Article Text

Original research
Redefining migraine prevention: early treatment with anti-CGRP monoclonal antibodies enhances response in the real world
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  1. Edoardo Caronna1,2,
  2. Victor José Gallardo2,
  3. Gabriella Egeo3,
  4. Manuel Millán Vázquez4,
  5. Candela Nieves Castellanos5,
  6. Javier A Membrilla6,7,
  7. Gloria Vaghi8,9,
  8. Joana Rodríguez-Montolio10,11,
  9. Neus Fabregat Fabra12,
  10. Francisco Sánchez-Caballero13,
  11. Alex Jaimes Sánchez14,
  12. Albert Muñoz-Vendrell15,
  13. Renato Oliveira16,
  14. Gabriel Gárate17,
  15. Yésica González-Osorio18,
  16. Daniel Guisado-Alonso19,
  17. Raffaele Ornello20,
  18. Cem Thunstedt21,
  19. Iris Fernández-Lázaro22,
  20. Marta Torres-Ferrús1,2,
  21. Alicia Alpuente1,2,
  22. Paola Torelli23,
  23. Cinzia Aurilia3,
  24. Raquel Lamas Pére4,
  25. Maria José Ruiz Castrillo6,
  26. Roberto De Icco8,9,
  27. Grazia Sances9,
  28. Sarah Broadhurst24,
  29. Hui Ching Ong24,
  30. Andrea Gómez García14,
  31. Sergio Campoy15,25,
  32. Jordi Sanahuja26,
  33. Gonçalo Cabral27,
  34. Isabel Beltrán Blasco28,
  35. Marta Waliszewska-Prosół29,
  36. Liliana Pereira30,
  37. Almudena Layos-Romero31,
  38. Isabel Luzeiro32,33,
  39. Laura Dorado34,
  40. María Rocio Álvarez Escudero35,
  41. Arne May36,
  42. Alba López-Bravo11,37,
  43. Isabel Pavão Martins38,
  44. Christina Sundal39,40,41,42,
  45. Pablo Irimia43,
  46. Alberto Lozano Ros44,
  47. Ana Beatriz Gago-Veiga22,
  48. Fernando Velasco Juanes45,
  49. Ruth Ruscheweyh21,
  50. Simona Sacco20,
  51. Elisa Cuadrado-Godia19,46,
  52. David García-Azorín18,
  53. Julio Pascual17,
  54. Raquel Gil-Gouveia16,47,
  55. Mariano Huerta-Villanueva15,25,
  56. Jaime Rodriguez-Vico14,
  57. Javier Viguera Romero13,
  58. Victor Obach12,
  59. Sonia Santos-Lasaosa10,11,
  60. Mona Ghadiri-Sani24,
  61. Cristina Tassorelli8,9,
  62. Javier Díaz-de-Terán6,7,
  63. Samuel Díaz Insa5,
  64. Carmen González Oria4,
  65. Piero Barbanti3,48,
  66. Patricia Pozo-Rosich1,2
  67. For the EUREkA study group
    1. 1 Headache Clinic, Neurology Department, Vall d'Hebron Hospital, Barcelona, Spain
    2. 2 Headache and Neurological Pain Research Group, Vall d'Hebron Research Institute, Barcelona, Spain
    3. 3 Headache and Pain Unit, IRCCS San Raffaele, Roma, Italy, Italian Migraine Registry (IGRAINE) study group
    4. 4 Unidad de Cefaleas, Hospital Universitario Virgen del Rocío, Sevilla, Spain
    5. 5 Headache Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe, Valencia, Spain
    6. 6 Headache Unit, Department of Neurology, La Paz University Hospital, Madrid, Spain
    7. 7 La Paz Institute for Health Research (IdiPAZ), Autonomous University of Madrid, Madrid, Spain
    8. 8 Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
    9. 9 Headache Science & Neurorehabilitation Center, IRCCS Mondino Foundation, Pavia, Italy
    10. 10 Department of Neurology, Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
    11. 11 Aragon Institute for Health Research (IIS Aragón), Zaragoza, Spain
    12. 12 Neurology Department Headache Unit, Hospital Clinic, Barcelona, Spain
    13. 13 Headache Unit, Hospital Virgen Macarena, Seville, Spain
    14. 14 Headache Unit, Hospital Universitario Fundación Jiménez Díaz Madrid, Madrid, Spain
    15. 15 Headache Unit, Neurology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
    16. 16 Hospital da Luz Headache Center, Neurology Department, Hospital da Luz, Lisboa, Portugal
    17. 17 Neurology Department, University Hospital Marqués de Valdecilla, Universidad de Cantabria, Santander, Spain
    18. 18 Headache Unit, Department of Neurology, Hospital Clínico Universitario de Valladolid, Valladolid, Spain
    19. 19 Department of Neurology, Hospital del Mar, Barcelona, Spain
    20. 20 Department of Applied Clinical Sciences and Biotechnology, University of L'Aquila, L'Aquila, Italy
    21. 21 Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
    22. 22 Headache Unit, Department of Neurology, Hospital Universitario La Princesa, Madrid, Spain
    23. 23 Neurology Unit, Department of Medicine and Surgery, Headache Center, University of Parma, Parma, Italy, Italian Migraine Registry (IGRAINE) study group
    24. 24 The Walton Centre NHS Foundation Trust, Liverpool, UK
    25. 25 Neurology Department, Hospital de Viladecans-IDIBELL, Viladecans, Barcelona, Spain
    26. 26 Headache Unit, Department of Neurology, Hospital Universitari Arnau de Vilanova-IRBLleida, Lleida, Spain
    27. 27 Neurology Department, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal
    28. 28 Headache Clinic, Neurology Departament, Hospital General Universitario Dr Balmis, ISABIAL, Alicante, Spain
    29. 29 Department of Neurology, Wrocław Medical University, Wrocław, Poland
    30. 30 Department of Neurology, Hospital Garcia de Orta, Almada, Portugal
    31. 31 Headache Unit, Neurology Department, Hospital General Universitario de Albacete, Albacete, Spain
    32. 32 Headache Outpatient Unit, Hospitalar and University Centre of Coimbra, Coimbra, Portugal
    33. 33 Coimbra Health School/ESTeSC, Coimbra, Portugal
    34. 34 Department of Neuroscience, Germans Trias i Pujol University Hospital, Badalona, Spain
    35. 35 Headache Unit, Department of Neurology, University Hospital Central de Asturias, Oviedo, Spain
    36. 36 University Clinic Hamburg, Hamburg, Germany
    37. 37 Headache Unit, Department of Neurology, Hospital Reina Sofía, Tudela, Spain
    38. 38 Headache Outpatient Clinic, Neurology Department, Hospital Universitario Sta Maria, Faculty of Medicine University of Lisbon & Campus Neurologico, Lisbon, Portugal
    39. 39 Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
    40. 40 NorHEAD, Norwegian Headache Research Centre, Oslo, Norway
    41. 41 Department of Neurology, NeuroClinic, Norway, Lillestrøm, Norway
    42. 42 Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden
    43. 43 Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain
    44. 44 Headache Unit, Hospital General Universitario Gregorio Marañón, Madrid, Spain
    45. 45 Department of Neurology, Hospital Universitario Cruces, Biocruces Bizkaia Health Research Institute, Bilbao, Spain
    46. 46 Neuroscience Research Program, Hospital del Mar Research Institute, Pompeu Fabra University, Barcelona, Spain
    47. 47 Center for Interdisciplinary Research in Health, Universidade Católica Portuguesa, Lisboa, Portugal
    48. 48 University San Raffaele, Rome, Italy
    1. Correspondence to Dr Patricia Pozo-Rosich; patricia.pozo{at}vallhebron.cat

    Abstract

    Background Anti-CGRP monoclonal antibodies (anti-CGRP MAbs) are approved and available treatments for migraine prevention. Patients do not respond alike and many countries have reimbursement policies, which hinder treatments to those who might respond. This study aimed to investigate clinical factors associated with good and excellent response to anti-CGRP MAbs at 6 months.

    Methods European multicentre, prospective, real-world study, including high-frequency episodic or chronic migraine (CM) patients treated since March 2018 with anti-CGRP MAbs. We defined good and excellent responses as ≥50% and ≥75% reduction in monthly headache days (MHD) at 6 months, respectively. Generalised mixed-effect regression models (GLMMs) were used to identify variables independently associated with treatment response.

    Results Of the 5818 included patients, 82.3% were females and the median age was 48.0 (40.0–55.0) years. At baseline, the median of MHD was 20.0 (14.0–28.0) days/months and 72.2% had a diagnosis of CM. At 6 months (n=4963), 56.5% (2804/4963) were good responders and 26.7% (1324/4963) were excellent responders. In the GLMM model, older age (1.08 (95% CI 1.02 to 1.15), p=0.016), the presence of unilateral pain (1.39 (95% CI 1.21 to 1.60), p<0.001), the absence of depression (0.840 (95% CI 0.731 to 0.966), p=0.014), less monthly migraine days (0.923 (95% CI 0.862 to 0.989), p=0.023) and lower Migraine Disability Assessment at baseline (0.874 (95% CI 0.819 to 0.932), p<0.001) were predictors of good response (AUC of 0.648 (95% CI 0.616 to 0.680)). These variables were also significant predictors of excellent response (AUC of 0.691 (95% CI 0.651 to 0.731)). Sex was not significant in the GLMM models.

    Conclusions This is the largest real-world study of migraine patients treated with anti-CGRP MAbs. It provides evidence that higher migraine frequency and greater disability at baseline reduce the likelihood of responding to anti-CGRP MAbs, informing physicians and policy-makers on the need for an earlier treatment in order to offer the best chance of treatment success.

    • migraine
    • health policy & practice

    Data availability statement

    Data are available on reasonable request. All data are available and any anonymised data will be shared on reasonable request from any qualified investigator.

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    WHAT IS ALREADY KNOWN ON THIS TOPIC

    • Anti-CGRP monoclonal antibodies (MAbs) have demonstrated their efficacy and tolerability in migraine prevention in clinical trials and real-world studies and they are currently available in many countries worldwide.

    • Evidence on how sex, age, migraine frequency and other clinical variables influence anti-CGRP MAbs response is scarce, yet relevant in clinical practice for an optimised patient management and to inform decisions on drug placement by regulatory agencies, as the prescription of these treatments is currently limited by strict reimbursement criteria in many countries.

    WHAT THIS STUDY ADDS

    • This is the largest real-world prospective study on the use of anti-CGRP MAbs in migraine, showing that, across countries, at least one out of two patients reaches a 50% or more reduction in monthly headache days with the treatment, with good tolerability.

    • Unilateral pain, less monthly migraine days and lower disability at baseline predict good and excellent response to anti-CGRP MAbs. Treatment response is not influenced by sex while older age is associated with a higher likelihood of response.

    HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

    • The present findings urge the redefinition of patient management in daily practice and provide scientific evidence to physicians and regulatory agencies on the need of starting preventive treatment earlier with anti-CGRP MAbs, this is before migraine becomes highly disabling, to offer patients the best chance of treatment success.

    Introduction

    Migraine prevention has advanced thanks to the introduction of new target-driven treatments antagonising the calcitonin gene-related peptide (CGRP) or its receptor.1 Specifically, galcanezumab, fremanezumab and eptinezumab are monoclonal antibodies targeting CGRP while erenumab targets the CGRP receptor (anti-CGRP MAbs). They have demonstrated their efficacy and tolerability in clinical trials2 and real-world studies3–8 for episodic (EM) and chronic migraine (CM) and are currently available in Europe.

    Since anti-CGRP MAbs introduction, several questions have been raised about the treatment response to these drugs. First, CGRP is differentially modulated according to sex9 and likely to age,10 which may result in different response rates based on these demographic characteristics. Second, patients with EM can evolve to CM throughout their life11 12 and treatment responses to anti-CGRP MAbs can be affected by the severity of the disease and headache frequency. Lastly, from the current use of these drugs, around 15%–25% of patients emerged as non-responders (<30% reduction in monthly headache days—MHD)13 14 and another 15%–25% as excellent responders (≥75% reduction in MHD),3 15 16 but predictors of response or non-response (NR) are currently lacking.

    All these questions have potentially relevant implications in terms of patient management and drug placement both in clinical practice and for regulatory agencies. Yet, they have been only marginally addressed to date.15–19 One of the reasons is that real-world studies, although particularly valuable to capture the clinical setting where anti-CGRP MAbs are used, have often limited sample size,20 predominantly because they are usually monocentric with precise prescription criteria. Clinical trials, on the other side, often have very specific inclusion criteria for participants, limiting the generalisability of their output to the broader spectrum of patients seen in daily practice.21 22

    Thus, our study aimed to investigate factors influencing good and excellent response (ER) to anti-CGRP MAbs at 6 months in a real-world large European cohort of migraine patients.

    Methods

    This is a prospective multicentre real-world study. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline has been followed.23 To participate, all centres were required to have an available prospective dataset of patients fulfilling the International Classification of Headache Disorders, third edition (ICHD-3) criteria for migraine,24 either EM or CM, and treated with anti-CGRP MAbs since March 2018, according to their own country prescription and reimbursement policy (online supplemental table 1). Although each country presented slightly different prescription criteria, our cohort was mainly composed of resistant patients with migraine who had failed multiple previous preventive treatments.25 We included patients with concomitant migraine preventive medications and patients with medication overuse.

    Supplemental material

    Each centre provided the following data to the multicentre study dataset: baseline demographics (age, sex and reproductive status), comorbidities (arterial hypertension, obesity, any cardiovascular disease, anxiety and depression, which were collected from medical records), migraine characteristics (aura, allodynia, accompanying symptoms, unilateral pain, unilateral cranial autonomic symptoms or signs—as defined by ICHD-3 for trigeminal autonomic cephalalgias, ipsilateral to the headache and present in the majority of patient’s migraine attack—time since migraine onset and chronification, if applicable), previously failed migraine preventive treatments, concomitant migraine preventive medications, date and type of anti-CGRP MAbs prescribed (erenumab 70 mg or 140 mg monthly, galcanezumab 120 mg monthly+240 mg loading dose, fremanezumab 225 mg monthly or fremanezumab 675 mg quarterly). Outcome variables used were MHD, monthly migraine days (MMDs) and monthly acute medication days (MAMDs). These data were collected through patients’ prospective headache diaries, either in paper or electronic depending on the centre, at baseline (M0), 3 months (M3) and 6 months (M6). The patient-reported outcomes questionnaires included in this study were the Migraine Disability Assessment (MIDAS)26 and the Headache Impact Test (HIT-6).27 We excluded patients with missing age, sex and MHD data at baseline or at follow-up.

    Response to anti-CGRP MAbs was categorised according to the mean reduction in MHD at 6 months from baseline: NR (NR—MHD reduction <30%), partial response (PR—MHD reduction 30%–49%), good response (GR—MHD reduction ≥50%) and ER (ER—MHD reduction ≥75%).

    We then searched the variables that were independently associated with GR and ER at 6 months.

    Statistical analysis

    We reported nominal (categorical) variables as frequencies (percentages), whereas the median and IQR were reported for continuous variables. We checked the normality assumption of continuous variables through visual methods (Q-Q plots). In the final dataset, we detected a rate of missing ranging from 4.6% to 44.3% in some variables, showing a missingness rate≥25% in MIDAS (44.3%), allodynia (40.8%), depression (26.3%) and unilateral cranial autonomic symptoms (25.7%) (online supplemental figure 1). We used random forest imputations in order to estimate these values according to basal MHD, age, sex and reproductive status using the multivariate imputation via chained equations package from R (V.3.16.0).28 Then, we tested in a sensitivity analysis the consistency of the main results reported in the raw dataset (without data imputation). Statistical significance between treatment responder’s subgroups was performed with Fisher’s exact test when comparing categorical variables, independent t-test was used for normal quantitative variables and the Wilcoxon rank-sum test for not-normally distributed quantitative variables.

    Then, a generalised mixed-effect regression model (GLMM) was estimated for a binary outcome variable (responder vs non-responder) in order to identify variables associated independently with treatment response rate. GLMM was, therefore, used for both GR and ER analysis. All participants, no matter if they continued or discontinued the anti-CGRP MAbs because of lack of efficacy, were included in the data modelling to avoid obtaining biased results due to treatment discontinuation. First, data were split into two subsets: training set (80% initial data) and test set (20% initial data). Then, a full GLMM was fitted within training dataset, adjusted by fixed-effect covariates (concomitant medication) and random effects (patients, headache centres and type of anti-CGRP-MAb). GLMM parameter estimation was performed using restricted maximum likelihood estimation. The best-fitting model was obtained according to the minimum corrected Akaike information criterion (AICc) and likelihood ratio tests were performed to ensure that the best AIC model was better than the full model. The final model was validated using repeated 10-fold cross-validation with 3 repetitions and model’s accuracy was evaluated in the test dataset, computing the corresponding confusion matrix and ROC curve.

    Models were fitted using R package glmmTMB V.1.1.7, variable selection was obtained using R package MuMIn V.1.1.7. Variance inflation factors for all the parameters were computed in order to estimate how much the variance of an estimated regression coefficient is inflated due to correlated variables so that we could avoid an overfitting problem in the final models. The analysis of the deviance table of the model’s main effect was performed and main effect plots were plotted using the R sjPlot package V.2.8.14. Variable importance of each predictor was estimated in terms of the differences in AICc between the full model and the model without each predictor.

    We did not conduct a statistical power calculation prior to the study because the sample size was based on available data. P values presented are for a two-tailed test and we considered p values <0.05 as statistically significant. Due to the exploratory nature of the present study, all p values were adjusted by applying the false discovery rate (FDR, Benjamini-Hochberg procedure). All analyses were done by using R V.4.3.0.

    Results

    Cohort description

    35 European hospitals from 7 countries participated (Spain, Italy, Portugal, the UK, Germany, Norway and Poland) with a total population of 6281 migraine patients who were started on anti-CGRP MAbs. We excluded 7.4% (463/6281) of patients during the data quality check and we finally included 5818 patients: 98.7% of data available at M3 (5742/5818) and 85.3% of data at M6 (4963/5818). The flow chart of the study cohort is shown in figure 1.

    Figure 1

    Flow chart of the study cohort. We included patients who started anti-CGRP MAbs from March 2018 to May 2023 who had available data at follow-up during the first 6 months of treatment. anti-CGRP MAb, anti-CGRP monoclonal antibody; FUP, follow-up; M0, baseline (month 0); M3, month 3; M6, month 6; MHD, monthly headache days.

    At baseline, of the 5818 patients, 82.3% (4786/5818) were female and the median age was 48.0 (40.0–55.0) years. The most represented countries were Spain (63.9%; 3719/5818) and Italy (22.5%; 1310/5818). Anxiety (34.7%; 2017/5818) and depression (29.6%; 1724/5818) were the most frequent comorbidities. 72.2% (4198/5818) had a baseline diagnosis of CM. The median MHD, MMD and MAMD were 20.0 (14.0–28.0) days/months, 15.0 (10.0–20.0) days/months and 15.0 (10.0–25.0) days/months, respectively. The median number of preventive treatment classes failed was 4.0 (3.0, 5.0). Table 1 shows all collected baseline variables.

    Table 1

    Baseline characteristics of the study cohort

    Effectiveness and tolerability

    At month 6, we observed a median reduction in MHD of −9.0 (−15.0, –3.0) days/month. The response rates were NR 30.3% (1503/4963), PR 13.2% (656/4963), GR 56.5% (2804/4963) and ER 26.7% (1324/4963).

    Treatment discontinuation occurred in 8.0% (462/5742) at M3 and in 7.4% (369/4963) at M6, mainly because of lack of efficacy (M3: 84.6%, 391/462; M6: 90.8%, 335/369). Discontinuation due to lack of tolerability at any time point occurred in 1.6% (91/5742). The presence of any adverse event (AE) was reported in 22.7% (1304/5742) at M3 and in 18.5% (920/4963) at M6, classified as mild. Main AEs reported were constipation (M3: 52.8%, 688/1304; M6: 54.1%, 498/920) and injection site reaction (M3: 14.0%, 183/1304; M6: 15.7%, 144/920). No patient had serious major safety concerns.

    Variables associated with a GR at 6 months

    The statistically significant variables of the univariate analysis, comparing patients with and without GR (≥50% vs <50% MHD reduction), are shown in online supplemental table 2.

    In the GLMM, statistically significantly independent variables associated with ≥50% MHD reduction were older age (1.08 (95% CI 1.02 to 1.15), p=0.016), the presence of unilateral pain (1.39 (95% CI 1.21 to 1.60), p<0.001), the absence of depression (0.840 (95% CI 0.731 to 0.966), p=0.014), less failure to onabotulinumtoxinA (BTX-A) (0.786 (95% CI 0.676 to 0.913), p=0.002) but more failure to beta-blockers (1.17 (95% CI 1.02 to 1.35), p=0.031), less concomitant oral medication (0.873 (95% CI 0.766 to 0.995), p=0.042), less MMD (0.923 (95% CI 0.862 to 0.989), p=0.023) and lower MIDAS at baseline (0.874 (95% CI 0.819 to 0.932), p<0.001) (table 2 and figure 2B–I). Figure 2A shows the importance of these variables within the model. The main results were reproducible in the sensitivity analysis (online supplemental table 3).

    Table 2

    Mixed-effects logistic regression model for the prediction of MHD reduction ≥50% and ≥75% after 24 weeks of anti-CGRP monoclonal antibodies treatment

    Figure 2

    Relative variable importance within the model (A) and fixed-effect plots (B–I) of the final mixed-effects logistic regression model for the prediction of MHD reduction ≥50% after 24 weeks of anti-CGRP monoclonal antibodies treatment. Relative variable importance of predictors was assessed by observing how much the model’s AIC changes when each predictor is removed individually. It provides insights into which predictors have a more significant impact on the model’s fit. AIC, Akaike information criterion; BB fail., failure to beta-blockers; Dep: depression; est. prob., estimated probability; MIDAS, migraine disability assessment; onabotA fail., failure to onabotulinum toxin A; MMD, monthly migraine days; Oral conc., concomitant oral medication; RR, response rate; MHD, monthly headache day; Unil. Pain, unilateral pain.

    The final fitted model presented an accuracy (95% CI) of 0.644 (0.630 to 0.658) and Area under the ROC Curve (AUC) of 0.692 (0.677 to 0.707) in the training set and an accuracy of 0.613 (0.583 to 0.641) and AUC of 0.648 (0.616 to 0.680) in the test set (online supplemental figure 2A).

    To better understand the influence of age on the probability of treatment response, we also conducted a sensitivity analysis of age cut-offs, where we found that participants aged 50 years or older had a higher probability of achieving good treatment response (51–55 years: 1.32 (95% CI 1.06 to 1.65), p=0.014; >56 years: 1.27 (95% CI 1.04 to 1.56), p=0.019). We conducted the same sensitivity analysis for MMD and we observed that only participants with baseline MMD greater than 20 days had a lower probability of achieving good treatment response (0.762 (95% CI 0.605 to 0.961), p=0.021).

    Variables associated with an ER at 6 months

    The statistically significant variables from the univariate analysis, comparing non-responders (<30% reduction in MHD) with excellent responders (≥75% reduction in MHD) at month 6, are shown in online supplemental table 4.

    In the GLMM, statistically significantly independent variables associated with ≥75% MHD reduction were older age (1.19 (95% CI 1.09 to 1.30); p<0.001), migraine diagnosis at baseline (CM) (1.91 (95% CI 1.50 to 2.43), p<0.001), the presence of unilateral pain (1.63 (95% CI 1.36 to 1.97), p<0.001), the absence of depression (0.705 (95% CI 0.584 to 0.850), p<0.001), less failure to BTX-A (0.699 (95% CI 0.568 to 0.861), p=0.001) and antihypertensive drugs (0.724 (95% CI 0.569 to 0.923), p=0.009), less concomitant oral medication (0.722 (95% CI 0.606 to 0.862), p<0.001), less MMD (0.767 (95% CI 0.690 to 0.852), p<0.001) and lower MIDAS at baseline (0.890 (95% CI 0.814 to 0.974), p=0.012) (table 2 and figure 3B–J). Variable importance is plotted in figure 3A. Main results were reproducible in the sensitivity analysis (online supplemental table 3).

    Figure 3

    Relative variable importance within the model (A) and fixed-effect plots (B–J) of the final mixed-effects logistic regression model for the prediction of MHD reduction ≥75% after 24 weeks of anti-CGRP monoclonal antibodies treatment. Relative variable importance of predictors was assessed by observing how much the model’s AIC changes when each predictor is removed individually. It provides insights into which predictors have a more significant impact on the model’s fit. AHD fail.: failure to antihypertensive drugs; MHD, monthly headache day; AIC, Akaike information criterion; Dep.: depression; DX: migraine diagnosis (EM, episodic migraine or CM, chronic migraine); est. prob.: estimated probability; MIDAS: migraine disability assessment; MMD: monthly migraine days; onabotA fail.: failure to onabotulinum toxin A; Oral conc.: concomitant with oral medication; Unil. Pain: unilateral pain.

    The fitted model presented an accuracy (95% CI) of 0.685 (0.667 to 0.702) and AUC of 0.736 (0.717 to 0.755) in the training set and an accuracy of 0.657 (0.620 to 0.693) and AUC of 0.691 (0.651 to 0.731) in the test set (online supplemental figure 2B).

    We conducted the same sensitivity analyses for age and MMD as we did for GR and we observed the same cut-offs for these variables also for excellent treatment response.

    Discussion

    At present, this is the largest real-world cohort of migraine patients treated with anti-CGRP MAbs. Baseline characteristics, effectiveness and tolerability are similar to the ones previously observed in other smaller real-world studies.3–5 7 8 However, our sample size allowed a more robust analysis of the factors influencing treatment response, thanks to the large representativeness of subgroups like men, older patients, non-responders, excellent responders, etc, usually very scarce in observational studies and clinical trials. We have obtained these results with consequently relevant implications for clinical practice.

    First, treatment responses to anti-CGRP MAbs do not depend on sex. This is in line with a previous retrospective study with a 3-month follow-up29 and may suggest a second-tier role of sex-related CGRP modulation at least in terms of drug effectiveness. Reproductive status did not emerge as a relevant variable in our model either. Gender perspective in healthcare is important for more personalised treatments, but our study does not support, at present, that anti-CGRP MAbs should have a preferred use based on sex. Nevertheless, new studies should further look into this research question, also considering that for other anti-CGRP drugs, the gepants, when used for migraine acute treatment, sex differences in response to treatment may exist.30

    Second, treatment responses to anti-CGRP MAbs depend on age. Interestingly, the older the patient, the higher is the likelihood of response. This is a novel finding that confirms recently published results indicating similar efficacy in patients ≥65 years old,31 32 underscoring the importance of age in relation to the biology of migraine and CGRP. The explanation behind this evidence is elusive at this time but may reflect the presence of age-dependent CGRP modulation, or a more relevant role of CGRP in migraine pathogenesis when other factors such as hormonal changes disappear.33 As a clinical implication, our study prompts to reconsider the current management of older migraine patients, often excluded in clinical trials or undertreated because of potential harm. Considering the longer life expectancy and age-related limitations of several oral preventive treatments, anti-CGRP MAbs appear to be a valuable option in older patients, this is starting from 50 years of age, in the absence of other contraindications.

    Third, migraine frequency influences treatment responses: the higher the number of MMD, the lower the likelihood of good or ER. The same trend is observed for migraine disability (MIDAS): the higher the disability, the lower the probability of response. These results are supported by other studies reporting the negative impact of daily headache in anti-CGRP MAbs response.34 The finding regarding the higher probability of CM to have ER seems apparently in contrast with the above-described pattern of better outcome in less affected patients. The fact that EM patients in our cohort have high frequency, being similar to CM,35 and that the diagnosis is determined at a specific time point, no capturing patients’ cyclic migraine behaviour, makes this variable probably more fictitious and little informative, whereas what should be considered clinically meaningful is migraine frequency. The influence of migraine frequency in anti-CGRP MAbs responses is a fundamental point raised by this study. Although anti-CGRP MAbs were approved by EMA starting from four migraine days/month,36–38 their higher cost compared with other migraine preventive treatments led to prescription/reimbursement restrictive criteria in the majority of countries and makes, at present, these drugs available to a limited group of patients with higher migraine frequency and several other preventive treatment failures. Thanks to this multicentre collaborative effort, our study has the strength of including a broad range of baseline headache frequency, something that is lacking in the current literature. Our data corroborate the higher effectiveness of an early treatment with anti-CGRP MAbs, as shown by a negative linear correlation between MMD and probability of treatment response that, translated into clinical practice, should warn policy-makers that current reimbursement criteria, covering prescription to patients with high migraine frequencies, have the potential disadvantage of reducing the likelihood of response to treatment. In light of this finding, reimbursement criteria could be reconsidered, especially for those countries where only CM is reimbursed, as the likelihood of response is clearly reduced when patients have more than 20 MMD. In addition, it is important to consider the potential evolution from EM to CM,12 and the reduced therapeutic armamentarium for EM patients, this is, the lack of BTX-A approval for EM.

    Finally, only considering clinical data, we were able to predict treatment response with a reasonable accuracy. The appropriate interpretation of treatment response comes from considering the combined effect of several variables simultaneously, rather than individually. For example, people who are young but also have high migraine frequency and disability will have less chances to respond than older individuals with less MMD. Our statistical models show that, among the combined set of variables that better predict good or ER, other factors also play an important role. Unilateral pain has emerged as a predictor of response in our study as well as in other observational studies14 16 39 40 and considering that it is one of the hallmarks of trigeminovascular activation,41 it suggests that patients with a well-defined migraine phenotype are more likely to respond. In addition, in the univariate analysis, we also found that cranial autonomic symptoms were associated with either good or ER, in line with previous studies,16 42 but eventually, this variable did not add any further information to our prediction model. Among comorbidities and previous treatment failures, having depressive symptoms and previous failure to BTX-A emerged as independent factors associated with less likelihood of anti-CGRP MAbs response, respectively. Migraine patients with depression seem to have higher levels of CGRP compared with those without, especially when they have higher migraine frequency,43 this may explain why this comorbidity influences treatment response, as observed also in other studies.44–46 Concerning BTX-A, recent studies have shown that mechanistically this drug also acts on CGRP release47 and may, in part, explain why failure to this treatment is a predictor of less likelihood of anti-CGRP MAbs response. Also, BTX-A is approved only for CM, which represents a severe form of the disease. The number of drug classes previously failed, on the contrary, did not add any relevant information in the models, indicating that patients respond to anti-CGRP MAbs regardless of the number of preventive treatments previously tried.16 48–50 The implication of having strong clinical predictors is twofold. In fact, selecting patients who are more likely to respond allows more precise migraine care and a reduction in healthcare costs. Overall, our work highlights the importance of properly phenotyping patients, especially through characterisation of migraine features that are able to guide clinicians in potentially detecting responders.51 Nevertheless, to achieve more precise predictions of anti-CGRP MAbs response in the future, we believe that more extensive, complete and standardised clinical data collection should be endeavoured in daily practice and integrated with non-clinical measures such as molecular and/or functional data.

    This study has several limitations. First, because of the multicentric nature, differences in data collection across centres may have occurred; however, the strength of our study is to use of an adjusted GLMM model to minimise this issue. Moreover, we imputed missing clinical data based on patients’ demographics, (age, sex, MHD) under the assumption that the remaining clinical variables may depend on these factors. However, we conducted a sensitivity analysis to assess the robustness and consistency of our results using the raw dataset. We are also aware that, because of reimbursement criteria in most of the participating countries, our population mainly included high-frequency EM and CM patients with failure to several other preventive treatments, therefore, limiting the possibility of understanding the influence of low-frequency EM and treatment-naiveness on anti-CGRP MAbs responses and, therefore, generalising our results to the entire migraine population. However, these treatment-resistant patients represent the majority of those seeking medical care in headache clinics. In addition, we also recognise that other variables, not included in this study, may affect anti-CGRP MAbs responses, nevertheless our study aimed to focus on the most relevant and commonly collected data in clinical practice with the strength of counting on an ample study cohort. Finally, we are aware that at present predictors of treatment response are scarcely translatable to single individuals, in other terms, patients with some negative predictors may still have GR to the treatment and it would be inequitable to exclude patients from receiving it. However, our main study objective was not to predict treatment for single individuals, but rather to gain insights on potentially relevant aspects that influence treatment response at group levels, as a way to help improving migraine care.

    Conclusion

    In this European real-world cohort including 5818 migraine patients treated with anti-CGRP MAbs, we confirm previous findings on their effectiveness and tolerability and we recognise the influence of unilateral pain, less monthly migraine days and lower disability in predicting good and excellent response. These treatment responses are not influenced by sex, but older age is associated with a higher likelihood of response. Overall, these robust and novel findings urge the redefinition of patient management in daily practice, especially in terms of starting preventive treatment with anti-CGRP MAbs earlier, before the disease becomes highly disabling.

    Data availability statement

    Data are available on reasonable request. All data are available and any anonymised data will be shared on reasonable request from any qualified investigator.

    Ethics statements

    Patient consent for publication

    Ethics approval

    The study was approved by the Vall d’Hebron Ethics Committee (EOM(AG)009/2023(6101)) as the coordinating centre and shared with all participating centres. All participating centres gave their consent to the use of their data and, if necessary, local ethical approval to pool data was obtained. Data were anonymised and handled confidentially. No informed consent for this study was obtained from patients, considering that they had previously consented to the collection and use of anonymous data at each centre, and no additional procedure, data collection or requirement was needed for the current study. The study was conducted in accordance with the Declaration of Helsinki.

    References

    Supplementary materials

    • Supplementary Data

      This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

    Footnotes

    • Collaborators European real-world study on the Use of anti-CGRP monoclonal antibodiEs in migrAine (EUREkA) study group: Daniel Guisado-Alonso, PhD, Neurology Department, Hospital del Mar, Barcelona, Spain; Neuroscience Research Program, Hospital del Mar Research Institute. Pompeu Fabra University, Barcelona, Spain. Raffaele Ornello, PhD, Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy. Cem Thunstedt, MD, Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany. Iris Fernández-Lázaro, MSc, Headache Unit. Neurology Department. Hospital Universitario La Princesa. Antonio Sánchez-Soblechero, MD, Headache Unit, Hospital General Universitario Gregorio Marañón, Madrid, Spain. Andreas Husoy, PhD, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway; NorHEAD, Norwegian Headache Research Centre, Oslo, Norway. Beatriz Nunes Vicente, MD, Headache Outpatient Clinic, Neurology Department, Hospital Universitario Sta Maria, Lisbon, Portugal. Hauke Basedau, University Clinic Hamburg, Hamburg, Germany. Nuria Pilar Riesco Pérez, PhD, Headache Unit, Department of Neurology, University Hospital Central de Asturias, Oviedo, Spain. Belen Flores Pina, MD, Department of Neuroscience, Germans Trias i Pujol University Hospital, Badalona, Spain. Catarina Fernandes, MD, Headache Outpatient Unit, Hospitalar and University Centre of Coimbra, Coimbra, Portugal. Alberto Andrés-López, MD, Headache Unit, Neurology Department, Hospital General Universitario de Albacete, Albacete, Spain. Elisa Martins-Silva, MD, Department of Neurology, Hospital Garcia de Orta, Almada, Portugal. Sławomir Budrewicz, PhD, Department of Neurology, Hospital Garcia de Orta, Almada, Portugal. Pablo Ros Arlanzón, MD, Headache Clinic, Neurology Departament, Hospital General Universitario Dr Balmis, ISABIAL, Alicante, Spain. André Caetano, PhD, Neurology Department, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal. Silvana Zapata, MD, Neurology Department, Universidad de Antioquia, Antioquia, Colombia. Sonsoles Aranceta, Neurology Department, Hospital Parc Tauli, Spain. Izaro Kortazar Zubizarreta, MD, Neurology Department, Hospital Universitario de Alava, Alava, Spain. Amalia Echeverria Urabayen, MD, Neurology Department, Hospital Universitario de Alava, Alava, Spain. Inês Marques, MD, Hospital da Luz Headache Center, Neurology Department, Hospital da Luz, Lisboa, Portugal. Elsa Parreira, MD, Hospital da Luz Headache Center, Neurology Department, Hospital da Luz, Lisboa, Portugal. Vicente González-Quintanilla, PhD, Neurology Department, University Hospital Marqués de Valdecilla, Universidad de Cantabria, Santander, Spain. Ángel Luis Guerrero-Peral, PhD, Headache Unit, Department of Neurology, Hospital Clínico Universitario de Valladolid, Valladolid, Spain; Department of Medicine, University of Valladolid, Valladolid, Spain. Isabel Miró, MD, Department of Neurology, Hospital del Mar, Barcelona, Spain. Julia Peris-Subiza, MD, Department of Neurology, Hospital del Mar, Barcelona, Spain. Valeria Caponnetto, MSN, PhD, Department of Applied Clinical Sciences and Biotechnology, University of L'Aquila, L'Aquila, Italy. Andreas Straube, MD, Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany. Alicia Gonzalez-Martinez, PhD, Headache Unit, Department of Neurology, Hospital Universitario La Princesa, Madrid, Spain. Sonia Quintas, MD, Headache Unit, Department of Neurology, Hospital Universitario La Princesa, Madrid, Spain. Margarita Sánchez-del-Río, MD, Headache Unit, Neurology Department, Clínica Universidad de Navarra, Madrid, Spain. Erling Tronvik, PhD, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway. NorHEAD, Norwegian Headache Research Centre, Oslo, Norway. Begoña Venegas Pérez, MD, Headache Unit, Department of Neurology, University Hospital Central de Asturias, Oviedo, Spain. Agustin Oterino Durán, PhD, Headache Unit, Department of Neurology, University Hospital Central de Asturias, Oviedo, Spain. Miguel Rodrigues, MD, Department of Neurology, Hospital Garcia de Orta, Almada, Portugal. Ana Fries Ramos, MD, Headache Clinic, Neurology Departament, Hospital General Universitario Dr Balmis, ISABIAL, Alicante, Spain. Yago Vaamonde Esteban, MD, Headache Clinic, Neurology Departament, Hospital General Universitario Dr Balmis, ISABIAL, Alicante, Spain. Sabina Cevoli, MD, PhD, Headache Center IRCCS Istituto delle Scienze Neurologiche Bologna, Italy; Italian Migraine Registry (IGRAINE) study group. Bruno Colombo, MD, Headache Unit Scientific Institute San Raffaele Hospital, Vita-Salute University, Milan, Italy; Italian Migraine Registry (IGRAINE) study group. Michele Trimboli, MD, Headache Centre, Department of Neurology, AOR "San Carlo", Potenza, Italy; Italian Migraine Registry (IGRAINE) study group. Fabio Frediani, MD, Headache Center, ASST Santi Paolo Carlo, Milan, Italy; Italian Migraine Registry (IGRAINE) study group. Florindo d’Onofrio, MD, Hedache Center, San Giuseppe Moscati Hospital, Avellino, Italy; Italian Migraine Registry (IGRAINE) study group. Marco Aguggia, MD, Headache Center Cardinal Massaia Hospital, Asti, Italy; Italian Migraine Registry (IGRAINE) study group. Antonio Salerno, MD, Headache Center, S Giovanni Addolorata Hospital, Rome, Italy; Italian Migraine Registry (IGRAINE) study group. Antonio Carnevale, MD, Headache Center, Ospedale San Filippo Neri - ASL Roma 1, Rome, Italy; Italian Migraine Registry (IGRAINE) study group. Maurizio Zucco, MD, Headache Center, Neurology Unit, San Camillo-Forlanini Hospital, Rome; Italian Migraine Registry (IGRAINE) study group. Maria Albanese, MD, PhD, Headache Center, University Hospital Tor Vergata, Rome, Italy; Italian Migraine Registry (IGRAINE) study group. Cinzia Finocchi, MD, Neurology Unit, San Paolo Hospital, ASL 2 Savona, Italy; Italian Migraine Registry (IGRAINE) study group. Angelo Ranieri, MD, Headache Center, AORN A. Cardarelli, Napoli, Italy; Italian Migraine Registry (IGRAINE) study group. Francesco Zoroddu, MD, Pediatric Headache Center, Neurology Unit, University of Sassari, Italy; Italian Migraine Registry (IGRAINE) study group. Massimo Autunno, MD, Headache Center, Department of Clinical and Experimental Medicine, University of Messina, Italy; Italian Migraine Registry (IGRAINE) study group.

    • Contributors PP-R and EC made substantial contributions to conception and study design. All authors worked for acquisition of data. EC and VJG contributed to data analysis. All authors contributed to the interpretation of data. EC and VJG wrote the first draft. All authors critically revised and finally approved the version to be published. All authors fully comply with and approve the version to be published. PPR acted as the guarantor.

    • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

    • Competing interests All authors have completed the ICMJE uniform disclosure form at http://www.icmje.org/disclosure-of-interest/ and declare: EC has received honoraria from Novartis, Chiesi, Lundbeck, MedScape; his salary has been partially funded by Río Hortega grant Acción Estratégica en Salud 2017–2020, Instituto de Salud Carlos III (CM20/00217). He is a junior editor for Cephalalgia. GE received travel grants and honoraria from Eli-Lilly, Novartis, Lusofarmaco, New Penta and Ecupharma. CNC has received honoraria for advisories, educational or commercial symposia from: Abbvie-Allergan, Kern Pharma, Chiesi, Lilly, Lundbeck, Novartis and Teva Pharmaceuticals And has participated as subinvestigator in Clinical Trials for: Abbvie-Allergan, Amgen, Biohaven, Lilly, Lundbeck, Pfizer and Teva Pharmaceuticals. JAM has received honoraria as consultant and/or speaker for Lilly, Novartis, Teva. FS-C received honoraria from Novartis, Lilly, TEVA, Abbvie. AM has received honoraria from Teva, Lilly, Roche, UCB, Bial, Chiesi, Allergan, Esai, Zambon, Kern Pharma, Pfizer, Biogen Idec, Novartis, TEVA, Merck, Janssen, Neuraxpharm, Genzyme, Sanofi, Bayer, Almirall and/or Celgene. JS received honoraria from Allergan, Lilly, Teva, Novartis. IBB received honoraria for presentations from Novartis, Lilly, Teva, Lundbeck and Abbvie. MW-P received honoraria from Pfizer, Allergan-Abbvie, TEVA, Polpharma. MW-P is member of Editorial Board: The Journal of Headache and Pain. LP received honoraria from Pfizer, Lilly, Abbvie, TEVA, Novartis. AL-R received honoraria for Abbvie, Lilly, Novartis and Teva. IL received honoraria from Novartis, Abbvie, Teva, Eisai, Tecnifar and Bial. LD received honoraria as a speaker for Allergan, Lilly, Teva and Lundbeck. MRA-E, received honoraria from ABBVIE, Lilly, and Novartis. AM has no COI to declare. The University Clinic Hamburg got an unrestricted scientific grant from Novartis (2019-2023). IPM has received honoraria from Allergan Teva, Novartis, Lundbeck and Eli Lilly for lecturing or participating in advisory boards; is principal investigator for phase IV trials sponsored by Novartis, Lundbeck and Teva. CS has received personal fees for lectures/ advisory boards: Novartis, Abbvie and TEVA. PI received honoraria from TEVA, Novartis, Lilly, Abbvie, Lundbeck, Exeltis. ALR received honoraria from TEVA. ABG-V has received speaker honoraria and/or clinical advisor from Novartis, Lilly, TEVA, Exeltis, Chiesi, Abbvie, Pfizer and Lundbeck. RR has received travel grants and/or honoraria for lectures or advisory boards from Allergan/AbbVie, Hormosan, Lilly, Lundbeck, Novartis, Pfizer and Teva. SS reports consultant, speaker or advisory board fees from Abbott, Allergan/Abbvie, AstraZeneca, Bayer, Bristol Myers Squibb, Daiichi-Sankyo, Eli Lilly, Medscape, Medtronic, Novartis, Pfizer, Starmed, Teva and Uriach. EC-G received honoraria from TEVA. DGA has received personal compensation for consulting/advising from the WHO. Non-profit board membership in the Spanish Society of Neurology, and the European Union of Medical Specialist section of Neurology. Research funding from the Regional Health Administration (Gerencia Regional de Salud SACYL) in Castilla y Leon, Spain and Carlos III institute, Madrid, Spain. Speaker/travel grants/ clinical trials from Teva, Allergan, Amgen, Eli Lilly, Lundbeck, Novartis and Biohaven. JP has received honoraria from Abbvie, Lilly, Lundbeck, Novartis and Teva. RG-G received honoraria from Allergan/ Abbvie, Lilly, Lundbeck, Novartis, Pfizer, Tecnifar, Teva. MH-V has received honoraria for participating on advisory boards and for collaborations as consultant, scientific communications, speaker, research support as well as funding for travel and congress-attending expenses for Abbie-Allergan, Novartis, Lundbeck, Lilly, Almirall, Chiesi, Esai, Exeltis, Kern Pharma, Menarini, TEVA and Zambon. His research group has received research grants from Abbie-Allergan and has received funding for clinical trials from Lilly, Novartis, TEVA. JVR received honoraria from Novartis, Abbvie, Lilly, TEVA, Lundbeck. SS-L received honoraria from Allergan, Almirall, Amgen, Chiesi, Eisai, Exeltis, Lilly, Lündbeck, Novartis, Pfizer y Teva. MG-S has received honoraria and been involved in research, education and advisory boards with Teva, Lily, Novartis and Abbvie. CT received personal fees for participating in advisory or for speaking at scientific events from AbbVie, Allergan, Biohaven, Dompé, Eli Lilly, Lundbeck, Novartis and Teva. CT has received research funding from the European Commission, the Italian Ministry of Health and Migraine Research Foundation. JDdT has received honoraria as consultant and/or speaker for Lilly, Novartis, Teva. SDI has received honoraria for advisories, educational or commercial symposia from: Abbvie-Allergan, Fundació Universitat-Empresa, Ipsen Pharma, Kern Pharma, Lilly, Lundbeck, MSD-Organon, Novartis and Teva Pharmaceuticals And has participated as PI in Clinical Trials for: Abbvie-Allergan, Alder, Amgen, Biohaven, Ipsen Pharma, Lilly, Lundbeck, Pfizer and Teva Pharmaceuticals. CGO participated in clinical trials from Novartis, St Jude Medical, Lilly, Lundbeck; TEVA, Biohaven, Pfizer. CGO received honoraria as consultant for Novartis, Lilly, Allergan-abbvie, Lundbeck, TEVA, Pfizer. CGO received honoraria as speaker for Allergan-Abbvie, TEVA, Novartis,Lilly, Chiesi, MSD, Almirall. PB reports personal compensation for consulting, serving on a scientific advisory board, speaking, research support, collaborated for clinical trials or other activities with Abbvie, Alder, Allergan, Amgen, Angelini, Assosalute, Bayer, Biohaven, ElectroCore, Eli-Lilly, Fondazione Ricerca e Salute, GSK, Lundbeck, Lusofarmaco, 1MED, MSD, New Penta, Noema Pharma, Novartis, Pfizer, Stx-Med, Teva, Visufarma, Zambon and serves as President with Italian Association of Headache Sufferers. PP-R has received, in the last 3 years, honoraria as a consultant and speaker for: AbbVie, Biohaven, Chiesi, Eli Lilly, Lundbeck, Medscape, Novartis, Pfizer and Teva. Her research group has received research grants from AbbVie, Novartis and Teva; as well as, Instituto Salud Carlos III, EraNet Neuron, European Regional Development Fund (001-P-001682) under the framework of the FEDER Operative Programme for Catalunya 2014-2020 - RIS3CAT; has received funding for clinical trials from AbbVie, Amgen, Biohaven, Eli Lilly, Novartis, Teva. She is the Honorary Secretary of the International Headache Society. She is in the editorial board of Revista de Neurologia. She is an associate editor for Cephalalgia, Headache, Neurologia, The Journal of Headache and Pain and Frontiers of Neurology. She is a member of the Clinical Trials Guidelines Committee of the International Headache Society. She has edited the Guidelines for the Diagnosis and Treatment of Headache of the Spanish Neurological Society. She is the founder of www.midolordecabeza.org. PP-R does not own stocks from any pharmaceutical company. VJG, MMV, GV, JR-M, NFF, AJS, RO, GG, YG-O, GC, AL-B, FVJ, JR-V and VO reports no disclosures. RO reports personal fees from Eli Lilly, Novartis, Teva, and Pfizer, and non-financial support from Novartis, Teva, and Allergan/AbbVie. CT has received honoraria for lectures from TEVA, Lundbeck and for advisory boards from TEVA. He has received travel support from TEVA and Lundbeck. SS received honoraria from TEVA. AH declares no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. HB received honoraria from Novartis, Teva and Lundbeck. NPRP received honoraria from ABBVIE, Lilly and Novartis. CF received honoraria from Novartis and Abbvie. AAL received honoraria for Abbvie, Lilly, Novartis and Teva. EMS received a grant from the Portuguese Headache Society, supported by Teva. MTF has received honoraria from Allergan-AbbVie, Novartis, Chiesi and Teva. AA has received honoraria from Allergan-AbbVie, Novartis, Chiesi. PT received grants and honoria from Novartis, Teva, Eli-Lilly and Allergan. CA received travel grants from FB-Health, Lusofarmaco, Almirall, Eli-Lilly Novartis and Teva. RDI received speaker honoraria from Eli-Lilly, TEVA and Lundbeck. GS received personal fees as speaker or advisory board from Eli Lilly, Novartis, Teva, Lundbeck, Pfizer. SB has received honoraria from Teva. SC has received honoraria from Teva, Lilly, Roche, UCB, Bial, Chiesi, Allergan, Esai, Zambon, Kern Pharma, Pfizer, Biogen Idec, Novartis, TEVA, Merck, Janssen, Neuraxpharm, Genzyme, Sanofi, Bayer, Almirall and/or Celgene. EP reports personal fees from Novartis, Teva and Lilly. ALGP Research funding from the Regional Health Administration (Gerencia Regional de Salud SACYL) in Castilla y Leon, Spain. Speaker/travel grants/ clinical trials from Teva, Allergan, Amgen, Eli Lilly, Lundbeck, Novartis, Pfizer and Biohaven. AS has received honoraria for advisory boards and lectures from Allergan/AbbVie, Hormosan, Lilly, Lundbeck, Novartis, Sanofi, Teva. AGM has received speaker honoraria from TEVA. SQ has received speaker honoraria from Novartis, Lilly and Exeltis. MSR has received consulting fees and honoraria for lectures/presentations from Eli Lily, Lundbeck, Novartis, Teva and Pfizer. Intellectual as Secretary of the European Headache Federation, Review Editor on the Editorial Board of Headache and Neurogenic Pain (specialty section of Frontiers in Neurology). Margarita Sanchez-del-Rio serves as a member of the Board of Directors in the European Headache Federation. ET has received personal fees for lectures/ advisory boards: Novartis, Eli Lilly, Abbvie, TEVA, Roche, Lundbeck, Pfizer, Biogen. Consultant for and owner of stocks and IP in Man & Science. Stocks and IP in Nordic Brain Tech and Keimon Medical. Non-personal research grants from EU, Norwegian Research Council, Dam foundation, KlinBeForsk. Commissioned research (non-personal): Lundbeck, Pfizer. BVP received honoraria from ABBVIE. AOD received honoraria from ABBVIE, Lilly, Teva, Novartis. MR received honoraria from Lilly, Novartis. BC received grants and honoria from Eli-Lilly, Novartis, Teva; SC received travel grants, honoraria for advisory boards, speaker panels or clinical investigation studies from Novartis, Teva, Lilly, Allergan, Abvie, Ibsa, Amgen, Angelini and Lundbeck; FF has received fees for participation on advisory boards, speaker honoraria or consulting activities from Angelini, Cristalfarma, Ecupharma, IBSA, Lundbeck, Novartis, PIAM, Teva; FdO received travel grant, honoraria as a speaker or for partecipating in advisory boards from Novartis, Teva, Neopharmed Gentili, Qbgroup srl, K link srl and Eli-Lilly; MA received grants from Novartis and Lilly; RR received honoraria for speaker panels from Teva, Lilly, Novartis, Allergan, Lundbeck; MZ received travel grants and honoraria from Novartis; MA received travel grants and honoraria from Novartis, Teva, Eli-Lilly and Lundbeck; CF received grants and honoraria from Novartis, Eli Lilly, TEVA, AIM group; AR received travel grants and honoraria from Teva and Eli-Lilly; SZ, RLP, MJRC, VGQ, HCO, SA, IKZ, DGA, IFL, BFP, SB, PRA, AC, AEU, AGG, IM, JPS, VC, AFR, YVE, MT, AS, AC, FZ and MA has no disclosures to declare.

    • Provenance and peer review Not commissioned; externally peer reviewed.

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