A Study of LY2951742 (Galcanezumab) in Japanese Participants With Migraine: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of LY2951742 (Galcanezumab) in Japanese Participants With Migraine (NCT02959190), a randomized phase 3 study. The primary outcome is Number of Participants Who Had Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs).

2. Clinical Question

The study’s broad question was whether galcanezumab could be evaluated for safety and effectiveness in Japanese participants with migraine. The primary outcome focused on the number of participants who had treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) during follow-up. The registry describes TEAEs as events that began on or after the first dose in this study, or began earlier and worsened after study treatment started.

The registry lists additional outcomes addressing drug concentration, immune response, and migraine or headache measures. These include pharmacokinetics, pharmacodynamics, anti-drug antibodies, changes in migraine headache days, and measures of headache days requiring acute-treatment medication. Outcome names alone do not show their results or establish the size of any treatment effect.

3. Trial Design

This was a Phase 3, randomized, parallel-group, open-label study of galcanezumab. It enrolled 311 participants and is recorded as completed. The study started on 2017-02-07, with primary completion on 2019-08-10. Masking was listed as none, so participants and study personnel were not blinded according to the registry record.

The study included six treatment descriptions. Four concerned participants with EM who rolled over from CGAN (NCT02959177): two groups had received galcanezumab previously and two had received placebo previously. In the current study, those groups received galcanezumab according to one of the listed regimens. The remaining descriptions concerned participants with CM enrolled in this study and assigned to one of the galcanezumab regimens.

The regimens differed in monthly dose and, for some groups, included a 240 mg loading dose followed by 120 mg monthly. Other groups received 240 mg monthly. The arm descriptions state that treatment continued once a month for a year. These are descriptions of treatment assignment and prior-study history; they do not establish that groups were comparable on every other characteristic.

Randomized allocation and open-label conduct describe different features of a trial. Randomization concerns how participants are assigned to groups, while masking concerns whether treatment assignment is concealed from participants or study personnel. In this study, allocation was recorded as randomized and masking as none. The registry record does not report further details of the randomization process, such as how the sequence was generated or whether assignment was stratified.

The primary outcome population was defined as participants who were randomized and received at least one dose of study drug. The registry reports a primary timeframe of up to 16 months. It does not report additional details about visit schedules or the length of individual follow-up within that timeframe.

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.

Open Label

Reasons for not completing this period:

Post Treatment Follow Up

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants who were randomized and received at least 1 dose of the 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 participants who were randomized and received at least 1 dose of the study drug.

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Who Had Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs), measured over Up To 16 Months.

The primary endpoint is the number of participants who had TEAEs and SAEs. A TEAE was defined by its timing relative to study treatment: it began on or after the date and time of the first dose in this study, or began before dosing and worsened after treatment started. The registry specifies a timeframe of up to 16 months and an analysis population of participants who were randomized and received at least one dose.

This is a participant-count endpoint. It describes how many people in a group experienced an event, rather than the total number of episodes or the duration of each event. The registry separates serious adverse events from other non-serious adverse events in its posted summaries. It also states that clinically significant events were defined as SAEs and other non-serious adverse events, with a separate reported adverse events module referenced for event details.

In general, safety endpoints are used to describe the occurrence of unwanted events during treatment and follow-up. Counts can give a straightforward account of how many participants experienced an event, but they do not by themselves describe event severity beyond the stated serious/non-serious classification, timing, duration, or causal relationship to treatment. Nor do counts alone establish whether observed differences between groups are due to treatment.

The registry record does not report a single inferential comparison for this outcome. Its note indicates that the primary outcome has several categories or time points and was not reduced to one comparison. The descriptive counts should therefore be read as safety summaries, not as a statistical test of a treatment difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry’s primary outcome is expressed as a number of participants with events. This is a binary outcome at the participant level: each participant either met the event definition during the relevant observation period or did not. The reported quantity is a count, accompanied by the number at risk in each group. It is not a rate per unit of follow-up time, and it is not the total number of event episodes.

What does a participant count tell us?

A count communicates the observed number of people who met the outcome definition. The corresponding group denominator gives context for that count, but a count by itself is not enough to compare groups fairly when group sizes or follow-up differ. Even when counts and denominators are available, comparisons can be influenced by population differences, follow-up, and how events are recorded. Here, the registry separates open-label treatment and post-treatment periods, and the group sizes differ. The reported values should therefore be kept within their stated group and phase rather than treated as one combined result.

In general, a confidence interval describes the statistical uncertainty around an estimate. A wider interval indicates less precision, while a narrower interval indicates greater precision under the analysis assumptions. Confidence intervals for the primary safety counts are not reported in the registry record. The posted counts alone do not show how uncertain a difference between groups might be.

Why does the endpoint definition matter?

The TEAE definition uses the timing of an event in relation to the first dose in this study. Events beginning after that point qualify, as do earlier events that worsened after treatment began. This operational definition determines which events contribute to the endpoint; it does not, by itself, establish that treatment caused an event. The record also distinguishes SAEs from other non-serious adverse events and refers readers to a separate module for event details.

Participant counts and event counts are not interchangeable. One participant could experience more than one event, but the primary outcome is framed as the number of participants who had events. The registry’s count therefore should not be read as a tally of all episodes. The record does not give the full event-level information in this summary, including the timing, duration, or individual participant overlap between categories.

How do design features affect interpretation?

Randomization can help balance measured and unmeasured characteristics across assigned groups, on average, when allocation is implemented as intended. However, this study was open-label, and its groups also reflect different migraine types, previous treatment histories, and treatment phases. Randomization does not remove the need to examine the actual comparison and analysis. Details of the randomization procedure and any adjusted analysis are not reported in the registry record.

Open-label conduct means treatment assignment was not masked. In general, knowledge of assignment can affect reporting or assessment, particularly for outcomes that depend on observation or participant reporting. The record does not describe whether or how outcome assessment was standardized to address that possibility. This is a design consideration, not evidence that reporting was biased.

The registry record lists zero analyses for the outcome information and notes that the primary outcome has several categories or time points and was not reduced to one comparison. It reports no p-value, confidence interval, or adjusted treatment estimate for that outcome. Accordingly, the primary figures are descriptive rather than evidence from a reported hypothesis test.

What is the role of planning calculations?

In general, sample-size planning asks how many participants may be needed to detect a chosen effect with specified assumptions. The registry’s planning description states a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it describes the effect to detect as a stated fraction of the observed effect. It also distinguishes participant-per-arm planning for non-time-to-event outcomes from total-event planning for time-to-event outcomes. These are planning assumptions, not observed trial results or observed power. The registry record does not report a sample-size justification for this study, and no numerical planning estimates are included in the information assessed.

10. Multiplicity, Missing Data and Analysis Populations

The registry states that the primary outcome has several categories or time points and was not reduced to one comparison. This matters because multiple outcomes or repeated time points can create multiple opportunities to observe an apparently notable result. In general, multiplicity methods address how statistical inference should account for a family of comparisons. The registry record does not report a multiplicity adjustment or a prespecified hierarchy for interpreting the primary outcome categories and time points.

The analysis count recorded for the outcome information is zero. No p-values, confidence intervals, or adjusted estimates are reported for the primary safety outcome. Without a reported inferential analysis, there is no statistical test result to interpret, and the posted counts should remain descriptive.

Missing-data methods are not reported in the registry record. The primary population is described as all participants who were randomized and received at least one dose. That definition identifies who was eligible for the primary analysis, but does not explain how incomplete follow-up, withdrawals, or missing event information were handled. The record also does not specify whether participants were included for the full timeframe when they had less follow-up.

The group-specific denominators are presented for the reported treatment or post-treatment summaries. They should not be assumed to represent identical observation periods for every participant; individual follow-up details are not reported in the registry record. In general, unequal or incomplete observation can affect how event counts are interpreted, especially when an outcome can occur at any time during follow-up.

The registry’s outcome population is not described as an intention-to-treat analysis, and the record does not report other analysis-population definitions. It is therefore most precise to use the stated definition—randomized participants who received at least one dose—without assigning a conventional analysis label that the record does not provide.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: stress cardiomyopathy (3.1%), appendicitis (3.1%), intervertebral disc protrusion (3.0%), uterine polyp (2.1%), breast cancer (1.7%).

The serious adverse event figures are participant counts within the named group and phase. During open-label treatment, the EM groups report 2 of 58, 0 of 62, 2 of 62, and 2 of 64 participants with SAEs, in the order 120mg/120mg, 240mg/240mg, placebo/120mg, and placebo/240mg. The CM groups report 1 of 32 participants with an SAE in the 120 mg group and 2 of 33 in the 240 mg group.

For the post-treatment phase, the EM 120 mg group reports 2 of 117 participants with SAEs, and the EM 240 mg group reports 1 of 120. The CM 120 mg and 240 mg groups each report 1 of 32. No deaths are listed in these groups. These are separate phase-specific summaries, not counts to add together.

The registry also reports participants with other non-serious adverse events: 54 of 58, 56 of 62, 54 of 62, and 61 of 64 in the open-label EM groups; 31 of 32 and 29 of 33 in the open-label CM groups. In the post-treatment groups, the counts are 40 of 117 and 37 of 120 for EM, and 10 of 32 and 13 of 32 for CM.

These summaries do not establish that treatment caused an event or that groups differ. The registry does not report comparative estimates or uncertainty intervals for these counts. Serious-event terms listed include Stress cardiomyopathy (3.1%), Appendicitis (3.1%), Intervertebral disc protrusion (3.0%), Uterine polyp (2.1%), Breast cancer (1.7%), and Cholangitis acute (1.6%). The record does not provide the denominators for interpreting these term percentages in this summary.

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

The registry reports safety counts for participants receiving galcanezumab in an open-label study, with summaries separated by migraine type, dose regimen, prior-study history, and treatment phase. These figures describe the number of participants recorded as having TEAEs or SAEs under the registry’s definitions. They do not show event-level severity beyond the serious/non-serious categories, whether events were related to treatment, or how long events lasted.

The primary endpoint is a count, and the registry does not report a single inferential comparison for it. The figures therefore do not establish a statistically supported difference between regimens or phases. They also do not demonstrate that one treatment strategy is safer or less safe than another. Comparisons are especially difficult to interpret because the groups include EM and CM participants, differing histories from the earlier study, and open-label and post-treatment reporting periods.

The study’s broad purpose included assessing effectiveness, and the registry lists secondary migraine and headache outcomes. However, numerical results for those outcomes are not included in the information assessed. The presence of outcome names cannot be treated as evidence of a benefit, lack of benefit, or a particular magnitude of effect.

In general, a trial result is interpreted in light of its design, outcome definition, analysis population, follow-up, and uncertainty. The registry record gives the primary population and timeframe, but does not report methods for handling missing data or inferential estimates for the safety counts. It also does not provide a sample-size justification or a reported statistical analysis plan in the information assessed. These omissions limit conclusions about precision and comparative effects.

The most defensible conclusion is narrow: the registry records participant counts for adverse-event categories across the listed study groups and phases, with no deaths listed in those group summaries. The data do not, on their own, establish causality or comparative treatment effects, and they do not answer the effectiveness question without the numerical secondary-outcome results and their analyses.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of how safety summaries can be difficult to compare even when participant counts and group denominators are reported. The study includes separate summaries for EM and CM, distinct dose regimens, participants who entered from a previous study, and post-treatment follow-up. Keeping those distinctions visible is essential: a count from one group or phase is not directly interchangeable with a count from another.

It also illustrates the difference between a trial’s broad stated purpose and the endpoint that is numerically summarized. The study aimed to evaluate safety and effectiveness, while the primary outcome is the number of participants with TEAEs and SAEs. The registry lists migraine and headache outcomes as secondary outcomes, but their numerical results are not included in the information assessed. An outcome list is not itself evidence of an effect.

Another important point is the distinction between randomization and masking. Randomized allocation is reported, but the study is open-label. The two features address different sources of bias and should not be treated as interchangeable assurances. The registry does not provide detailed randomization methods or a reported adjusted comparison for the safety outcome.

Finally, descriptive safety counts have a clear role but a limited scope. They show what the registry records in each group; without an inferential comparison and measures of precision, they cannot determine whether apparent differences are more than chance variation or reflect treatment. Interpreting these results accurately means retaining the group and phase labels, avoiding derived totals, and separating recorded event counts from causal or comparative conclusions.

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 study is open-label, with no masking reported. Knowledge of treatment assignment can matter when adverse events are identified or reported, although the registry record does not establish whether this affected the results. Details of event ascertainment and consistency across groups are not reported in the registry record.

The study combines participants with EM and CM, and some EM participants rolled over from CGAN (NCT02959177). Their prior-study treatments differed, while CM participants were enrolled in the current study. These histories and group structures should be considered when reading the summaries; the record does not report an adjusted analysis accounting for them.

The registry reports participant counts for open-label treatment and post-treatment phases, but does not describe individual follow-up duration or how incomplete observation was handled. Missing-data methods are not reported in the registry record. The primary population is defined as randomized participants who received at least one dose, but further analysis-population definitions are not reported.

The primary outcome has several categories or time points and was not reduced to one comparison. The registry record does not report multiplicity procedures, confidence intervals, p-values, or comparative estimates for the safety counts. Consequently, the precision of the counts and the strength of any between-group evidence cannot be assessed from this information.

Although secondary efficacy-related outcomes are listed, their numerical results are not included in the information assessed. Sample-size justification, detailed statistical methods, and reasons for the selected design are not reported in the registry record. These limitations constrain interpretation to the posted descriptive safety summaries rather than broader conclusions about comparative effects or effectiveness.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of LY2951742 (Galcanezumab) in Japanese Participants With Migraine — NCT02959190.
• Registry record last updated 2020-09-29; status last verified 2019-08.
• Results first posted 2020-08-24.
• 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

NCT02959190 is recorded as a completed Phase 3, randomized, parallel-group, open-label study of galcanezumab in Japanese participants with migraine. Enrollment was 311. The study started on 2017-02-07 and reached primary completion on 2019-08-10.

The primary outcome was the number of participants with TEAEs and SAEs, with a timeframe of up to 16 months. The defined population was randomized participants who received at least one dose. Registry summaries report serious and other non-serious adverse-event participant counts across open-label treatment and post-treatment groups, with no deaths listed in those summaries.

The record also lists pharmacokinetic, pharmacodynamic, anti-drug antibody, migraine-day, and headache-day outcomes. Numerical results for those secondary outcomes are not included in the information assessed. A single inferential comparison for the primary outcome, missing-data methods, multiplicity procedures, and detailed statistical methods are not reported in the registry record.