming a conventional crossover model or a particular analysis of log-transformed data.
The endpoint is reported as an average total concentration at steady state over the interval from 240 to 420 minutes on Day 22. In general, averaging measurements over a defined window can summarize the concentration during that window, but interpretation depends on how the measurements were collected and combined. The registry does not describe the sampling schedule within that interval or the calculation details beyond identifying the average concentration.
How should planning illustrations be read?
In general, a sample-size calculation based on an observed effect is a planning illustration: it asks what study size might be needed to detect an assumed effect under stated statistical conditions. It is not the power observed in the completed trial. The registry’s stated illustration assumptions include a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects defined as fractions of the observed effect. Any resulting sample-size figure would depend on those assumptions and on the effect chosen. Such planning values do not replace an analysis of the data collected in this crossover study.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists four outcome measures, but it does not report secondary outcome results. It notes that values were missing or not estimable for a two-arm comparison for another endpoint. The registry record does not explain which measurements were unavailable, why they were missing, or whether they were excluded before or after analysis. It also does not report a missing-data method or sensitivity analysis.
Multiplicity refers, in general, to the increased chance of a false-positive finding when several outcomes or comparisons are tested. A prespecified strategy may control that risk, for example by prioritizing an endpoint or adjusting tests. The registry does not report a multiplicity plan, the number of tests performed, or p-values for the primary endpoint. It therefore cannot establish whether or how multiplicity was addressed.
The primary population is described as all participants who were randomized and received at least one dose. Treatment-specific endpoint summaries each list 14 participants. The record does not give a participant flow account, explain the relationship between enrollment of 15 and the endpoint summaries, or state whether all randomized participants contributed data in both crossover periods.
In general, missing observations in a crossover study can affect paired comparisons if one treatment-period measurement is absent. Whether that matters, and how it is handled, depends on the missingness pattern and analysis method. Neither is described in the registry record. The posted summaries therefore cannot be used to determine whether the comparison used a complete-pair population or another approach.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Insulin Peglispro | 0 | 14 | 0.0% |
| Insulin Glargine | 1 | 14 | 7.1% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Insulin Peglispro | 4 of 14 |
| Insulin Glargine | 5 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | Insulin Peglispro | Insulin Glargine |
|---|---|---|---|
| Dermoid cyst | Congenital, familial and genetic disorders | 0 of 14 | 1 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Insulin Peglispro | Insulin Glargine |
|---|---|---|---|
| Influenza | Infections and infestations | 1 of 14 | 2 of 14 |
| Abdominal discomfort | Gastrointestinal disorders | 0 of 14 | 1 of 14 |
| Abdominal pain upper | Gastrointestinal disorders | 1 of 14 | 0 of 14 |
| Nausea | Gastrointestinal disorders | 1 of 14 | 0 of 14 |
| Vomiting | Gastrointestinal disorders | 0 of 14 | 1 of 14 |
| Chills | General disorders | 1 of 14 | 0 of 14 |
| Non-cardiac chest pain | General disorders | 1 of 14 | 0 of 14 |
| Nasopharyngitis | Infections and infestations | 1 of 14 | 0 of 14 |
| Post procedural haematoma | Injury, poisoning and procedural complications | 1 of 14 | 0 of 14 |
| Blood glucose increased | Investigations | 1 of 14 | 0 of 14 |
Serious events with the highest arm-level rate: dermoid cyst (7.1%).
The registry reports serious adverse event counts for the two treatment groups: 0 for insulin peglispro and 1 for insulin glargine. Each group lists 14 participants at risk. It also reports other adverse event counts of 4 and 5, respectively, with 14 at risk in each group. These are the registry’s group-specific counts, not a comparative safety analysis.
The record lists “Dermoid cyst” as a top serious adverse event term with 7.1%. It does not specify in the information which treatment group that term belongs to. Death counts are not reported in the registry record; a missing death value should not be read as zero.
In general, adverse-event counts are descriptive. They do not, by themselves, establish that a treatment caused an event or that the treatments differ in risk. This study used a crossover design, but the safety summary is organized by treatment group and does not provide information about event timing, severity beyond serious status, exposure-adjusted rates, or a statistical comparison. The record also does not report definitions or adjudication details for these counts.
The figures should be read in the context of a small phase 1 study and its reported observation period, without extrapolating to broader populations or longer-term use. The registry’s counts describe what was posted for this study; they are not a basis for medical advice.
12. What the Result Does, and Does Not, Mean
The primary endpoint provides a snapshot of VLDL-TG concentration under each treatment during a defined interval on Day 22. The registry reports a geometric mean of 0.27 μmol/L for insulin peglispro and 0.17 μmol/L for insulin glargine, with geometric coefficients of variation of 55.0% and 66.0%. Those summaries characterize the recorded endpoint values but do not quantify a paired treatment difference.
The study’s randomized crossover design is relevant because each participant received both study treatments. A direct treatment comparison would need to preserve the pairing and account for the study periods. The registry does not report such an estimate, its confidence interval, or a formal test. Without those, the precision and statistical evidence for a contrast cannot be assessed from the posted summaries alone.
The endpoint is a metabolic measure, not a clinical outcome. It concerns concentration over the stated measurement window and does not establish effects on long-term health outcomes, on lipid values outside that interval, or on other aspects of diabetes care. The registry does not report change-from-baseline results, so the treatment-specific means should not be interpreted as individual improvement or worsening.
The posted information also does not establish why endpoint values were unavailable or not estimable for another outcome, how missing measurements were handled, or how many participants contributed complete paired measurements. Safety counts are descriptive and do not establish causation or a difference in risk.
In short, the record documents a phase 1 metabolic comparison and posts treatment-specific endpoint summaries. It does not provide enough comparative statistical information to determine the size, precision, or significance of a treatment effect. That distinction separates a numerical difference between summaries from evidence about a treatment contrast.
13. Why This Trial Matters Statistically
This trial is statistically instructive because the study design and the reported summaries answer different parts of a research question. Randomized crossover allocation means that participants received both treatments, creating the possibility of a within-person comparison. Yet the registry posts treatment-specific geometric means and variability rather than a paired effect estimate. The design alone does not supply the missing comparative result.
The endpoint also illustrates why the summary scale matters. Geometric means and geometric coefficients of variation are suited to descriptions on a multiplicative scale, while an interpretation of treatment differences requires a clearly defined contrast on an appropriate scale. Readers cannot infer that contrast or its uncertainty simply from separate summaries. A confidence interval and an explanation of the analysis would help distinguish precision from variability among measurements.
The record makes the boundary between descriptive reporting and inferential analysis especially clear: it lists outcome measures but no analyses, and it does not report a formal primary comparison. A posted numerical result can be informative about what was measured while still leaving the central comparative question unresolved.
Finally, the missing information is itself important to statistical interpretation. Participant flow, paired data availability, sequence and period handling, and missing-data methods all affect how a crossover result should be understood. The record’s compact summaries do not answer those methodological questions. Recognizing what is reported, and what remains unreported, is essential to avoid overstating what a small metabolic study can establish.
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.
This study’s primary result is reported as separate treatment-specific geometric means and geometric coefficients of variation. The registry does not report a paired treatment contrast, confidence interval, p-value, or formal analysis. Consequently, the precision and statistical significance of the comparison cannot be assessed from the record.
The crossover design makes participant-level pairing relevant, but the registry does not describe treatment sequence, any washout interval, or how period effects were assessed. It also does not say how many participants contributed measurements in both treatment periods. Although enrollment is listed as 15 and each treatment result lists 14, reasons for that difference are not reported in the registry record.
The record does not provide baseline VLDL-TG values, change-from-baseline estimates, the sampling schedule within the endpoint window, or detailed calculation methods for the average concentration. It reports that another endpoint had values missing or not estimable for a two-arm comparison, without explaining the reason or handling. A missing-data strategy and sensitivity analyses are not reported.
Four outcome measures are listed, but secondary results are not posted. The record does not report a multiplicity plan, analysis plan, or details of any analyses. Safety reporting is also limited: the registry gives group counts and a top serious adverse event term but does not supply further comparative analysis or report death counts. These limitations restrict interpretation to the descriptive information recorded for this phase 1 study.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Insulin Peglispro and Glargine on Fats in Participants With Type 1 Diabetes — NCT01771250.
- Registry record last updated 2019-03-11; status last verified 2018-11.
- Results first posted 2019-03-11.
- 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.
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18. Record Summary
NCT01771250 is a completed phase 1 randomized, unmasked crossover study comparing daily insulin peglispro with daily insulin glargine in participants with type 1 diabetes. Each participant received each treatment in a separate period; the registry describes periods of 3 to 4 weeks and stable daily subcutaneous dosing for at least 21 days.
The primary endpoint was average VLDL-TG concentration from 240 to 420 minutes on Day 22, summarized by geometric mean and geometric coefficient of variation. The posted treatment-specific geometric means were 0.27 μmol/L for peglispro and 0.17 μmol/L for glargine. No paired comparative estimate or formal analysis is reported. Safety counts are descriptive, and the registry does not report secondary outcome results or explain missing endpoint information.