Effect of Erenumab-aooe on Disability and Work Productivity in Employed Subjects With Episodic Migraine: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of Erenumab-aooe on Disability and Work Productivity in Employed Subjects With Episodic Migraine (NCT03912337), a randomized phase 4 study. The primary outcome is Sum of Monthly Changes From Baseline in Modified MIDAS Total Score Over the 6-month DBTP.

2. Clinical Question

The trial also considered migraine days, monthly work impairment, and migraine-related functioning. These outcomes can add context to the disability endpoint, but they are not interchangeable: they capture different aspects of the burden associated with episodic migraine. The registry record describes a population selected for employment and prior failure of preventive treatments, so the trial question is specific to that group. It does not directly address people outside those eligibility characteristics.

3. Trial Design

This was a phase 4, randomized, quadruple-masked, parallel-group trial comparing erenumab with placebo. The registry describes a 1:1 allocation after participants completed baseline and were found eligible. The listed arms were placebo QM and erenumab 140 mg QM. Enrollment was 29. The trial started on 2019-12-04, had a primary completion date of 2021-07-28, and is listed as terminated. The reason for termination is not reported in the registry record.

The primary endpoint was assessed at baseline and during Months 1 to 6 of the 6-month DBTP. The efficacy analysis set is described as a subset of participants from traditional study sites or DCTS who received at least 1 dose of investigational product and had a baseline value and at least 1 post-baseline value for the endpoint of interest. The registry record does not fully state the remaining analysis-population rules in the endpoint description.

Group summaries for the primary endpoint include 15 participants in the placebo arm and 14 in the erenumab arm. The posted numerical summaries for secondary outcomes have varying analysis counts. Such differences mean that the endpoint summaries do not all describe an identical analysis set. The registry record does not report the reasons for these variations or a detailed account of participant flow.

The record identifies the design and outcome measures but does not report the trial’s original sample-size justification, full statistical analysis plan, or reason for termination. Those omissions limit how closely the posted estimates can be connected to the trial’s planned analysis.

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: Eligible participants were randomized in a 1:1 ratio to either erenumab 140 milligrams (mg) or placebo once monthly (QM).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The respective efficacy analysis set (EAS) consisted of a subset of participants from traditional study sites or DCTS who received at least 1 dose of investigational product (IP) and had a baseline value and at least 1 post baseline value for the endpoint of interest. Participants were analyzed according to their randomized treatment, regardless of the treatment received.

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: The respective full analysis set consisted of all participants who were randomized in the study through traditional study sites or decentralized clinical trial sites (DCTS).

6. Primary Endpoint

The registry lists the primary outcome as Sum of Monthly Changes From Baseline in Modified MIDAS Total Score Over the 6-month DBTP, measured over Baseline and Months 1 to 6.

The primary endpoint was the sum of monthly changes from baseline in modified MIDAS total score over the 6-month DBTP. The modified MIDAS is a 5-item questionnaire about headache-related disability, including lost time or reduced productivity in paid work or school, housework, and non-work activities. Participants reported productive days lost or productivity reduced by half or more because of headache during the past month.

The five item scores are summed to form a total score, and each monthly change is calculated by subtracting the baseline total score from that month’s total. The monthly changes from Months 1 to 6 are then summed. The registry gives a possible range of -558 to 558 for this sum and states that a negative sum indicates a better outcome. It also notes that productive days counted in items 1 and 3 are not included again for items 2 and 4.

Summing monthly changes makes the endpoint a measure of accumulated change over the assessment period rather than a single-month snapshot. It was used to evaluate disability over time in a population for whom work and other productive activities are relevant. The registry record does not report a threshold for interpreting the size of a change as clinically important.

7. Results Posted in the Registry

• Erenumab 140 mg QM: mean -98.03 versus -71.17 on control; difference -26.86 (95% CI -75.15 to 21.43), standardized effect d = -0.41; z-test p = 0.276.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Change From Baseline in Mean MMD Over Months 4, 5, and 6 of the 6-month DBTP

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Erenumab 140 mg QM: mean -5.60 versus -3.01 on control; difference -2.59 (95% CI -4.92 to -0.26), standardized effect d = -0.82; z-test p = 0.030.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Erenumab 140 mg QM than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change From Baseline in Mean Monthly Percent Work Impairment Over Months 4, 5, and 6 of the 6-month DBTP

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Erenumab 140 mg QM: mean -31.72 versus -28.84 on control; difference -2.88 (95% CI -14.71 to 8.95), standardized effect d = -0.19; z-test p = 0.633.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Erenumab 140 mg QM and the control. The interval gives the range of effects that remain compatible with the data.

Change From Baseline in Mean MFIQ Physical Functioning Domain Score Over Months 4, 5, and 6 of the 6-month DBTP

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Erenumab 140 mg QM: mean -31.99 versus -22.44 on control; difference -9.55 (95% CI -29.99 to 10.89), standardized effect d = -0.36; z-test p = 0.360.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Erenumab 140 mg QM and the control. The interval gives the range of effects that remain compatible with the data.

The numerical secondary results cover migraine days, monthly work impairment, and physical functioning. Across these outcomes, the group means have a consistent direction: the erenumab group’s mean change is more negative. That broad pattern is directionally aligned with the primary endpoint’s group means, but consistency in direction is not the same as independent confirmation. The measures capture different outcomes, and their estimates have differing uncertainty.

Among the numerical secondary comparisons, the migraine-days interval excludes zero, while the intervals for work impairment and physical functioning include zero. The registry also lists usual-activities and social-functioning outcomes, but numerical results for those outcomes are not reported in the registry record. The available secondary results therefore do not cover every listed secondary measure.

The migraine-days comparison has an unadjusted p-value of 0.03. It is one of several secondary outcomes, and the record does not report a correction for multiple testing or a prespecified hierarchy for interpreting them. When several outcomes are examined, some can appear more persuasive by chance even if no underlying effect exists. For that reason, unadjusted secondary results generally carry less confirmatory weight than a prespecified primary analysis with a documented testing strategy.

These secondary measures can help describe whether the primary disability finding is accompanied by patterns in migraine frequency and functioning. They do not resolve the primary estimate’s uncertainty, and they should not be combined into a single overall conclusion. The registry record does not report the original statistical plan or analysis details for these measures, so their role in the trial’s intended evidence hierarchy is unclear.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Change From Baseline in Mean MMD Over Months 4, 5, and 6 of the 6-month DBTP
• Change From Baseline in Mean Monthly Percent Work Impairment Over Months 4, 5, and 6 of the 6-month DBTP
• Change From Baseline in Mean MFIQ Physical Functioning Domain Score Over Months 4, 5, and 6 of the 6-month DBTP
• Change From Baseline in Mean MFIQ Usual Activities Domain Score Over Months 4, 5, and 6 of the 6-month DBTP
• Change From Baseline in Mean MFIQ Social Functioning Domain Score Over Months 4, 5, and 6 of the 6-month DBTP

9. Statistical Interpretation

10. Statistical Methods Explained

The posted continuous outcomes are summarized using group means and standard deviations. A mean describes the center of the observed values, while a standard deviation describes their spread. These summaries are useful for describing each arm, but they do not by themselves show how precisely the between-group difference has been estimated.

What does the mean difference represent?

The comparison is the mean in the erenumab group minus the mean in the placebo group. For the primary endpoint, the recalculated mean difference is -26.86. Since lower, more negative values indicate a better outcome on this measure, a negative difference points toward a more negative mean in the erenumab group. This is a direction-of-estimate description, not proof that the groups differ in the population. The confidence interval and analysis plan matter when judging the uncertainty and evidential weight of that estimate.

How should the confidence interval be read?

In general, a confidence interval expresses the uncertainty around an estimated effect under the assumptions of the method used to construct it. A narrower interval indicates greater precision than a wider interval. For the primary comparison, the interval ranges from -75.15 to 21.43 and includes zero. Thus, the estimate is not precise enough to distinguish clearly between a negative and positive difference using this interval. The interval does not tell the reader which values are clinically important; the registry record does not report a clinical-importance threshold.

What does the p-value add?

The primary unadjusted p-value is 0.276. In general, a p-value measures how unusual the observed data, or data more extreme, would be under a specified null model. It is not the probability that the null hypothesis is true, and it does not measure the size or importance of an effect. Because the posted value is unadjusted and the registry record does not provide the sponsor’s full inferential analysis, it should be read as a descriptive component of the recalculated comparison rather than as a complete account of the trial’s statistical evidence.

The posted values labeled as comparisons are simple, unadjusted recalculations from the arm summaries. They are not adjusted for baseline characteristics or other covariates. The registry record does not report whether the sponsor used a different model, how repeated monthly observations were handled in the primary analysis, or whether model assumptions were assessed. If a sponsor analysis is available elsewhere, it takes precedence only when the registry comparison is identified as discrepant; the record does not identify a discrepancy.

Why do group counts vary across outcomes?

The primary group summaries include 15 participants for placebo and 14 for erenumab. Secondary summaries use varying counts, including an outcome with 12 participants in the erenumab arm. An analysis count is the number contributing to that particular endpoint summary; it need not be identical across measures. In general, variation can arise when endpoint data are unavailable or when analysis eligibility differs, but the specific reasons are not reported in the registry record. The numbers should not be interpreted as a full account of attrition or missingness.

The efficacy analysis-set description requires a dose, a baseline measurement, and at least 1 post-baseline measurement for the endpoint of interest. The remainder of the description is truncated in the registry record. It does not fully explain how participants with incomplete follow-up were handled, whether imputation was used, or what assumptions were made about missing values. These details matter because methods for incomplete repeated measurements can affect both estimated differences and their uncertainty.

Why can over-dispersion matter for count outcomes?

General statistical context: for count outcomes such as migraine days, a model that assumes less variability than is present in the data can underestimate uncertainty. Over-dispersion means that the observed variability exceeds what a simpler count model expects. Methods that account for extra variability can produce more appropriate standard errors and intervals. The registry record does not report whether over-dispersion was assessed or how the sponsor analyzed the migraine-day outcome; the posted comparison is an unadjusted recalculation from summary statistics.

Likewise, the primary endpoint sums monthly changes, but the registry record does not specify the sponsor’s model for the repeated measurements or for the resulting summed score. General statistical practice requires assumptions suited to the endpoint and study design; the method cannot be reconstructed from arm means and standard deviations alone. The recalculated comparison is consequently a transparent summary-based contrast, not a reconstruction of the full trial analysis.

11. Confidence Intervals and Precision

The primary mean difference is -26.86, with a 95% confidence interval from -75.15 to 21.43. This interval is broad relative to the point estimate and includes zero. It permits values consistent with a more negative mean change in the erenumab group, as well as values consistent with a difference in the opposite direction. The estimate’s direction is therefore clearer than its magnitude or whether the population difference is meaningfully different from zero.

In general, a confidence interval describes sampling uncertainty under the method’s assumptions; it is not a range containing every participant’s result. A confidence interval that includes zero does not demonstrate that the groups are identical. It indicates that these data, analyzed in this way, do not rule out zero as a plausible value for the difference. Conversely, the point estimate alone should not be treated as an established effect.

The group standard deviations are 60.81 for placebo and 71.04 for erenumab, and the endpoint summaries include 15 and 14 participants, respectively. These small analysis groups contribute to uncertainty, although precision also depends on variability and the analysis method. The registry record does not report an adjusted sponsor interval or additional model-based precision measures for the primary endpoint.

The secondary intervals also vary in precision. The interval for migraine days excludes zero, while the intervals for work impairment and physical functioning include zero. These are unadjusted comparisons across multiple outcomes, so their intervals do not by themselves account for the chance of observing an apparently unusual result when examining several measures. The registry record does not report a multiplicity adjustment. Precision and statistical significance should therefore be considered alongside the number of outcomes and the incompleteness of the posted analysis details.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning estimates are participants per arm, not total events. They are illustrations based on the observed effect, not the trial’s original design assumptions. The calculation assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is the stated fraction of the observed effect. The trial’s own original sample-size justification is not reported in the registry record.

For the primary endpoint, planning for 100% of the observed effect gives 95 participants per arm for 80% power and 127 participants per arm for 90% power. Planning for 75% of the observed effect gives 169 participants per arm for 80% power and 226 participants per arm for 90% power. Planning for 50% of the observed effect gives 379 participants per arm for 80% power and 507 participants per arm for 90% power. The estimates illustrate that smaller effects require more participants to detect under the stated assumptions.

In general, 80% power means that a study designed under the specified assumptions would have an 80% chance of detecting the chosen effect at the stated significance level if that effect were the true one. The 90% column describes a higher chance of detecting that same chosen effect, which generally requires a larger planned sample. These estimates are planning illustrations, not observed power for the completed trial.

The observed enrollment was 29, so the planning figures should not be read as a claim about the trial’s original targets or as evidence of what the trial was designed to detect. They depend on the observed effect, which is uncertain, and the registry record does not report whether the original design used these assumptions.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -26.860; pooled standard deviation σ = 65.934.
2. n = 2 × (1.96 + 0.842)² × 65.934² / -26.860² = 94.6, rounded up to 95 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -26.86                      # observed difference in means
sigma <- 65.933986683652                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(3912337)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 95 (80% power), 127 (90% power)
 75% of observed effect: n per arm = 169 (80% power), 226 (90% power)
 50% of observed effect: n per arm = 379 (80% power), 507 (90% power)
power.t.test: 95.6 
Simulated power at n = 95 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary outcome and lists five secondary outcomes. It does not report a multiplicity-control strategy, such as an adjustment to the significance threshold or a specified order for testing outcomes. Without that information, an unadjusted p-value for a secondary measure should not be interpreted as if it were the sole planned statistical test. Examining multiple outcomes raises the possibility of chance findings, especially when the analyses are not adjusted or organized by a prespecified hierarchy.

The record reports zero analyses in the analysis listing, while numerical arm summaries and recalculated comparisons are available for the primary endpoint and some secondary measures. The registry record does not provide sponsor-reported inferential analyses for these outcomes. It also does not report whether interim analyses were performed, whether any stopping boundaries were used, or how the posted comparisons relate to the original analysis plan.

The efficacy population is described as participants from traditional study sites or DCTS who received at least 1 dose and had baseline and at least 1 post-baseline value for the endpoint of interest. The remainder of the population description is incomplete. The registry record does not report a full participant-flow account, the reasons for endpoint-specific analysis counts, or the method used to handle missing outcome values. It is therefore not possible to determine from the record whether missingness was related to observed outcomes or how sensitive results are to missing-data assumptions.

Analysis counts vary across outcomes, and this can affect comparability between their estimates. In general, different available-data sets may represent different subsets of participants; the record does not explain the specific sources of variation in this trial. The posted numbers should be read as endpoint-specific summaries rather than proof that every outcome was measured and analyzed in an identical population.

These reporting gaps do not establish that an inappropriate method was used. They do limit independent assessment of multiplicity, missing-data handling, and the analysis population. A complete protocol and statistical analysis plan are not reported in the registry record.

15. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events in 0 participants at risk in the placebo group and 0 participants at risk in the erenumab group. It reports 0 deaths in each group. These are the posted serious-event counts; they do not establish that no other safety events occurred.

For other adverse events, 7 of the 15 participants at risk in the placebo group were affected, and 9 of the 14 participants at risk in the erenumab group were affected. These are counts of participants affected, not counts of individual event episodes. The registry record does not provide serious adverse-event terms, since no top serious-event terms are listed, and it does not report a detailed account of event type, severity, timing, or relationship to study treatment.

Safety counts in a trial of this size are descriptive and provide limited precision about uncommon events. The observed counts should not be interpreted as establishing comparative safety or as a basis for medical advice. The registry record’s adverse-event summary does not replace a full clinical safety assessment.

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

The posted primary group means are more negative in the erenumab arm, and the endpoint definition states that a negative sum indicates a better outcome. However, the recalculated primary mean difference has a 95% confidence interval that includes zero and an unadjusted p-value of 0.276. The estimate is uncertain and does not establish a clear between-group difference on this endpoint.

This result does not prove that the groups are equivalent, nor does it establish that erenumab improves disability. The interval includes values in both directions, and the registry record does not report a threshold for what would count as a clinically important change in modified MIDAS score. The magnitude of the point estimate alone cannot determine whether a difference would matter to participants.

The migraine-days secondary comparison is more suggestive in its unadjusted interval, but it is one of several secondary outcomes and no multiplicity strategy is reported. The other numerical secondary comparisons have intervals that include zero. Together, these findings are exploratory context rather than a substitute for a fully reported primary analysis and prespecified testing plan.

The trial enrolled employed subjects with episodic migraine who had previously failed 1 or more preventive treatments. Its findings, whatever their statistical interpretation, pertain to that defined study population and do not automatically apply to other groups. Enrollment was 29, and the reason for termination is not reported in the registry record. The record also lacks details needed to assess missing-data handling and the sponsor’s full statistical methods.

Overall, the posted data describe group-level changes and their uncertainty. They do not provide a basis for treatment recommendations, a definitive statement about efficacy, or a conclusion about the cause of the trial’s termination.

17. Why This Trial Matters Statistically

This trial raises a statistical question that is relevant to clinical research: how should change in a repeated measure of disability be summarized and compared between groups? The primary endpoint sums monthly changes over the 6-month DBTP. That construction captures accumulated change across the assessment period, but its interpretation depends on the endpoint definition and on how repeated measurements are handled in the analysis.

The registry defines the direction of the primary score: a negative sum indicates a better outcome. That definition makes the sign of the estimated difference interpretable, but it does not by itself indicate the precision, clinical importance, or robustness of the estimate. The primary confidence interval is broad and includes zero, illustrating why effect direction and evidential certainty need to be considered together.

The trial also illustrates why endpoint-specific counts and analysis methods matter. The number of participants contributing to posted results varies by outcome, while the registry record does not explain the reasons or fully describe missing-data handling. Those details affect how readers assess whether outcome comparisons are on a common footing and whether estimates may be sensitive to incomplete data.

Finally, the secondary outcomes span migraine frequency, work impairment, and functioning. Their numerical results provide related but distinct perspectives, yet multiple unadjusted comparisons are not equivalent to a single confirmatory test. The absence of a reported multiplicity plan makes it important to distinguish exploratory patterns from a primary conclusion. These are general statistical considerations applied to the design and reporting details in this record.

18. 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.

Enrollment was 29, and the primary endpoint summaries include 15 participants in the placebo arm and 14 in the erenumab arm. The primary confidence interval is wide and includes zero, so the estimated group difference is not precise. The registry record does not report the reason for termination, which prevents assessment of whether termination affected follow-up, recruitment, or the planned analysis.

The posted endpoint counts vary. The registry record does not explain why, provide a full participant-flow account, or describe missing-data methods. Its efficacy analysis-set description is incomplete, limiting assessment of exactly who contributed to each estimate. The sponsor’s full statistical analysis plan, original sample-size justification, interim-analysis information, and inferential results are not reported in the registry record.

There are five listed secondary outcomes, but numerical summaries are available for only migraine days, work impairment, and physical functioning. Results for usual activities and social functioning are not reported in the registry record. No multiplicity strategy is reported, so unadjusted secondary comparisons warrant caution. The primary and secondary comparisons presented are unadjusted recalculations from group summary statistics and do not reproduce any unreported covariate-adjusted or longitudinal sponsor analysis.

The endpoint is specific to employed subjects with episodic migraine who had previously failed 1 or more migraine preventive treatments. The record does not report a clinical-importance threshold for the modified MIDAS sum. These limitations restrict interpretation of generalizability, the clinical meaning of the estimated difference, and the robustness of the results; they do not establish that any particular unreported analysis or trial procedure was inappropriate.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Effect of Erenumab-aooe on Disability and Work Productivity in Employed Subjects With Episodic Migraine — NCT03912337.
• Registry record last updated 2022-07-20; status last verified 2022-07.
• Results first posted 2022-07-20.
• 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.

22. Record Summary

NCT03912337 is a phase 4 randomized, quadruple-masked, parallel-group trial of erenumab 140 mg QM versus placebo QM in employed subjects with episodic migraine who had previously failed 1 or more migraine preventive treatments. Enrollment was 29. The trial is listed as terminated; the reason is not reported in the registry record.

The primary endpoint was the sum of monthly changes from baseline in modified MIDAS total score over the 6-month DBTP. The recalculated mean difference was -26.86, with a 95% confidence interval from -75.15 to 21.43 and p = 0.276. The interval includes zero, leaving substantial uncertainty about the between-group difference.

Some secondary outcomes have numerical summaries, but the record does not report results for every listed secondary measure or a multiplicity strategy. Missing-data methods, the full analysis plan, and the original sample-size justification are not reported in the registry record.