Erenumab (AMG 334) in episodic migraine: Interim analysis of an ongoing open-label study

Reliability, validity, and responsiveness of the Arabic version of HIT-6 questionnaire in patients with migraine indicated for preventive therapy: A multi-center study

BACKGROUND

The Headache Impact Test (HIT-6) is an important patient-reported outcome measure (PROM) in migraine prevention trials.

OBJECTIVES

This study aimed to (i) assess the reliability and validity of the Arabic version of HIT-6 in Arabic-speaking patients experiencing migraine, and (ii) evaluate the responsiveness of HIT-6 following migraine preventive therapy.

METHODS

In this prospective study, patients with migraine (n = 145) were requested to fill out a headache diary, the Arabic version of HIT-6, and Migraine Disability Assessment Scale (MIDAS) at two time points (baseline and 3 months after initiation of prophylactic treatment). Some respondents (n = 73) were requested to fill out HIT-6 again 1 week from the baseline for test-retest reliability. The intensity of migraine headache attacks was evaluated using the Visual Analogue Scale (VAS). An anchor-based method was used to establish the minimal important change (MIC) value and responsiveness of HIT-6.

RESULTS

The total scores of HIT-6 were significantly correlated to a fair degree with MIDAS (r = 0.41), as well as VAS (r = 0.53), and monthly migraine days (r = 0.38) at the baseline while at the follow-up (after 3 months), the correlations were of moderate degree with MIDAS scores (r = 0.62) and monthly migraine days (r = 0.60; convergent validity). Reliability estimates of the Arabic HIT-6 were excellent (Cronbach's α = 0.91 at baseline and 0.89 at follow-up). The average measure interclass correlation coefficient (ICC) value for the test-retest reliability was 0.96 (95% confidence interval = 0.94-0.98, p < 0.001). The HIT-6 total score is sensitive to change, being significantly reduced after prophylactic treatment compared to before (effect size = 1.5, standardized response mean = 1.3). A reduction from baseline of 4.5 on HIT-6 showed the highest responsiveness to predict improvement with an area under the curve equal to 0.66, sensitivity of 80%, specificity of 45%, and significance at 0.021. Changes in the HIT-6 total score were positively correlated with changes in monthly migraine days (r = 0.40) and VAS scores (r = 0.69) but not with changes in the score of MIDAS (r = 0.07).

CONCLUSION

The Arabic version of HIT-6 is valid, reliable, and sensitive to detect clinical changes following migraine prophylactic treatment with a MIC of 4.5 points.

Safety considerations in the treatment with anti-CGRP(R) monoclonal antibodies in patients with migraine

Background

Anti-CGRP-(receptor-)monoclonal antibodies (anti-CGRP(R)-mAbs) represent a novel class of drugs for migraine treatment, but their long-term cerebrovascular and cardiovascular (CV) safety warrants further examination.

Methods

In this observational cohort study we assessed the CV safety for erenumab and fremanezumab in a real-world setting during a follow-up period of at least 1 year. Patients with hypertension or CV history were excluded. We conducted ECGs and collected clinical data at treatment initiation and thereafter every 3 months, including liver and kidney function, lipid-, electrolyte-and glucose levels.

Results

Among patients receiving erenumab (n = 101) or fremanezumab (n = 92), 3.1% (6/193) developed abnormal ECGs or CV adverse events. Of these, three (1.6%) experienced moderate to severe CV adverse events (cerebellar stroke, spontaneous coronary artery dissection, and pericarditis) and discontinued treatment. The remaining three (1.6%) developed non-threatening ECG abnormalities without physical complaints. No significant changes were observed in liver and kidney function, lipid-, electrolyte-, or glucose levels.

Discussion

We observed CV events in 1.6% of patients with 1.5-year follow-up of anti-CGRP(R)-mAbs treatment. We advise awareness regarding CV events in patients with migraine undergoing CGRP-targeted treatment, not as a confirmation of increased risk but as a proactive measure to address potential multifactorial influences.

Therapeutic Antibodies in Medicine

Antibody engineering has developed into a wide-reaching field, impacting a multitude of industries, most notably healthcare and diagnostics. The seminal work on developing the first monoclonal antibody four decades ago has witnessed exponential growth in the last 10-15 years, where regulators have approved monoclonal antibodies as therapeutics and for several diagnostic applications, including the remarkable attention it garnered during the pandemic. In recent years, antibodies have become the fastest-growing class of biological drugs approved for the treatment of a wide range of diseases, from cancer to autoimmune conditions. This review discusses the field of therapeutic antibodies as it stands today. It summarizes and outlines the clinical relevance and application of therapeutic antibodies in treating a landscape of diseases in different disciplines of medicine. It discusses the nomenclature, various approaches to antibody therapies, and the evolution of antibody therapeutics. It also discusses the risk profile and adverse immune reactions associated with the antibodies and sheds light on future applications and perspectives in antibody drug discovery.

Migraine: Advances in the Pathogenesis and Treatment

This article presents a comprehensive review on migraine, a prevalent neurological disorder characterized by chronic headaches, by focusing on their pathogenesis and treatment advances. By examining molecular markers and leveraging imaging techniques, the research identifies key mechanisms and triggers in migraine pathology, thereby improving our understanding of its pathophysiology. Special emphasis is given to the role of calcitonin gene-related peptide (CGRP) in migraine development. CGRP not only contributes to symptoms but also represents a promising therapeutic target, with inhibitors showing effectiveness in migraine management. The article further explores traditional medical treatments, scrutinizing the mechanisms, benefits, and limitations of commonly prescribed medications. This provides a segue into an analysis of emerging therapeutic strategies and their potential to enhance migraine management. Finally, the paper delves into neuromodulation as an innovative treatment modality. Clinical studies indicating its effectiveness in migraine management are reviewed, and the advantages and limitations of this technique are discussed. In summary, the article aims to enhance the understanding of migraine pathogenesis and present novel therapeutic possibilities that could revolutionize patient care.

Long-term efficacy and safety of erenumab in Japanese patients with episodic and chronic migraine: results from a 28-week open-label treatment period of a randomised trial

OBJECTIVES

To evaluate the 1-year efficacy and safety of once-monthly erenumab 70 mg following a 24-week double-blind treatment period (DBTP) of a phase III randomised study of Japanese patients with episodic migraine (EM) or chronic migraine (CM).

DESIGN

Multicentre open-label study.

SETTING

A total of 41 centres in Japan.

PARTICIPANTS

Patients completing the DBTP continued into the 28-week open-label treatment period (OLTP). 254 of 261 (97.3%) randomised patients continued into the OLTP; 244 (93.5%) completed treatment.

INTERVENTIONS

Once-monthly subcutaneous erenumab 70 mg.

MAIN OUTCOME MEASURES

Changes from baseline in monthly migraine days (MMD) and monthly acute migraine-specific medication treatment days (MSMD) reported via patient eDiary; proportion of ≥50% and ≥75% responders in MMD reduction from baseline; incidence and exposure-adjusted incidence of treatment-emergent adverse events (TEAEs).

RESULTS

At week 24 of the DBTP, the mean (SE) change from baseline in MMD for the erenumab group was -3.8 (0.4) days (EM, -3.0 (0.4); CM, -5.2 (0.8)); in MSMD, -2.6 (0.4) days (EM, -2.1 (0.4); CM, -3.4 (0.7)). At the end of the OLTP (52 weeks postbaseline), the mean (SE) change from baseline in MMD was -4.7 (0.3) days (EM, -3.4 (0.3); CM, -6.9 (0.6)); in MSMD, -3.3 (0.3) days (EM, -2.4 (0.3); CM, -4.6 (0.5)). The proportion of ≥50% responders for MMD reduction in the erenumab group was 34.1% at week 24; 44.4% at week 52. The exposure-adjusted incidence of TEAEs was 219.7 per 100 patient-years during the OLTP (DBTP, 251.0 for the erenumab group). The most common TEAEs during the OLTP were nasopharyngitis, constipation and influenza. No new safety concerns were identified.

CONCLUSIONS

Erenumab treatment was associated with reduced migraine frequency in Japanese patients with EM or CM for up to 1 year. Overall safety results from the OLTP were consistent with DBTP results.

TRIAL REGISTRATION NUMBER

NCT03812224.

Erenumab efficacy in migraine headache prophylaxis: A systematic review

OBJECTIVE

This systematic review aims to show the efficiency of Erenumab in the preventive therapy of episodic and chronic migraine, which is still under research.

BACKGROUND

Migraine is a chronic neurovascular disorder that causes disability and a social burden. There are various medications used for migraine prevention regimens, most of which have unwanted side effects and aren't often quite effective. Erenumab is a monoclonal antibody that targets calcitonin gene-related peptide receptors and was recently approved by the Food and Drug Administration for migraine prevention.

METHODS

For this systematic review, we searched through Scopus and PubMed databases using "Erenumab" or "AMG 334" and "migraine" as keywords, and all the studies from 2016 to March 18, 2022, were included. Original English articles assessing any outcomes referring to the efficacy of Erenumab in migraine headache treatment were included in this study.

RESULTS

We found 53 out of 605 papers eligible to be investigated. Erenumab in both dosages of 70 mg and 140 mg could decrease the mean of monthly migraine days and monthly acute migraine-specific medication days. Erenumab also has a higher rate of ≥ 50 %, ≥ 75 %, and 100 % reduction in monthly migraine days from the baseline in different regions. The efficacy of Erenumab was initiated in the first week of administration and sustained throughout and after treatment. Erenumab was also potent in the treatment of migraine with allodynia, aura, prior preventive therapy failure, medication overuse headache, and menstrual migraine. Erenumab also had favorable outcomes in combination therapy with other preventive drugs like Onabotulinumtoxin-A.

CONCLUSION

Erenumab had remarkable efficacy in the short and long-term treatment of episodic and chronic migraine, notably the patients with difficult-to-treat migraine headaches.

Evaluation of vascular risk in patients with migraine with and without aura treated with erenumab: Post hoc analysis of pooled long-term clinical trial data

OBJECTIVE

To assess cardiovascular (CV) safety of erenumab in clinical trial patients associated with degree of CV risk.

BACKGROUND

Hypertension has been considered a theoretical risk associated with the inhibition of the calcitonin gene-related peptide pathway in migraine management, particularly in a patient population with pre-existing CV risk factors.

METHODS

Data pooled from four double-blind, randomized trials were used to assess blood pressure (BP) changes and CV safety in patients grouped based on 10-year risk of cardiac, cerebrovascular, and peripheral artery disease as no-risk-factors, low-risk (>0% to ≤10%), moderate-risk (>10% to ≤20%), and high-risk (>20%) categories. CV safety was assessed as ischemic cardiovascular and cerebrovascular adverse events (ICCAE).

RESULTS

There was no apparent difference between placebo- (N = 1032) and erenumab-treatment groups (70 mg, N = 885; 140 mg, N = 504) in clinical worsening of BP category from baseline to Months 1-3 (14% [143/1032] placebo vs. 13% [114/885] and 14% [71/504] for erenumab 70 and 140 mg, respectively) regardless of baseline BP category. The adverse event (AE) profile of erenumab was similar across CV risk categories throughout the long-term analysis. Erenumab-treated patients with high and moderate 10-year CV risk (N = 107) did not experience any ICCAEs during the double-blind treatment period; there was a single ICCAE (a cerebral dural venous sinus thrombosis) observed in the low-risk erenumab group (N = 273). There were no increases in AEs during the long-term extensions of up to 5 years (N = 2499; 3482 patient-years of exposure to erenumab) with exposure-adjusted incidence rates of cardio/cerebrovascular disorder AEs of 0.4, 0.5, 0.0, and 1.1 (per 100 patient-years) for no risk factor (N = 1805), low (N = 492), moderate (N = 121), and high (N = 81) 10-year CV risk groups, respectively.

CONCLUSIONS

Ischemic CV and cerebrovascular AEs were uncommon and the incidence rates were similar across the 10-year CV risk categories. This analysis helps provide more detail on the CV safety of erenumab.

Migraine Disability Improvement during Treatment with Galcanezumab in Patients with Chronic and High Frequency Episodic Migraine

BACKGROUND

The aim of the present study was to assess the migraine outcome, in particular migraine disability, in chronic (CM) and high frequency episodic migraine (HFEM) patients in treatment with galcanezumab.

METHODS

The present study was conducted at the Headache Centre of Spedali Civili of Brescia. Patients were treated with galcanezumab 120 mg monthly. Clinical and demographical information were collected at the baseline (T0). Data about outcome, analgesics consumption and disability (MIDAS and HIT-6 scores) were collected quarterly.

RESULTS

Fifty-four consecutive patients were enrolled. Thirty-seven patients had a diagnosis of CM, 17 of HFEM. During treatment, patients reported a significant reduction in terms of mean headache/migraine days (p < 0.001), the attacks' pain intensity (p = 0.001) and monthly consumed analgesics (p < 0.001). The MIDAS and HIT-6 scores also documented a significant improvement (p < 0.001). At the baseline, all patients documented a severe degree of disability (MIDAS score ≥ 21). Following six months of treatment, only 29.2% of patients still documented a MIDAS score ≥ 21, with one third of patients documenting little or no disability. A > 50% MIDAS reduction, compared to baseline, was observed in up to 94.6% of patients, following the first three months of treatment. A similar outcome was found for HIT-6 scores. A significant positive correlation was found between headache days and MIDAS at T3 and T6 (T6 > T3), but not baseline.

DISCUSSION

Monthly prophylactic treatment with galcanezumab was found to be effective in both CM and HFEM, especially in reducing migraine burden and disability.

Open-label trials for CGRP-targeted drugs in migraine prevention: A narrative review

BACKGROUND

Calcitonin gene-related peptide-targeted drugs have proven safe and effective for migraine prevention in large randomized-controlled, double-blind trials with an average duration of six months. Open-label studies may provide additional information on the long-term safety and efficacy of these substances.

METHODS

We searched PubMed for open-label trials with calcitonin gene-related peptide(-receptor) monoclonal antibodies and calcitonin gene-related peptide-receptor antagonists. We summarized and critically analyzed the literature in a narrative way.

RESULTS

Overall, 13 open-label trials were included in this review (n = 4 for erenumab, n = 4 for galcanezumab, n = 3 for fremanezumab, n = 1 for eptinezumab, n = 1 for atogepant). Open-label trial duration ranged between 12 and 264 weeks. No safety concerns emerged, and the adverse events profile was similar to the double-blind study phase. Discontinuation rates were generally low with >75% of patients remaining in the trials after one year. Efficacy data showed a sustained reduction of migraine frequency throughout the trials, along with a lasting improvement in quality of life.

CONCLUSIONS

The open-label study program for calcitonin gene-related peptide-targeted migraine preventives confirms the favorable safety and efficacy profile of these drugs over time. Treatment adherence appears higher than with previous unspecific migraine preventives. Real-world data and post-marketing surveillance studies may corroborate and complement open-label results.

Health State Utility Mapping of Rimegepant for the Preventive Treatment of Migraine: Double-Blind Treatment Phase and Open Label Extension (BHV3000-305)

INTRODUCTION

The objectives of this study were to (1) report long-term health-related quality of life (HRQoL) outcomes among patients using rimegepant preventatively in BHV3000-305 (NCT03732638) open-label extension (OLE) and (2) map Migraine-Specific Quality of Life questionnaire version 2.1 (MSQv2) to EQ-5D-3L utility values over the double-blind treatment (DBT; 0-12 weeks) and the OLE (13-64 weeks) to assess the influence of treatment on these values.

METHODS

This was a post hoc analysis using data from a rimegepant study for the prevention of migraine (BHV3000-305). Adult patients with migraine took either rimegepant 75 mg or placebo every other day (EOD) during the DBT phase. All patients received rimegepant during the OLE. MSQv2 was measured at baseline, weeks 12, 24, and 64. A validated algorithm was used to map MSQv2 scores to EQ-5D utilities.

RESULTS

Baseline data were available for 347 patients treated with placebo and 348 treated with rimegepant in the DBT period, who continued to the OLE. Baseline EQ-5D utilities were similar between trial arms: 0.598 for placebo and 0.614 for rimegepant. EQ-5D improved from baseline to week 12 and utilities increased by + 0.09 for placebo and + 0.10 for rimegepant (p value = 0.011). By 24 weeks, at which point patients who were originally randomized to placebo had received rimegepant 75 mg EOD for 12 weeks, HRQoL measures (MSQv2 and EQ-5D) were similar across groups, demonstrating rapid onset of treatment effect. This HRQoL improvement was durable out to 64 weeks.

CONCLUSION

Compared to placebo, treatment with rimegepant 75 mg was associated with greater improvement in EQ-5D utilities during the 12-week DBT phase. Patients originally randomized to placebo experienced a similar improvement in EQ-5D utilities after switching to rimegepant during the OLE, demonstrating that benefits are realized within 12 weeks of active treatment. This preventive effect was durable out to 64 weeks and was associated with an additional increase in HRQoL over time.

TRIAL REGISTRATION

NCT03732638.

Recent advances in targeting calcitonin gene-related peptide for the treatment of menstrual migraine: A narrative review

Menstrual migraine (MM) has a longer duration and higher drug resistance than non-perimenstrual migraine. Calcitonin gene-related peptide (CGRP) and CGRP receptors are expressed in the peripheral and central nervous systems throughout the trigeminovascular system. The CGRP/CGRP receptor axis plays an important role in sensory physiology and pharmacology. CGRP receptor antagonists and anti-CGRP monoclonal antibodies (mAbs) have shown consistent efficacy and tolerability in the prevention of chronic or episodic migraine and are now approved for clinical use. However, few studies have reported the use of these drugs in MM, and no specific treatment for MM has been approved. This review aimed to shed light on the recent advances in targeting calcitonin gene-related peptides for the treatment of menstrual migraines in PubMed. In this review, we first discuss the axis of the CGRP/CGRP receptor. We then discuss the role of CGRP receptor antagonists and anti-CGRP mAbs in MM treatment. Finally, we discuss the role of the combination of anti-CGRP mAbs and CGRP receptor antagonists in migraine treatment and the drugs that inhibit CGRP release. Altogether, the anti-CGRP mAbs or CGRP receptor antagonists showed good efficacy and safety in the treatment of MM.

Post-marketing safety surveillance of erenumab: new insight from Eudravigilance

BACKGROUND

We aimed at evaluating adverse drug reactions during the post-marketing phase with erenumab as the suspected/interacting drug in Eudravigilance, with the final goal of investigating the consistency of the disproportionality signals (DS) for erenumab in Eudravigilance and the American Food and Drug Administration Adverse Event Reporting System (FDA FAERS) and undetected disproportionality signals from Eudravigilance.

RESEARCH DESIGN AND METHODS

Eudravigilance was screened in the period from October 2019 to October 2020. Disproportionality measure was performed using the Reporting Odds Ratio (ROR) according to the guidelines by the European Medicine Agency and using sumatriptan as the control group.

RESULTS

3381 cases were reported in the study period. Forty DS were identified both in Eudravigilance and FAERS. Sixteen DS were not identified in FAERS, 10 DS were found to have a biological probability and six DS were considered false-positive and potentially related to confounding by indication. The three system organ classes with the highest proportion of adverse events were general disorders and administration site conditions (16.12%), nervous system disorders (15.95%), and gastrointestinal disorders (13.59%).

CONCLUSIONS

Adverse events reports were mostly reported as non-serious. The co-analysis of multiple spontaneous reported databases unveiled undetected disproportionality signals for erenumab in individual databases. Future studies should be conducted to confirm the associations and potential clinical implications.

Erenumab efficacy predictors for chronic migraine

The diagnosis of chronic migraine (CM) is made when there are 15 or more days of headache per month in a patient with migraine. Approximately 2.5% of patients with episodic migraine develop chronic migraine, which is more difficult to treat and often leads to drug-induced headache (LIH). Such patients are rarely included in clinical trials. Aim. To analyze in clinical practice the effectiveness of the CGRP monoclonal antibody erenumab after 6 months of therapy in patients with CM with and without LIHD, and to evaluate possible predictors of the effectiveness of prophylactic therapy. Materials and methods. The study included 47 patients with CM taking erenumab at a dose of 70 mg monthly for at least 3 months. Patients completed a headache diary throughout the study. The 12-item Allodynia Symptom Checklist (ACS-12) was used to assess the presence of allodynia. After 6 months of therapy, the efficacy and safety of treatment, the presence of LAH and possible predictors of efficacy were evaluated. Results. After 6 months of therapy, 22 (78.6%) patients no longer met the criteria for LIHD. The factors that positively influenced the outcome of therapy were the absence of allodynia (p0.05), the presence of photo- and phonophobia, and the one-sidedness of pain (p0.05). The age and number of days with headache in patients with HM before treatment did not have a statistically significant effect on the effect of therapy. The presence of LIHD did not statistically significantly affect the outcome of therapy. Conclusion. CGRP monoclonal antibodies are reasonable in patients with LIHD. The presence of LIHD does not affect the efficacy of erenumab prophylactic therapy, the presence of allodynia may be a predictor of failure, and the unilaterality of pain and irritability to light and sound indicate likely efficacy. Real-world studies with a large cohort of patients and longer durations of therapy are required to confirm these results.

Calcitonin gene related peptide in migraine: current therapeutics, future implications and potential off-target effects

Migraine is the second largest cause of years lost to disability globally among all diseases, with a worldwide prevalence over 1 billion. Despite the global burden of migraine, few classes of therapeutics have been specifically developed to combat migraine. After 30 years of translational research, calcitonin gene-related peptide (CGRP) inhibitors have emerged as a promising new tool in the prevention of migraine. Like all new therapeutics; however, we have limited real-world experience and CGRP has several known systemic actions that warrant consideration. This article provides a narrative review of the evidence for CGRP antagonists and summarises the known and potential side effects that should be considered.

Beneficial Effects of Kiatsu™ with Ki Training on Episodic Migraine: An Exploratory Study

OBJECTIVE

To conduct an exploratory study of KiatsuTM with Ki training as a potential therapy for treating episodic migraine in women.

BACKGROUND

Current therapies for migraine have proven partially effective, highlighting the need for alternative treatment options. In preparation for development of a randomized controlled study, the authors conducted a single arm pilot exploratory study to evaluate the effect of Kiatsu with Ki training in adult females with episodic migraine.

METHODS

Study subjects established a baseline migraine frequency over 4 weeks. During the following 4 weeks, each subject received instruction in Ki training (to improve concentration, balance, and relaxation), accompanied by Kiatsu (a focused touch method that reduces tension, swelling, and pain). Subjects then participated in one session a month for additional 6 months. The initial session was 1 hour; subsequent sessions averaged 30 minutes. Subjects documented migraine frequency, migraine-specific quality of life scores, and medication use.

RESULT

Sixty-nine subjects met the study inclusion criteria, and 21 completed the study. Subjects reported a significant reduction in migraine frequency after 1 month (from 7.2 to 3.8 migraines/month; p < 0.05), with an overall 53% reduction at 6 months (p < 0.001). Significant improvements in quality of life (QoL) were reported after 1 month, with continued improvements until study completion (p < 0.0001). A moderate reduction in medication use was also documented (p < 0.03), corresponding to improved QoL scores.

CONCLUSION

Kiatsu with Ki training may be an effective treatment option for females with migraines, either in combination with medications or as a potential alternative to medications for patients who do not benefit from conventional therapies. The results of this pilot study justify the development of a randomized controlled study designed to investigate the potential benefits of this novel therapeutic method for treating migraine.

Optimal dose of erenumab for preventive treatment of episodic migraine: a systematic review and meta-analysis

Background:

Erenumab is a novel monoclonal calcitonin gene-related peptide receptor antibody that is used for the preventive treatment of migraine.

Objectives:

This study aimed to evaluate the overall safety, efficacy, and dose-response relationship of erenumab in patients with episodic migraine and patients with prior migraine treatment failures.

Methods:

We searched randomized clinical trials on PUBMED, EMBASE database, and Cochrane Library database. A pair-wise meta-analysis and Bayesian network analysis were performed.

Results:

For efficacy outcomes, the network meta-analysis suggests that in comparison to erenumab 70 mg, participants who received erenumab 140 mg reported a significant decrease in monthly acute Migraine-Specific Medication Days (MSMD) and 50% increase in response rate, and erenumab was most likely to be ranked first for Monthly Migraine Days (MMD), MSMD, and 50% response rate. For safety outcomes, the network meta-analysis has found no significant difference between the 70 mg group and the 140 mg group measured by adverse events and serious adverse events. In the 140 mg erenumab group, a significant decreased in MMD and MSMD and 50% and 75% increased in response rate were reported in patients with ≥ 2 treatment failures compared to placebo. For safety outcomes, no significant difference was found between the 140 mg erenumab group and the placebo group.

Conclusion:

Erenumab was effective in patients with episodic migraine. A total of 140 mg erenumab was associated with better efficacy outcomes without any increased risk for developing adverse events compared to 70 mg erenumab. Furthermore, 140 mg erenumab was effective in patients with prior migraine treatment failures.

Timing and durability of response to erenumab in patients with chronic migraine

Background

Erenumab is a human anti‐calcitonin gene‐related peptide receptor monoclonal antibody approved for migraine prevention. We sought to further assess the temporal patterns of response to erenumab in patients with chronic migraine (CM), specifically the onset and sustainability of monthly migraine day (MMD) response.

Methods

This is a post hoc analysis of a 12‐week, randomized, double‐blind, placebo‐controlled study of erenumab for migraine prevention in patients with CM (≥15 headache days/month, including ≥8 migraine days/month). Onset and sustainability were assessed according to MMD reduction from baseline, with the following response categories: responders (≥50% reduction), partial responders (≥30% and <50%), or nonresponders (<30%).

Results

Among the erenumab 140 mg group (n = 187), 54.0% (101/187) achieved a response at any month during the study with a median time to onset of monthly response of 1 month. This improvement was maintained in most patients with continued treatment. An initial response was achieved at Month 1 by 28.3% (53/187) of patients; 69.8% (37/53) of whom maintained a response at Months 2 and 3. Although many patients responded early, some patients required longer treatment to achieve a response; 79.4% (27/34) of initial partial responders and 21.0% (21/100) of initial nonresponders subsequently achieved a response. Similar findings were observed for the erenumab 70mg group (n = 188).

Conclusion

A majority of erenumab‐treated patients with CM who achieved an initial response at Month 1 sustained this benefit. Many patients responded later with continued treatment. Our data support recommendations to assess outcomes after ≥3 months of preventive treatment with erenumab in CM.

Reduction in acute migraine-specific and non-specific medication use in patients treated with erenumab: post-hoc analyses of episodic and chronic migraine clinical trials

Background

In patients with migraine, overuse of acute medication, including migraine-specific medication (MSM) such as triptans and ergots, can lead to adverse health outcomes, including development of medication overuse headache. Here, we examined the effect of erenumab on reducing acute medication use, in particular MSM, in patients with episodic migraine (EM) and chronic migraine (CM).

Methods

The current post-hoc analyses were based on data from the double-blind treatment phase (DBTP) of two erenumab studies, a pivotal EM (N = 955) and a pivotal CM (N = 667) trial, and their respective extensions. Patients were administered subcutaneous placebo or erenumab (70 or 140 mg) once monthly. Daily acute headache medication use (including MSM and non-MSM) was recorded using an electronic diary during a 4-week pretreatment baseline period until the end of the treatment period. Outcome measures included change in monthly acute headache medication days (HMD) in acute headache medication users at baseline, and changes in monthly MSM days (MSMD) in MSM users at baseline and non-MSMD in non-MSM users at baseline.

Results

In total, 60 and 78 % of patients (all acute headache medication users) with EM and CM used MSM at baseline, respectively. For acute headache medication users, the change in mean monthly acute HMD over Months 4, 5 and 6 compared with the pre-DBTP was 1.5, 2.5, and 3.0 for placebo, erenumab 70 mg and 140 mg, respectively for the EM study. The respective change in monthly MSMD in MSM users was 0.5, 2.1 and 2.8, and in monthly non-MSMD in non-MSM users was 2.3, 2.6, and 2.7. In the acute headache medication users at baseline, the change in monthly acute HMD at Month 3 compared with pre-DBTP was 3.4, 5.5, and 6.5 for placebo, erenumab 70 mg and 140 mg, respectively for the CM study. The respective change in monthly MSMD in MSM users was 2.1, 4.5, and 5.4, and in monthly non-MSMD in non-MSM users was 5.9, 6.4, and 6.6. Reductions in MSMD versus placebo were sustained in the extension periods of both studies. Erenumab was also associated with a higher proportion of MSM users achieving ≥ 50 %, ≥ 75 and 100 % reduction from baseline in monthly MSMD versus placebo in both EM and CM.

Conclusions

In both EM and CM, treatment with erenumab is associated with a significant and sustained reduction in the use of acute headache medication, in particular MSM.

Trial registrations

NCT02456740; NCT02066415; NCT02174861.

Comprehensive management of adults with chronic migraine: Clinical practice guidelines in Mexico

Introduction:

Migraine is a polygenic multifactorial disorder with a neuronal initiation of a cascade of neurochemical processes leading to incapacitating headaches. Headaches are generally unilateral, throbbing, 4–72 h in duration, and associated with nausea, vomiting, photophobia, and sonophobia. Chronic migraine (CM) is the presence of a headache at least 15 days per month for ≥3 months and has a high global impact on health and economy, and therapeutic guidelines are lacking.

Methods:

Using the Grading of Recommendations, Assessment, Development, and Evaluations system, we conducted a search in MEDLINE and Cochrane to investigate the current evidence and generate recommendations of clinical practice on the identification of risk factors and treatment of CM in adults.

Results:

We recommend avoiding overmedication of non-steroidal anti-inflammatory drugs (NSAIDs); ergotamine; caffeine; opioids; barbiturates; and initiating individualized prophylactic treatment with topiramate eptinezumab, galcanezumab, erenumab, fremanezumab, or botulinum toxin. We highlight the necessity of managing comorbidities initially. In the acute management, we recommend NSAIDs, triptans, lasmiditan, and gepants alone or with metoclopramide if nausea or vomiting. Non-pharmacological measures include neurostimulation.

Conclusions:

We have identified the risk factors and treatments available for the management of CM based on a grading system, which facilitates selection for individualized management.

Drug interactions and risks associated with the use of triptans, ditans and monoclonal antibodies in migraine

PURPOSE OF REVIEW

The aim of this study was to review current evidence concerning potential risks and interactions associated with concomitant use of drugs indicated for the abortive treatment of migraine, namely triptans and ditans, and more recently developed drugs used for the preventive treatment. The latter drug class encompasses monoclonal antibodies (mAbs), which target either calcitonin gene-related peptide (CGRP) or its receptor.

RECENT FINDINGS

To date, no pharmacokinetic interactions between these drug classes have been reported. However, patients who suffer from triptan- (or ditan-) induced medication overuse headache or those who are nonresponders to triptans might respond less effectively to mAbs. Caution is warranted when coadministrating these drugs in migraine patients with comorbid cardiovascular disease or with an increased cardiovascular risk profile.

SUMMARY

In this review, the main mechanisms of action of triptans, ditans and mAbs targeting CGRP or its receptor are summarized as well as the current evidence on their individual risks. Studies on risks and interactions in case of concomitant use of triptans, ditans and mAbs in migraine patients are relatively scarce. Therefore, these aspects have been considered from a theoretical and hypothetical point of view by taking both their overlapping target, CGRP, and contraindications into account.

Long-term efficacy and safety during open-label erenumab treatment in Japanese patients with episodic migraine

Objective

To assess long‐term (up to 2 years) efficacy, tolerability, and safety of erenumab for the prevention of episodic migraine (EM) in Japanese patients.

Background

Previously published results from the double‐blind treatment phase (DBTP) of a phase 2 clinical study have demonstrated the efficacy and safety of erenumab in Japanese patients with EM.

Methods

Patients completing the 24‐week placebo‐controlled DBTP could continue into the 76‐week open‐label treatment phase (OLTP), receiving erenumab 70 mg or 140 mg subcutaneously once monthly. The initial dose in the OLTP was erenumab 70 mg monthly, which was later changed to 140 mg. After study completion, the following were assessed: change from baseline in monthly migraine days (MMD), change from baseline in monthly acute migraine‐specific medication days (MSMD), percentage of patients achieving ≥50% and ≥75% reduction in MMD, change from baseline in the 6‐item Headache Impact Test (HIT‐6™) score, and safety (exposure‐adjusted patient‐incidence of adverse events [AEs], calculated as number of patients per 100 patient‐years).

Results

Of 475 patients enrolled in the DBTP, 459 (96.6%) continued in the OLTP. The mean (SD) MMD was 7.9 (2.3) at baseline with the overall change from baseline at week 100 of –2.9 (4.1) days. The monthly acute MSMD was 5.7 (2.8) at baseline with change from baseline at week 100 of −1.7 (3.7) days. The proportion of patients who achieved ≥50% and ≥75% reduction in MMD from baseline at week 100 was 177/398 (44.5%) and 94/398 (23.6%), respectively. The HIT‐6™ score was 58.4 (5.4) at baseline with a change of −6.4 (8.2) at week 100. The exposure‐adjusted patient‐incidence of AEs during the OLTP was 207.1/100 patient‐years for the combined erenumab group, similar to that observed for either erenumab (271.0/100 patient‐years) or placebo (257.3/100 patient‐years) during the DBTP, and no new safety signals were detected during the OLTP.

Conclusion

Long‐term erenumab treatment in Japanese patients with EM demonstrated sustained efficacy for up to 2 years, with a safety profile similar to previous studies, supporting erenumab as a potential new therapy for EM prevention in Japan.

Cost-Effectiveness of Erenumab for the Preventive Treatment of Migraine in Patients with Prior Treatment Failures in Sweden

BACKGROUND

Migraine is a common neurological disease that disproportionately affects females and has a peak incidence during productive years, resulting in significant burden.

OBJECTIVE

The aim of the study was to determine the cost effectiveness of erenumab for the preventive treatment of migraine.

METHODS

A hybrid decision-tree plus Markov model was developed to evaluate the cost effectiveness of erenumab as a migraine treatment compared with best supportive care only for patients experiencing at least 4 monthly migraine days for whom at least two prior preventive treatments had failed. Clinical efficacy data were based on results from four randomized controlled trials of erenumab against placebo. The primary outcomes were costs, migraine days, and quality-adjusted life-years (QALYs). An incremental cost-effectiveness ratio (ICER) was estimated as the cost per QALY gained. The cost per migraine day avoided was also estimated, as were disaggregated direct and indirect costs. The analysis was conducted from Swedish societal and healthcare system perspectives based on total migraine, chronic migraine and episodic migraine populations, using a discount rate of 3% applied to both costs and health benefits and using year 2019 values.

RESULTS

In the base-case deterministic analyses, erenumab treatment resulted in ICERs of Swedish krona (SEK) 34,696 (€3310) and SEK301,565 (€28,769) per QALY gained in the total migraine and episodic migraine populations, respectively. Erenumab was dominant in the chronic migraine population. In the total migraine population, the use of erenumab resulted in a net benefit to society of SEK81,739 (€7773) per patient, assuming a willingness-to-pay threshold of SEK300,000 (€28,528) per QALY.

CONCLUSIONS

Our analysis suggests that erenumab is a cost-effective treatment for migraine with a willingness-to-pay threshold of SEK300,000 per QALY.

Functional impairment and disability among patients with migraine: evaluation of galcanezumab in a long-term, open-label study

PURPOSE

Migraine can negatively impact patient functioning and quality of life. Here, we report the effects of galcanezumab (GMB), a humanized monoclonal antibody that binds to calcitonin gene-related peptide, on patient-reported outcome (PRO) measures in migraine.

METHODS

CGAJ was a Phase III, randomized, open-label study (12-month open-label and 4-month post-treatment follow-up) in patients with episodic or chronic migraine. Patients aged 18-65 years with diagnosis of migraine (≥ 4 migraine headache days per month) as defined by International Classification of Headache Disorders (ICHD)-3 beta guidelines were included in the study. Patients were randomized 1:1 with subcutaneous GMB 120 mg (with a loading dose of 240 mg) or GMB 240 mg given once monthly for 12 months. Changes from baseline in PRO measures such as Migraine-Specific Quality of Life Questionnaire v2.1 (MSQ) and Migraine Disability Assessment (MIDAS) were assessed.

RESULTS

A total of 135 patients were randomized to each galcanezumab dose group. Mean (SD) baseline MSQ total scores were 53.85 (20.34) [GMB 120 mg] and 53.69 (18.79) [GMB 240 mg]. For MIDAS, mean (SD) total scores were 45.77 (42.06) [GMB 120 mg] and 53.96 (61.24) [GMB 240 mg]. Within-group mean improvement from baseline on MSQ and MIDAS total scores and all individual item/domain scores were statistically significant for both GMB dose groups, at all-time points during the treatment phase (p < 0.001). For MSQ domain scores, greatest improvement was observed in the Role function-restrictive (RF-R) domain (overall least squares (LS) mean change ± SE: 31.55 ± 1.20 [GMB 120 mg] and 33.40 ± 1.16 [GMB 240 mg]). For MIDAS, the overall LS mean change ± SE from baseline across the entire 12-month treatment phase in total scores were: -33.58 ± 2.11 (GMB 120 mg) and -32.67 ± 2.04 (GMB 240 mg).

CONCLUSION

Galcanezumab was associated with statistically significant changes from baseline in the PRO measures across the entire 12-month treatment period. These results indicate improved health-related quality of life and decreased disability among patients treated with galcanezumab.

Monoclonal Antibodies as Neurological Therapeutics

Over the last 30 years the role of monoclonal antibodies in therapeutics has increased enormously, revolutionizing treatment in most medical specialties, including neurology. Monoclonal antibodies are key therapeutic agents for several neurological conditions with diverse pathophysiological mechanisms, including multiple sclerosis, migraines and neuromuscular disease. In addition, a great number of monoclonal antibodies against several targets are being investigated for many more neurological diseases, which reflects our advances in understanding the pathogenesis of these diseases. Untangling the molecular mechanisms of disease allows monoclonal antibodies to block disease pathways accurately and efficiently with exceptional target specificity, minimizing non-specific effects. On the other hand, accumulating experience shows that monoclonal antibodies may carry class-specific and target-associated risks. This article provides an overview of different types of monoclonal antibodies and their characteristics and reviews monoclonal antibodies currently in use or under development for neurological disease.

Long-term efficacy and safety of erenumab in migraine prevention: Results from a 5-year, open-label treatment phase of a randomized clinical trial

BACKGROUND AND PURPOSE

Although erenumab has demonstrated significant reduction in migraine frequency and improved quality of life in studies lasting 3 to 12 months, little is known about long-term therapy.

METHODS

This study was an open-label, 5-year treatment phase following a 12-week, double-blind, placebo-controlled trial in adults with episodic migraine. Patients initially received open-label erenumab 70 mg, which increased to 140 mg following a protocol amendment. Efficacy analyses included change from baseline in monthly migraine days (MMDs), monthly acute migraine-specific medication (AMSM) days, and health-related quality of life.

RESULTS

Of 383 patients enrolled, 250 switched to 140 mg; 215 (56.1%) completed open-label treatment. Mean (standard error) change in MMDs from baseline of 8.7 (0.2) days was -5.3 (0.3) days; an average reduction of 62.3% at year 5. Among patients using AMSM at baseline (6.3 [2.8] treatment days), mean change in monthly AMSM days was -4.4 (0.3) days at the end of 5 years. Patient-reported outcomes indicated stable improvements in disability, headache impact, and migraine-specific quality of life. Exposure-adjusted patient incidence rates of adverse events (AEs) were 123.0/100 patient-years; AEs were most frequently nasopharyngitis, upper respiratory tract infection, and influenza. Serious AEs (SAEs) reported by 49 patients (3.8/100 patient-years) were mostly single occurrence. Two fatal adverse events were reported. There were no increases in incidence of AEs, SAEs, or AEs leading to treatment discontinuation over 5 years of exposure.

CONCLUSIONS

Treatment with erenumab was associated with reductions in migraine frequency and improvements in health-related quality of life that were maintained for at least 5 years. No new safety signals were observed.

Improvements in pain, medication use and quality of life in onabotulinumtoxinA-resistant chronic migraine patients following erenumab treatment - real world outcomes

Background

The CGRP antagonists offer a novel therapeutic approach in migraine. Their utility in patients with severe forms of chronic migraine is a subject of particular interest. We present outcomes of 9 months of erenumab treatment in a cohort of patients with difficult-to-control chronic migraine, all of whom had prior unsatisfactory response to onabotulinumtoxinA.

Methods

We offered erenumab to 98 patients with a prior unsatisfactory response to onabotulinumtoxinA. Eighty of 98 had trialled greater occipital nerve injections (82%), 32/98 peripheral neurostimulation (33%) and 18/98 intravenous dihydroergotamine (18%). Thirty eight of 98 (39%) met the definition of triptan overuse and 43/98 (44%) analgesic overuse. All patients met the EHF criteria for ‘resistant migraine’. Outcome measures (recorded monthly) included days with headache limiting activities of daily living (“red”), not limiting (“amber”), headache free (“green”), and requiring triptans or other analgesics. Quality of life scores - headache impact test 6 (HIT-6), patient health questionnaire 9 (PHQ-9) and pain disability index (PDI) - were also measured.

Results

Mean number of red days improved by − 6.4 days (SE 0.67, 95%CI − 7.7 to − 5.1, p=0.001) at 3 months; − 6.8 days (SE 0.96, 95%CI − 8.80 to − 4.9, p=0.001) at 6 months and − 6.5 days (SE 0.86, 95%CI − 8.3 to − 4.8, p=0.001) at 9 months. Repeated measures ANOVA confirmed improvements in the number of red (p=0.001), green (p=0.001), triptan (p=0.001) and painkiller days (p=0.001) as well as scores of the HIT-6 (p=0.001), PHQ-9 (p=0.001), and PDI (p=0.001) across the duration of study.

Conclusion

We observed improvements in pain, medication use and quality of life in onabotulinumtoxinA-resistant chronic migraine patients following erenumab treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-020-01214-2.

Changing levels of sex hormones and calcitonin gene-related peptide (CGRP) during a woman's life: Implications for the efficacy and safety of novel antimigraine medications

Migraine is a neurovascular disorder that is three times more prevalent in women than in men and represents a large socio-economic burden. Therefore, the development of new preventive medications is an urgent matter. Currently, calcitonin gene-related peptide (CGRP), a neuropeptide released from trigeminal fibres, is an important target for migraine treatment. Accordingly, antibodies directed against CGRP or its receptor, as well as small-molecule CGRP receptor antagonists, have been developed for the prophylactic and acute treatment of migraine. Results from clinical phase III trials show a significant decrease in migraine days and relatively mild side-effects. However, CGRP is not only present in the trigeminal nerve, but it is also abundant in perivascular nerve fibres. Moreover, CGRP levels and hormones vary between sexes and during different life stages, and hormones affect CGRP, with a seemingly greater role for CGRP in females. In this review we discuss whether these aspects could be associated with differences in response and efficacy of drugs interfering with the CGRP pathway. Furthermore, CGRP has been described as playing a protective role in ischemic events, and CGRP seems to play a larger role in cardiac ischemic events in female patients. As cardiovascular risk is increased in female migraine patients and also increases significantly in females after menopause, further research into the risk of blocking CGRP in these patients is needed.

A systematic review, meta-analysis and meta-regression evaluating the adverse reactions to erenumab in the preventive treatment of migraine

Background: Erenumab has recently been approved as a pharmacological treatment for the prevention of migraine. However, the incidence estimates of adverse drug reactions (ADRs) were not consistent among studies. Consequently, pooled measures of the incidences of ADRs that accounts for inter-study heterogeneity are desirable. In addition, little is known on the factors leading to such heterogeneity.Research design and methods: Clinical trials evaluating the occurrence of ADRs related to erenumab in migraine patients were searched with Ovid MEDLINE until April 2020. Random intercept models were used to estimate the pooled incidence of the ADRs reported at least in 5 different study populations. To examine whether specific factors correlated with the pooled incidence, we performed random-effects meta-regression.Results: Of 138 retrieved references, 8 clinical trials were included in the meta-analysis. We observed a significant heterogeneity of the incidence estimates of back pain, influenza, nasopharyngitis, and upper respiratory tract infection (URTI). Most of the observed heterogeneity is ascribed to treatment duration for back pain (p = 0.045), influenza (p < 0.001) and URTI (p < 0.001), and significantly attributed to Body Mass Index (BMI) for nasopharyngitis (p < 0.001).Conclusions: Back pain, influenza, nasopharyngitis and URTI showed a significant heterogeneity of incidence estimates.

Reversion from chronic migraine to episodic migraine following treatment with erenumab: Results of a post-hoc analysis of a randomized, 12-week, double-blind study and a 52-week, open-label extension

Objective

To determine reversion rates from chronic migraine to episodic migraine during long-term erenumab treatment.

Methods

A daily headache diary was completed during the 12-week, double-blind treatment phase of a placebo-controlled trial comparing erenumab 70 mg, 140 mg, and placebo, and weeks 1–12, 21–24, 37–40, and 49–52 of the open-label treatment phase. Chronic migraine to episodic migraine reversion rates were assessed over the double-blind treatment phase; persistent reversion to episodic migraine over 24 weeks (double-blind treatment phase through the first 12 weeks in the open-label treatment phase), long-term persistent reversion to episodic migraine over 64 weeks (double-blind treatment phase plus open-label treatment phase); delayed reversion to episodic migraine through the first 12 weeks of the open-label treatment phase among patients remaining in chronic migraine during the double-blind treatment phase.

Results

In the double-blind treatment phase, 53.1% (95% confidence interval: 47.8–58.3) of 358 erenumab-treated completers had reversion to episodic migraine; monthly reversion rates to episodic migraine were typically higher among patients receiving 140 mg versus 70 mg. Among 181 completers (receiving erenumab for 64 weeks), 98 (54.1% [95% confidence interval: 46.6–61.6]) had reversion to episodic migraine during the double-blind treatment phase; of those, 96.9% (95% confidence interval: 91.3–99.4) had persistent reversion to episodic migraine, 96.8% (95% confidence interval: 91.1–99.3) of whom had long-term persistent reversion to episodic migraine. Delayed reversion to episodic migraine occurred in 36/83 (43.4% [95% confidence interval: 32.5–54.7]) patients; of these, 77.8% (95% confidence interval: 60.9–89.9) persisted in reversion through week 64.

Conclusions

Patients with reversion to episodic migraine at week 12 will likely persist as episodic migraine with longer-term erenumab; others may achieve delayed reversion to episodic migraine.

Clinical trial registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02066415

[Headache in multiple sclerosis]

The relationship between headache and multiple sclerosis (MS) has been a matter of controversy for over 60 years. Headaches are still rated as a "red flag", indicating alternative diagnoses to MS, although in the last few years numerous studies have shown a frequent association between headache and MS. In recent studies on MS patients, a link was found between lower age/shorter disease duration of MS and frequent headaches. A study of 50 patients manifesting MS for the first time showed the highest headache prevalence in MS of 78% reported so far.Headaches can also be a possible side effect of most disease-modifying MS drugs. In many cases, however, the headache appears to be a symptom of MS in terms of secondary headache. This is also supported by pathophysiological implications, for example, by detecting B cell follicles in the meninges of MS patients.Migraine is the most common type of headache in MS. In some cases, this is a comorbidity of two diseases with many similarities, but headaches caused by inflammatory MS lesions also appear to be phenomenologically very similar to classic migraines; thus, distinguishing between them is often only successful with the help of thorough differential diagnostics (cerebrospinal fluid, MRI etc.).The task of future studies must be to specify the phenomenology of headache in MS even more precisely, in order to, to gain knowledge in, among others, patients with radiologically isolated syndrome, who often suffer from headache, because in these patients a considerable differential diagnostic and therapeutic uncertainty exists.

Update on Calcitonin Gene-Related Peptide Antagonism in the Treatment of Migraine

The discovery of calcitonin gene-related peptide (CGRP) and its role in migraine has promoted a new era in migraine treatment: CGRP antagonism. Two classes of medications are currently available: small molecules targeting the CGRP receptor and monoclonal antibodies targeting the CGRP receptor or CGRP ligand. The revolution of these medications is represented by blurring the borders between acute and preventive treatments, episodic and chronic migraine, naïve and refractory patients and even between migraine and other headache disorders.

Real-World Patient Experience With Erenumab for the Preventive Treatment of Migraine

BACKGROUND

Erenumab, a calcitonin gene-related peptide (CGRP) receptor monoclonal antibody, has been well tolerated with good efficacy for the preventive treatment of episodic and chronic migraine in phase 2 and phase 3 clinical trials. Limited post-market observations are available to validate these findings in a real-world tertiary headache clinic population with complex comorbidities and refractory migraine.

OBJECTIVE

The goal of this study is to demonstrate the real-world performance of erenumab among patients in a tertiary care headache clinic by describing patient selection, experience, and clinical characteristics after 6 months of erenumab therapy.

METHODS

A retrospective, exploratory, observational study was conducted on patients receiving at least 1 erenumab injection (70 or 140 mg). Baseline data obtained by chart review and telephone calls were compared to 6-month follow-up telephone calls. The primary outcome was the reduction in self-reported headache days per month at baseline compared to 6 months for those with complete 6-month data. The significance level was set at P < .05. Secondary analyses explored the distribution of headache severity, responder rates, Migraine Disability Assessment scores, adverse effects, ineffective preventives, comorbidities, wearing-off, and discontinuation.

RESULTS

Of the 101 patients who consented to participate, 89.1% (90/101) were women, and the mean age of all patients was 49 years (range, 19-80 years). At baseline, 94.1% (95/101) of patients had chronic migraine, 5.0% (5/101) had episodic migraine, and 18.8% (19/101) had medication overuse headache. The mean (SD) number of baseline headache and migraine days per month for the entire cohort were 24.3 (8.2) and 18.2 (9.3) days, respectively. Participants had numerous comorbidities and had tried a mean of 11.2 unique oral medications and 4.8 unique medication categories before receiving erenumab, including 83.2% (84/101) who had also received onabotulinumtoxinA. Six-month post-erenumab follow-up data were available for 42.6% (43/101) of participants. For these 43 participants, the number of headache days per month decreased significantly by 6.5 days from a baseline mean (SD) of 24.8 (6.47) days to 18.3 (12) days at 6-month follow-up (P < .001); similarly, the monthly migraine days decreased significantly by 8.4 days from a baseline mean of 19.1 (9.3) days to 10.7 days at 6-month follow-up (P < .001). The 50% responder rate was 34.9% (15/43) for monthly headache days and 54.8% (23/43) for monthly migraine days. Of all 101 participants, 28 (27.7%) discontinued erenumab, primarily because it was ineffective (39.3%, 11/28) or because of adverse effects (42.9%, 12/28).

CONCLUSION

This post-market observational study of patient experience describes response to erenumab in a real-world tertiary headache clinic with a complex patient population. Overall, these complex patients had a significant positive clinical response to erenumab, but with high rates of discontinuation. This study also noted a 1-week wearing-off response and high rates of constipation. Further post-market studies are needed to better characterize patient selection and real-world response to erenumab.

The Spectrum of Response to Erenumab in Patients With Episodic Migraine and Subgroup Analysis of Patients Achieving ≥50%, ≥75%, and 100% Response

Objective

To assess the efficacy of erenumab at the ≥50%, ≥75%, and 100% reduction in monthly migraine days (MMD) response thresholds, using data from the 6‐month double‐blind treatment phase (DBTP) of the Study to Evaluate the Efficacy and Safety of Erenumab in Migraine Prevention (STRIVE) pivotal clinical trial.

Methods

Enrolled patients with episodic migraine (EM; ≥4 MMD and <15 monthly headache days) were randomized (1:1:1) to erenumab 70 mg (n = 312), erenumab 140 mg (n = 318), or placebo (n = 316) once monthly. We determined the proportions of patients with ≥50%, ≥75% and 100% reduction in MMD over the last 3 months of the STRIVE DBTP (months 4 through 6) and conducted post hoc analyses to contextualize the treatment benefit in patient subgroups achieving, and not achieving, these response thresholds. Outcome measures included changes in MMD, acute migraine‐specific medication days (MSMD), and patient‐reported outcomes.

Results

The proportions of patients with a reduction in MMD from baseline were greater for erenumab than for placebo at all response thresholds. As previously reported for the ≥50% response threshold, 135/312 (43.3%) of patients on erenumab 70 mg and 159/318 (50.0%) on erenumab 140 mg responded, vs 84/316 (26.6%) for placebo. At months 4 through 6, 65/312 (20.8%) and 70/318 (22.0%) of those on erenumab 70 mg and erenumab 140 mg, respectively, achieved ≥75% reductions vs 25/316 (7.9%) on placebo. A reduction of 100% response, which required no migraine days over 3 consecutive months based on observed data, was achieved by 10/312 (3.2%) of patients treated with erenumab 70 mg and 16/318 (5.0%) for erenumab 140 mg, vs 9/316 (2.8%) for placebo. At all response thresholds, responders achieved numerically greater reductions in mean MMD and MSMD, and greater improvements in disability than did the overall population; importantly, these remarkable responses were noted early. Meanwhile, 60/312 (19.2%) and 53/318 (16.7%) patients on erenumab 70 and 140 mg, respectively, had no reduction in MMD from baseline in months 4 through 6, compared with 104/316 (32.9%) patients on placebo.

Conclusions

The responses at the ≥50%, ≥75%, and 100% thresholds provide context for establishing realistic patient and physician expectations regarding the magnitude of treatment benefit that may be achieved by patients with EM responding to erenumab (STRIVE, NCT02456740).

Anti-migraine Calcitonin Gene-Related Peptide Receptor Antagonists Worsen Cerebral Ischemic Outcome in Mice

Objective

Calcitonin gene–related peptide (CGRP) pathway inhibitors are emerging treatments for migraine. CGRP‐mediated vasodilation is, however, a critical rescue mechanism in ischemia. We, therefore, investigated whether gepants, small molecule CGRP receptor antagonists, worsen cerebral ischemia.

Methods

Middle cerebral artery was occluded for 12 to 60 minutes in mice. We compared infarct risk and volumes, collateral flow, and neurological deficits after pretreatment with olcegepant (single or 10 daily doses of 0.1–1mg/kg) or rimegepant (single doses of 10–100mg/kg) versus vehicle. We also determined their potency on CGRP‐induced relaxations in mouse and human vessels, in vitro.

Results

Olcegepant (1mg/kg, single dose) increased infarct risk after 12‐ to 20‐minute occlusions mimicking transient ischemic attacks (14/19 vs 6/18 with vehicle, relative risk = 2.21, p < 0.022), and doubled infarct volumes (p < 0.001) and worsened neurological deficits (median score = 9 vs 5 with vehicle, p = 0.008) after 60‐minute occlusion. Ten daily doses of 0.1 to 1mg/kg olcegepant yielded similar results. Rimegepant 10mg/kg increased infarct volumes by 60% after 20‐minute ischemia (p = 0.03); 100mg/kg caused 75% mortality after 60‐minute occlusion. In familial hemiplegic migraine type 1 mice, olcegepant 1mg/kg increased infarct size after 30‐minute occlusion (1.6‐fold, p = 0.017). Both gepants consistently diminished collateral flow and reduced reperfusion success. Olcegepant was 10‐fold more potent than rimegepant on CGRP‐induced relaxations in mouse aorta.

Interpretation

Gepants worsened ischemic stroke in mice via collateral dysfunction. CGRP pathway blockers might thus aggravate coincidental cerebral ischemic events. The cerebrovascular safety of these agents must therefore be better delineated, especially in patients at increased risk of ischemic events or on prophylactic CGRP inhibition. ANN NEUROL 2020;88:771–784

Migraine and Two-Pore-Domain Potassium Channels

Migraine is a common, disabling neurological disorder with a genetic, environmental, and hormonal component with an annual prevalence estimated at ~15%. It is characterized by attacks of severe, usually unilateral and throbbing headache, and can be accompanied by nausea, vomiting, and photophobia. Migraine is clinically divided into two main subtypes: migraine with aura, when it is preceded by transient neurological disturbances due to cortical spreading depression (CSD), and migraine without aura. Activation and sensitization of trigeminal sensory neurons, leading to the release of pro-inflammatory peptides, is likely a key component in headache pain initiation and transmission in migraine. In the present review, we will focus on the function of two-pore-domain potassium (K_2P) channels, which control trigeminal sensory neuron excitability and their potential interest for developing new drugs to treat migraine.

Calcitonin gene-related peptide (CGRP)-targeted therapies as preventive and acute treatments for migraine-The monoclonal antibodies and gepants

Calcitonin Gene-Related Peptide (CGRP) plays a pivotal role in migraine pathophysiology. Two types of CGRP function-blocking modalities, monoclonal antibodies, and small molecules (gepants), have been developed to target the CGRP ligands and CGRP receptors. Four CGRP monoclonal antibodies have received FDA approval for the prevention of migraine: erenumab, fremanezumab, galcanezumab, and eptinezumab. Two gepants have been approved by the FDA for the acute treatment of migraine: ubrogepant and rimegepant. Multiple clinical trials of the CGRP monoclonal antibodies and gepants, and now some open-label long-term extension data, established their efficacy, safety, and tolerability. In this chapter, we summarize the major clinical trials, pharmacokinetic insights, safety and tolerability profiles, and real-world data (if available) of the CGRP monoclonal antibodies and gepants.

One-year sustained efficacy of erenumab in episodic migraine: Results of the STRIVE study

Objective

To assess efficacy and tolerability of 1-year erenumab treatment in patients with episodic migraine.

Methods

Patients were randomized (n = 955; 1:1:1) during the 24-week double-blind treatment phase (DBTP) to monthly subcutaneous placebo or erenumab 70 or 140 mg. At week 24, 845 patients were rerandomized (1:1) to erenumab 70 or 140 mg during the 28-week dose-blinded active-treatment phase (ATP). Monthly migraine days (MMD), achieving ≥50%, ≥75%, and 100% reduction in MMD, and safety/tolerability were assessed.

Results

Mean MMD at DBTP baseline was 8.3. At week 52, mean changes (SE) from pre-DBTP baseline/week 24 (pre-ATP baseline) in MMD were −4.2 (0.2)/−1.1 (0.2) (70 mg) and −4.6 (0.2)/−1.8 (0.2) (140 mg) irrespective of treatment during the DBTP. For patients reducing dose from 140 (DBTP) to 70 mg (ATP), change in MMD from week 24 to 52 was −0.1 (0.3), and for those increasing from 70 (DBTP) to 140 mg (ATP), −1.8 (0.3). At week 52, 61.0%, 38.5%, and 19.8% of patients on erenumab 70 mg, and 64.9%, 40.8%, and 21.2% on erenumab 140 mg, achieved ≥50%, ≥75%, and 100% reduction in MMD from DBTP baseline, respectively. Among erenumab-treated patients in DBTP who showed ≥50% reduction in MMD during the last 3 months of DBTP and completed ATP, 86% showed sustained responses at ≥50% during the last 3 months of ATP. Safety of erenumab in ATP was similar to DBTP; exposure-adjusted incidence rates of adverse events were similar for either dose.

Conclusion

Over 52 weeks, erenumab provided sustained efficacy in episodic migraine; the safety profiles were similar between erenumab dose groups in the presence of dose blinding.

Clinicaltrials.gov identifier

NCT02456740.

Classification of evidence

Class II evidence that 52 weeks of treatment with erenumab 70 and 140 mg subcutaneously monthly results in sustained reductions in monthly migraine days and similar dose tolerability for patients with episodic migraine.

Pharmacological treatment of migraine: CGRP and 5-HT beyond the triptans

Migraine is a highly disabling neurovascular disorder characterized by a severe headache (associated with nausea, photophobia and/or phonophobia), and trigeminovascular system activation involving the release of calcitonin-gene related peptide (CGRP). Novel anti-migraine drugs target CGRP signaling through either stimulation of 5-HT1F receptors on trigeminovascular nerves (resulting in inhibition of CGRP release) or direct blockade of CGRP or its receptor. Lasmiditan is a highly selective 5-HT1F receptor agonist and, unlike the triptans, is devoid of vasoconstrictive properties, allowing its use in patients with cardiovascular risk. Since lasmiditan can actively penetrate the blood-brain barrier, central therapeutic as well as side effects mediated by 5-HT1F receptor activation should be further investigated. Other novel anti-migraine drugs target CGRP signaling directly. This neuropeptide can be targeted by the monoclonal antibodies eptinezumab, fremanezumab and galcanezumab, or by CGRP-neutralizing L-aptamers called Spiegelmers. The CGRP receptor can be targeted by the monoclonal antibody erenumab, or by small-molecule antagonists called gepants. Currently, rimegepant and ubrogepant have been developed for acute migraine treatment, while atogepant is studied for migraine prophylaxis. Of these drugs targeting CGRP signaling directly, eptinezumab, erenumab, fremanezumab, galcanezumab, rimegepant and ubrogepant have been approved for clinical use, while atogepant is in the last stage before approval. Although all of these drugs seem highly promising for migraine treatment, their safety should be investigated in the long-term. Moreover, the exact mechanism(s) of action of these drugs need to be elucidated further, to increase both safety and efficacy and to increase the number of responders to the different treatments, so that all migraine patients can satisfactorily be treated.

Early clinical experience with a monoclonal antibody against the calcitonin gene-related peptide receptor in adolescents with migraine: A case series

Management of migraine in adolescents poses a great challenge, as many of the approved pharmacological migraine preventive agents have age restrictions. Following favorable safety and efficacy reports of the new class agent calcitonin gene-related peptide (CGRP) monoclonal antibody for use in migraine prevention, there is growing interest in its application in pediatric migraine. We present here a case series detailing our experience of using erenumab, a CGRP monoclonal antibody, in six adolescent patients. Two patients had a reduction of at least 50% in the mean number of monthly migraine days, one patient reported subjective improvement, while three patients did not respond to the first dose of erenumab and discontinued treatment. One patient reported constipation associated with erenumab use. We speculate that CGRP monoclonal antibody could potentially be a viable option in adolescent patients with migraine. Further evidences that support efficacy and safety of erenumab in this group is needed.

The role of erenumab in the treatment of migraine

Calcitonin gene related peptide (CGRP) monoclonal antibodies (mAbs) have been the first class of specifically developed preventive treatments for migraine. Clinical trials data suggest superiority of the CGRP mAbs to placebo in terms of prevention of migraine symptoms, migraine-specific quality of life and headache related disability. Treatment-related side effects overall did not differ significantly from placebo and discontinuation rate due to side effects has been low across the clinical trials, perhaps in view of their peripheral mode of action. Along with their route and frequency of administration, these novel class of drugs may constitute an improvement compared with the established arsenal of migraine treatments. Erenumab is a fully human antibody and the only mAb acting on the CGRP pathway by blocking its receptor. It is the first of the CGRP mAb class approved by the US Food and Drug Administration (May 2018) and the European Medicines Agency (July 2018). Erenumab exists in two different doses (70 mg and 140 mg) and it is administered with monthly subcutaneous injections. This review summarises erenumab pharmacological characteristics, clinical trials data, focusing on the potential role of this treatment in clinical practice.

Emerging Treatment Options for Migraine

Migraine is one of top 5 medical conditions that contribute to Years Lived with Disability and affects approximately 1 billion people from around the world. To date, preventive treatment and acute therapies for migraine are limited, have undesirable side effects and are poorly tolerated in patients. In the last few decades, considerable advances in our understanding of migraine and its pathophysiology have paved the way for the development of targeted treatment options. Calcitonin gene-related peptide (CGRP) plays an integral role in the neurobiology of migraine, and new classes of drugs that target the CGRP pathway have included gepants and CGRP pathway monoclonal antibodies. Serotonin 5-HT1F receptor agonists—namely ditans—have also been developed to treat acute migraine. Lastly, non-invasive neuromodulation offers another treatment option for migraine patients who prefer treatments that have fewer side effects and are well tolerated. In this review, we discussed emerging treatment options for migraine that were made available in recent years. Ann Acad Med Singapore 2020;49:226–35 Key words: Calcitonin gene-related peptide monoclonal antibody, Gepants, Headache, Lasmiditan, Neuromodulation

Long-term safety and efficacy of erenumab in patients with chronic migraine: Results from a 52-week, open-label extension study

Background

This study reports the long-term safety and efficacy of erenumab in chronic migraine patients.

Methods

This was a 52-week open-label extension study of a 12-week double-blind treatment phase study. During the double-blind treatment phase, patients received placebo or once-monthly erenumab 70 mg or 140 mg. During the open-label treatment phase, the initial monthly dose was erenumab 70 mg. Following protocol amendment, patients continued to receive erenumab 70 mg if they had already completed their Week 28 visit, otherwise, patients switched from 70 mg to 140 mg; if enrolled after the amendment, patients received 140 mg monthly throughout.

Results

In all, 451/609 (74.1%) enrolled patients completed the study. The exposure-adjusted patient incidence rate for any adverse event was 126.3/100 patient-years for the overall erenumab group. Overall, the adverse event profile was similar to that observed in the double-blind treatment phase. Adverse event incidence rates did not increase with long-term erenumab treatment compared with the double-blind treatment phase, and no new serious or treatment-emergent events were seen. Efficacy was sustained throughout the 52 weeks. Clinically significant reductions from double-blind treatment phase baseline (about half) were observed for monthly migraine days and migraine-specific medication days. Achievement of ≥50%, ≥75% and 100% reductions from the double-blind treatment phase baseline in monthly migraine days at Week 52 were reported by 59.0%, 33.2% and 8.9% of patients, respectively, for the combined dose group. A numerically greater benefit was observed with 140 mg compared with 70 mg at Weeks 40 and 52.

Conclusions

Sustained efficacy of long-term erenumab treatment in patients with chronic migraine is demonstrated, with safety results consistent with the known safety profile of erenumab and adverse event rates comparable to placebo adverse event rates in the double-blind treatment phase.

Trial registration:

This study is registered at ClinicalTrials.gov (NCT02174861)

How much do calcitonin gene-related peptide monoclonal antibodies improve the quality of life in migraine? A patient's perspective

PURPOSE OF REVIEW

Migraine is a prevalent and extremely disabling brain disorder, with an impact on the individual, family, workplace and society. This review focuses on describing Calcitonin Gene Related Peptide Monoclonal Antibodies (CGRP-mABs) efficacy on improving the quality of life (QoL) and decreasing the disability and impact of migraine measured with patient related outcomes (PROs), on patients who participated in clinical trials with erenumab, fremanezumab, galcanezumab and eptinezumab. The goal is to better reflect the effect of these preventive migraine treatments in the daily life of our patients.

RECENT FINDINGS

CGRP-mABs have been approved by the Food and Drug Administration's (FDA) and European Medicines Agency (EMA) as the first migraine specific treatment for the prevention of migraine. In clinical trials, CGRP-mABs have proven to achieve their primary endpoint which is to reduce the number of headache days, and also have shown to have an impact on disability, QoL and workplace productivity.

SUMMARY

CGRP-mABs have an impact on the disability, QoL, workplace productivity and global impression of improvement of migraine, which will translate into changes in the real world of migraine patients who are treated with CGRP-mABs.

Calcitonin gene-related peptide (CGRP): role in migraine pathophysiology and therapeutic targeting

Introduction: The neuropeptide calcitonin gene-related peptide (CGRP) is recognized as a critical player in migraine pathophysiology. Excitement has grown regarding CGRP because of the development and clinical testing of drugs targeting CGRP or its receptor. While these drugs alleviate migraine symptoms in half of the patients, the remaining unresponsive half of this population creates an impetus to address unanswered questions that exist in this field.Areas covered: We describe the role of CGRP in migraine pathophysiology and CGRP-targeted therapeutics currently under development and in use. We also discuss how a second CGRP receptor may provide a new therapeutic target.Expert opinion: CGRP-targeting drugs have shown a remarkable safety profile. We speculate that this may reflect the redundancy of peptides within the CGRP family and a second CGRP receptor that may compensate for reduced CGRP activity. Furthermore, we propose that an inherent safety feature of peptide-blocking antibodies is attributed to the fundamental nature of peptide release, which occurs as a large bolus in short bursts of volume transmission. These facts support the development of more refined CGRP therapeutic drugs, as well as drugs that target other neuropeptides. We believe that the future of migraine research is bright with exciting advances on the horizon.

Calcitonin Gene-Related Peptide Antagonists for the Prevention of Migraine: Highlights From Pivotal Studies and the Clinical Relevance of This New Drug Class

Objective: To review the new drug class of calcitonin gene-related peptide antagonists (monoclonal antibodies) and their clinical relevance in migraine prophylaxis. Data Sources: A literature search was performed in PubMed (January 2009 to November 2019) using the terms migraine, calcitonin gene-related peptide (CGRP), erenumab, fremanezumab, and galcanezumab for clinical trials and studies. Study Selection and Data Extraction: Reports from human studies in English were evaluated for clinical evidence supporting pharmacology, efficacy, and adverse events. Initial pharmacokinetic and preclinical studies were excluded. Data Synthesis: In chronic and episodic migraine, prophylaxis with injections of monoclonal antibodies antagonizing CGRP reduced monthly migraine days with minimal clinically significant adverse events. In addition, there is evidence supporting efficacy in refractory migraine despite optimal prophylaxis. Relevance to Patient Care and Clinical Practice: This is the first target-specific migraine prophylaxis treatment to show efficacy with minimal adverse effects. A higher drug cost is a barrier but is balanced by improved quality of life. Current therapies have limited efficacy and tolerability because of poor side effect profiles. CGRP antagonists represent a shift to more precise migraine treatments. Conclusions: Monoclonal antibodies inhibiting CGRP are effective in migraine prophylaxis with minimal adverse effects. Targeting CGRP is a novel clinical strategy in managing migraine.

Vascular safety of erenumab for migraine prevention

Objective

To examine the cardiovascular, cerebrovascular, and peripheral vascular safety of erenumab across migraine prevention studies.

Methods

Vascular adverse events (AEs) and blood pressure data were integrated across 4 double-blind, placebo-controlled studies of erenumab and their open-label extensions in patients with chronic or episodic migraine. Subgroup analyses were conducted by acute migraine-specific medication use and number of vascular risk factors at baseline. Standardized search terms were used to identify vascular AEs (cardiovascular, cerebrovascular, or peripheral). An independent committee adjudicated whether targeted events were vascular in origin.

Results

In placebo-controlled studies, 2,443 patients received placebo (n = 1,043), erenumab 70 mg (n = 893), or erenumab 140 mg (n = 507) subcutaneously once monthly. Regardless of acute migraine-specific medication use or vascular risk factors at baseline, AE incidence was similar across the placebo and erenumab treatment groups. Hypertension AEs were reported for 0.9% (placebo), 0.8% (erenumab 70 mg), and 0.2% (erenumab 140 mg) of patients. Vascular AEs, which were similar across double-blind and open-label treatment, generally were confounded, with plausible alternative etiologies. In 18 patients with events reviewed by the independent committee, 4 events were positively adjudicated as cardiovascular in origin: 2 deaths and 2 vascular events. All 4 positively adjudicated cardiovascular events occurred during open-label erenumab treatment.

Conclusion

Selective blockade of the canonical calcitonin gene-related peptide receptor with erenumab for migraine prevention had a vascular safety profile comparable to that of placebo over 12 weeks, with no increased emergence of events over time. Further study of long-term safety of erenumab in patients with migraine is needed.

Clinicaltrials.gov identifiers

NCT02066415, NCT02456740, NCT01952574, NCT02483585, NCT02174861, and NCT01723514.

Classification of evidence

This analysis provides Class II evidence that for patients with migraine, erenumab does not increase the risk of vascular AEs.

Content Validity of HIT-6 as a Measure of Headache Impact in People With Migraine: A Narrative Review

Background

The short‐form Headache Impact Test (HIT‐6) is a widely used patient‐reported outcome measure that assesses the negative effects of headaches on normal activity. It was developed using the general headache population and prior to the establishment of the now well‐accepted FDA patient‐reported guidance.

Objective

The objective of this narrative review was to examine existing qualitative research in patients with migraine and headache, providing insight into the relevance and meaningfulness of HIT‐6 items to the lives of migraine patients.

Methods

Articles were identified through database searches (National Library of Medicine and Google Scholar) and review of reference lists of candidate articles.

Results

A total of 3227 articles were identified through database and hand searching. Of these, 12 contained patient‐ or expert‐generated qualitative information regarding headache patients’ experience (8 specific to migraine [episodic and chronic] patients and 4 citing general headache patients). The combined publications described a total of 283 patient interviews. Overarching themes and specific information were identified that provide support of the relevance of content for each HIT‐6 item to migraine patients’ lives. Identified effects of headaches on patients with migraine included limitations in daily activities, needing to lie down during headaches, feeling tired, being irritated by headaches, difficulty concentrating, and the experience of pain. Further, previous research specific to the HIT‐6 indicated that patients understood the instructions, items, and response scales as intended by the instrument authors.

Conclusions

This narrative literature review demonstrates qualitative research support for the relevance of the items of the HIT‐6 in migraine patients, supporting its ongoing use in clinical migraine research and practice.

Long-term tolerability and nonvascular safety of erenumab, a novel calcitonin gene-related peptide receptor antagonist for prevention of migraine: A pooled analysis of four placebo-controlled trials with long-term extensions

BACKGROUND

Efficacy and safety of erenumab have been evaluated in a comprehensive clinical development program resulting in approval for migraine prevention in over 40 countries to date.

METHODS

This integrated safety analysis included four double-blind randomized trials and their extensions (up to three-plus years). Safety endpoints included exposure-adjusted patient incidences of adverse events, serious adverse events, and anti-erenumab antibodies.

RESULTS

In all, 2375 of the patients randomized across the four studies received at least one dose of erenumab (70 mg or 140 mg), with cumulative exposure of 2641.2 patient-years. Exposure-adjusted adverse event rates during the double-blind treatment phase were similar to placebo, with the exception of injection-site reactions (17.1 vs. 10.8 per 100 patient-years), constipation (7.0 vs. 3.8 per 100 patient-years), and muscle spasm (2.3 vs. 1.2 per 100 patient-years). During the long-term extensions, adverse events reported were similar to those observed during the double-blind treatment phase, and rates of injection site reactions, constipation, and muscle spasm were reported at lower rates than in the double-blind treatment phase. There were two deaths reported, both confounded by pre-existing conditions.

CONCLUSIONS

This pooled safety analysis revealed a favorable and stable adverse event profile over time for erenumab with more than three years of exposure.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01952574, NCT02483585, NCT02456740, NCT02066415, and NCT02174861.