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 Novel Insight Into Migraine Pathophysiolgy and Galcanezumab Mechanisms of Action (NCT04271202), a na phase 4 study. The primary outcome is Change in Gray Matter Thickness in the Somatosensory Cortex.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04271202 |
| Phase | Phase 4 |
| Condition | Chronic Migraine |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 64 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Beth Israel Deaconess Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with chronic migraine. For the primary endpoint, the specified population was migraine patients who completed both the pre-treatment and post-treatment MRI visits. The registry record does not report how many participants completed both visits.
Intervention
The intervention was open-label treatment with galcanezumab, identified in the record as Emgality. The arm description states an injectable 240 mg initial dose followed by 120 mg treatments 1 and 2 month later. The stated purpose was to examine brain functioning and mechanisms of action.
Comparator
There was no placebo or control group. This was a single-group study, so its design does not provide a concurrent comparison with untreated participants or another treatment group.
Primary question
The primary endpoint was change in gray matter thickness in the somatosensory cortex, measured from MRI at baseline and at the treatment-effect visit. The study aimed to investigate mechanisms of action of CGRP-targeted monoclonal antibodies in migraine prevention, including whether their main site of action is inside or outside the brain. The registry record does not report numerical results for the endpoint or an analysis addressing that mechanistic question.
3. Trial Design
This completed phase 4 study was a single-group, open-label treatment study sponsored by Beth Israel Deaconess Medical Center. The registry lists chronic migraine as the condition and an enrollment of 64. The study began on 2020-07-29, reached primary completion on 2023-11-22, and has a completed status in the registry record.
The intervention is identified as Emgality 120 MG in 1 ML Prefilled Syringe. The treatment-arm description states that participants received an injectable 240 mg initial dose, followed by 120 mg treatments 1 and 2 month later. The record describes assessing treatment effects on brain functioning. It does not report further details about adherence, treatment deviations, or the exact schedule beyond that wording.
There was no random allocation and no masking. The record identifies the design as single group and describes the group as open-label treatment with no placebo or control. Therefore, the study does not compare outcomes between randomized treatment arms. Its primary endpoint uses MRI visits at baseline (day 0) and treatment effect (day 90), but the registry record does not report the number of participants who completed both visits.
The primary outcome is change in gray matter thickness in the somatosensory cortex, expressed in mm. The record specifies a median and inter-quartile range and defines the primary endpoint population as migraine patients who completed both pre- and post-treatment MRI visits. Six outcome measures are listed, while the registry record lists zero analyses. The statistical analysis plan, any prespecified covariate adjustment, and the rationale for the enrollment target are not reported in the registry record.
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
| Stage | Open Label Treatment With no Placebo or Control |
|---|---|
| STARTED | 64 |
| COMPLETED | 36 |
| NOT COMPLETED | 28 |
Reasons for not completing this period:
| Reason | Open Label Treatment With no Placebo or Control |
|---|---|
| Withdrawal by Subject | 18 |
| Lost to Follow-up | 10 |
Analysis population for the primary outcome, as defined in the registry: Migraine patients that completed both pre and post treatment MRI visits.
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.
| Characteristic | Unit | Treatment |
|---|---|---|
| Participants analysed | 64 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 64 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 52 |
| Sex: Female, Male: Male | Participants | 12 |
| Race/Ethnicity, Customized: white | Participants | 58 |
| Race/Ethnicity, Customized: black or African American | Participants | 3 |
| Race/Ethnicity, Customized: Asian | Participants | 1 |
| Race/Ethnicity, Customized: Native Hawaiian or other pacific islands | Participants | 0 |
| Race/Ethnicity, Customized: American Indian or Alaskan native | Participants | 0 |
| Race/Ethnicity, Customized: multiracial | Participants | 1 |
| Race/Ethnicity, Customized: other | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Gray Matter Thickness in the Somatosensory Cortex, measured over baseline MRI (day 0), treatment effect MRI (day 90).
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | mm |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint concerns gray matter thickness in the somatosensory cortex, measured from MRI images. Its stated timeframe compares baseline MRI on day 0 with a treatment-effect MRI on day 90. The endpoint is described as a difference in thickness over that study timeframe, with units of mm. The registry specifies that the summary measure is the median and that dispersion is described with the inter-quartile range.
As general context, an MRI-based measure can provide a structural brain measurement rather than relying only on participants’ reports of symptoms. A before-and-after measure can describe how the measured quantity differs across visits among people with observations at both time points. A median summarizes the center of a distribution, while the inter-quartile range describes the spread of its middle portion. These summaries can be useful when the distribution is skewed or contains values far from the center, although the registry record does not say why these summaries were selected.
The specified endpoint population includes only migraine patients who completed both MRI visits. The number of people in that population and the numerical median, inter-quartile range, and change are not reported in the registry record. Nor does the record describe image processing, measurement reliability, or how differences between visits were statistically tested. The endpoint is relevant to the study’s stated interest in brain mechanisms, but a structural measure by itself does not identify where a medicine acts or establish a mechanism.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study’s design and endpoint, but it does not provide the numerical primary outcome results. It specifies gray matter thickness in the somatosensory cortex, measured in mm, with a median and inter-quartile range, and identifies MRI visits at baseline (day 0) and treatment effect (day 90). The population for this endpoint is participants who completed both scans. The actual summaries for either visit, the change between visits, and any uncertainty interval or test result are not reported in the registry record.
The study enrolled 64 participants overall, but that enrollment does not establish how many contributed to the primary endpoint. The record does not give the number who completed both MRI visits or describe any difference between enrolled and analyzed participants. As a result, the primary endpoint’s precision and the potential influence of incomplete follow-up cannot be assessed from the registry information.
The design is single group and open label, without a placebo or control group. Consequently, even if a before-and-after change were reported, this design would not by itself separate a treatment-associated change from other explanations, such as changes over time, measurement variability, or factors occurring alongside treatment. This is a general limitation of interpreting change over time without a concurrent comparison; it is not evidence that any particular alternative explanation occurred in this study.
The registry’s stated objective is to understand mechanisms of action of CGRP-targeted monoclonal antibodies and to investigate whether the main site of action is inside or outside the brain. The primary endpoint measures gray matter thickness at a specified brain region; it does not directly observe a drug’s site of action. The record does not report an analysis that links the MRI measure to a mechanistic conclusion.
The registry lists six outcome measures and zero analyses. It does not report an inferential statistical method, an effect estimate, a confidence interval, a p-value, or an analysis population beyond the primary endpoint’s completer definition. These omissions mean that the posted registry record cannot support a judgment about the magnitude or statistical precision of the primary finding. The accompanying tables and plots should be read in light of these reporting limits and the uncontrolled, single-group design.
9. Statistical Methods Explained
What does the endpoint summary describe?
The registry identifies the primary outcome as change in gray matter thickness in the somatosensory cortex. It states that thickness is measured from MRI images, uses mm as the unit, and sets the timeframe as baseline MRI (day 0) and treatment effect MRI (day 90). It also specifies a median and inter-quartile range. These are descriptive summaries: the median represents the center of the observed values, while the inter-quartile range describes the spread of the middle part of those values. As general statistical context, summaries of this kind do not, by themselves, show how precise an estimate is or whether a difference is compatible with chance variation.
The primary endpoint description refers to a difference across the study timeframe, but the registry record does not provide the values or say exactly how the difference was calculated. It does not report whether the analysis used participant-level paired changes, a model, or another method. Although participants had MRI visits at two time points, the precise statistical handling of those repeated measurements is not reported in the registry record.
What would a confidence interval add?
As general statistical context, a confidence interval gives a range of values compatible with an estimate under the assumptions of the analysis. It helps readers assess precision: a narrower interval indicates greater precision than a wider interval, all else being equal. The registry information does not report a confidence interval for the primary endpoint, so the precision of any estimated change cannot be assessed from this record. No interval should be inferred from the enrollment alone.
Why does the design matter for interpretation?
The registry describes a single-group, open-label study with no placebo or control and no random allocation. As general context, random allocation and concurrent comparison groups can help address differences between groups and changes that would have occurred over time regardless of treatment. Without a comparison group, a within-study difference between MRI visits can describe change among observed participants, but it cannot establish that treatment caused that change. Open-label status also means that masking was absent, although the registry does not say how, if at all, awareness of treatment affected image acquisition or analysis.
The primary endpoint population consists of migraine patients who completed both pre- and post-treatment MRI visits. A complete-visit analysis can omit people without both measurements. As general context, if completion is related to participant characteristics or outcomes, results among completers might not represent all enrolled participants. The registry record does not report the number of completers, reasons for missing MRI visits, or methods for addressing missing data, so the relevance of this concern cannot be evaluated.
What do the planning illustrations mean?
The sample-size section uses planning assumptions based on an observed effect, rather than describing the trial’s own design justification. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. For time-to-event tables, the stated quantity is the total number of events; other tables give participants per arm. These are planning illustrations, not observed power and not evidence that this single-group study enrolled or analyzed two randomized arms.
As general context, sample-size planning asks how many observations would be needed under specified assumptions to detect an effect with a chosen probability, if the assumed effect and analysis conditions hold. An illustration based on an observed effect is conditional on that effect and the stated assumptions. It does not replace a prospective justification, and it cannot show what the study was designed to detect unless that design information is reported. The registry record does not report a sample-size justification for this trial. Numerical planning outputs are not reported in the registry information, so no values can be interpreted in this discussion.
What is not available about the statistical analysis?
The registry lists six outcome measures and zero analyses. It does not report the inferential test, any model specification, adjustment for covariates, handling of repeated measurements, or a prespecified statistical analysis plan. It also does not report an effect estimate, standard error, confidence interval, or p-value for the primary endpoint. Those details matter because the same descriptive data can be analyzed in different ways, and the analysis method determines what uncertainty statements mean.
As general context, dispersion and over-dispersion matter when a model assumes a particular level of variation. If observed variation exceeds the model’s assumption, standard errors can be too small and uncertainty can be understated unless the analysis accounts for it. That concept is not a reported feature of this study: the registry record does not describe a count model, a dispersion assessment, or any model-based inference. The available endpoint description supports explanation of the intended measure, but not reconstruction of an unreported analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures but zero analyses. It identifies one primary endpoint in the record: change in gray matter thickness in the somatosensory cortex. The statistical analysis plan, any hierarchy among outcomes, and any adjustment for testing multiple outcomes are not reported in the registry record. As general context, when several outcomes or analyses are tested, the chance of at least one apparently noteworthy result can increase; methods for controlling that risk depend on the analysis plan. No such method can be attributed to this study from the available record.
The primary endpoint population is described as participants who completed both pre- and post-treatment MRI visits. The number completing both visits, the number with missing measurements, reasons for missingness, and any imputation or other missing-data method are not reported in the registry record. The registry also does not describe analysis populations for the other outcome measures.
These gaps limit assessment of whether the reported population matches the enrolled group and whether incomplete follow-up could affect interpretation. They also mean that readers cannot determine how multiplicity or missing data were handled in analyses. The enrollment of 64 is reported, but the number contributing to each outcome is not reported in the registry record.
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 |
|---|---|---|---|
| Open Label Treatment With no Placebo or Control | 1 | 64 | 1.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Open Label Treatment With no Placebo or Control | 1 of 64 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Open Label Treatment With no Placebo or Control | 1 of 64 |
Most frequent serious adverse event terms
| Event term | Organ system | Open Label Treatment With no Placebo or Control |
|---|---|---|
| dizziness | Nervous system disorders | 1 of 64 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Open Label Treatment With no Placebo or Control |
|---|---|---|
| dizziness | Nervous system disorders | 1 of 64 |
Serious events with the highest arm-level rate: dizziness (1.6%).
The registry presents adverse-event figures for the group titled “Open Label Treatment With no Placebo or Control.” It lists 64 participants at risk for serious adverse events and 1 affected, and 64 at risk for other adverse events and 1 affected. It also lists 1 death. The top serious adverse-event term shown is dizziness, at 1.6%.
These are registry counts, not comparisons between treatment groups: there was no placebo or control group. The record does not report whether the serious adverse event, other adverse event, listed dizziness term, and death refer to distinct participants or overlapping events. It does not report the circumstances or timing of the death, whether any event was considered related to treatment, or further clinical details. The figures therefore describe what the registry lists, but they do not establish cause or permit a comparative safety estimate.
As general context, adverse-event counts are interpreted alongside how events were defined, collected, and attributed. Those details are not reported. The listed figures should not be read as evidence that treatment caused an event or that no unlisted events occurred.
12. What the Result Does, and Does Not, Mean
This record describes a completed phase 4, open-label, single-group study of galcanezumab in people with chronic migraine. Its primary endpoint was change in somatosensory-cortex gray matter thickness between MRI at baseline (day 0) and treatment effect (day 90), among participants who completed both scans. The record also describes the study’s broader aim of investigating mechanisms of action of CGRP-targeted monoclonal antibodies.
The registry information does not report the primary endpoint’s numerical result, its uncertainty, or a statistical test. It therefore does not establish the direction, size, or precision of any change in gray matter thickness. Although enrollment was 64, the record does not report how many participants contributed to the primary endpoint. The listed adverse-event counts are descriptive and are not comparative evidence because the study had no control group.
As general context, a before-and-after measurement can describe change among people measured at both visits, but a single-group design cannot separate treatment effects from other changes over time. Nor does a change in a brain imaging measure, by itself, demonstrate where a medicine acts or explain a biological mechanism. A mechanistic conclusion would require evidence linking the measured findings to the proposed mechanism; such an analysis is not reported in the registry record.
The tables, plots, and planning section can help readers inspect displayed summaries and hypothetical planning illustrations, but they should not be mistaken for a randomized comparison or for observed power. The registry record does not report a sample-size justification, analysis plan, or numerical primary outcome results. The appropriate interpretation is therefore limited to the stated design, measures, and recorded safety counts, with the main efficacy and mechanistic findings not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable for the distinction between a mechanistic research question and the endpoint used to address it. The stated aim concerns where CGRP-targeted monoclonal antibodies act, while the primary endpoint is a structural MRI measure of gray matter thickness in a specified brain region. That measure can be informative about brain structure, but the registry record does not report an analysis establishing a link between the endpoint and the proposed site of action.
The single-group, open-label design also shapes what can be learned. Measurements at baseline and day 90 may describe change among participants with both MRI visits, but without a concurrent control group the observed time pattern cannot by itself identify a treatment effect. This is a general design principle, not a claim about the direction or cause of any unreported result.
Statistical reporting is central because the registry describes the endpoint and its summaries but lists zero analyses. It does not provide the endpoint values, uncertainty, inferential method, or number of participants with both scans. Those omissions make it impossible to assess the magnitude and precision of the primary finding from the registry information. They also prevent readers from evaluating how missing observations or multiple outcomes were handled.
The trial therefore illustrates why a stated endpoint, a completed study, and an enrollment figure are not substitutes for reported estimates and analysis details. The sample-size section’s assumptions are planning illustrations, not the study’s own design justification or observed power. Keeping these distinctions clear helps readers assess what the record can support without extending it to causal or mechanistic conclusions it does not report.
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 for interpreting this trial is its single-group, open-label design without a placebo or control. The record describes no randomized comparison, so any difference between MRI visits would not, on its own, distinguish a treatment-associated change from other changes over time. This limitation concerns the design; it does not imply that any particular alternative explanation occurred.
The primary endpoint is restricted to participants who completed both MRI visits. The registry does not report how many participants met that definition, why other participants may not have completed both visits, or how missing measurements were handled. As a result, the extent to which the endpoint population represents all enrolled participants cannot be assessed.
The registry record does not report the primary endpoint’s numerical results, inferential analysis, uncertainty estimates, or the statistical analysis plan. It lists six outcome measures and zero analyses, but does not describe how outcomes were prioritized or whether multiplicity was addressed. Image acquisition and processing procedures, measurement reliability, and any adjustment for other variables are also not reported in the registry record.
Finally, the stated mechanistic objective is broader than the primary structural MRI endpoint alone can answer. The registry does not report an analysis demonstrating whether the medicine acts inside or outside the brain. The planning assumptions described for sample-size illustrations do not provide the missing trial-specific design rationale, and the registry does not report a sample-size justification. These limitations restrict conclusions about effect size, precision, causality, and mechanism.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Novel Insight Into Migraine Pathophysiolgy and Galcanezumab Mechanisms of Action — NCT04271202.
- Registry record last updated 2026-03-24; status last verified 2026-03.
- Results first posted 2026-03-24.
- 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.
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18. Record Summary
The registry record describes a completed phase 4 study sponsored by Beth Israel Deaconess Medical Center in people with chronic migraine. It lists enrollment of 64, a single-group, open-label design, and treatment with Emgality. The arm description states an injectable 240 mg initial dose followed by 120 mg treatments 1 and 2 month later.
The primary endpoint was change in gray matter thickness in the somatosensory cortex, measured in mm from MRI at baseline (day 0) and treatment effect (day 90). The specified summary is the median with inter-quartile range, among participants who completed both MRI visits. The registry lists six outcome measures and zero analyses.
Numerical primary endpoint results, the number completing both MRI visits, the statistical analysis plan, and the sample-size justification are not reported in the registry record. The safety listing includes 1 serious adverse event among 64 at risk, 1 other adverse event among 64 at risk, 1 death, and dizziness at 1.6% among the top serious terms. The study had no placebo or control group.